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HomeMy WebLinkAboutAgenda 06_SD-22-10_500 Old Farm_OBrien Eastview_FP 1 1 of 29 TO: South Burlington Development Review Board FROM: Marla Keene, Development Review Planner SUBJECT: #SD-22-10 500 Old Farm Road Final Plat Application DATE: October 6, 2022 Development Review Board meeting PROJECT DESCRIPTION Final plat application #SD-22-10 of O’Brien Eastview, LLC to create a planned unit development of six existing parcels currently developed with three single family homes and a barn and totaling 102.6 acres. The development is to consist of 155 homes plus additional inclusionary offset units in single family, duplex, and three-family dwellings on eleven (11) lots totaling 23.9 acres, eighteen (18) commercial development lots totaling 39.8 acres, and 25.2 acres of undeveloped or recreational open spaces, 500 Old Farm Road. PUBLIC NOTICE The applicant has notified Staff that they inadvertently used an outdated abutters list for the initial warning and thus some of the newer owners in the adjacent O’Brien Hillside neighborhood did not receive a public meeting notice by mail. Staff worked with the applicant to send supplemental letters on September 29, with a note indicating that an opportunity to provide public comment would take place on October 6 (less than 15 day notice) and again at a continued hearing in November. 24 VSA 4464 states “No defect in the form or substance of any requirements in subdivision (1) or (2) of this subsection shall invalidate the action of the appropriate municipal panel where reasonable efforts are made to provide adequate posting and notice. However, the action shall be invalid when the defective posting or notice was materially misleading in content.” Staff considers reasonable efforts to have been made and therefore recommends the Board proceed with the hearing as scheduled. CONTEXT The Board held hearings on this application on July 19 and September 7, 2022. On those dates, the Board reviewed what has changed since preliminary plat, connection to Tilley Drive, the sidewalk on Old Farm Road, lot coverage, general site plan review standards, and the applicant’s proposed plan for the C1-LR zoning district. Remaining topics newly included herein include the detailed site plan review standards of 14.07, PUD standards, inclusionary housing standards, and miscellaneous final details such as stormwater, lighting and other utilities. The applicant has not provided revised materials since the September 7 hearing. Instead, the applicant intends to submit a set of revised materials incorporating all the Board’s feedback after initial review of all criteria is complete. Therefore Staff recommends the Board proceed by reviewing these staff comments with the Board and then continue the hearing to a future date to allow time for the applicant to prepare revised materials and Staff to review those materials fully. #SD-22-10 Staff Comments 2022-10-06 2 2 of 29 Plans and documents included in this packet are ordered to mirror this staff report and are limited to items Staff is highlighting for the Board’s attention. The September 7 packet included a full set of submitted materials Staff reminds the Board that this project is subject to the LDR effective December 28, 2020 since those were the regulations in effect when a complete preliminary plat application was submitted. For lots being created in the C1-LR and I/O district for which no site plan has yet been submitted, the regulations in effect at the time of application will apply, modified by any approvals that the Board may elect to grant at this stage of review. The remaining paragraphs of this Context section of this report are unchanged from the July 19, 2022 Staff Comments. The project is located in the Residential 12, Commercial 1-LR, Residential 1-PRD, and Mixed Industrial- Commercial Zoning Districts. The project also lies in Traffic Overlay Districts Zone 1 and 3 as well as the Transit Overlay District. The fraction of the project in each of the applicable zoning districts, and the allowable coverage in each district, follows. Zoning District Fraction of Project Area Allowable Lot Coverage R1-PRD 38% 30% C1-LR 23% 70% R12 1% 60% IC 38% 70% The development is subject to PUD/subdivision standards, site plan standards, and the standards of the applicable zoning districts, including allowed uses. The project is also required to provide inclusionary housing. The project contains both Class II and Class III wetlands, though only Class III wetlands and their buffers are proposed to be impacted. The project is adjacent to the Hillside phase of the O’Brien development, referred to as MP1 and Hillside herein. Hillside includes 490 homes, plus bonus inclusionary units, of which two buildings containing approximately 81 units have as yet only received preliminary plat approval. As noted in the project description, this proposed final plat consists of the following elements: • 155 homes in single family, duplex, and three-family dwellings. These homes are centered along Old Farm Road. This represents an increase of nine (9) units over what was approved at preliminary plat • eighteen (18) commercial development lots totaling 39.8 acres. This is 4.2 acres and one lot fewer than was proposed at preliminary plat. These development lots are located in the C1-LR and I-C zoning districts, which have different allowed uses but similar dimensional standards. No development of these lots is proposed at this time, but the road network serving these lots and a framework for development of the lots in the C1-LR, including connectivity to the currently proposed residential phase, is presented for approval. Staff proposes to discuss these areas at a later hearing date. • 25.2 acres of spaces of undeveloped and recreational spaces, including spaces used for stormwater treatment. #SD-22-10 Staff Comments 2022-10-06 3 3 of 29 COMMENTS Development Review Planner Marla Keene and Planning Director Paul Conner (“Staff”) have reviewed the plans submitted on June 10 and August 22, 2022 and offer the following comments. Numbered items for the Board attention are in red. UPDATES FROM SEPTEMBER 7, 2022 HEARING C1-LR Zoning District The Board deliberated on the applicant’s presentation of September 7 and directed Staff to provide feedback, including that there must be a minimum of two stories in the C1-LR. Staff recalls the Board’s discussion focusing on the buildings transitioning from the proposed 155 homes to the C1- LR district. The applicant has asked whether other buildings could be allowed to be one story or to have the appearance of two stories. 1. Staff recommends the Board discuss whether they will allow certain buildings to be one story or to have the appearance of two stories. Staff considers the Board may choose to limit such an allowance to buildings under a certain footprint, or buildings on the interior of the C1-LR district without frontage on Kennedy, Kimball, Old Farm or O’Brien Farm Road. TOPICS NOT PREVIOUSLY DISCUSSED AT FINAL PLAT STAGE OF REVIEW ➢ 14.07 SPECIFIC REVIEW STANDARDS In all Zoning Districts and the City Center Form Based Codes District, the following standards shall apply: A. Access to Abutting Properties. The reservation of land may be required on any lot for provision of access to abutting properties whenever such access is deemed necessary to reduce curb cuts onto an arterial or collector street, to provide additional access for emergency or other purposes, or to improve general access and circulation in the area. Business Park North Lot 4: Staff understood there to be existing dedicated pedestrian easement across the northern side of Business Park Lot 4 as a “placeholder” for a future trail network. Based on the provided plat plans, it does not seem that this easement in fact exists. The Applicant asked where the future trail network is supposed to go. The purpose of the easement on this and adjoining lots is to, over time, create a walking path along the south side of Potash Brook and is shown on the City’s official map. The preliminary plat finding was for the applicant to include an off-road footpath across this lot. Due to designation of Lot 4 as a sensitive archaeological resource area, the applicant has removed proposed development from this lot. They have indicated in their narrative that they have provided an easement, but no such easement is shown on the provided plat plans. Staff recommends the Board direct the applicant to provide a 20-ft easement in the location of the future trail as shown on the City’s official map. Staff considers since no development is proposed, a simple easement is sufficient. See additional findings pertaining to access under 14.06B(1) and (3) and 14.06C(1) and (2) above. B. Utility Services. Electric, telephone and other wire-served utility lines and service connections shall be underground insofar as feasible and subject to state public utilities regulations. Any utility #SD-22-10 Staff Comments 2022-10-06 4 4 of 29 installations remaining above ground shall be located so as to have a harmonious relation to neighboring properties and to the site. Standards of Section 15.13, Utility Services, shall also be met. Proposed utilities are underground. Old Farm Road is currently served by overhead utility lines. The applicant is proposing to relocate the lines underground through the project area, but it does not appear provision has been made for connecting to the existing home located at 200 Old Farm Road. Staff recommends the Board require the applicant to provide for connection of the existing home to the relocated utility line as a condition of approval. The telecom cabinet on Lot 42 conflicts with the proposed driveway. Staff recommends the Board require the applicant to relocate the cabinet outside the right of way as a condition of approval. C. Disposal of Wastes. All dumpsters and other facilities to handle solid waste, including compliance with any recycling, composting, or other requirements, shall be accessible, secure and properly screened with opaque fencing to ensure that trash and debris do not escape the enclosure(s). Small receptacles intended for use by households or the public (ie, non-dumpster, non-large drum) shall not be required to be fenced or screened. No solid waste disposal areas are proposed. D. Landscaping and Screening Requirements. See Article 13, Section 13.06 Landscaping, Screening, and Street Trees. This criterion was not reviewed in detail at preliminary plat. The Board notes landscaping standards applicable to parking lots will apply to both off-street parking areas and the plans must be revised to show compliance at final plat. 13.06A Purpose [excerpt]. Street tree planting shall be required for all public streets in a subdivision or planned unit development. In evaluating landscaping, screening, and street tree plan requirements, the Development Review Board shall promote the retention of existing trees while encouraging the use of recommended plant species. The applicant has provided street tree spacing of 30-ft. The applicant has requested the Board consider allowing street tree spacing up to 40-ft. Up until this point, the Board has been reviewing the plans with the 30-ft spacing and has used those plans as the presumed backdrop for decision making. 2. The applicant has provided a plan demonstrating their proposal. Staff considers the larger spacing should still result in the feeling of a treed street when trees reach maturity, perhaps to include larger trees or more varied, rather than simply taking the same trees and spacing them farther apart. Staff recommends the Board review the alternative tree spacing plan and determine whether to accept it. 13.06B. Landscaping of Parking Areas. Except for parking spaces accessory to a one-family or two-family dwelling, all off-street parking areas subject to review by the Development Review Board, shall be curbed and landscaped with appropriate trees, shrubs, and other plants including ground covers, as approved by the Development Review Board. Sections of recessed curb are permitted if their purpose is to allow stormwater runoff from the adjacent parking area to reach stormwater collection, treatment and management infrastructure. The Development Review Board shall consider the adequacy of the proposed landscaping to assure the establishment of a safe, convenient, and attractive parking area and the privacy and comfort of abutting properties. (1) All off-street parking areas shall be landscaped around the perimeter of the lot with trees, shrubs and other plants. Perimeter planting shall be set back from the curb sufficiently to allow #SD-22-10 Staff Comments 2022-10-06 5 5 of 29 for snow storage. The purpose of perimeter planting shall be to mitigate the view of the parking lot from the public way and from adjacent uses and properties, and to provide shade and canopy for the parking lot. In some situations it may be necessary both for surveillance purposes and for the perception of safety to install the size and type of plants that leave visual access between the parking lot to the public way or other pedestrian areas. The applicable parking areas are limited to those at the barn amenity and at the dog park. Staff considers this criterion met for the barn amenity. 3. At the dog park amenity, the area where landscaping would be located is not yet programmed (will be the perimeter of the C1-LR zoning district). Staff recommends the Board determine whether to require additional landscaping at the dog park parking area. (2) In all parking areas containing twenty-eight (28) or more contiguous parking spaces and/or in parking lots with more than a single circulation lane, at least ten percent (10%) of the interior of the parking lot shall be landscaped islands planted with trees, shrubs and other plants. Such requirement shall not apply to structured parking or below-ground parking. Not applicable. (3) All interior and perimeter planting shall be protected by curbing unless specifically designed as a collection and treatment area for management of stormwater runoff as per 13.06(B)(5)(c) below. Interior planted islands shall have a minimum dimension of six (6) feet on any one side, and shall have a minimum square footage of sixty (60) square feet. Large islands are encouraged. 4. In the barn area parking, no curbing is proposed, and the sidewalk is proposed to be differentiated from the parking by using different colored gravel. Curbing is recommended for protection of both landscaping and pedestrians. Staff considers a softer option, such as curb stops or bollards, could be effective and recommends the Board direct the applicant to propose a solution. (4) Landscaping Requirements #SD-22-10 Staff Comments 2022-10-06 6 6 of 29 (a) Landscaping shall include a variety of trees, shrubs, grasses and ground covers. All planting shall be species hardy for the region and, if located in areas receiving road runoff or salt spray, shall be salt-tolerant. (b) At least one (1) major deciduous shade tree shall be provided within or near the perimeter of each parking area, for every five (5) parking spaces. The trees shall be placed evenly throughout the parking lot to provide shade and reduce glare. Trees shall be placed a minimum of thirty (30) feet apart. More than 5 trees are provided for the 17-space barn amenity therefore this criterion is met. Fewer than 5 spaces are provided at the dog park therefore this criterion is met. (c) Trees shall have a caliper equal to or greater than two and one-half (2 ½) inches when measured on the tree stem, six (6) inches above the root ball. Paring lot trees are proposed to be greater than 2 ½ inches. This criterion is met. (d) Where more than ten (10) trees are installed, a mix of species is encouraged; the species should be grouped or located in a manner that reinforces the design and layout of the parking lot and the site. Fewer than ten parking lot trees are proposed, therefore this criterion is not applicable. However, the Board typically applies this criterion to entire sites, not just parking lots. Staff considers this criterion to be met for the project as a whole. (5) Planting islands – Not applicable (6) Snow storage areas must be specified and located in an area that minimizes the potential for erosion and contaminated runoff into any adjacent or nearby surface waters. The applicant has not specified snow storage areas. However, Staff considers that since each parking area is to serve an open space, snow storage is not an issue. Snow storage for the project streets will be along the green strip between street and sidewalk, recreation path, or property line, as applicable. 13.06C. Screening or buffering. The Development Review Board will require landscaping, fencing, land shaping and/or screening along property boundaries (lot lines) whenever it determines that a) two adjacent sites are dissimilar and should be screened or buffered from each other, or b) a property’s appearance should be improved, which property is covered excessively with pavement or structures or is otherwise insufficiently landscaped, or c) a commercial, industrial, and multi-family use abuts a residential district or institutional use. The applicant requested two waivers at preliminary plat related to the requirement to screen between adjacent properties. The first is that screening between commercial and non-residential uses be allowed to be on either the residential or the commercial lot. The Board accepted this waiver request, but on more detailed review of this criterion, Staff considers no waiver to be necessary as there is no requirement as to which lot contain the screening. Utility cabinets are required to be screened with evergreens, a mix of evergreens and deciduous trees and shrubs, and/or a solid fence. The applicant has proposed screening for utility cabinets within the residential area but has not shown screening of utility cabinets in the commercial and industrial areas. Staff recommends the Board include a condition that utility cabinet screening be provided when development occurs on lots containing or adjacent to approved utility cabinets. 13.06G. Landscaping Standards #SD-22-10 Staff Comments 2022-10-06 7 7 of 29 (3) Landscaping Budget Requirements. The Development Review Board shall require minimum planting costs for all site plans, as shown in Table 13-9 below. In evaluating landscaping requirements, some credit may be granted for existing trees or for site improvements other than tree planting as long as the objectives of this section are not reduced. The costs below are cumulative; for example, a landscaping budget shall be required to show a planned expenditure of three percent of the first $250,000 in construction or improvement cost plus two percent of the next $250,000 in construction or improvement cost, plus one percent of the remaining cost over $500,000. The landscaping budget shall be prepared by a landscape architect or professional landscape designer. The required minimum landscaping value is calculated based on the cost of buildings on shared lots. Single family homes and duplexes on their own lots are not subject to minimum landscaping budget requirements. The provided landscaping value excludes the value of street trees. Staff has also excluded the value of foundation plantings for the homes from the landscaping value because the applicant has previously made the request that foundation plantings not be required to be retained in perpetuity. This is discussed below under landscaping maintenance. The applicant has provided a computation of required minimum landscaping budget and provided landscaping value. No homes on their own lot are proposed, and the computations correctly exclude street trees. The applicant has also indicated that the value of proposed plantings outside of the red line on the landscaping plan are excluded from the provided value. They do not intend to install these plantings until such time as the development occurs in those areas. The areas outside the red line include the dog park, the walking trail through the I/C zoning district, and the street trees on Potash Road. Staff notes the Board is requiring construction of the dog park be tied to construction of the residential and C1-LR areas, and is otherwise establishing its phasing. The landscaping in the dog park will be required as part of the construction of the dog park regardless of whether the applicant considers it as contributing to the required minimum landscaping budget. The required minimum landscaping value for 155 homes with a cost of $52,700,000 is $534,500. The applicant is proposing the following landscaping. Trees $526,675.00 Tree Whips $5,950.00 Shrubs $146,710.00 Perennials & Grasses $22,233.00 Total $701,568.00 Required Minimum $534,500.00 Staff considers the required minimum landscaping to be provided. The applicant has requested the Board allow the excess landscaping expenditure to be applied as credit towards future phases, and has also requested the landscaping be allowed to be provided anywhere within the PUD. Staff recommends the Board allow the excess landscaping expenditure be allowed as credit towards future phases of the O’Brien Eastview project, and that it be allowed anywhere within the PUD, so long as required landscaping standards including those pertaining to screening are met. In other words, just because the Board may permit landscaping required for construction of a building to be installed in a park, they are not required to if such an approval would result in the building site being poorly landscaped. The applicant will be required to demonstrate the requested amount of credit is available at the time of each application for which they wish to use the credit. The Board made the #SD-22-10 Staff Comments 2022-10-06 8 8 of 29 following relevant finding at preliminary plat, which Staff recommends the Board continue to hold as a finding of this final plat. Landscaping design shall result in the following criteria being met. • each lot must be adequately landscaped • each lot must have a reasonably proportionate amount of open space, with adequate landscaping • the landscaping shall not be inconsistent with the development program approved by the Board Further pursuant to landscaping in the dog park, the applicant has proposed a wooded area to remain, but has not identified specific trees or specific tree preservation measures which will be employed. Staff recommends the Board defer detailed review of the wooded area to remain until after such time as the City’s recommendations on open space ownership are available, but notes it here as an outstanding issue for later discussion. 13.06I. Landscaping Maintenance The applicant is requesting waiver of the requirement to maintain landscaping in perpetuity in the single family, duplex and three family home area currently proposed for development. The Board at preliminary plat denied this request since the applicant has not shown individual lots; all lands are proposed to be common lands. Staff notes if the applicant wishes to propose individual building lots for the single family and duplex homes, such a waiver would not be necessary as there is no requirement for minimum landscaping on single family home or duplex lots. The applicant has revised their request to be that non tree and shrub vegetation be allowed to be modified by the homeowners. Staff considers the Board may permit vegetation to be removed or replaced if it is not counted towards the required minimum landscaping budget and if the Board does not consider the landscaping to be necessary to create the type of development stipulated by the LDR and reviewed by the Board. Staff notes the applicant’s landscaping plans show vegetation around the footprints of homes that does not necessarily match the proposed foundation plantings on the provided detail sheets. 5. Staff recommends the Board discuss whether the proposed foundation plantings are necessary to create the type of development stipulated by the LDR and reviewed by the Board and determine whether to allow the applicant waiver of the requirement to maintain foundation plantings, be they woody or non-woody vegetation, in perpetuity. E. Modification of Standards. Except within the City Center Form Based Code District, where the limitations of a site may cause unusual hardship in complying with any of the standards above and waiver therefrom will not endanger the public health, safety or welfare, the Development Review Board may modify such standards as long as the general objectives of Article 14 and the City's Comprehensive Plan are met. However, in no case shall the DRB permit the location of a new structure less than five (5) feet from any property boundary and in no case shall be the DRB allow land development creating a total site coverage exceeding the allowable limit for the applicable zoning district in the case of new development, or increasing the coverage on sites where the pre-existing condition exceeds the applicable limit. At preliminary plat the applicant provided a list of 25 requested waivers. The applicant has not submitted a revised list of waiver requests therefore Staff assumes there are no changes. Some of the #SD-22-10 Staff Comments 2022-10-06 9 9 of 29 applicant’s requested waivers have been incorporated into this report as applicable, while others were determined to not be applicable at a previous stage of review. The remaining applicable waiver requests are discussed below. Residential Lot Setback waivers: At preliminary plat the Board found that they generally accepted of the configuration in the residential lots shown on the plans, but the applicant must present a simplified setback waiver request. The applicant has requested that the Board approve the development program shown including footprint lots with a minimum setback of five (5) feet. Staff considers this to be a problematic proposal for three reasons. First, the City does not recognize footprint lots. Second, the homes are depicted as being set back 10-ft or more on the provided plans. Third, the applicant is proposing a range of home types be allowed to be built on each lot and therefore limiting the applicant to what is shown will necessarily limit their available offerings. 6. Staff instead recommends the Board provide a waiver within the residential area of the front setback requirement to 10-ft, with open porches or decks less than 12-ft in depth allowed to encroach into the front setback up to 5-ft. Staff recommends a waiver within the residential area of side and rear setbacks to 5-ft. Staff also recommends the Board include a condition that for street-facing garages there be enough room between the face of the garage and the sidewalk to park a full size car without overhanging the sidewalk, or that there be clearly not enough room (ie a car would be in the street). Landscape Screening: The applicant is requesting a waiver of the requirement to screen between residential and commercial lots. The applicant clarified that the intent of this request is that they intend to provide screening, but would prefer to be allowed to provide it on either the residential lots or commercial lots. The Board at preliminary plat found the clarified waiver request to be acceptable. Heights: The applicant is requesting a waiver of the requirement that building heights on commercial lots be no more than one story higher than adjacent residential buildings. The Board found at preliminary plat this requirement will be waived if the framework for the C1-LR zoning district is accepted at final plat. Porches: The applicant requests that all single family, duplex and three family homes may convert their porches to covered porches with only the issuance of a zoning permit. Porches are generally considered to be covered and constitute building footprint, while decks are uncovered and do not count as building footprint, though they do count as lot coverage. The Board directed the applicant to clarify this request at final plat. The applicant has provided the following statement. In a single-family home on its own lot, if an owner wanted to redo the roof on their porch and potentially change the roof angle or aesthetic, and screen in the porch at the same time, they would file a zoning permit on one piece of paper and it would issue. In this PUD, the Applicant wants to make sure the permits allow similar flexibility. The Applicant is worried that since a change to roofline or structure is not shown in the plans presented, a PUD amendment could be required. The Applicant is merely requesting a procedural waiver to ensure that the administrative officer can have the authority to approve and deny requests pertaining to converting decks shown on the proposed elevations to covered decks and three season rooms. This seems fairly straightforward, and will simply reduce the complexity and administration of these requests. Staff considers that redoing the roof on a porch or adding a screen is subject to a zoning permit and no waiver is needed. Staff notes that enclosing a porch to make it “three season” by adding walls would be #SD-22-10 Staff Comments 2022-10-06 10 10 of 29 a modification of the approved building and would require review against the allowances of the PUD, such as the Board will adopt. This would not necessarily require PUD amendment but may. Process Waivers: The applicant requests that sketch plan and preliminary plat not be required for subsequent applications within the PUD, and that site plan review be allowed instead of final plat review for single buildings on single lots. The LDRs reserve the authority to grant procedural waivers to applications for master plan as described in 15.07D(2). As there is no master plan, this waiver request is not appropriate and the Board denied the request at the preliminary plat level. Staff considers that the applicant’s request is not necessarily for a waiver, but instead is for the Board to establish a procedure for review of projects within the PUD. Staff considers the Board may establish, as part of this final plat decision, that site plan review is allowed by right for single buildings on single lots. Staff considers that under the LDR applicable to this decision, all modifications of lot lines or applications involving multiple lots require subdivision review, including sketch and preliminary plat. However, since there is no vesting, any future amendments to the PUD would be reviewed under the PUD in effect at the time of application. The latest LDR has a process by which subdivision amendments (of which PUD amendments are a subset) are categorized as minor or major, which would apply to future applications within this PUD. Parking: Staff recommends the Board carry forward this preliminary plat finding as drafted. “Applicant requests a finding that parking may be permitted with only site plan and conditional use review in the context of site plan review for a building on any approved lot in the PUD.” The applicant explained they are asking to be allowed to permit shared parking on an adjacent lot when no other development is proposed on that lot. The Board notes such a configuration would not be allowed with individual site plans such as requested in waiver requests 18-20. The Board finds this to be allowed if the following additional criteria are met. • Parking must be to the sides and rear of existing or proposed buildings. • Parking without a building shall be allowed for three (3) years without a development proposal, otherwise the applicant shall be required to install buffering. A buffering plan shall be submitted at the time of application for parking on a lot not otherwise proposed to be developed, and bonding for the proposed buffer shall be provided in accordance with 15.15 at the time of zoning permit issuance for construction of the parking. Sureties: This waiver request pertains to bonding requirements. The preliminary plat finding stated that the applicant must work with City Staff, including the Director of Public Works, to develop a specific proposal for presentation to the Board at final plat. However, since preliminary plat, the applicant and Staff have had several meetings and determined that bonding requirements can be largely handled administratively and need not be reviewed by the Board. The applicant has most recently requested that the Board allow the applicant to establish separate sureties for earthwork and for infrastructure construction. Staff considers they can draft the surety language such that it does not preclude such an arrangement, which will allow Staff and the applicant to continue to develop appropriate sureties without the needs for Board review. I/C Zoning District: the applicant requests waiver of the requirement that construction in the IC zoning district be exempt from the requirements to have common elements with the remainder of the PUD. The specific standards are as follows. 14.06B. Relationship of Proposed Structures to the Site. #SD-22-10 Staff Comments 2022-10-06 11 11 of 29 (1) The site shall be planned to accomplish a desirable transition from structure to site, from structure to structure, and to provide for adequate planting, safe pedestrian movement, and adequate parking areas. (3) Without restricting the permissible limits of the applicable zoning district, the height and scale of each building shall be compatible with its site and existing or anticipated adjoining buildings. 14.06C Relationship of Structures and Site to Adjoining Area. (1) The Development Review Board shall encourage the use of a combination of common materials and architectural characteristics (e.g., rhythm, color, texture, form or detailing), landscaping, buffers, screens and visual interruptions to create attractive transitions between buildings of different architectural styles. (2) Proposed structures shall be related harmoniously to themselves, the terrain and to existing buildings and roads in the vicinity that have a visual relationship to the proposed structures. The applicant noted that the approved uses in the I/C cover a broad range, and therefore the function of the buildings may not lend themselves to matching residential structure. The Board notes this criterion does not require industrial buildings to look like single family homes, but to prevent the industrial buildings from being disharmonious with the residential buildings. The Board found at preliminary plat that there are a number of ways to meet these criteria. The presence of an intervening open space and roadway reduces the needed reliance on architectural similarity. Common elements can be complimentary without needing to be exactly the same. The site design should also support complimentary relationships. The Board denied the requested waiver at the preliminary plat stage of review. The applicant at this final plat stage of review is requesting more robust findings. Staff considers the finding to be sufficiently descriptive to establish the expectations for how these criteria will be met, and, in addition, since development on the lands within the I/C zoning district is not proposed at this time, they will be subject to the LDR in effect at the time of application. The currently effective LDR significant modifies and explains these criteria. F. Low Impact Development. The use of low impact site design strategies that minimize site disturbance, and that integrate structures, landscaping, natural hydrologic functions, and various other techniques to minimize runoff from impervious surfaces and to infiltrate precipitation into underlying soils and groundwater as close as is reasonable practicable to where it hits the ground, is required pursuant to the standards contained within Article 12. The City Stormwater Section provided the comments via email on July 8, 2022 which were included in the packet for the July 19, 2022 hearing. The applicant has not yet provided a response. Since a number of comments may have an impact on the project design, Staff recommends the Board require them to be addressed prior to closing the hearing. G. Standards for Roadways, Parking and Circulation. Standards of Section 15.12 Standards for Roadways, Parking, and Circulation shall be met. See above under transportation #SD-22-10 Staff Comments 2022-10-06 12 12 of 29 ➢ 15.18A SUBDIVSION AND PLANNED UNIT DEVELOPMENT STANDARDS These criteria apply to both the portion of the project proposed for development at this time and the commercial lots proposed for subdivision but not development. (1) Sufficient water supply and wastewater disposal capacity is available to meet the needs of the project in conformance with applicable State and City requirements, as evidenced by a City water allocation, City wastewater allocation, and/or Vermont Water and Wastewater Permit from the Department of Environmental Conservation. The applicant has received preliminary water and wastewater allocation for 155 homes. The Board at preliminary plat found no allocation for the commercial lots to be necessary at this time. Staff recommends the applicant coordinate with the Department of Public Works as they develop their program for the commercial lots as there may be necessary system upgrades. The South Burlington Water Department provided comments on the water line design at preliminary plat, which Staff has reviewed and found to be incorporated into the final plat plans. Staff considers additional changes to the water system will be incidental and can be incorporated as a field change. Staff considers this criterion met. (2) Sufficient grading and erosion controls will be utilized during construction and after construction to prevent soil erosion and runoff from creating unhealthy or dangerous conditions on the subject property and adjacent properties. In making this finding, the DRB may rely on evidence that the project will be covered under the General Permit for Construction issued by the Vermont Department of Environmental Conservation. The comments of the City stormwater section included review of erosion prevention and sediment control measures. Staff recommends the Board require the EPSC comments of the City stormwater section to be addressed prior to closing the hearing. (3) The project incorporates access, circulation and traffic management strategies sufficient to prevent unreasonable congestion of adjacent roads. In making this finding the DRB may rely on the findings of a traffic study submitted by the applicant, and the findings of any technical review by City staff or consultants. 15.12F(1) The nearest signalized intersection or those intersections specified by the DRB shall have an overall level of service “D” or better, at the peak street hour, including the anticipated impact of the fully developed proposed PUD or subdivision. In addition, the level of service of each through movement on the major roadway shall have a level of service “D” or better at full buildout. The Board discussed access, circulation, and traffic management at the July 19 and September 7 meetings. Staff generally considers this criterion to be met. Specific follow-up items from the preliminary plat decision follow. • Off-site Improvements o Installation of turn lanes on Kimball Ave. At preliminary plat, the Board found the applicant must work with Staff to determine when installation of exclusive turn lanes be installed. Staff at preliminary plat recommended a framework for reservation of funds for this work such that each commercial lot contribute towards the necessary improvements that will be eventually required when sufficient trips are generated. This would allow the applicant to exclude from their bonding the cost of the off-site intersection improvements. #SD-22-10 Staff Comments 2022-10-06 13 13 of 29 The applicant is instead proposing to install turn lanes on Kimball Ave at Old Farm Road and at Potash Road at the time these intersections are constructed. BFJ’s preliminary plat recommendation was to delay installation of exclusive turn lanes until movements reach LOS E. Staff considers that premature installation of infrastructure may create higher speeds and the expectation that a high LOS will persist. If the applicant wishes to construct necessary pavement at the time of intersection construction, temporary measures like line striping or concrete barriers can be installed until such time as the turn lanes are warranted. 7. Staff recommends the Board discuss and provide DPW an opportunity to consider and provide feedback on any proposal. o Hinesburg Road and Old Farm Road. At preliminary plat, the applicant had proposed a right and left turn lane onto Hinesburg Road at Old Farm Road. It appears the applicant may no longer be proposing improvements at this intersection, though the applicant’s pavement marking plans do not cover it. 8. Staff recommends the Board confirm with the applicant that they still intend to make minor alignment and lane modifications at this intersection and require the plans to be updated to include this area. The Board at preliminary plat found that the first application for development in the commercial zoning districts, and the application that occurs every 5-years after that initial application, shall include an updated traffic evaluation if the commercial development varies from the uses included in this initial traffic study. Notwithstanding development, an updated traffic study shall be prepared after 10 years. Staff considers this condition should be reworded to specify that the traffic evaluation shall be updated concurrently with development applications in the C1-LR or IC areas at the time of first application and every 5 years thereafter. Old Farm Road and O’Brien Farm Road: The Board at preliminary plat required the applicant to provide an executable plan for a signal at Old Farm Road and O’Brien Farm Road. The applicant has provided a plan that shows a full signal. Staff recommends at this time the Board require the applicant to only install conduit sleeve as shown on the provided plan at the time the intersection is constructed. The applicant’s traffic study concludes no signal at this intersection is required, therefore Staff considers installation of conduit sleeve should be the limit of the applicant’s obligation for this intersection. Traffic Overlay District: The north end of Old Farm Road presently is in the Traffic Overlay District Zone 1. The applicant may not generate more than 15 vehicle trips per PM peak hour per 40,000 sf of development area at the Old Farm intersection without access management, additional connections between properties, and improved pedestrian and/or transit access that produces “a net benefit for traffic flow in the immediate vicinity of the project” (LDR 10.02H(1)). This calculation allows for a trip budget of 1675 pm peak hour vehicle trips. The current traffic study demonstrates the development build-out projections are consistent with the traffic overlay district. Staff considers updated traffic studies should confirm the development remains in compliance with the traffic overlay district at each subsequent phase of development. Should applicant develop a program that generates more than 1675 pm peak hour vehicle trips, they may at a future application provide a quantifiable demonstration of the increased capacity due to the relocation of Old Farm Road and installation of a signal at the Old Farm Road/Kimball Road intersection. (4) The project’s design respects and will provide suitable protection to wetlands, streams, wildlife habitat as identified in the Open Space Strategy, and any unique natural features on the site. In #SD-22-10 Staff Comments 2022-10-06 14 14 of 29 making this finding the DRB shall utilize the provisions of Article 12 of these Regulations related to wetlands and stream buffers, and may seek comment from the Natural Resources Committee with respect to the project’s impact on natural resources. The applicant has updated their plans to show wetlands and wetland buffers. The applicant has updated their wetland delineation since preliminary plat and has identified an additional Class III wetland within the IC area. The applicant is proposing to impact three Class III wetlands and their buffers for the purpose of stormwater treatment. The applicant has submitted a field delineation and wetland report as required by the LDR. 12.02E. Standards for Wetlands Protection (1) Consistent with the purposes of this Section, encroachment into wetlands and buffer areas is generally discouraged. (2) Encroachment into Class II wetlands is permitted by the City only in conjunction with issuance of a Conditional Use Determination (CUD) by the Vermont Department of Environmental Conservation and positive findings by the DRB pursuant to the criteria in (3) below. No encroachment into Class II wetlands or buffers is proposed. (3) Encroachment into Class II wetland buffers, Class III wetlands and Class III wetland buffers, may be permitted by the DRB upon finding that the proposed project’s overall development, erosion control, stormwater treatment system, provisions for stream buffering, and landscaping plan achieve the following standards for wetland protection: (a) The encroachment(s) will not adversely affect the ability of the property to carry or store flood waters adequately; (b) The encroachment(s) will not adversely affect the ability of the proposed stormwater treatment system to reduce sedimentation according to state standards; (c) The impact of the encroachment(s) on the specific wetland functions and values identified in the field delineation and wetland report is minimized and/or offset by appropriate landscaping, stormwater treatment, stream buffering, and/or other mitigation measures. The impacted wetlands were found to have low function as water storage and surface and groundwater protection/nutrient removal. The proposed impacts are for the purpose of stormwater treatment, therefore Staff considers these criteria met. 9. At preliminary plat, the Board found that the applicant must enumerate permanent and temporary wetland and wetland buffer impacts as part of the final plat application package. No numerical assessment of impacts has been provided. Staff recommends the Board require the applicant to provide areas in square feet of permanent and temporary wetland and wetland buffer impacts. (5) The project is designed to be visually compatible with the planned development patterns in the area, as specified in the Comprehensive Plan and the purpose of the zoning district(s) in which it is located. This criterion is addressed under 14.06B(1) and (3) and 14.06C(1) and (2) above. #SD-22-10 Staff Comments 2022-10-06 15 15 of 29 (6) Open space areas on the site have been located in such a way as to maximize opportunities for creating contiguous open spaces between adjoining parcels and/or stream buffer areas The applicant is proposing 18.24 acres of active or passive recreation space plus an additional 6.96 acres of undeveloped lots not proposed for use because of encumberance with wetlands or archaeologically sensitive sites. Other wetland and archaeological sites exist throughout the development and are distributed between the residential, commercial, and recreational lots. Some of the areas proposed to be left open are at the perimeter of the site adjacent to natural resource areas. Staff considers this criterion met. The Board’s preliminary plat findings discussed the design and ownership of the proposed recreational spaces as part of review of this criterion. Staff notes this could have also been reviewed under 14.06 Site Plan General Review Standards. The applicant has proposed an initial recommendation for ownership of the proposed recreational spaces. Staff and the applicant are presently meeting on this and anticipate having a recommendation for ownership at the continued hearing. Staff recommends the Board direct the applicant to include a detail of the proposed dog park fence as a condition of final plat. The Recreation and Parks Committee reviewed the project and provided comments on the preliminary plat, which were incorporated into the preliminary plat decision. (7) The layout of a subdivision or PUD has been reviewed by the Fire Chief or his designee to insure that adequate fire protection can be provided, with the standards for approval including, but not be limited to, minimum distance between structures, street width, vehicular access from two directions where possible, looping of water lines, water flow and pressure, and number and location of hydrants. All aspects of fire protection systems shall be designed and installed in accordance with applicable codes in all areas served by municipal water. This standard shall not apply to Transect Zone subdivisions. The Deputy Fire Chief reviewed the plans on August 18, 2022 and did not indicate any specific issues. (8) Roads, recreation paths, stormwater facilities, sidewalks, landscaping, utility lines and lighting have been designed in a manner that is compatible with the extension of such services and infrastructure to adjacent properties. For Transect Zone subdivisions, this standard shall only apply to the location and type of roads, recreation paths, and sidewalks. (9) Roads, utilities, sidewalks, recreation paths, and lighting are designed in a manner that is consistent with City utility and roadway plans and maintenance standards, absent a specific agreement with the applicant related to maintenance that has been approved by the City Council. For Transect Zone subdivisions, this standard shall only apply to the location and type of roads, recreation paths, and sidewalks. Detailed review of the proposed roadway network, including street trees, utilities, lane markings, lighting, signage, etc., was provided in the Staff report for July 19, 2022. Specific updates on preliminary plat findings are as follows. Street segments: The Board directed the applicant to extend road stubs to the property line as required by 15.12D. The applicant has not done so on Barn Road. Staff recommends the Board require the applicant to revise their plans to extend Barn Road to the property line. Staff notes the Director of Public Works #SD-22-10 Staff Comments 2022-10-06 16 16 of 29 had requested a turn-around in this location, but Staff alternatively suggested that the extension beyond Daniel Drive be used as a turn around. The Director accepted this suggestion, but indicated that the extreme end of Barn Road would not be plowed until such future time as it is connected to the adjacent parcel since it does not serve as access. Curb cuts: The preliminary plat approval include several conditions related to curb cuts. These comments have been addressed with the revised plans. Staff recommends the Board including a finding that the curb cuts on the approved plans are the approved curb cuts, and additional curb cuts shall not be permitted without a PUD amendment. In other words, modifications to curb cuts shall not be allowed to be reviewed as part of site plan review for individual lot development. Staff recommends the Board retain the following two preliminary plat findings as conditions of final plat approval. ▪ There shall be a maximum of one curb cut on each side of Old Farm Road between Kimball Ave and O’Brien Farm Road. ▪ No additional curb cuts beyond that for I/C Road, and those needed for infrastructure maintenance, onto Kennedy Drive or Kimball Avenue shall be permitted. The proposed cul-de-sac has three driveways which are proposed to be located off of it. Staff recommends the Board require the applicant to orient the driveways perpendicular to the arc of the cul-de-sac and not perpendicular to the centerline of the street. This may require adjustment of the angle of the homes as well. Further, the cul-de-sac should be signed for No Parking as it is designed to be the minimum size necessary for vehicular circulation. Sidewalks and Recreation Paths: The Board required recreation paths to be 10-ft wide, though left room for the applicant discuss site-specific exceptions with the Board at final plat. The applicant has proposed for the recreation path to be 8-ft wide through the core of the development where the triplexes are located. The Board has reviewed and accepted the bike and pedestrian design at prior hearings, therefore Staff assumes there are no concerns with this proposal. 10. The fitness trail is outlined by a dashed line on either side, with a different shading indicated inside the dashed lines on the landscape plans. Staff recommends the Board ask the applicant to identify the meaning of this line and shading on the plans, and, if it is necessary and acceptable, require it to be properly identified on the civil and landscape plans. See below screenshots. #SD-22-10 Staff Comments 2022-10-06 17 17 of 29 The site plan sheeting does not cover the dog park parking area, therefore it cannot be determined if curbing is proposed. The parking is adjacent to a sidewalk, therefore curbing is recommended. Staff recommends the Board require the applicant to demonstrate the dog park parking area is curbed. The Board included the requirement to construct a sidewalk along the eastern side of Old Farm Road from the southern terminus of the proposed rec path on the western side to Hinesburg Road in their preliminary plat review of this criterion. The Board reviewed this sidewalk design on July 19, including the Director of Public Works’ comments about maintenance, and the applicant indicated they would provide a revised plan that attempted to satisfy both the directives of the Board and the comments of the Director of Public Works. Staff anticipates the applicant will provide this revised layout for a continued hearing and will review when the applicant provides it. 11. The landscaping plans show additional lines on Old Farm Road towards the north end. Staff recommends the Board ask the applicant to identify the meaning of these lines on the plans, and, if it is necessary and acceptable, require them to be properly identified on the civil and landscape plans. See below screenshot. The sidewalk along Legacy Farm Extension must be extended to the terminus of the ROW as required by 15.12D. The Board required the applicant to revise plans throughout to ensure that sidewalks and recreation paths are aligned with one another as they cross streets and driveways. This has not been done in places, as identified in the DPW comments provided to the applicant at the July 19 hearing. The Board required the applicant to identify the surface for pedestrian connections. The applicant has indicated materials are called out in the pedestrian report. Staff notes some materials are called out on landscaping plans, but has generally been unable to locate materials on the civil drawings. Materials should be called out on the plans since the plans represent the approved condition for the project. Staff recommends the Board require the applicant to correct the plans to provide this information. 15.12D Criteria for Public and Private Roadways: The Board found that all roads with the exception of the proposed alley on Lot 32 are required to be public. The applicant has added a second alley on Lots 23 and 24. Staff recommends the Board include a condition that both alleys shall remain private. #SD-22-10 Staff Comments 2022-10-06 18 18 of 29 This section was reviewed under PP as part of 14.06 General Site Plan Review Standards. Staff considers it to be equally applicable under this criterion. The applicant is proposing an east- west easement in the I/C district, between lots 41 and 42. This easement is proposed to be 50- feet wide and is presumably to address the fact that Lots 43 and 44 otherwise have no access to a road. As a condition of approving the subdivision of land in the IC zoning district as part of this application, the Board included a preliminary plat finding that the applicant must provide this road as a ROW rather than an easement, and meet the minimum ROW width for a commercial road of 60-ft. The applicant has requested to not comply with this preliminary plat finding. Commercial roads are required by 15.12D(2) to be built to public roadway standards and be dedicated to the City as a public roadway. LDR 14.06 requires parking to be located to the rear or side of the building relative to the public street. The applicant is concerned that by offering a ROW, they will be required to locate parking to the rear or side relative to the ROW. Staff recommends the Board require the road to be built to public roadway standards but include a condition that the road is not intended to remain a private road, as allowed under 15.12D(3)(a): The DRB may it is discretion approve a roadway to be private if the proposed roadway functions as a private service or access road within a commercial subdivision or PUD). 14.06B(2) Parking The Board is prohibited by 15.02A(4) from granting waivers of this criterion even in the case of a PUD. (a) Parking shall be located to the rear or sides of buildings. Any side of a building facing a public street shall be considered a front side of a building for the purposes of this subsection. (b) The development review Board may approve parking between a public street and one or more buildings if the Board finds that one or more or of the following criteria are met. The Board shall approve only the minimum necessary to overcome the conditions below. (i) the parking area is necessary to meet minimum requirement of the Americans with Disabilities Act (ii) the parking area will serve a single or two-family home Most of the parking falls under this exemption. (iii) and (iv) Not applicable (v) The principal use of the lot is for public recreation The Board preliminarily that as configured, the Resident Club (open space Lot 32) to be principally for public recreation and accepts the parking as proposed. Staff considers no modification of this finding to be necessary. Staff considers a similar finding to be appropriate for the dog park parking. (10) The project is consistent with the goals and objectives of the Comprehensive Plan for the affected district(s). See above under 14.06A Relationship to the Comprehensive Plan. (11) The project’s design incorporates strategies that minimize site disturbance and integrate structures, landscaping, natural hydrologic functions, and other techniques to generate less runoff from developed land and to infiltrate rainfall into underlying soils and groundwater as close as #SD-22-10 Staff Comments 2022-10-06 19 19 of 29 possible to where it hits the ground. For Transect Zone subdivisions, this standard shall apply only to the location of natural resources identified in Article XII of these Regulations. See discussion of similar criterion under 14.07F above. ➢ ZONING DISTRICT & DIMENSIONAL REQUIREMENTS The Board found at preliminary plat that if the project meets the objectives and considerations discussed elsewhere in this document, minor modification of specific dimensional standards needed to provide the well thought out and activated neighborhood design discussed herein will be granted. Zoning district and dimensional standards pertain to the following elements of lot layout. • Density • Setbacks • Heights • Lot Size Density The applicant has calculated that 102.6 acre project has an available density of 452 homes based on the acreage of each included zoning district. The applicant has proposed 155 homes. Staff considers this criterion met. Setbacks Setbacks are discussed under waivers above. Staff will incorporate the Board’s findings on setbacks into this section of the final plat decision. Heights 151 homes are proposed in the R1-PRD, and 4 homes are proposed in the C1-LR. Heights in both zoning districts are limited to 28-ft for a pitched roof. Height waivers for the C1-LR district are discussed above and will be incorporated into this section of the final plat decision. The provided homes appear able to accommodate the required maximum height, taking into consideration that height is measured from average pre-construction grade. Staff considers this criterion met. Lot Size The homes are proposed on shared lots therefore minimum lot size does not apply. The applicant has proposed footprint lots. Staff recommends the Board include a condition that the City does not recognize footprint lots. The footprint lots are not considered in review of this application. ➢ 18.01 INCLUSIONARY HOUSING REQUIREMENTS B. Inclusionary Units (1) For covered development, at least fifteen percent (15%) of the total dwelling units offered for rent. Inclusionary Rental Units and at least ten percent (10%) of the total dwelling units offered for sale, including units offered for sale in fee simple, shared, condominium or cooperative ownership, shall be Inclusionary Ownership Units. Prior to or upon request for the Certificate of #SD-22-10 Staff Comments 2022-10-06 20 20 of 29 Occupancy the applicant shall notify the City whether the units will be Inclusionary Rental Units or Inclusionary Ownership Units so that the City, or its designee, may confirm that the offered rents or sales prices meet these requirements prior to issuance of the Certificate of Occupancy. In addition: (a) Where the application of this formula results in a fractional dwelling unit, that fractional dwelling unit shall be rounded to the nearest whole number (fractions that are greater than n.00 but less than n.50 are rounded down; fractions that are greater than or equal to n.50 but less than n+1.00 are rounded up). The applicant is proposing to construct 155 units, all of which will be for-sale units. Therefore the applicant must provide 15.5, rounded to 16, inclusionary units. At preliminary plat, the Affordable Housing Committee testified that they were happy with the applicants proposal, including the proposal to provide inclusionary units with higher bedroom counts, provided that amenities be available to all units. The applicant is proposing eight (8) three bedroom inclusionary units and two (2) four bedroom units. 18.01E allows three bedroom units to count as 1.5 inclusionary units each, and four bedroom units to count as 2.0 inclusionary units each, provided they not be used as offset or bonus units. Therefore the applicant has provided 8 x 1.5 + 2 x 2 = 16 inclusionary units, meeting the required minimum. 12. The applicant proposes to achieve a four-bedroom unit by providing a finished basement. The applicant has indicated that they are not committing to four bedroom units and are instead leaving the option of whether to provide three or four bedrooms to the home buyer. If four bedroom units are not provided, the project will not achieve the required minimum number of inclusionary units. Staff therefore considers the Board should require the applicant to commit to the specified bedroom mix or instead commit to a higher number of 3-bedroom or smaller units. Whichever solution, Staff considers the commitment must be made now, at this final plat stage of review. (2) Inclusionary units required under this section shall be: (a) Constructed on site, unless off-site construction is approved under Subsection (E)(1)(b) (Off-Site Construction) of this Article. The units are proposed to be constructed on site. (b) Integrated into the overall project layout and similar in architectural style and outward appearance to market rate units in the proposed development. (i) Inclusionary units shall be physically integrated into and complement the overall layout, scale, and massing of the proposed development; this criterion may be achieved in a single building or multiple buildings. The inclusionary units are proposed to be the middle unit in the eight three-family buildings and two of the units on the north end of lot 16 (Units 16-15 through 16-20). (ii) Inclusionary units shall be constructed with the same exterior materials and architectural design details quality of those of the market rate units in the development. However, the exterior dimensions of the inclusionary units may differ from those of the market rate units. As long as no architecture specific to inclusionary units is developed, the Board found at preliminary plat that criterion will be met. #SD-22-10 Staff Comments 2022-10-06 21 21 of 29 (iii) Inclusionary units shall be no less energy efficient than market rate units; O’Brien Brothers has touted energy efficiency as in important element of this development. They testified that all units will meet the stretch code and will include measures such as additional insulation and higher efficiency fixtures. Additional costs will be required for measures such as solar panels and heat pumps. The Board preliminarily found this criterion met. Staff considers no changes are proposed which would result in a change in compliance with this criterion. (iv) Inclusionary units may differ from market rate units with regard to both interior amenities and amount of Habitable Area. However, the minimum Habitable Area of inclusionary units shall be 450 square feet for studios, 650 square feet for 1-bedroom units, 900 square feet for 2-bedroom units and 1,200 square feet for three (3) or more bedrooms. If the average (mean) area of the Habitable Area of the market rate units is less than the minimum area required for the Habitable Area of inclusionary units, then the Habitable Area of the inclusionary units shall be no less than 90% of the average (mean) Habitable Area of the market rate units. The applicant has testified that the available footprints for the units planned to be affordable is 1,256 sf or greater, therefore this criterion is met. (v) Inclusionary units developed as part of a housing development of predominantly market rate duplexes and/or multi-family dwellings may be of varied types. Inclusionary units developed as part of a predominantly-single-family housing development may be accommodated in buildings containing up to four (4) dwelling units that have the appearance of single family homes through their scale, massing, and architectural style. The Board’s preliminary plat decision considered this criterion as restricting inclusionary units to buildings with no more than four units and with the appearance of single family homes and found this criterion met. Staff considers no change has been proposed which would alter compliance with this criterion. (vi) There shall be no indications from common areas that these units are inclusionary units. The Board found this criterion met at preliminary plat. Staff considers no change has been proposed which would alter compliance with this criterion. (vi) The average (mean) number of bedrooms in the inclusionary units shall be no fewer than the average number of bedrooms in the market rate units. For projects involving 50 or more dwelling units, the applicant shall provide a revised estimate to the Administrative Officer at each interval of 50 dwelling units; the revised estimate shall account for the differences in estimates vs. actuals for the units permitted to date and shall apply to inclusionary units for which the Administrative Officer has not issued a zoning permit. The applicant has provided a chart demonstrating compliance with this criterion. In summary, 12% of the offered floor plans are for two bedroom units, while 75% of the offered floor plans are for three bedroom units and 13% of the offered floor plans are for four bedroom units. 75% of the inclusionary units will be three bedroom units, and the remaining 25% will be four bedroom units. Staff considers this criterion met, though the applicant is still obligated under this criterion to update this computation at each interval of 50 dwelling units. #SD-22-10 Staff Comments 2022-10-06 22 22 of 29 (vii) Unfinished space within an Inclusionary Ownership Unit that is not initially constructed as bedroom, but which can be converted to such, may count as a bedroom. No more than one (1) bedroom per inclusionary ownership unit may be counted in this manner. 13. All units are proposed to have unfinished basements. The applicant does not intend to include egress from unfinished basements unless the buyer requests it. Staff recommends the Board ask the applicant to explain how this criterion affects their proposal to offer buyers the option for three or four bedroom units. As noted above, the applicant is relying on the presence of four bedroom units in their inclusionary unit calculation. (c) Constructed and made available for occupancy concurrently with market rate units. The applicant shall provide a proposed phasing plan demonstrating concurrent development and occupancy of the market rate units and the inclusionary units. The Development Review Board may attach conditions necessary to assure compliance with this section and may, based on documentation from a financial institution denying financing or on physical site constraints, approve a plan allowing non-concurrent construction of the inclusionary units. The Boards preliminary plat finding is as follows: The inclusionary units are proposed in the first phase that includes dwelling units. However, since the applicant has requested that subsequent phases be allowed to proceed concurrently with the first phase, the Board finds that 25% of the inclusionary units shall be constructed and made available for occupancy prior to 25% of the market rate units, and so on for each additional 25% construction. This condition need not come into play unless things evolve in a different manner than the applicant is anticipating. Staff considers no change has been proposed which would require modification of this finding. Staff understands that three and four bedroom inclusionary units count at 1.5 and 2 times the rate of two bedroom inclusionary units, respectively, and anticipates this will be taken into account in the permitting, but considers it not something the Board need to specifically address. D. Affordability Requirements The basis for determining maximum rental and purchase prices for inclusionary units and applicant rental or purchaser household eligibility for accessing inclusionary units under this section are described below. The data used to determine the incomes, rents and purchase prices is updated annually by U.S. Department of Housing and Urban Development (HUD). The Vermont specific data is updated annually on the Vermont Housing Data website, managed by the Vermont Housing Finance Agency, in a table titled “Maximum rent and purchase price affordability thresholds by income and household size”. Refer to this table in administration of this section. This section pertains to monthly housing, which may not exceed one twelfth of 30% of the targeted Area Median Income (80%) corresponding to the size of the specific unit as measured in number of bedrooms. It also requires utility costs to be included. Income eligibility must be determined based on Annual Median Income of no more than 100% Area Median Income targets as measured by HUD. Administration of continued compliance with these criteria is delegated to the City Manager or their designees. The Board found at preliminary plat that the applicant must provide the required deed restrictions for continued affordability prior to issuance of a zoning permit. Staff considers no change has been proposed which would require modification of this finding. #SD-22-10 Staff Comments 2022-10-06 23 23 of 29 ➢ 13.16 EARTH PRODUCTS The applicant at preliminary plat proposed a “gravel extraction area” and construction staging area on Potash road. They have revised their proposal to also include a soil stockpile and fill area on the far west of the PUD near Potash Brook. The gravel extraction and construction staging area is currently the steepest portion of the Industrial/Commercial zone, is presently wooded, and abuts a large area of Class II wetland. Without any plans for development, the applicant is proposing significant regrading of this area, including blasting to remove ledge. The applicant at preliminary plat provided extensive discussion of why they believe this ledge blasting is advantageous including that the blasting “will facilitate a much more level and aesthetically pleasing commercial project, and will create a buildable site shielded from view of Old Farm Road.” Since no commercial development is proposed at this time, the Board found this proposed ledge removal through blasting shall be reviewed under 13.16 pertaining to resource extraction, as well as the specific noise and vibration standards of LDR Appendix A, as well as separate Public Nuisance Ordinances and included specific conditions to be addressed at final plat. 13.16 Earth Products A. General Requirements. The conduct of a resource extraction operation that involves the removal of loam, gravel, stone, fill, topsoil, sod or similar substance, except when incidental to or in connection with the construction of a building on the same lot, shall be permitted in any district, except as limited by the Surface Water Protection Standards and Interstate Highway Overlay District, subject to site plan approval by the Development Review Board after public notice. The Board found these standards apply. The applicant has provided an assessment of proposed blasting operations and noise impacts due to crushing of materials. B. Site Plan Requirements. An application for the removal of more than twenty (20) cubic yards within one (1) calendar year period shall include the submittal of a site plan showing the area from which earth products are to be removed. Also, the application shall include specific information pertaining to the following factors and such other information as the Development Review Board may require. At minimum, the following information shall be required: (1) Depth of excavation, in proximity to roads or adjacent properties. Maximum depth of cut is 25-ft. (2) Existing grade and proposed grade created by removal of material. This is shown on Sheet Q-4. Cross sections are also provided. (3) Effect upon public health and safety. (4) Creation of a nuisance. (5) Effect upon the use of adjacent properties by reason of noise, dust or vibration. The applicant has prepared a noise study evaluating the impacts of rock crushing operations. The applicant is proposing to blast materials and crush them on site for use as foundation materials for the proposed development. The study concludes that continuous noise levels from the rock crushing will be below ambient levels. Staff has not readily found information on anticipated noise levels from blasting. 14. Staff recommends the Board ask the applicant to discuss anticipated noise from blasting, including whether the noise levels from blasting could be considered a nuisance. #SD-22-10 Staff Comments 2022-10-06 24 24 of 29 The applicant has stated that dust will not be a problem due to the location of the area relative to existing development. Dust is proposed to be controlled by use of water, and drill machines are proposed to be equipped with dust collectors. 15. Staff recommends the Board discuss whether to include a condition that places responsibility on the applicant for removal of dust deposited outside of the approved area. The applicant has provided a blast impact assessment, which includes the following statement as to vibrations. Vibrations may be noticeable and therefore may result in complaints, at PPVs as low as 0.02 to 0.06 in/sec. This is equivalent to the vibrations generated from a heavy truck traveling down a bumpy road, and vibrations of this magnitude should be expected for neighboring residences Experience has shown that blasting operations in locations such as the Project will be felt by neighbors and that the impacts will feel significant, even if they are well below the design standard. There is no correlation between the design standard that is studied and documented to be safe for structures, and the human experience of vibration in their home. The Project Owner is keenly aware of this, having experience from the Phase I blasting operations. It is impossible to set a design standard for blasting that is imperceptible as the blasts would be too small to make meaningful progress, but this Project has set its design standard at 50% of the levels we know to cause damage, well below what is required. We believe that this reduction in allowable vibration is meaningful, will greatly reduce the perception of vibrations for neighbors, and will eliminate the risk of damage to surrounding structures. Staff considers no additional review of vibration to be necessary. (6) Effect upon traffic hazards in residential areas or excessive congestion or physical damage on public ways. The applicant has stated that they will be using “haul roads” to truck material to and from the construction staging area, but no information about the haul roads appears to have been provided. Additional discussion of haul roads is below. (7) Erosion potential due to removal of vegetative cover. The applicant is proposing to use a sediment trap to control runoff. This project will be subject to a state general or individual permit for stormwater runoff from construction sites, which will impose design requirements on sediment control measures. The applicant has indicated that the area could be potentially used for construction staging for as long as 15 years. The applicant has proposed to vegetated the site six months after when rock removal and crushing operations are complete. City erosion control measures require the following. 16.03B Erosion and Sediment Control (1) The smallest practical area of land should be exposed at any one time during development. When land is exposed during development, the exposure should be kept to the shortest practical period of time. Areas of disturbance must have temporary or permanent stabilization within 21 days of initial disturbance. (2) Land shall not be left exposed between October 15 and April 15. #SD-22-10 Staff Comments 2022-10-06 25 25 of 29 (3) Where necessary, temporary vegetation and/or mulching and structural measures shall be required by the Development Review Board to protect areas exposed during the development. (4) Sediment basins (debris basins, desalting basins, or silt traps) shall be installed and maintained during development to remove sediment from run off water and from land undergoing development. (5) The permanent final vegetation and structures shall be installed as soon as practical in the subdivision. Exposed soil must be seeded and mulched or covered with erosion control matting within 48 hours of final grading. (6) Adequate and permanent measures shall be taken at culvert outfalls to minimize or prevent erosion and disruption of drainageway areas. 16. Staff recommends the Board require the applicant to modify their stabilization plan to comply with the timelines in the City’s erosion and sediment control measures. Where bare rock is left exposed, or excavation is within a fully contained depression, erosion control measures are not necessary. The Board required the applicant submit following additional information regarding earth products as part of their final plat application. a. specific impacts and durations (both overall and frequency of operations) The applicant has indicated that 70,000 cubic yards of materials are proposed to be removed in cuts up to 25-ft. They estimate 75 days of drilling and blasting. Staff notes drilling and blasting will not occur continuously but instead will have delay windows while equipment is repaired. They anticipate 5 – 10 blasts per week. 17. Staff recommends the Board ask the applicant to describe the duration over which they anticipate the 75 blast days will take place. Staff notes the 75 days does not include blasting outside of the construction staging area as may be necessary for construction of the approved project. b. specific mitigation measures – visual, noise, dust, roadway impacts Proposed Mitigation measures are generally limited to best practices and do not seem to include site specific measures. 18. Staff recommends the Board ask the applicant to describe the impact on Kimball Ave and Old Farm Road. Blasting operations are proposed to begin at 7AM and end before 5PM Monday through Friday. The City’s public nuisance ordinance prohibits use of power equipment or machinery, and noise resulting from construction, before 7AM. In order to begin blasting at 7AM, will there be other work taking place before 7AM? Will there be road closures during the blasting? Staff further recommends the Board prohibit blasting and crushing work on Federal Holidays. c. construction access road – location, plans, phasing and how it affects houses. The construction should proceed from the most remote end back towards the staging area, and be removed as construction is completed. The plan should show how construction access road is retired including timing and physical appearance. #SD-22-10 Staff Comments 2022-10-06 26 26 of 29 The applicant has stated they are not able to provide a location for construction access roads. Staff considers the factors that should come into play are: - disturbance to areas not otherwise disturbed, and specifically areas not otherwise approved for disturbance such as phases for which no zoning permit has yet been issued or areas within the PUD but outside the area approved for development - disturbance to areas to remain vegetated - disturbance to wooded areas - road crossings The applicant has provided the following statement as pertains to this requirement of preliminary plat. The construction of haul roads and internal maneuvering of equipment is not something that the Applicant can provide to the Board. The Applicant has provided some conceptual haul road locations in the EPSC plans. Those roads may need to move, be relocated, or re-oriented to facilitate construction. This is a massive site work project that is impacted by hundreds of variables on a daily basis which are analyzed by our project team of dozens of individuals working to build the Project. To presume that we can plan to this level of detail with regard to internal haul roads would be an error. We must have the flexibility to adapt and to build the project as required by the facts on the ground and simply cannot provide this level of detail on internal site maneuvering. Staff recommends the Board clarify whether the described uncertainty is only within this construction/staging area or if they are referring to the movement of construction vehicles from this construction/staging area to the project as a whole. It is understandable that movement of construction vehicles within the construction/staging area will be variable as materials is excavated, but there should be a plan for movement of vehicles and materials outside of this area to appropriately mitigate the impacts describe above. 19. Staff recommends the Board either require the applicant to present a plan for movement of construction vehicles and materials between the staging area and the project to the Director of Public Works for consideration prior to closing the hearing, or include a condition that the construction vehicle management plan requires DPW approval prior to issuance of a zoning permit to construct. d. plan for site restoration in the event of work stoppage As noted above pertaining to erosion prevention and sediment control, the applicant is proposing to topsoil and seed the site six months after when rock removal and crushing operations are complete. No provision is made for if the applicant does not complete the grading as designed. 20. Staff recommends the Board ask the applicant to describe how the material is proposed to be removed with the intent of understanding what interim situations may occur. If there is the potential for leaving a large depression/pit, the Board may wish to require a surety for site restoration. C. Conditions of Approval. The Development Review Board, in granting its approval, may impose conditions on the following: #SD-22-10 Staff Comments 2022-10-06 27 27 of 29 (1) Duration of the permit for any length of time that the Development Review Board deems appropriate. The applicant has requested six years to complete the work in the construction staging area. However, they are also asking that the stone pad proposed for crushing and blasting operations be allowed to remain indefinitely as a construction staging area. They anticipate a timeline of 10- 15 years, but Staff anticipates a longer timeline if the area is allowed to be used as staging for the entire PUD. 21. Staff instead recommends the Board include a condition that the construction staging area be restored no longer than eighteen months after the issuance of the most recent zoning permit for the approved homes. This would mean that should the applicant fail to pull a zoning permit for the approved homes for 18 months, even if all 155 homes were not built, the applicant would need to remove the construction staging area. 18 months is suggested as a top-end estimate of how long it may take to construct a home, though in reality the grading and foundation work should be completed much more quickly than that. Should the applicant later wish to use the construction staging area for construction in the C1-LR or IC zoning districts, or there be an unanticipated but finite delay, they may apply for approval to do so at that time. (2) Submission of an acceptable plan for the rehabilitation of the site at the conclusion of the operations, including grading, seeding and planting, fencing, drainage, and other appropriate measures. The applicants proposed rehabilitation plan has already been discussed. (3) Hours of operation, routes of transportation, and amount of material to be removed. The applicant is requesting to be permitted to work 7AM to 7PM Monday to Friday with no weekend hours for blasting or crushing. They request standard construction be allowed on weekends from 8AM to 5PM. 22. The City’s public nuisance ordinance prohibits construction noise between 9PM and 7AM. Staff recommends the Board accept the applicant’s proposal but also exclude federal holidays from blasting and crushing operations. (4) Provision of a suitable bond or other security in accordance with Section 15.15 adequate to assure compliance with the provisions of these Regulations. The applicant is proposing a $50,000 bond for site restoration. They argue that the crushed rock has it’s own value and could be used should additional funds be needed to restore the site. The applicant will also have other sureties in place. However, the other sureties will be for specific improvements and cannot be applied to restoration in this area. 23. Staff has requested DPW review of the proposed amount and anticipates having an update at the time of the hearing. Appendix A Performance Standards Staff considers that these are written as performance standards for operations, and that construction by its nature exceeds the performance standards, but they remain a useful guidepost. A.2(a) No vibration shall be produced which is transmitted through the ground and is discernable without the aid of instrument at or beyond the lot lines, nor shall any vibration produced exceed 0.002g peak at up to 60 cps frequency, measured at or beyond the lot lines using either seismic or electronic vibration measuring equipment. #SD-22-10 Staff Comments 2022-10-06 28 28 of 29 The proposed blasting, by the applicant’s own testimony, will exceed these limits. The Board at preliminary plat determined this standard is not directly applicable because it was written for permanent operations. Notwithstanding, the Board reserved the right to include conditions at final plat or when specific lots are proposed for development limiting the duration for which the numeric standards in this criterion may be exceeded. Staff considers the above analysis of blasting operations to adequately address this criterion. A.3 Noise (a) The following acts are declared to be loud, disturbing and unnecessary noises and shall be deemed detrimental to the health and safety of the residents of the City of South Burlington. (vi) Noise in general. Any noise which is deemed objectionable because of volume, frequency or beat and is not muffled or otherwise controlled. (b)(i) The creation of, permitting or operation of any of the above sets, instruments, devices or vehicles causing said noise in such a manner as to be plainly audible at a distance of fifty feet (50’) from the building, structure or vehicle from which noise emanates shall be prima facie evidence of a nuisance and a violation of these Regulations. (c)(iii) Temporary actions benefiting the public, including but not limited to roadway construction, sewer and water line construction, and special public events, are specifically exempt from the provisions of these Regulations upon approval of such an exemption by the City Manager. The Board at preliminary plat determined these criteria are not directly applicable because they were written for permanent operations. Notwithstanding, the Board may include conditions at final plat or when specific lots are proposed for development limiting the duration for which the numeric standards in this criterion may be exceeded. Staff considers the above analysis of noise to adequately address this criterion. ➢ ENERGY There are no specific criteria in the LDR requiring energy efficiency. The comprehensive plan includes the following goal. • Comprehensive Plan Goal: Green & Clean. Emphasizing sustainability for long-term viability of a clean and green South Burlington The Energy Committee provided comments on the preliminary plat on 1/5/2021. Excerpts from the comments of the Energy Committee follow. The City of South Burlington has committed to reduce the greenhouse gas emissions of all of South Burlington by 26-28% below 2005 levels by 2025. The City is not on track to meet that goal and it is very difficult to see how the City would meet this goal if new homes in the City continue to be built with fossil fuel infrastructure. It is critically important for the City, the State and the larger global community to reduce greenhouse gas emissions as quickly as possible to avoid the worst effects of climate change. • The SBEC’s first and very strong recommendation is that all the homes to be built be fully electric (and not built with any fossil fuel infrastructure). Since the electric grid in South Burlington is already very “clean” (94%+ carbon-free), and is targeted to be 100% carbon fee by 2025, such homes will generate no (or few) greenhouse gas emissions. #SD-22-10 Staff Comments 2022-10-06 29 29 of 29 • We also recommend that all new homes be built with 240v lines into each garage to facilitate electric vehicle charging, or better yet that level 2 chargers are pre-installed. • The residential stretch code already requires that new residential homes be built “solar ready”. We would further recommend that attention be paid to the orientation and roof lines of each home to maximize solar potential. • Consideration should also be given to constructing a community solar array. • Finally, the SBEC would appreciate if the applicant would provide a submission that demonstrates how each of the homes will comply with the residential stretch code, particularly the elements set forth in Table 5.6 of the 2020 Vermont Residential Energy Code Handbook (attached). The Board’s preliminary plat finding was that this development, through its mixed use character, density, and location within the transit overlay district, is consistent with the goal of the Comprehensive Plan. The Board encouraged the applicant to strive towards incorporating the comments of the SBEC and requested a report on how they have done so at the final plat stage of review. The applicant has indicated they will be installing natural gas but will install electrical heating systems if the home buyer wishes. They will only rough-in electric car charging where future modification would be difficult or where requested by the home buyer. They provide solar ready roofs and rough in conduit for solar charging. They are not requiring roof lines be oriented for maximum solar gain and instead are leaving it up to the home buyer. They are not proposing ground mounted solar arrays. They described in detail how the Residential Energy Code Handbook is used. Based on preliminary plat comments of the Natural Resources and Conservation Committee, the Board at preliminary plat included a statement encouraging the applicant to use roofing materials with a reflectance index of 20 or higher. 24. Staff recommends the Board discuss whether to require a certain percentage of roofs be oriented for optimum solar gain. RECOMMENDATION This completes initial review of relevant criteria. Staff recommends that the Board work with the applicant to address the issues identified herein and continue the hearing for the purpose of allowing the applicant to make modifications necessary to address the feedback of the Board. Respectfully submitted, Marla Keene, Development Review Planner HILLSIDE @ O'BRIEN FARM - EASTVIEW KENNEDY DRIVE, KIMBALL AVENUE, & OLD FARM ROAD APRIL 1, 2022 Ke n n e d y D r i v e Hinesburg RoadOld Farm Road Kimball Avenue Williston RoadSOUTH BURLINGTON, VERMONT 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C14 C13 C16 C17 C18 C15 C16.1 C5.1 C8.1 C2.1 C18.2 C18.1 C19 C7.1 Tilley DriveEldredge Str e e t DANIEL DRIVEOLD FARM ROAD MABEL WAYMABEL WAYMABEL WAY LEO LANE OL D F A R M R O A DO'BR I EN FARM ROAD O'BRIEN FARM RD EASTBARN ROAD POTASH ROAD 8' MIN 8' MIN XXXX X X X X X X X XXX X XXX X XXXX X XXXX X X X X X XXXXXX8' MIN 8' MIN XL101 L104A L105 L104B L102 L106 L107 L108A L108B L115 L116 L117 L118 L119 L120 L114L113L112L111 L109 L110 L103A L103B # DESCRIPTION 1 DESCRIPTION 2 00.00.0000 LANDSCAPE ARCHITECTURE WAGNER HODGSON © WHLA ALL RIGHTS RESERVED 2020 VT 802.864.0010 JOB NO. SCALE: DRAWN BY: DATE: wagnerhodgson.comNY518.567.1791 NO.DESCRIPTION DATE HILLSIDE @ O'BRIEN FARM EASTVIEW PHASE OLD FARM ROAD & KENNEDY DRIVE SOUTH BURLINGTON, VT 039 430 Warren Street Hudson, NY 12534 PLOT DATE: 4/5/2022 3:02 PMOVERALL SITE PLAN 1"=100' CO 04.01.2022 L100 SCALE OF FEET 1000100 200 SCALE OF FEET MATCHLINE - SEE INSET BELOWFOR SHEET L106 8' MIN 8' MIN XXXX X X X X X X XXX X XXX X XXXX X XXXX X X X X X XXXXXX8' MIN 8' MIN XXXXX XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXX L101 L104A L105 L104B DANIEL DRIVEOLD FARM ROAD MABEL WAYMABEL WAYMABEL WAY LEO LANE OL D F A R M R O A DO'BR I EN FARM ROAD O'BRIEN FARM RD EASTBARN ROAD POTASH ROAD L102 L106 L107 L108A L108B L115 L116 L117 L118 L119 L120 L114L113L112L111 L109 L110 L103A L103B # DESCRIPTION 1 DESCRIPTION 2 00.00.0000 LANDSCAPE ARCHITECTURE WAGNER HODGSON © WHLA ALL RIGHTS RESERVED 2020 VT 802.864.0010 JOB NO. SCALE: DRAWN BY: DATE: wagnerhodgson.comNY518.567.1791 NO.DESCRIPTION DATE HILLSIDE @ O'BRIEN FARM EASTVIEW PHASE OLD FARM ROAD & KENNEDY DRIVE SOUTH BURLINGTON, VT 039 430 Warren Street Hudson, NY 12534 PLOT DATE: 9/27/2022 5:21 PMOVERALL SITE PLAN 1"=100' CO 02.25.2022 L100 SCALE OF FEET 1000100 200 SCALE OF FEET MATCHLINE - SEE INSET BELOWFOR SHEET L106 S N O W S N O W S N O W O L D F A R M R O A D OLD FARM ROAD GRAVELPAVE POROUS GRAVEL PAVING PEA STONE COURTYAD WITH PICNIC TABLES L A W N L A W N P L A Y L A W N SCORED CONCRETE BITUMINOUS WALK BENCH, TYP. PLANTD BERM, TYP.5' 8' S E A S O N A L S K A T I N G R I N K E X I S T I N G B A R N P A V I L I O N S L E D D I N G H I L L S I L O P A R K I N G10' INTEGRAL COLOR CONCRETE GRAVELPAVE POROUS GRAVEL WALK 9-JC 2-IV 4-JS 12-AMA 52-SH 7-JC 6-PA 39-RF 22-RF 7-PA 8-JC27-SH 3-JS 23-SH 4-JS 1-IVJ 3-IV 9-AMA 12-RA 18-RA 13-CAK 13-RA 13-CAK GRAVELPAVE POROUS GRAVEL PAVING IN CONTRASTING COLOR TO PARKING LOT BIKE PARKING L A W N # DESCRIPTION 1 DESCRIPTION 2 00.00.0000 LANDSCAPE ARCHITECTURE WAGNER HODGSON © WHLA ALL RIGHTS RESERVED 2020 VT 802.864.0010 JOB NO. SCALE: DRAWN BY: DATE: wagnerhodgson.comNY518.567.1791 NO.DESCRIPTION DATE HILLSIDE @ O'BRIEN FARM EASTVIEW PHASE OLD FARM ROAD & KENNEDY DRIVE SOUTH BURLINGTON, VT 039 430 Warren Street Hudson, NY 12534 PLOT DATE: 4/5/2022 4:57 PMENLARGED COMMUNITY/BARN CENTER PLAN 1/16" = 1'-0" CO 04.01.2022 L200 SCALE OF FEET 16016 32 SCALE OF FEET PAVILION PEA STONE WITH PICNIC TABLES PEA STONE COURTYARD NIGHT SCENE PICNIC TABLE OUTDOOR ICE SKATING RINK P L A N T S C H E D U L E KEY QTY.SCIENTIFIC NAME COMMON NAME SIZE SPACING S H R U B S AMA 21 Aronia melanocarpa 'Autmn Magic'AUTUMN MAGIC CHOKECHERRY 5 GAL.4' O.C. IV 5 Ilex verticillata 'Afterglow'WINTERBERRY (female)5 GAL.6' O.C. IVJ 1 Ilex verticillata "Jim Dandy'WINTERBERRY (male)5 GAL.5' O.C. JC 24 Juniperus chinensis 'Sea Green'SEA GREEN JUNIPER 5 GAL.6' O.C. JS 11 Juniperus sargenti 'Green Sargent'GREEN SARGENT JUNIPER 5 GAL.6' O.C. RA 43 Rhus aromatica 'Gro-Low'GRO LOW SUMAC 1 GAL.4' O.C. P E R E N N I A L S PA 13 Perovskia atriplicifolia 'Filgran'FILGRAN RUSSIAN SAGE 1 GAL.30" O.C. RF 61 Rudbeckia fulgida 'Goldsturm'BLACK-EYED SUSAN #1 18" O.C. O R N A M E N T A L G R A S S E S SH 102 Sporobolus heteolepis PRAIRIE DROPSEED #1 18" O.C. CAK 26 Calamagrostis acutiflora 'Karl Foerster'FEATHER REED GRASS 2 GAL.18" O.C. DINING DECK KITCHEN PANTRY POWDER FOYER 2-CAR GARAGE PORCH2-CAR GARAGE OWNER'S BATH PATIO/DECK KITCHEN WINE DINING O.E. PANTRY W.I.C. LAUNDRY POWDER FOYER P.O.8' min.4' min. 4' min. 3' min. DECK DINING FAMILY KITCHEN STORAGE 2-CAR GARAGE P.O. STUDY FOYER PORCH 10' min.4' min. 3' min.15' min.DECK FAMILY DINING KITCHEN P.O.POWDER FOYER 2-CAR GARAGE FLEX PORCH 10'-1"3' min.15' min.4' min. COV. DECK FAMILY POWDER KITCHEN PORCH DINING ALIGN4' min. 4' min. 2' min. 6' min. 30" min. 4' min.4' min.4' min.LANDSCAPE ARCHITECTURE WAGNER HODGSON © WHLA ALL RIGHTS RESERVED 2020 VT 802.864.0010 JOB NO. SCALE: DRAWN BY: DATE: wagnerhodgson.comNY518.567.1791 NO.DESCRIPTION DATE HILLSIDE @ O'BRIEN FARM EASTVIEW PHASE OLD FARM ROAD & KENNEDY DRIVE, SOUTH BURLINGTON, VT 039 430 Warren Street Hudson, NY 12534 PLOT DATE: 4/5/2022 5:14 PMTYPICAL UNIT PLANTING LAYOUTS AND GUIDELINES AS SHOWN CO 04.01.2022 L301 # DESCRIPTION 1 DESCRIPTION 2 00.00.0000 4 1/8" = 1'-0" TYPICAL 2 UNIT TOWNHOME PLANTING 2 1/8" = 1'-0" TYPICAL SINGLE FAMILY PLANTING31/8" = 1'-0" TYPICAL ALLEY LOAD SINGLE FAMILY PLANTING 2 1/8" = 1'-0" TYPICAL SINGLE FAMILY PLANTING LEGEND EDGE OF PLANTING BED ORNAMENTAL GRASSES LARGE UPRIGHT SHRUB MEDIUM SHRUB SMALL SHRUB PERENNIALS5' min.3' min.UNIT PLANTING GUIDELINES *OVERALL: CHOOSE PLANT MATERIAL FOR ALL UNITS FROM THE ATTACHED PLANT LIST A.TOWNHOMES: Plant low shrubs such as Low-Gro Sumac or salt tolerant ornamental grasses in the space between driveways. B.Place medium shrubs or ornamental grasses in front of and around the corner of all front porches. C.Use a varied mixture of large, medium and small shrubs throughout beds, with taller plants at the back and shorter plants at the front of the bed. D.Use a varied mix (of both color, texture, and bloom time) of perennials and ornamental grasses. E.Use shade or sun tolerant varieties where applicable SINGLE FAMILY HOMES: A.Plant medium shrubs or oramental grasses on the side of the driveway nearest neighbor at a minimum length of 15'. B.Plant medium shrubs or ornamental grasses along the length of all front porches. C.Use a varied mixture of large, medium and small shrubs throughout beds, with taller plants at the back and shorter plants at the front of the bed. D.Use a varied mix (of both color, texture, and bloom time) of perennials and ornamental grasses. E.Use shade or sun tolerant varieties where applicable11/8" = 1'-0" TYPICAL 3-UNIT TOWNHOME PLANTING 50' Wetland Setback Wetland A T y p e I I I 50' We t l a nd Se t ba c k Wetland B T y p e I I I 50' WetlandSetbackWetland C Type III 8' MIN 8' MIN TR1 TP5 TR1 TP4 TR1 TP3 TR1 TP2 TR1 TP1 TR7 TP2 TR7 TP1 TR5 TP2 TR5 TP1 TR3 TP2 TR3 TP1 TR4 TP2 TR4 TP1 TR6 TP3 TR6 TP2 TR6 TP1 TR2 TP1 TR2 TP2 TR2 TP3TR2 TP4 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-1 OVERALL SITE PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com pcg 338.5 EASTVIEW LIMIT OF EASTVIEW EX. POND #1 EX. POND #2 EX. POND #3 WET POND A GRAVEL WETLAND #1 GRAVEL WETLAND #2 GRAVEL WETLAND #3 GRAVEL WETLAND #4 GRAVEL WETLAND #5 GRAVEL WETLAND #6B GRAVEL WETLAND #7 GRAVEL WETLAND #8 Lot 1 8.9 ac Lot 2 5.0 ac Lot 3 2.0 ac Lot 4 1.1 ac Lot 5 8.8 ac Lot 6 3.0 ac Lot 7 2.4 ac Lot 5 8.8 ac Lot 8 4.6 ac Lot 9 1.9 ac Lot 10 0.9 ac Lot 11 1.2 ac Lot 13 2.78 ac Lot 15 2.38 ac Lot 12 1.6 ac Lot 14 1.1 ac Lot 17 3.11 ac Lot 16 2.81 ac Lot 20 2.13 ac Lot 21 2.30 ac Lot 22 1.25 ac Lot 23 0.12 ac Lot 24 1.25 ac Lot 25 2.53 ac Lot 26 1.88 ac Lot 27 1.00 ac Lot 28 2.11 ac Lot 33 2.38 ac Lot 31 2.39 ac Lot 32 4.80 ac Lot 35 2.38 ac Lot 47 Open Space 12.64 ac Lot 29 1.04 ac Lot 40 1.90 ac Lot 41 3.65 ac Lot 46 3.96 ac Lot 48 Open Space 4.56 ac Business Park North Lot 4 2.4 ac Archaeology Zone Archaeology Zone Lot 34 1.30 ac Lot 39 3.54 ac Lot 18 Open Space 1.17 ac Lot 19 Open Space 1.51 ac 16-1 16-2 16-3 16-4 16-716-616-5 16-8 16-9 16-10 16-11 16-12 16-13 16-14 20-132-132-232-332-432-532-632-732-832-932-1032-1132-1232-1332-143 2 - 1 5 32 -1632-1732-1832-1932-2032-2132-2232-2332-24 31-1 31-5 31 - 7 3 1 - 9 3 1 - 1 3 3 1 - 1 4 3 1 - 1 5 3 1 - 1 6 3 1 - 1 7 3 1 - 1 8 3 1 - 1 9 34-1 34-3 34-6 34-7 39-139-239-3 39-4 39-539-639-739-839-9 39-1039-1138-138-238-338-4 38-5 34-2 34-4 34-5 34-8 34-9 31-2 31-3 31-4 31-6 31 - 8 3 1 - 1 0 31-1131-1220-220-320-420-520-620-720-820-920-1020-1120-1220-1320-1420-1520-1620-1720-1820-1920-2020-2120-2220-2320-2420-2520-263 1 - 2 0 3 1 - 2 1 Lot 38 1.55 ac 35-1 35-2 35-3 35-4 35-5 35-6 35-7 35-8 35-9 35-10 Lot 42 3.14 ac Lot 43 3.95 acLot 44 3.51 ac Lot 45 2.90 ac Lot 37 1.10 ac 3 1 - 2 2 3 1 - 2 3 3 1 - 2 4 3 1 - 2 5 3 1 - 2 632-25 35-12 35-13 35-14 35-15 35-16 35-17 35-18 36-137-1 35-11 34-10 Lot 30 0.30 ac Lot 36 0.66 ac 24-1 24-124-2 24-3 24-436-236-336-436-537-2 37-3 37-4 37-5 37-6 GRAVEL WETLAND #6A16-1516-1616-17 16-18 16-19 Lot 49 0.54 ac Lot 50 1.15 ac Pedestrian easement PROPOSED SIDEWALK EXTENSION REQUIRED BY DEVELOPMENT REVIEW BOARD PRELIMINARY PLAT APPROVAL Airport Appro a c h C o n e Airport Appr o a c h C o n e Airpor t A p p r o a c h C o n e P:\2019\19083 O'Brien\dwg\19083-K1 K2 Signal Plans.dwg 3/10/2022 13:57:33 1 : 1 P:\2019\19083 O'Brien\dwg\19083-K1 K2 Signal Plans.dwg 3/30/2022 09:47:31 1 : 1 New SMh Rim 336.3 Inv. in 330.53 Inv. out 330.43 New 6" PVC SDR 35 sanitary sewer stub, cap , and witness Lot 48 Open Space 4.56 ac Lot 41 3.65 ac Lot 45 2.90 ac Inv. ud 329.5 Inv. in 329.0 Inv. out 328.9 New rip rap dispersal pad New End Section Inv. out 327.1 New SMh Rim 345.0 Inv. in 336.51 Inv. out 336.41 New 6" PVC SDR 35 sanitary sewer stub, cap , and witness New SMh Rim 334.5 Inv. in 327.84 Inv. out 327.74 New 8" PVC Sewer s=0.009 New SMh Rim 335.25 Inv. in 329.55 Inv. out 329.45 Ne w 8 " P V C S e w e r s = 0 . 0 0 7 5 New 8" PVC Sewer s=0.0075Ne w 8 " P V C S e w e r s = 0 . 0 2 New Outlet Structure 7. See detail. Forebay New rip rap dispersal pad New 6" PVC cross pipe between cells New berm with stone weir overflow 2, New 18" PVC vertical inlet pipes 2, New 18" PVC vertical inlet pipes New stone berm New CB Rim 336.5 Inv. ud 332.5 Inv. out 332.05 10' p a v e d m u l t i - u s e p a t h New End Section Inv. out 328.3 Gravel Wetland #7 Cell#1 83' x 63' Elev. 328.0 Gravel Wetland #7 Cell#2 83' x 63' Elev. 328.0 New 15" HDPENew 18" HDPE s=0.01New 15" HDPENew Emergency Spillway. See detail New 8" tee with valve and thrust block 12' wide stabilized grass maintenance drive 10' paved multi-use pathHILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-16.1 SITE PLAN - I/C Sewer & Gravel Wetland #7 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com EASTVIEW Lot 48 Open Space 4.56 ac Lot 46 3.96 ac New DMh Rim 342.3 Inv. in 335.83 Inv. out 335.73 New End Section Inv. out 331.5 Forebay 2, New 15" PVC vertical inlet pipes New stone berm New 6" PVC cross pipe between cells New berm with stone weir overflow 2, New 15" PVC vertical inlet pipes New rip rap dispersal pad New End Section 330.35 New Outlet Structure 7. See detail. New rip rap dispersal padNew 1 5" HDPE Gravel Wetland #8 Cell#1 90' x 50' Elev. 332.0 Gravel Wetland #8 Cell#2 90' x 50' Elev. 332.0 New 18" HDPE s=0.008 New Emergency Spillway. See detail New End Section Inv. out 329.1 New End Section Inv. out 329.25 New DMh Rim 339.5 Inv. in 333.3 Inv. out 333.2 New 15" H D P E s = 0 . 0 1 12' wide stabilized grass maintenance drive HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-18.2 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com SITE PLAN - Stormwater Line & Gravel Wetland #8 EASTVIEW 26 Smith Pl., Ste. 2, Cambridge, MA 02138 | 617.714.5784 | www.BrierleyAssociates.com March 14, 2022 O’Brien Brothers Agency 1855 Williston Road South Burlington, VT 05403 Attention: Mr. Andrew Gill, Director of Development Blasting Impacts Assessment Rock Excavation at Borrow Pit Area Hillside at O’Brien Farm Phase 2 South Burlington, VT This letter presents our assessment of the blasting impacts from rock excavation by drill and blast methods at the Borrow Pit area which is a part of the Hillside at O’Brien Farm Phase 2 project in South Burlington, Vermont. The purpose for our work was to assess the area on site where drilling and blasting will be required for bedrock excavation and to assess the potential impacts from the blasting work on the existing residential and commercial buildings and people in the area. Bedrock excavation by drill and blast methods will be completed by Maine Drilling and Blasting (MD&B) of Argyle, NY. Background We have reviewed the following background information to complete our assessment: • Blasting Plan for Hillside @ O’Brien Farm – Borrow Pit by Maine Drilling & Blasting, Inc., dated March 10, 2022. • State of Vermont Department of Environmental Conservation – Waste Management Prevention Division, 2014 Best Management Practices (BMPs) for Blasting to Avoid Environmental Contamination. • State of Vermont Blasting Plan Guidance Document. • NFPA 495 Explosives Materials Code, 2013 Edition. As part of our evaluation, Mr. Jay Perkins of Brierley Associates has corresponded on the proposed rock excavation and abutter concerns with Andrew Gill at O’Brien Brothers Agency, and has discussed the submitted Blasting Plan with the Project Manager for MD&B. The site is approximately 5.5 acres of farming landscape and slightly wooded area located at the west side of Kimball Avenue across from #70 Kimball Ave. Site grades are relatively level across the area. The purpose for the borrow pit is to mine and excavate approximately 70,000 cubic yards of bedrock for processing crushed stone as a construction material for the Hillside Phase 2 - Eastview residential development. The maximum depth of rock excavation at the pit area will be approximately 25’ below the existing grade. The Blasting Contractor has estimated the blasting duration for the borrow pit area to be 75 days assuming two drill crews completing 5 to 10 blast rounds per week throughout the project duration. Hillside at O’Brien Farm Phase 2 – Borrow Pit Blasting Impacts Assessment March 14, 2022 Page 2 of 6 Site Safety and Mitigation Given the proximity of the blasting activities to the surrounding residents, site safety is paramount to the successful completion of the project. The following provides a list of site safety measures and security that MD&B will implement during blasting: • Worker: Conduct daily safety meetings. • Blast Area Security: Designated Access Points, Safe Areas and Sentry Locations (see Blast Plan). • Charged Hole Area: Posted, guarded and barricaded. • Warning Signals: Three (5 minutes), two (1 minute), one (all clear). • Kimball Ave.: Vehicle and pedestrian traffic paused briefly as needed. • Blasted Rock Control (flyrock): Use of matting and blast rock berms. • Blast Monitoring: Two seismographs to measure ground and air vibrations as per ISEE Guidelines. • Misfires: Wait, reconnect and reshoot, reprime, washout with water or air, recover, displace (drill and shoot adjacent hole), and disposal to separate magazine, as per IME Safety Library Publication 17. Blast Designs MD&B has provided a blast design in their submitted Blasting Plan for the borrow pit area. For pit blasting approximately 70,000 cy of rock with a cut of 20’ that has been designed and will be used on this project. The pit blast design includes drilling a 3.5” diameter hole at a burden and spacing of 8’x8’ for pit blasting. The number of holes per blast round will range from approximately 20 up to 40 with an average of approximately 30 resulting in approximately 1,400 cy (neat lines) of rock excavation per blast round. Explosives to be used will be MD&B’s 1966 bulk Emulsion Blend of Ammonium Nitrate and Fuel Oil (ANFO) using a Dyno Nobel Cast Booster as a primer. Dyno Nobel Blastex Emulsion with a cast booster primer will also be used for supplemental explosives and for much smaller blast rounds. The initiation and trunkline system will be the Dyno Nobel NONEL (nonelectric) delay detonators. Timing diagrams show 25 msec delays between holes and 42 msec delays between rows. For the submitted blasting design, a corresponding Powder Factor (PF) will be approximately 1.3 lbs./cy. The maximum explosive charge weight per delay will be as high as 52 lbs. and will be dependent on the distance to the nearest structure. This blast design has incorporated features that should minimize blasted rock Oversize and the need for rehandling blasted materials, and limit Overbreak at subgrades and lateral blast lines and the need for additional backfill material placement by the General Contractor. Anticipated Closest Residences to Blasting The following is a list of the existing residential buildings located nearest to the blast areas, and their approximate distance from nearest blast to that structure: • #70 Kimball Ave. (Immigration Building): 334’ • #102 Kimball Ave. (Warehouse): 484’ Hillside at O’Brien Farm Phase 2 – Borrow Pit Blasting Impacts Assessment March 14, 2022 Page 3 of 6 • #102 Kimball Ave. (Tennis Store): 496’ • #200 Old Farm Road residence: 854’ Brierley has reviewed the Project blast plan and blast design with these structures in mind. Specific plans are in place for all blasting of structures with criteria that we believe will keep the project impacts below design standards, and will not cause damage to these closest structures, or any other neighboring structures. One of the first steps in the blasting process is to protect the abutting homeowners and the contractor, and to help prevent or mitigate potential property damage claims by completing pre-blast condition surveys of structures near the blast area. Upon acceptance from the property owners, these surveys will be performed at the interior and exterior of all structures to a radial distance of at least 500’ from the closest blasting, which is twice the distance generally used and required by the NFPA 495 Code. Pre-blast surveys will be completed by MD&B using photographs, videos and written and oral documentation. All pre-blast surveys will be conducted prior to the commencement of the project. Potential Blasting Impacts on Buildings The primary concerns with blasting close to buildings and their occupants are ground vibrations, air blast overpressures, flyrock, noise and dust, all of which can be controlled with experienced Blasters and Engineers applying modern techniques to blasting designs and mitigation measures. As a part of the project outreach, we have included a “Blasting and Vibration Q&A” handout to be provided to the abutting residents. This two-page handout provides a basic description of blasting and explanation on the impacts of blasting to buildings and their occupants. These impacts are also briefly discussed below: Ground Vibrations: Seismographs measure ground vibrations in Peak Particle Velocity (PPV) recorded in units of inches per sec (in./sec), given standards of damage are based on the ground particle velocity. The PPV from each blast round will be monitored using the seismograph set up immediately adjacent to the nearest residence or structure of concern. In the interest of minimizing blasting impacts and annoyance levels to occupants of the buildings Nearby, the PPV from ground vibrations is designed to be below 1.0 in./sec, which is one-half the industry standard safe limits line recommended by the U.S. Bureau of Mines (USBM RI 8507, 1980). These limits are half of the studied and documented safe limits for preventing cosmetic damage (hairline cracking, or the extension of existing hairline cracks) to residential structures. It should be noted that vibrations levels generally attenuate at a rate of one-third for every time the distance is doubled. Setting the blast design standard at 50% of the proven safe industry-standard level is being done at the request of the Project owner and Brierly not because the proven limit is in any way unsafe or known to cause damage to structures. This design threshold was developed to reduce the vibrations perceived by Project neighbors and to ensure that neighbors to the project are respected and that all reasonable efforts to minimize impacts are taken. These reduced standards have a cost, which is that more blasts will be necessary to achieve the ledge removal required by the Project and the blasting will therefore take longer. However, our belief is that the 1.0 in./sec standard achieves a good balance between efficiency of process and reduction of impacts. Any further reductions in blast design vibration limits could Hillside at O’Brien Farm Phase 2 – Borrow Pit Blasting Impacts Assessment March 14, 2022 Page 4 of 6 greatly extend the Project duration, and because vibrations are perceptible at 0.02 in./sec, would be unlikely to reduce the physical perception of neighbors to a point where the blasting was not felt. Air Blast Overpressures: Blasting air overpressure, recorded in units of pounds per square inch, (psi) is also measured with seismographs on a Linear Peak scale and is converted and reported as the sound equivalent in decibels (dBL). Air blast overpressures produces an atmospheric pressure wave transmitted from the blast outward into the surrounding area. Air blasts at nearby residences will be kept below a limit of 133 dBL, or 0.014 psi, which is an industry standard limit recommended by the U.S. Bureau of Mines to minimize the probability of both human annoyance and potential damage to windows. This pressure is equivalent to a wind gust of 27 mph. Actual breakage of some older windows would not be expected until air blast overpressures reach 150 dBL (0.095 psi) or approximately seven (7) times higher pressure than the USBM safe limit. This is equivalent to a wind gust of 80 mph. Our experience has shown that if ground vibrations are kept below recommended safe limits, the air blast overpressures from blasting are not a threat to damage buildings. Flyrock: In general, flyrock, or the uncontrolled ejection of blasted rock, can come from either the face of the blast or the top of the blast, both of which can be controlled by proper blast designs. To reduce the potential for flyrock, the Blasting Plan has provided the following controls: • Placement of blasting mats to fully cover the blast area for every blast. • Drillers logs will be kept for all blast holes drilled, documenting open joints, seams, and other anomalies; and the logs will be reviewed by the blaster prior to each blast. • Observation of each blast round detonated so that small problems can be detected and corrected. Noise and Dust: A detailed noise evaluation and impact has been completed and will be reviewed on a separate document. Dust produced from the drilling and blasting activities will be controlled using water or other fluid placed at its source, and drill machines equipped with dust collectors. Potential Blasting Impacts on People People can perceive vibrations from blasting at significantly lower levels than might cause cosmetic damage to buildings. Blast designs have been provided to generate vibration levels that should reduce the impact to people. Vibrations may be noticeable and therefore may result in complaints, at PPVs as low as 0.02 to 0.06 in/sec. This is equivalent to the vibrations generated from a heavy truck traveling down a bumpy road, and vibrations of this magnitude should be expected for neighboring residences Experience has shown that blasting operations in locations such as the Project will be felt by neighbors and that the impacts will feel significant, even if they are well below the design standard. There is no correlation between the design standard that is studied and documented to be safe for structures, and the human experience of vibration in their home. The Project Owner is keenly aware of this, having experience from the Phase I blasting operations. It is impossible to set a design standard for blasting that is imperceptible as the blasts would be too small to make meaningful progress, but this Project has set its design standard at 50% of the levels we know to cause damage, well below what is required. We believe that this Hillside at O’Brien Farm Phase 2 – Borrow Pit Blasting Impacts Assessment March 14, 2022 Page 5 of 6 reduction in allowable vibration is meaningful, will greatly reduce the perception of vibrations for neighbors, and will eliminate the risk of damage to surrounding structures. Conclusions In summary, it is our opinion that proposed Blasting Plan submitted by MD&B for rock excavation at the borrow pit site provides the safety controls and mitigation measures and design that should not adversely impact structures in the area or cause excessive human annoyance. The primary concerns have been discussed and addressed in the Blasting Plan. The following provides a brief summary of our assessment: 1. A Blasting and Vibration Q&A handout (attached) will be provided to the residents to offer a basic understanding of blasting and impacts of blasting. 2. All the necessary site safety and security measures will be implemented for the duration of the blasting activities. 3. To minimize potential damage claims pre-blast condition surveys will be conducted at the interior/exterior of all buildings within a 500’ radius of the blast area. 4. A blast design has been provided to minimize blasted rock Oversize, and to limit Overbreak. 5. Blasting at the pit area will start at a location furthest away from the nearest buildings. 6. At least two seismographs will be used during each blast to monitor ground and air vibrations. 7. To minimize human annoyance, blast induced vibrations as recorded at the nearest buildings will be kept to less than 1.0 in./sec which is one-half the industry standard limit. 8. Blast rounds have been designed to maintain air blast overpressures below 133 dBL (0.014 psi) safe limit as per USBM standard. This is equivalent to a wind gust of 27 mph. Actual breakage of some older windows would not be expected until air blast overpressures reach 150 dBL (0.095 psi) or approximately seven (7) times higher pressure than the USBM safe limit. 9. When ground vibrations are kept below recommended safe limits, the air blast overpressures from blasting are not a threat to damage buildings. 10. The blast is typically felt by the overpressure more than heard by the noise. 11. Residents in the area may feel vibrations, and be slightly disturbed by them, even though the vibration levels are well below the safe limit to cause cosmetic damage. 12. Flyrock will be controlled by proper blast designs, placement of blast mats, review of driller’s logs and observation of each blast round. 13. Dust generated from drilling and blasting will be controlled by placement of water in the blast area and drill machines equipped with dust collectors. Hillside at O’Brien Farm Phase 2 – Borrow Pit Blasting Impacts Assessment March 14, 2022 Page 6 of 6 We hope the above assessment has addressed any concerns regarding the proposed methods for bedrock removal at the O’Brien Farm Phase 2 borrow pit. If you have any questions or require additional information, please feel free to contact me. Sincerely yours, BRIERLEY ASSOCIATES Jay R. Perkins, P.E. Geotechnical Engineer Attachment: Blasting and Vibrations Q&A Handout For more information, contact Andrew Gill: 802-658-5000, andrew@obrienbrothersvt.com Blasting is an important part of the O’Brien Farm – Eastview project. Construction for the building involves bedrock excavation by drill and blast methods below the ground surface. The challenge is to balance the effective fracturing of the rock with the control of impacts from the blast. The following provides questions and answers for the residents of the surrounding area on the art of Blasting and the science of Vibrations. We encourage residents to continue to ask questions, raise concerns, and share ideas. The developer, O’Brien Brothers Agency and the Contractor, are constantly seeking new and innovative ways to reduce impacts and improve construction procedures and blasting methods in ways that should benefit the environment and residents. A blast is a controlled event that places a designed amount of explosive energy into rock to fragment for excavation. Noise and vibration from the blast is energy that was not consumed in the fragmentation of the rock. Designing a blast is about balancing the need to adequately fragment the bedrock with the need to minimize environmental impacts. A blast begins with the design by the blasting contractor (Maine Drillng & Blasting) and the Blasting Consultant (Brierley Associates). A plan of the drill hole pattern is developed that identifies the size of the holes, the number of holes, spacing between the holes, the size of the burden, and the sequence in which the holes detonate in the blast. The drill pattern is then laid out on the ground and measured to ensure accurate spacing and depth of holes. The drill machine then drills a 3.5” diameter column into the rock. When drilling is complete, each hole is loaded with a specific weight of explosive. The first thing down the hole is a non-electric detonator inserted into the explosive at the bottom of the hole. The detonator sets off the explosive in the borehole. The explosives are transported to the site each day by a secure magazine truck on the day of a planned blast. Bags of bulk emulsion or boxes of emulsion cartridges each 2.5” diameter by 16” long are loaded from the truck into a portable magazine. The hole is not filled to the top with explosives; space is left at the top which is referred to as the collar. The collar at the top of each borehole is then filled with crushed stone stemming material. The purpose of the stemming is to contain the explosive energy during detonation. All explosives not used are removed from the site at the end of each day. Each hole is detonated separately. A blast is actually a series of small detona- tions as each hole is detonated. Each hole is detonated with at least 8 millisec- ond delay between them. A typical blast would be not more than 1 second in duration. What the blasting contractor does to minimize nuisance of blasting effects: ⇒ Designs all shots with millisecond delays between holes to reduce vibration. ⇒ Notifies abutting residents in advance. ⇒ Monitors ground and air vibration levels at the nearest occupied locations. There are two types of energy produced from a blast: 1. air overpressure 2. ground vibration The detonation of an explosive produces a very rapid and dramatic increase in volume due to the conversion of the explosive from a solid to a gaseous state. When this occurs within the confines of a borehole, the bedrock in the area imme- diately adjacent to the explosive product is crushed. As the energy from the deto- nation radiates outward from the borehole, the bedrock between the boreholes becomes fragmented and is displaced, while the bedrock at the perimeter is fractured. Energy not used in the fracturing and displacement of the bedrock dissipates in the form of ground vibrations, sound, and air concussion. This energy attenuates rapidly from the blast site due to geometric spreading and natural damping. The rate at which ground vibrations attenuate or decrease with increased distance from a blast depends on a variety of conditions, including the type and condi tion of the bedrock being blasted, any depth and composition of the earth covering deposits (soil), and the general topography. Air overpressure effects are influenced by the prevailing weather conditions. On a still day, air overpressure travels in the opposite direction of ground vibration. However , wind direction has an impact on air overpressure and can focus it in one direction. Whether conditions do not change the intensity of the air concussion, whether only influences how that energy is distributed. Ground vibrations and air overpressures from a blast are controlled by controlling the amount of explosives activated within any single delay within the blast. The amount of explosives detonated is controlled by the size and depth of the hole and the timing of detonation of each hole. O’Brien Farm - Eastview Project: Blasting and Vibrations Q&A What is a blast? We’re working on it….. How does the energy of the blast move? How are blasts controlled? Blasting and Vibration For more information, contact Andrew Gill: 802-658-5000, andrew@obrienbrothersvt.com Because there are two types of energy from blasting, blast monitors or seismographs need two different instruments to measure them: one, a geophone, to measure the seismic waves caused by ground vibration and a microphone to measure the pressure waves travelling through the air caused by air overpressure. Both the geophone and microphone are connected to the seismograph. The International Society of Explosives Engineers (ISEE) Performance Specification for Blasting Seismographs 2017 has established guidelines for monitoring vibrations and air overpressure and is followed by the Contractor. Brierley has established the limits for both air and ground vibrations provided in the Contract Documents. Air overpressure is determined by measuring the peak pressure level. The ground vibration is determined by measuring the vibration velocity. The peak particle velocity (PPV) limit for ground vibration resulting from blasting operations for the project is a maximum of 1.0 in/s and is a function of the frequency. This is one-half of the industry standard to address potential human annoyance. The limit for air overpressure resulting from blasting operations for the project is 133 dBL. Air overpressure is measured as decibels in the Linear or unweighted mode. The human body can detect vibrations at very low levels. Humans can start to feel vibrations at levels of 0.02 - 0.05 in/s. This threshold of human perception of vibration is well below the levels at which cosmetic damage occurs to structures and below the limits set by USBM RI 8507 1980. How people perceive vibrations will depend on what they're doing. People who are sitting or lying down would be more perceptive to vibrations than those taking part in an activity. The determination of whether a vibration is annoying is dependent on the individual. Vibration from blasting can be perceived as annoying as it is unexpected unlike the vibrations that we regularly experience in our homes, such as when we walk up and down stairs or open and close doors. Door slamming can produce vibrations have up to 0.5 in/s. When blasting, the weather conditions, such as high humidity or the presence of cloud cover, can cause the levels of overpressure and noise to seem more severe than there would be on a day when the humidity is low and there is a lack of cloud cover. Structural Response to Ground Vibrations Peak Particle Velocity Ground Vibration Effect in/s 24.0 Microcracks start developing in rock 6.0 Lower limit often set for concrete 3.0 Cracks start developing in plaster 2.0 Industry Standard Limit 1.0 Project Contract limit 0.5 Ground Vibrations Annoying to humans 0.02 Ground vibrations become perceptible to humans in/s = inches per second Structural Response to Air Vibrations Over- pre ssure Air Blast Effect dBL 180 Conventional structures severely damaged 170 Most windows break 150 Some older windows may break 133 Contract Limit 124 Some windows could rattle dBL = decibels, linear (different from noise) Blasting and Weather Contract Blasting Requirements and Restrictions ⇒ Provide an independent qualified Blasting Consultant. ⇒ Blasting operations M-F, 7 AM – 5 PM. ⇒ Provide audible signals to warn of impending blasts. ⇒ Not more than 5-10 blasts in one week. ⇒ Ground and air vibration limits set at 1.0 in/s and 133 dBL, respectively. ⇒ Monitor each blast at nearest occupied locations. ⇒ Post blast reports posted on project website. Measuring Vibrations How do humans perceive vibrations? O’Brien Farm - Eastview Project - Blasting and Vibration Q&A MEMO RSG 55 Railroad Row, White River Junction, Vermont 05001 www.rsginc.com TO: Andrew Gill FROM: Dana Lodico, PE, INCE Bd. Cert. DATE: March 10, 2022 SUBJECT: Hillside Development Phase 2 Quarry Construction Sound Study This memo describes the results of ambient sound measurements and sound modeling of drilling and crushing operations at the quarry site during construction for the O’Brien Brothers Hillside Development Phase 2 in South Burlington, Vermont. An acoustics primer is attached as Appendix A. Executive Summary Temporary drilling and crushing are proposed as part of the construction of Phase 2 of the O’Brien Brothers Hillside Development in South Burlington, Vermont. Drilling is anticipated to occur at the quarry site on 73 days. Drilling activities would occur periodically on these days. The estimated total cumulative drill time for the Project quarry site is 10.5 full construction days. Construction would occur during daytime hours (7 am to 7 am) only. Based on sound propagation modeling, the maximum sound levels from Project drilling and crushing activities at the quarry site are expected to range from 35 to 57 dBA Lmax at the nearest existing homes when drilling is located adjacent to residences. Sound levels inside these homes with windows closed would be about 9 to 30 dBA Lmax, assuming a 27 dBA reduction from outside to inside. In comparison, the existing average daytime exterior sound levels in the vicinity of the project, generated primarily from aircraft and vehicular traffic, are in the range of 55 to 72 dBA Leq, with maximum sound levels from aircraft in the range of 70 to 80 dBA Lmax. There are no State or local statutes or regulations that establish quantitative noise standards applicable to construction of this Project. For informational purposes, Project construction sounds are given with respect to the Vermont Act 250 commonly applied noise limit for operational sound sources of 55 dBA Lmax. Maximum sound levels are modeled to be as high as 57 dBA Lmax when drilling is closest to residences for seven cumulative days or fewer at each individual location. Sound levels from the crusher are not modeled to exceed 55 dBA Lmax at any existing residences. 2 Given the short duration of construction sounds at any individual receptor, exceedance of the operational limit would not cause an adverse impact on aesthetics with regard to noise. Project construction could exceed 55 dBA Lmax for periods of up to seven days at individual receptors and would typically be similar in level or below background sound levels generated by aircraft and vehicular traffic. Given the short duration of these sounds at any individual receptor, Project construction would not cause an undue adverse impact on aesthetics with regard to noise. Project Description O’Brien Brothers is proposing to construct the second phase of the Hillside Development in South Burlington, Vermont. The project would construct approximately 152 residences to the east and west of Old Farm Road and southwest of Kimball Avenue. Project operations are not anticipated to include any notable sound sources that would negatively affect the community. Project construction is anticipated to involve land clearing, drilling, and blasting. To reduce construction truck trips, a portion of the blasted material would be crushed in the eastern portion of the site and the crushed stone would be used on-site. Construction will take place during daytime hours only. Drilling is anticipated to occur intermittently at the quarry site on a total of 73 days. Sound Level Standards There are no State or local statutes or regulations that establish quantitative noise standards applicable to construction of this Project. The noise limit commonly applied to operational sounds generated by Projects in the State of Vermont through Act 250 is 55 dBA Lmax at homes and areas of frequent human use during the day. For informational purposes, Project construction sounds are given with respect to the operational 55 dBA Lmax limit. However, given the short duration of these sounds at any individual receptor, exceedance of the operational limit would not cause an adverse impact on aesthetics with regard to noise. Background Sound Levels The existing sound environment is comprised primarily of aircraft arriving and departing from Burlington Airport, vehicular traffic from Interstate 89 (I-89) and Kimball Avenue, and other local natural, agricultural, and traffic sounds. The northern extent of the project area is about 1,000 feet south of the 65 dBA DNL1 contour shown in the Burlington International Airport noise exposure maps and within the 50 to 55 dBA 24-hr equivalent A-weighted sound level (24-hr Leq) on the National Transportation Noise Map. The Chittenden County Noise Map, developed by RSG, estimates daytime traffic equivalent average sound levels of 50 to 60 dBA Leq. 1 The DNL is a day-night equivalent average sound level, with 10 dB added to the nighttime noise. It is the standard metric used in airport noise mapping. 3 To supplement this information, RSG conducted sound monitoring at three locations in the vicinity of the site from Wednesday, July 5th, 2021 to Wednesday, July 14th, 2021. The monitoring locations included a site along the southern property line (Monitor A), a site near Kimball Avenue (Monitor B), and a site located at 150 Old Farm Road (Monitor C). The sound monitoring locations are shown in Figure 1. FIGURE 1: SOUND MONITORING LOCATIONS Sound level data from each monitor were averaged into 10-minute periods and summarized over the entire monitoring period. Data occurring during undesirable meteorological conditions or periods with extraneous sounds such as equipment interactions by RSG staff were excluded from averaging. Sound monitoring results are presented in Figures 2, 3, 4 for Monitors A, B, and C, respectively. Data is presented as weekly graphs of sound level as a function of time throughout the monitoring period. Each point on the graph represents data summarized for a single 10-minute interval. Equivalent continuous sound levels (Leq) are the energy- average level over 10 minutes. Tenth-percentile sound levels (L90) are the statistical value above which 90% of the sound levels occurred during the 10-minutes. The data from periods which were excluded from processing are included in the graphs but shown in lighter colors. The bands at the top of the graph indicates that data were excluded in the particular 10-minute period; the color designates the reason that data were excluded. 4 FIGURE 2: SOUND PRESSURE LEVELS OVER TIME - MONITOR A, 7/5/2021 TO 7/14/2021 FIGURE 3: SOUND PRESSURE LEVELS OVER TIME - MONITOR B, 7/7/2021 TO 7/14/2021 5 FIGURE 4: SOUND PRESSURE LEVELS OVER TIME - MONITOR C, 7/5/2021 TO 7/14/2021 As shown in the data, aircraft flyovers occur regularly, resulting in elevated noise levels during the flyover event. Sound levels at all three monitoring locations exhibit a diurnal pattern due to traffic and aircraft being greater during the day than at night. An overall summary of the monitor results is provided in Table 1. Sound levels are summarized over the entire monitoring period (overall) and by daytime and nighttime periods. TABLE 1: SUMMARY OF BACKGROUND SOUND LEVELS BY MONITOR LOCATION Location Sound Levels (dBA) Overall Day Night Leq L90 L50 L10 Leq L90 L50 L10 Leq L90 L50 L10 A-South Property Line 56 38 45 51 58 41 46 52 45 37 41 47 B-Kimball Avenue 57 37 46 54 59 42 49 55 47 35 40 49 C-150 Old Farm Road 54 39 45 51 55 41 47 52 45 36 42 48 Average 56 38 45 52 57 41 47 53 46 36 41 48 Project construction will occur during the daytime only. As shown in Table 1, daytime sound levels at the monitoring locations ranged from 55 to 59 dBA Leq. All three monitor locations include aircraft flyover sounds, which are calculated to result in an average daytime sound level of about 55 dBA Leq throughout the site. The lowest sound levels occur at Monitor C, which is not located adjacent to any major traffic sound sources. 6 Vehicular traffic on Kimball Avenue and I-89 result in elevated levels at Monitors A and C, respectively. The arithmetic average of the Leq across all sites is 57 dBA during the day, 46 dBA during the night, and 56 dBA overall. Sound Propagation Modeling Sound propagation modeling was conducted to determine the maximum sound levels expected by drilling and crushing operations at nearby dwellings. METHODOLOGY Modeling for Project construction was in accordance with the standard ISO 9613-2, “Acoustics – Attenuation of sound during propagation outdoors, Part 2: General Method of Calculation.” The ISO standard states, This part of ISO 9613 specifies an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. The method predicts the equivalent continuous A-weighted sound pressure level … under meteorological conditions favorable to propagation from sources of known sound emissions. These conditions are for downwind propagation … or, equivalently, propagation under a well-developed moderate ground-based temperature inversion, such as commonly occurs at night. The model takes into account source sound power levels, surface reflection and absorption, atmospheric absorption, geometric divergence, meteorological conditions, walls, barriers, berms, and terrain. The acoustical modeling software used here was CadnaA, from Datakustik GmbH. CadnaA is a widely accepted acoustical propagation modeling tool, used by many noise control professionals in the United States and internationally. Modeling of background traffic noise levels was conducted using the Federal Highway Administration’s (FHWA) Traffic Noise Model (TNM), as implemented in CadnaA. A 20-meter by 20-meter grid of receivers was set up at a height of 1.5 m (5 ft) in the model, covering approximately 1,000 hectares (2,500 acres) around the Project. The cumulative number of construction days of exposure of sound levels exceeding 55 dBA at surrounding residential locations was also determined. ASSUMPTIONS The following assumptions were used in the sound modeling, 1) Construction will occur during daytime hours only; 7am to 7pm Monday through Saturday. 2) Tree removal will be phased to keep as much cover as possible during the drilling/crushing phase. By keeping trees in place, off-site noise will be reduced. For a conservative analysis, foliage was not included in the sound propagation model. 7 3) A 15- to 20-foot-high topsoil stockpile will be located to the northeast of the quarry location. This stockpile is modeled as a 15-foot-high embankment in the sound model. 4) For the development of the sound contour mapping, the drill and crusher were each represented by point sources. The drill had a sound power rating of 128 dBA when drilling into exposed ledge and 125 dBA when drilling directly into overburden, and the crusher had a sound power rating of 121 dBA. The crusher sound power includes the sound from loading and material conveying. 5) Area sources were used to represent the area in which drilling would take place in order to calculate the duration of sound level exposure at specific receptors. The number of days of drilling was estimated based on the size of the drilling area divided by the drilling rate provided by the blaster of about 465 m2 (5,000 ft2) per day. 6) Residences owned by the company or by shareholders in the development entity are not included in the analysis. This includes 100, 150, 200, and 205 Old Farm Road. MODELING RESULTS Sound contour mapping runs were conducted for three scenarios, representing existing background sound levels and two phases of construction at the quarry site: drilling and crushing. The results are shown as contours of equal sound pressure level overlaid on ortho-imagery of the area surrounding the proposed Project. The cumulative number of days of exposure of sound levels exceeding 55 dBA at representative locations was also modeled. Note that background sound levels are given in terms of an hourly average sound level (Leq), while the sound levels for the Project drilling and crushing operations are given in terms of maximum sound levels (Lmax). 8 Background Sound Levels Modeling of existing daytime background sound levels, including aircraft and vehicular traffic sound sources, was validated to sound levels measured during the sound monitoring survey. The model includes vehicular traffic along I-89, Kimball Avenue, and Kennedy Drive. The aircraft exposure was assumed to be 55 dBA Leq throughout the site and surrounding area. As shown in Figure 5, existing background levels at receptors in the vicinity of the Project range from 55 to 72 dBA Leq during daytime hours. Maximum sound levels from aircraft flyovers (not shown) are in the range of 70 to 80 dBA Lmax throughout the area. FIGURE 5: MODELED BACKGROUND (LEQ) SOUND LEVELS FROM VEHICULAR AND AIRCRAFT TRAFFIC 9 Drilling at the Quarry Site The first Project scenario includes drilling at the quarry site only. Drilling at the quarry site would be into exposed ledge and would not be conducted simultaneously to crushing operations. Crushing would only begin once drill at the quarry site was completed. As shown in Figure 6, the maximum sound level at the closest home, located along Millham Court, is 57 dBA Lmax. Sound levels inside the home with windows closed would be about 30 dBA Lmax, assuming a 27 dBA reduction from outside to inside (Source EPA 1974). Background sound levels at this location are modeled to be 57 dBA Leq (see Figure 5). Therefore, while drilling at the quarry site may be audible at these locations, it would be similar in level to sound generated by local traffic along Kimball Avenue and below maximum levels generated by vehicular traffic and aircraft flyovers. FIGURE 6: MODELED MAXIMUM EXTERIOR SOUND LEVELS FROM DRILLING AT QUARRY SITE 10 Crushing at the Quarry Site The second Project scenario includes crushing on a pad in the quarry area. As shown in Figure 7, the maximum sound level at the closest home, located along Millham Court, is 53 dBA Lmax. Sound levels inside the home with windows closed would be about 27 dBA lower, or 26 dBA Lmax. Maximum sound levels are not anticipated to exceed 55 dBA Lmax at any receptors during this scenario and would generally be similar to or below background sound levels. FIGURE 7: MODELED MAXIMUM EXTERIOR SOUND LEVELS FROM CRUSHING AT QUARRY SITE 11 Duration of Sound Level Exposure The cumulative number of days of exposure of sound levels exceeding 55 dBA at surrounding residential locations was determined by modeling the areas in which drilling would take place at the quarry. The areas slated for drilling at the quarry, totaling about 0.5 hectares (1.2 acres), are represented by area sources in the model. Although drilling is anticipated to occur on 73 days at the quarry site, drilling would occur only periodically on these days. The number of cumulative (full) days of drilling was estimated based on the size of the individual drilling area divided by the drilling rate provided by the blaster of 465 m2 (5,000 ft2) per day. Sound levels generated at five representative receptors, shown in Figure 8, were tracked as the drilling moved between the drilling areas. Throughout the two-year construction period, the estimated cumulative drill time at the quarry site is 10.5 full (12-hour) construction days. FIGURE 8: REPRESENTATIVE RECEPTORS AND DRILLING AREA SOURCES Results of this analysis are shown in Figure 9. The sound levels represent the average of the maximum sound level from drilling during operation of the drill; the levels are not sustained or daily averages. That is, for each hole drilled in an area, there is a maximum sound level. The figures in the graphic represent the equivalent average of these 12 maximum sound levels as the drill operates. The overall average sound levels would be 3 to 8 dB lower, depending on several factors. The highest sound levels from quarry construction activity occur at 42 Millham Road. Table 2 shows the number of days for which the maximum drilling sound levels will be in specified sound levels ranges and Table 3 lists the sound levels at the representative receivers from the crusher operation only. FIGURE 9: AVERAGE MAXIMUM INSTANTANEOUS DRILLING SOUND LEVELS OVER TIME AT REPRESENTATIVE RESIDENCES TABLE 2: NUMBER OF DAYS MAXIMUM DRILLING SOUND LEVELS ARE EXCEEDED Maximum Sound Level, dBA Receptor Location 80 Old Farm Road 103 Old Farm Road 175 Kennedy Drive 91 Bayberry Lane 42 Millham Court Less than 55 11 11 11 11 4 55 to 60 0 0 0 0 7 60 to 65 0 0 0 0 0 65 to 70 0 0 0 0 0 Greater than 70 0 0 0 0 0 Total days greater than 55 dBA 0 0 0 0 7 13 TABLE 3: MAXIMUM SOUND LEVEL OF CRUSHING OPERATION S Sound Source Receptor Location 80 Old Farm Road 103 Old Farm Road 175 Kennedy Drive 91 Bayberry Lane 42 Millham Court Crusher 50 44 39 40 53 CONCLUSIONS Temporary drilling and crushing are proposed as part of the construction of Phase 2 of the O’Brien Brothers Hillside Development in South Burlington, Vermont. On-site crushing reduces the number of truck trips required to bring material to the site, resulting in reduced sound and traffic impacts along roadways serving the site. Drilling is anticipated to occur intermittently on a total of 73 days at the quarry site. The maximum sound levels from Project drilling and crushing activities are expected to range from 35 to 57 dBA Lmax at the nearest existing homes. Sound levels inside residences would be about 27 dBA lower with windows closed. Maximum sound levels that exceed 55 dBA Lmax will occur when drilling is closest to residences but will last seven full construction days or fewer at each individual location as drilling moves around the site. In comparison, the existing average daytime sound levels in the vicinity of the project, generated primarily from aircraft and vehicular traffic, are in the range of 55 to 72 dBA Leq, with maximum sound levels from aircraft in the range of 70 to 80 dBA Lmax. There are no State or local statutes or regulations that establish quantitative noise standards applicable to construction of this Project. The noise limit commonly applied to operational sounds generated by Projects in the State of Vermont through Act 250 is 55 dBA Lmax at homes and areas of frequent human use during the day. Project construction could exceed 55 dBA Lmax for periods of up to seven full construction days at individual receptors and would typically be similar in level or below background sound levels generated by aircraft and vehicular traffic. Given the short duration of these sounds at any individual receptor, Project construction would not cause an undue adverse impact on aesthetics with regard to noise. 14 APPENDIX A. ACOUSTICS PRIMER Sound consists of tiny, repeating fluctuations in ambient air pressure. The strength, or amplitude, of these fluctuations determines the sound pressure level (SPL). “Noise” can be defined as “a sound of any kind, especially when loud, confused, indistinct, or disagreeable.” Expressing Sound in Decibel Levels The varying air pressure that constitutes sound can be characterized in many different ways. The human ear is the basis for the metrics that are used in acoustics. Normal human hearing is sensitive to sound fluctuations over an enormous range of pressures, from about 20 micropascals (the “threshold of audibility”) to about 20 Pascals (the “threshold of pain”).2 This factor of one million in sound pressure difference is challenging to convey in engineering units. Instead, sound pressure is converted to sound “levels” in units of “decibels” (dB, named after Alexander Graham Bell). Once a measured sound is converted to dB, it is denoted as a level with the letter “L”. The conversion from sound pressure in pascals to sound level in dB is a four-step process. First, the sound wave’s measured amplitude is squared and the mean is taken. Second, a ratio is taken between the mean square sound pressure and the square of the threshold of audibility (20 micropascals). Third, using the logarithm function, the ratio is converted to factors of 10. The final result is multiplied by 10 to give the decibel level. By this decibel scale, sound levels range from 0 dB at the threshold of audibility to 120 dB at the threshold of pain. Typical sources of noise, and their sound pressure levels, are listed on the scale in Figure 10. Human Response to Sound Levels: Apparent Loudness For every 20 dB increase in sound level, the sound pressure increases by a factor of 10; the sound level range from 0 dB to 120 dB covers 6 factors of 10, or one million, in sound pressure. However, for an increase of 10 dB in sound level as measured by a meter, humans perceive an approximate doubling of apparent loudness: to the human ear, a sound level of 70 dB sounds about “twice as loud” as a sound level of 60 dB. Smaller changes in sound level, less than 3 dB up or down, are generally not perceptible. 2 The pascal is a measure of pressure in the metric system. In Imperial units, they are themselves very small: one pascal is only 145 millionths of a pound per square inch (psi). The sound pressure at the threshold of audibility is only 3 one-billionths of one psi: at the threshold of pain, it is about 3 one-thousandths of one psi. 15 FIGURE 10: A SCALE OF SOUND PRESSURE LEVELS FOR TYPICAL NOISE SOURCES 16 Frequency Spectrum of Sound The “frequency” of a sound is the rate at which it fluctuates in time, expressed in Hertz (Hz), or cycles per second. Very few sounds occur at only one frequency: most sound contains energy at many different frequencies, and it can be broken down into different frequency divisions, or bands. These bands are similar to musical pitches, from low tones to high tones. The most common division is the standard octave band. An octave is the range of frequencies whose upper frequency limit is twice its lower frequency limit, exactly like an octave in music. An octave band is identified by its center frequency: each successive band’s center frequency is twice as high (one octave) as the previous band. For example, the 500 Hz octave band includes all sound whose frequencies range between 354 Hz (Hertz, or cycles per second) and 707 Hz. The next band is centered at 1,000 Hz with a range between 707 Hz and 1,414 Hz. The range of human hearing is divided into 10 standard octave bands: 31.5 Hz, 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz, 8,000 Hz, and 16,000 Hz. For analyses that require finer frequency detail, each octave-band can be subdivided. A commonly-used subdivision creates three smaller bands within each octave band, or so-called 1/3-octave bands. Human Response to Frequency: Weighting of Sound Levels The human ear is not equally sensitive to sounds of all frequencies. Sounds at some frequencies seem louder than others, despite having the same decibel level as measured by a sound level meter. In particular, human hearing is much more sensitive to medium pitches (from about 500 Hz to about 4,000 Hz) than to very low or very high pitches. For example, a tone measuring 80 dB at 500 Hz (a medium pitch) sounds quite a bit louder than a tone measuring 80 dB at 60 Hz (a very low pitch). The frequency response of normal human hearing ranges from 20 Hz to 20,000 Hz. Below 20 Hz, sound pressure fluctuations are not “heard”, but sometimes can be “felt”. This is known as “infrasound”. Likewise, above 20,000 Hz, sound can no longer be heard by humans; this is known as “ultrasound”. As humans age, they tend to lose the ability to hear higher frequencies first; many adults do not hear very well above about 16,000 Hz. Most natural and man-made sound occurs in the range from about 40 Hz to about 4,000 Hz. Some insects and birdsongs reach to about 8,000 Hz. To adjust measured sound pressure levels so that they mimic human hearing response, sound level meters apply filters, known as “frequency weightings”, to the signals. There are several defined weighting scales, including “A”, “B”, “C”, “D”, “G”, and “Z”. The most common weighting scale used in environmental noise analysis and regulation is A- weighting. This weighting represents the sensitivity of the human ear to sounds of low to moderate level. It attenuates sounds with frequencies below 1000 Hz and above 4000 Hz; it amplifies very slightly sounds between 1000 Hz and 4000 Hz, where the human ear is particularly sensitive. The C-weighting scale is sometimes used to describe louder sounds. The B- and D- scales are seldom used. All of these frequency weighting scales are normalized to the average human hearing response at 1000 Hz: at this frequency, the filters neither attenuate nor amplify. When a reported sound level has been filtered 17 using a frequency weighting, the letter is appended to “dB”. For example, sound with A- weighting is usually denoted “dBA”. When no filtering is applied, the level is denoted “dB” or “dBZ”. The letter is also appended as a subscript to the level indicator “L”, for example “LA” for A-weighted levels. Time Response of Sound Level Meters Because sound levels can vary greatly from one moment to the next, the time over which sound is measured can influence the value of the levels reported. Often, sound is measured in real time, as it fluctuates. In this case, acousticians apply a so-called “time response” to the sound level meter, and this time response is often part of regulations for measuring noise. If the sound level is varying slowly, over a few seconds, “Slow” time response is applied, with a time constant of one second. If the sound level is varying quickly (for example, if brief events are mixed into the overall sound), “Fast” time response can be applied, with a time constant of one-eighth of a second.3 The time response setting for a sound level measurement is indicated with the subscript “S” for Slow and “F” for Fast: LS or LF. A sound level meter set to Fast time response will indicate higher sound levels than one set to Slow time response when brief events are mixed into the overall sound, because it can respond more quickly. In some cases, the maximum sound level that can be generated by a source is of concern. Likewise, the minimum sound level occurring during a monitoring period may be required. To measure these, the sound level meter can be set to capture and hold the highest and lowest levels measured during a given monitoring period. This is represented by the subscript “max”, denoted as “Lmax”. One can define a “max” level with Fast response LFmax (1/8-second time constant), Slow time response LSmax (1-second time constant), or Continuous Equivalent level over a specified time period LEQmax. Note that, in the Act 250 precedents set by the former Environmental Board and the Vermont Superior Court Environmental Division utilizes LSmax. Accounting for Changes in Sound over Time A sound level meter’s time response settings are useful for continuous monitoring. However, they are less useful in summarizing sound levels over longer periods. To do so, acousticians apply simple statistics to the measured sound levels, resulting in a set of defined types of sound level related to averages over time. An example is shown in Figure 11. The sound level at each instant of time is the grey trace going from left to right. Over the total time it was measured, the sound energy spends certain fractions of time near various levels, ranging from the minimum (about 28 dB in the figure) to the maximum (about 65 dB in the figure). The simplest descriptor is the average sound level, known as the Equivalent Continuous Sound Level. Statistical levels are used to 3 There is a third time response defined by standards, the “Impulse” response. This response was defined to enable use of older, analog meters when measuring very brief noises; it is no longer in common use. 18 determine for what percentage of time the sound is louder than any given level. These levels are described in the following sections. Equivalent Continuous Sound Level - LEQ One straightforward, common way of describing sound levels is in terms of the Continuous Equivalent Sound Level, or Leq. The Leq is the average sound pressure level over a defined period of time, such as one hour or one day. Leq is the most commonly used descriptor in noise standards and regulations. Leq is representative of the overall sound to which a person is exposed. Because of the logarithmic calculation of decibels, Leq tends to favor higher sound levels: loud and infrequent sources have a larger impact on the resulting average sound level than quieter but more frequent noises. For example, in Figure 11, even though the sound levels spends most of the time near about 34 dBA, the Leq is 41 dBA, having been “inflated” by the maximum level of 65 dBA. FIGURE 11: EXAMPLE OF DESCRIPTIVE TERMS OF SOUND MEASUREMENT OVER TIME Percentile Sound Levels – LN Percentile sound levels describe the statistical distribution of sound levels over time. “LN” is the level above which the sound spends “N” percent of the time. For example, L90 (sometimes called the “residual base level”) is the sound level exceeded 90% of the time: the sound is louder than L90 most of the time. L10 is the sound level that is 19 exceeded only 10% of the time. L50 (the “median level”) is exceeded 50% of the time: half of the time the sound is louder than L50, and half the time it is quieter than L50. Note that L50 (median) and Leq (mean) are not always the same, for reasons described in the previous section. L90 is often a good representation of the “ambient sound” in an area. This is the sound that persists for longer periods, and below which the overall sound level seldom falls. It tends to filter out other short-term environmental sounds that aren’t part of the source being investigated. L10 represents the higher, but less frequent, sound levels. These could include such events as barking dogs, vehicles driving by and aircraft flying overhead, gusts of wind, and work operations. L90 represents the background sound that is present when these event noises are excluded. Note that if one sound source is very constant and dominates the noise in an area, all of the descriptive sound levels mentioned here tend toward the same value. It is when the sound is varying widely from one moment to the next that the statistical descriptors are useful. Sound Levels from Multiple Sources: Adding Decibels Because of the way that sound levels in decibels are calculated, the sounds from more than one source do not add arithmetically. Instead, two sound sources that are the same decibel level increase the total sound level by 3 dB. For example, suppose the sound from an industrial blower registers 80 dB at a distance of 2 meters (6.6 feet). If a second industrial blower is operated next to the first one, the sound level from both machines will be 83 dB, not 160 dB. Adding two more blowers (a total of four) raises the sound level another 3 dB to 86 dB. Finally, adding four more blowers (a total of eight) raises the sound level to 89 dB. It would take eight total blowers, running together, for a person to judge the sound as having “doubled in loudness”. Recall from the explanation of sound levels that a difference of 10 decibels is a factor of 20 in sound pressure and a factor of 10 in sound power. (The difference between sound pressure and sound power is described in the next Section.) If two sources of sound differ individually by 10 decibels, the louder of the two is generating ten times more sound. This means that the loudest source(s) in any situation always dominates the total sound level. Looking again at the industrial blower running at 80 decibels, if a small ventilator fan whose level alone is 70 decibels were operated next to the industrial blower, the total sound level increases by only 0.4 decibels, to 80.4 decibels. The small fan is only 10% as loud as the industrial blower, so the larger blower completely dominates the total sound level. The Difference between Sound Pressure and Sound Power The human ear and microphones respond to variations in sound pressure. However, in characterizing the sound emitted by a specific source, it is proper to refer to sound power. While sound pressure induced by a source can vary with distance and 20 conditions, the power is the same for the source under all conditions, regardless of the surroundings or the distance to the nearest listener. In this way, sound power levels are used to characterize noise sources because they act like a “fingerprint” of the source. An analogy can be made to light bulbs. The bulb emits a constant amount of light under all conditions, but its perceived brightness diminishes as one moves away from it. Both sound power and sound pressure levels are described in terms of decibels, but they are not the same thing. Decibels of sound pressure are related to 20 micropascals, as explained at the beginning of this primer. Sound power is a measure of the acoustic power emitted or radiated by a source; its decibels are relative to one picowatt. Sound Propagation Outdoors As a listener moves away from a source of sound, the sound level decreases due to “geometrical divergence”: the sound waves spread outward like ripples in a pond and lose energy. For a sound source that is compact in size, the received sound level diminishes or attenuates by 6 dB for every doubling of distance: a sound whose level is measured as 70 dBA at 100 feet from a source will have a measured level of 64 dBA at 200 feet from the source and 58 dBA at 400 feet. Other factors, such as walls, berms, buildings, terrain, atmospheric absorption, and intervening vegetation will also further reduce the sound level reaching the listener. The type of ground over which sound is propagating can have a strong influence on sound levels. Harder ground, pavement, and open water are very reflective, while soft ground, snow cover, or grass is more absorptive. In general, sounds of higher frequency will attenuate more over a given distance than sounds of lower frequency: the “boom” of thunder can be heard much further away than the initial “crack”. Atmospheric and meteorological conditions can enhance or attenuate sound from a source in the direction of the listener. Wind blowing from the source toward the listener tends to enhance sound levels; wind blowing away from the listener toward the source tends to attenuate sound levels. Normal temperature profiles (typical of a sunny day, where the air is warmer near the ground and gets colder with increasing altitude) tend to attenuate sound levels; inverted profiles (typical of nighttime and some overcast conditions) tend to enhance sound levels. ___________________________________ Blasting Plan For Hillside @ O’Brien Farm – Borrow Pit _____________________________________ South Burlington, Vermont 05403 March 10, 2022 Prepared By: Maine Drilling & Blasting, Inc Western Construction 7190 State Route 40 Argyle, NY 12809 Telephone: 518 824-3309 Fax: 518 632 5716 Joseph Happy / Cole Dube Division Manager / Field Engineer ___________________________________________ ___________________________________________ Name Title 1 Table of Contents General Project Specifics Pre-Blast Surveys Blast Monitoring Sequence of Blasting Blasting Procedures Blasting Mats Blast Area Security and Warning Signals Explosives Blaster Qualifications Blasting Personnel Licenses and Permits Blast Vibration Blast Reports Typical Blast Design General Maine Drilling & Blasting, Inc. considers safety as the priority during all phases of blasting operations. We are knowledgeable of and will follow all local, state and federal regulations related to transportation and use of explosives. The project specifications and conditions have been reviewed. Details of procedures for pre-blast surveys, explosives use, blast security, monitoring and documentation are enclosed. Project Specifics Through a series of ledge probes in all accessible areas of the proposed site, MD&B has estimated an approximate 70,000 cubic yards of dolostone/limestone ledge to be removed in order to reach grade for the proposed project. Blasting will be utilized to remove the ledge as cuts are as deep as 25’. It is estimated to take 75 days to drill & blast on site with two drills running simultaneously without delay. MD&B will blast 5-10 times per week throughout the duration of the project. Attached to this blast plan is a project phasing plan and start location of blasting. Pre-Blast Surveys / Notifications Pre-blast surveys will be offered to all property owners within 500 foot radius of the blast site. Appropriate notices will be given and appointments arranged for those owners who desire a survey. Pre-blast surveys will be conducted by a Company Representative. Results of those surveys will be documented through video or still photographs and appropriate narration or written reports. Blast Monitoring All blasts will be monitored by a representative of Maine Drilling & Blasting, Inc. who has been properly trained in the setup and use of seismic monitoring equipment. At least one seismograph will be in use at all times. Placement of monitoring equipment will be at the nearest structure to the blast site. Maine Drilling & Blasting, Inc monitoring equipment will consist of Instantel type seismographs. Details are enclosed. Results of blast monitoring will typically be available before the next blast, usually immediately following a blast. Results can be reviewed and modifications can be made to the blast design for the next blast if necessary. Sequence of Blasting All blasting operations will be strictly coordinated with the contractor, engineers, and Fire Department. Emphasis will be on the safe and efficient removal of the rock existing on this project without impact to surrounding structures. Blasts will be developed so as to create adequate relief which will minimize ground vibrations and offer the greatest protection possible to the surrounding structures. Blasting Procedures 1. Blasting operations shall commence after 7:00 AM and cease before 5:00 PM, Monday through Friday. 2. Blasting cannot be conducted at times different from those announced in the blasting schedule except in emergency situations, such as electrical storms or public safety required unscheduled detonation. 3. Warning and all-clear signals of different character that are audible within a range of one-quarter mile from the point of the blast shall be given. All persons within the permit area shall be notified of the meaning of the signals through appropriate instructions and signs posted. 4. Access to blasting area shall be regulated to protect the public from the effects of blasting. Access to the blasting are shall be controlled to prevent unauthorized entry before each blast and until the perimeter's authorized representative has determined that no unusual circumstances exist after the blast. Access to and travel in or through the area can then safely resume. 5. Areas in which charged holes are awaiting firing shall be guarded, barricaded and posted, or flagged against unauthorized entry. 6. All blasts shall be made in the direction of the stress relieved face previously marked out or previously blasted. 7. All stemming shall be minimum as specified using clean, dry 3/8'' crushed stone. 8. Blasting mats shall be used as necessary to cover blasts. 9. The Blasting Contractor shall insure that extra safety and judgment is exercised by his blaster to prevent the simultaneous blasting of numerous holes. 10. Maine Drilling & Blasting will consistently review the results of each blast to ensure the customer is receiving a manageable product with little oversize. Though it will be impossible to eliminate ALL oversize, adjustments to the blast design can be made to reduce oversize amounts significantly. Depending on blasting location and cut depth, adjustments to the pattern size, explosive loads, and stemming height can be made to create a better product. 11. A minimum hole depth is required in order to effectively break rock without high spots and oversize. This can create overblast in certain locations/cut depths. MD&B will communicate with the contractor in order to leave a certain amount of overburden to reduce overblast Blasting Mats Blasting mats and backfill will be used to control excessive amounts of rock movement when blasting in close proximity to structures. Placement and number of mats are typically determined by the blaster. Mats will be placed so as to protect all people and structures on, or surrounding the blast site and property. Rubber tire type blasting mats will be utilized on this project and will be approximately 12' x 24' in size; Rubber mat @ 12' x 24' 38 lbs./s.f. = 10,944 lbs./ea. Blast Security and Warning Whistles Each blast will be preceded by a security check of the affected area and then a series of warning whistles. Communications will be made with job site supervisors and local officials as required to ensure the safest possible operation. All personnel in the vicinity closest to the blast area will be warned. The warning whistles will follow the following sequence: 3 Audible Signal Pulses - 5 Minutes to Blast 2 Audible Signal Pulses - 1 Minute to Blast 1 Audible Signal Pulses - All Clear No blast will be fired until the area has been secured and determined safe. The blast site will be examined by the blaster prior to the all-clear signal to determine that it is safe to resume work. Explosives All explosives will be delivered to the job site on a daily basis. Overnight storage will be a licensed secure magazine site only the amount of explosives required to perform the day's work will be brought to the site. All explosives will be stored in approved magazines when not in use. Enclosed are Technical Data and SDS sheets for the explosive products proposed for use on this project. Any one of, or a combination of these products may be in use at any one time on the site. Blaster Qualifications All Maine Drilling & Blasting, Inc. blasters on this job will be licensed in the State of Vermont and have received various amounts of training in the safe use and handling of explosives. Additionally, Maine Drilling & Blasting, Inc. blasters are familiar with all OSHA Regulations, State Regulations, and Federal Regulations regarding construction site safety, including transportation, use, and handling of explosive materials. Weekly safety meetings are to be held on site by the Maine Drilling & Blasting, Inc. job foreman, with a record of that meeting returned to the Maine Drilling & Blasting, Inc. office. Blasting Personnel All blasting operations shall be conducted by experienced, trained and competent persons who understand the hazards involved. Persons working with explosive materials shall: 1. Have demonstrated knowledge of, and a willingness to comply with, safety and security requirements. 2. Be capable of using mature judgment in all situations. 3. Be of good physical condition and not addicted to intoxicants, narcotics, or other similar type of drugs. 4. The person(s) responsible for the explosives shall possess current knowledge of the local, State and Federal laws and regulations applicable to his work. 5. The person(s) responsible for the explosives shall have obtained a Certificate of Competency or a license as required by State law. Licenses and Permits Maine Drilling & Blasting, Inc. is fully licensed and insured for the transportation, use, and handling of explosives. Evidence of insurance is available. Blasting permits will be applied for as required from the local authorities by the Maine Drilling & Blasting, Inc. Blaster/Foreman when blasting is about to begin. Blast Vibration Blast vibration will be monitored at the blast site, typically at the structure(s) closet to the blast site. Vibration limits will closely follow industry limits and the State and Local Regulations. MD&B’s blast design for the proposed project is based on 50% of the allowable Peak Particle Velocity. Blast designs will be modified as required to stay within the guidelines and meet project schedules as well. Blasting operations will be modified accordingly when approaching buildings and utilities. Enclosed are preliminary vibration calculations based on known distances to the structures of concern and anticipated initial blast designs. Ground vibration peak particle velocity limits shall not exceed USBM Alternative Blasting Criteria * US Bureau of Mines (USBM) RI 8507 Appendix B * Standard, and applicable State Regulations (VOSHA related to blasting, N.F.P.A. No. 295) Airblast overpressure level not to exceed 133 peak dB (linear) two Hertz high -pass system. Blast Reports Enclosed is a sample of a Maine Drilling & Blasting, Inc Blast Report. This report will be filled out for each blast and copies supplied as needed. Typical Blast Design Enclosed are what would be considered typical blast designs for this project. Hole sizes, depths, spacing and loading information is provided. These designs are to be considered a good starting point. Modifications are usually made, if necessary, following the first blasts to meet control and seismic considerations Blasting Location Sketch 54555657585960616263DESCRIPTIONDATEREV PreblastSurveyDrawing500ft PREBLASTSURVEY RADIUSSouth Burlington, VT HILLSIDE PHASE II - EASTVIEW 54555657585960616263CUT/FILLDRAWINGDESCRIPTIONDATEREV South Burlington, VT HILLSIDE PHASE II - EASTVIEW 50' Wetland Setback Wetland A T y p e I I I 50' We t l and Se tb a c k Wetland B Ty p e I I I 50' WetlandSetbackWetland C Type III 8' MIN 8' MIN EASTVIEW HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: Q-1 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com EX. POND #1 EX. POND #2 EX. POND #3 WET POND A GRAVEL WETLAND #1 GRAVEL WETLAND #2 GRAVEL WETLAND #3 GRAVEL WETLAND #4 GRAVEL WETLAND #5 GRAVEL WETLAND #6B GRAVEL WETLAND #7 GRAVEL WETLAND #8 Lot 1 8.9 ac Lot 2 5.0 ac Lot 3 2.0 ac Lot 4 1.1 ac Lot 5 8.8 ac Lot 6 3.0 ac Lot 7 2.4 ac Lot 5 8.8 ac Lot 8 4.6 ac Lot 9 1.9 ac Lot 10 0.9 ac Lot 11 1.2 ac Lot 13 2.78 ac Lot 15 2.38 ac Lot 12 1.6 ac Lot 14 1.1 ac Lot 17 3.11 ac Lot 16 2.81 ac Lot 20 21.3 ac Lot 21 2.30 ac Lot 22 1.25 ac Lot 23 0.12 ac Lot 24 1.25 ac Lot 25 2.53 ac Lot 26 1.88 ac Lot 27 1.00 ac Lot 28 2.11 ac Lot 33 2.38 ac Lot 31 2.39 ac Lot 32 4.80 ac Lot 35 2.38 ac Lot 47 Open Space 12.64 ac Lot 29 1.04 ac Lot 41 3.65 ac Lot 46 3.96 ac Lot 48 Open Space 4.56 ac Archaeology Zone Archaeology Zone Lot 34 1.30 ac Lot 39 3.54 ac Lot 18 Open Space 1.17 ac Lot 19 Open Space 1.51 ac 16-1 16-2 16-3 16-4 16-716-616-5 16-8 16-9 16-10 16-11 16-12 16-13 16-14 20-132-132-232-332-432-532-632-732-832-932-1032-1132-1232-1332-143 2 - 1 5 32- 1 632-1732-1832-1932-2032-2132-2232-2332 -24 31-1 31-5 31-7 31-9 3 1 - 1 3 3 1 - 1 4 3 1 - 1 5 3 1 - 1 6 3 1 - 1 7 3 1 - 1 8 3 1 - 1 9 34-1 34-3 34-6 34-7 39-139-239-3 39-4 39-539-639-739-839-9 39-1039-1138-138-238-338-4 38-5 34-2 34-4 34-5 34-8 34-9 31-2 31-3 31-4 31-6 31-8 31-10 31 -1131-1220-220-320-420-520-620-720-820-920-1020-1120-1220-1320-1420-1520-1620-1720-1820-1920-2020-2120-2220-2320-2420-2520-263 1 - 2 0 3 1 - 2 1 Lot 38 1.55 ac 35-1 35-2 35-3 35-4 35-5 35-6 35-7 35-8 35-9 35-10 Lot 42 3.14 ac Lot 43 3.95 ac Lot 44 3.51 ac Lot 45 2.90 ac Lot 37 1.10 ac 3 1 - 2 2 3 1 - 2 3 3 1 - 2 4 3 1 - 2 5 3 1 - 2 632-25 35-12 35-13 35-14 35-15 35-16 35-17 35-18 36-137-1 35-11 34-10 Lot 30 0.30 ac Lot 36 0.66 ac 24-1 24-124-2 24-3 24-436-236-336-436-537-2 37-3 37-4 37-5 37-6 GRAVEL WETLAND #6A16-1516-1616-17 16-18 16-19 Lot 49 0.54 ac OVERALL SITE PLAN- Rock Extraction & Crushing Area APPROXIMATE LIMIT OF ROCK EXTRACTION AREA APPROXIMATE LIMIT OF ROCK EXTRACTION AREA Lot 40 1.90 ac Lot 50 1.15 ac HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: Q-2 SITE PLAN - Rock Extraction & Crushing Area Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Temporary gravel pad for rock crushing operations Area of re-grading and rock extraction Area of re-grading and rock extraction P O T A S H R O A D A L I G N M E N T KIMBALL AVENUEEASTVIEW Temporary sediment trap for runoff from earth moving and crushing operations Stabilized construction entrance Stabilized construction haul road from crusher area to residential development A ABB ARCHAELOGY ZONE APPROXIMATE LIMIT OF ROCK EXTRACTION AREA APPROXIMATE LIMIT OF ROCK EXTRACTION AREA HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: Q-4 SITE RECLAMATION PLAN - Rock Extraction & Crushing Area Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com P O T A S H R O A D KIMBALL AVENUEEASTVIEW A ABB ARCHAELOGY ZONE · · · · · · · · · · Finish Grade Finish Grade Depth of cut (typical) Depth of cut (typical) Potash Road HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: Q-3 SITE SECTIONS - Rock Extraction & Crushing Area Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com EASTVIEW