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Responses to Engineering Comments 38 High Rock Avenue, Suite 3 | P.O. Box 272 | Saratoga Springs, NY 12866 | 518.450.4030 January 31, 2022 Craig Brown Zoning Administrator and Code Compliance Officer Town of Queensbury 742 Bay Road Queensbury, New York 12804 Email: CraigB@queensbury.net Re: Civitella Residence – 104 Knox Road, Town of Queensbury, Warren County, New York- SWPPP Review Comments Dear Mr. Brown: We are in receipt of LaBella Associates’ review letter, dated January 13, 2022, pertaining to the above referenced project located in the Town of Queensbury, New York. It should be noted that since the original submission, the site plans have been modified to reflect a design more compliant to Queensbury’s Waterfront Residential zoning requirements within the dimensional bulk and area schedule. However, much of the layout remains similar. HydroCAD models and stormwater calculations have been updated to reflect the new conditions. With respect to the comments provided in LaBella’s letter please see the following responses: Comment 1: In response to comment 2 of LaBella’s September 23, 2021 comment letter regarding the minor project stormwater calculations, the Applicant has provided two methodologies the 1.5 gallons/net square feet in impervious and a 25-year storm hydraulic/hydrologic model. Both calculation methodologies require additional information to make a determination if the stormwater requirements are being satisfied. 25-year Storm Model The Hydrocad model does not appear to show all model inputs, including but not limited to, the time of concentration calculations. Also, the time of concentration flow paths shall be included on the pre/post development subcatchment maps. Further, it does not appear that soil test pits and infiltration test pits were performed for the rain garden, which is modeled as an infiltration practice. The Applicant shall show all HydroCAD model inputs and revise the subcatchment maps accordingly. The Applicant shall provide test pits and infiltration tests for all practices modeled with infiltration. 1.5 Gallon Method The Applicant provides calculations on sheet SC-2, which state that 957 cubic feet is the volume to be infiltrated using this methodology. The Applicant provides the available storage breakdown, which totals 1,099 cubic feet. However, the 957 cubic feet shall be directed to an infiltration practice and this requirement does not appear to be satisfied since the gravel trench and permeable pavers patio are not being considered infiltration practices by the Applicant. The Applicant shall provide test pits and infiltration tests for all infiltration practices required to meet this methodology that appears to include the gravel trench, permeable pavers patio, and rain garden. Response 1: Studio A has modified their calculations to attenuate stormwater runoff to meet pre- construction conditions for the 25-year storm only. All necessary model inputs have been provided in HydroCAD. The time of concentration was assumed to be instantons due to the small size of the site. Within the Stormwater Management Narrative a note on the subcatchment drawings, SC-1 and SC-2, states this. Two test pits and three infiltration tests were observed on the project site prior to design. Due to the small size of the site, Studio A feels these test pits and infiltration tests provide enough information to provide an accurate enough infiltration rate for the proposed infiltrating stormwater practices. The infiltration test result closest to the proposed infiltration practice was used to calculate the most conservative infiltration rate observed in the field. Additionally, the NRCS Soil Resource Report indicates the soils on the site are uniformly Charlton fine sandy loam, HSG B (see Appendix B of the Stormwater Management Narrative), therefore, soils across the site are not expected to vary greatly. The test pits and infiltration tests already conducted support the NRCS Soil Resource Report’s findings. Lastly, Studio A requests that the town consider that this is a minor project, and less than 15,000 square feet of disturbance is proposed. Therefore, complete compliance to the rigorous infiltration test requirements stated in the New York State Stormwater Design Manual should be considered as a recommendation, rather than required practice. Comment 2: In response to comment 8 of LaBella’s September 23, 2021 comment letter regarding soil and infiltration tests, the Applicant suggested performing more tests at the time of construction. However, it does not appear that test pits/infiltration tests have been performed in close proximity or within each practice location (also commented above). The Applicant shall perform soil tests and infiltration tests within or in close proximity to all infiltration practices required to meet the stormwater requirements. Response 2: See the last paragraph in Response 1. Comment 3: In response to comment 10 and 12 of LaBella’s September 23, 2021 comment letter regarding the separation distance requirements for the proposed, the Applicant has stated that the “permeable paves will no longer be infiltrating stormwater…” Ultimately the NYS DOH will review the proposed well location, so we have no further comment. Response 3: The site plan has been revised to allow for both areas of permeable pavers to infiltrate without the need for any variances. The well has been removed from the site plan and potable water will now be sourced from the Lake. This removes the 100’ setback requirement from a well head. The proposed porous pavers are also at least 35’ setback from the Lake MHW mark and at least 20’ setback from the wastewater absorption field. Comment 4: In response to comment 11 of LaBella’s September 23, 2021 comment letter regarding neighboring septic fields and neighboring water wells, the Applicant states that prior to construction, staff will verify the location of neighboring fields and wells. Since this is applicable to the stormwater review, the Applicant shall depict neighboring water wells within a reasonable distance (200 feet) and should depict neighboring septic absorption fields if they are within 20 feet of a proposed infiltration device. Response 4: A FOIL request was submitted to the Town of Queensbury. Documents indicating the approximate locations of neighboring wastewater absorption fields were provided and this information has been added to the site plan drawings, L-1.10, L-2.10, and L-4.10. However, the Town does not keep record of a property’s well locations. In a conversation with the Town’s Land Use Planner, Laura Moore, it was indicated that most properties on Assembly Point source their potable water supply from Lake George. Included in this revised Site Plan Review Application please find a revised site plan drawing set and SWPPP. If you have any questions or comments, please do not hesitate to reach me at the office phone, (518) 832-4005, or email me at mhuntington@studioadpc.com. Yours truly, Kirsten A. Catellier, RLA, ASLA for Studio A | Landscape Architecture and Engineering, DPC