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Engineering Responses 2/18/2022900 Route 146 Clifton Park, NY 12065 (P) 518.371.7621 (F) 518.371.9540 edpllp.com Date: February 18, 2022 To: Mr. Craig Brown Zoning Administrator and Code Compliance Officer Town of Queensbury 742 Bay Road Queensbury, NY 12804 Re: West Residence – Guest House Queensbury Ref #SP52-2021 Dear Mr. Brown: The Environmental Design Partnership, LLP (EDP) is providing you this letter in response to review comments provided by the LaBella dated February 18, 2022. On behalf of the applicant Brett West, we offer the following response to comments and additional information: 1. In response to comment 2 of LaBella’s August 18, 2021 comment lette r, the applicant noted the comment. The Minor project requirements state that all newly created impervious surfaces shall be directed to an infiltration practice. The existing condition includes no impervious surfaces (according to the existing conditions model), so all impervious surfaces shall be directed to an infiltration practices. Based on the subcatchment map, subcatchment 13 is tributary to SMA #12 (Grass Depression 3), which is not an infiltration practice, and therefore the design does not meet th e requirements for Minor projects. The Applicant to revise accordingly: Response: The impervious surface within subcatchment has been redirected to SMA #11 (Rain Garden #6). SMA #11 has been expanded to account for this increased drainage area. SMA #12 has been removed from the model and grading plan. 2. It does not appear that the grading plan for Rain Garden 5 and 6 match the HydroCAD model. This appears to be the case for all of the rain gardens for both projects and the broader comment is as follows: It does not appear that the grading plan for Rain Garden #1 matches the HydroCAD model. First, the surface area in HydroCAD states a surface area of 308 square feet, however the plans appear to indicate approximately 275 square feet. Second, there is not sufficient spot grades on the grading plan to allow for a full review of the elevations in the HydroCAD model. The HydroCAD model would indicate the basal surface area would be 324.25 and the top of the garden would be 325.00, however the grading plan does not show either of those elevations. Third, based on the rain garden detail (sheet 8), it is unclear how the HydroCAD model takes exfiltration credit for the whole surface area, however based on the footing drain/impermeable line, exfiltration would not occur over the entire surface area. This comment appears to also apply to Rain Garden 2, Rain Garden 3, Rain Garden 4, Rain Garden 5, and Rain Garden 6. The Applicant to revise accordingly. Response: First, the areas of the rain gardens have been revised in the HydroCAD model to match what is shown on the plans. Second, to avoid crowding the grading plan with spot grades showing the different elevations of the rain gardens a chart showing the elevations has been added to the rain garden detail on Sheet 7. Third, the detail for the rain garden has been revised to remove the footing drain and to pull the impermeable line back to only be along the foundation wall and rain garden wall. 2 900 Route 146 Clifton Park, NY 12065 (P) 518.371.7621 (F) 518.371.9540 edpllp.com Mr. Craig Brown February 18, 2022 Page 2 3. In response to comment 3 of LaBella’s August 18, 2021 comment letter, the Applicant updated the mapping. However, the thickness of the subcatchment boundary lines compared to the thickness of other linetypes makes the subcatchment map undiscernible. We respectfully request the Applicant revise the subcatchment map so it is discernable. Roof leaders will be corresponded to the subcatchment areas once the maps are discernible. Response: The subcatchment map has been updated to be more legible. 4. In response to comment 5 of LaBella’s August 18, 2021 comment letter, the applicant performed five test pits and three infiltration tests. However, none of the test appear to be within the limits of the proposed infiltration practices for this application. The Applicant to perform test pits (and infiltration tests) within the boundaries of the infiltration practices to ensure these practices can be infiltration facilities as proposed and meet the separation distances . Response: The infiltration practices were designed based on the closest preformed test pit, the observed water and modeling level consistently drop closer to the lake. Due to existing site conditions, it is not possible to do test pits in all proposed infiltration areas, additional test pits and infiltration test will be performed prior to construction to confirm the feasibility of the proposed practice. 5. In response to comment 7 of LaBella’s August 18, 2021 comment letter, the Applicant stated that approximate locations of adjacent wastewater treatment systems and water wells are being located and will be shown on the plans once located. The Applicant to provide the information on the plan sheets once available. Response: EDP has received a plan showing the location of the septic to be more than 80’ from the property line, the drinking water is also confirmed to be drawing from the lake. 6. There does not appear to be a porous pavement detail. The Applicant to provide a detail in the next submission. Response: A porous pavement detail has been added to the plans on Sheet 7 detail 1. If you have questions or require additional information, please contact our office at your convenience. Very truly yours, Gavin Vuillaume, R.L.A.