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2023.09.14 Staff Report.pdfSeptember 14 2023 Staff Report To: From: RE: Conservation Commission Sarah LaValley Staff Report, September 14 2023 Commission Meeting 5:30 PM Request for Determination of Applicability to determine if septic system installation within riverfront and buffer zone is subject to the Wetlands Protection Act or Northampton Wetlands Ordinance. Dan Zulawski. 88 West Farms Rd, Map ID 35-215 Application Overview: The application proposes construction of a replacement septic system. Plans note a ‘seasonal’ stream (this is a perennial stream with associated riverfront), and omit a wetlands resource area (shown – yellow flag is a test pit as indicated on plan) September 14 2023 Staff Report 2 Consistency with the WPA and Northampton Wetlands Ordinance, Staff Recommendations: The RDA application and plans indicate that the work is more than 50 feet away from wetlands resource areas, but the stream was the only resource area included on the plan, and no information about bank delineation was provided. There are clear bordering vegetated wetlands adjacent to the perennial stream that extend into the work area. The 10.03 (3) exemption noted on the RDA form does not apply; the limit of work is located less than 20 feet from the stream, and within a BVW. The application proposes construction of a leach field within a bordering vegetated wetland. The work will alter a resource area, and as such, may also not comply with Title V requirements. The Health Department engineer’s questions regarding the plan are attached; these have not been addressed by the designer and are not reflected in the plan included with the RDA. A negative determination is not appropriate; the work will directly alter resource areas. Issue a positive determination by checking box 1, to indicate that ‘The area described on the referenced plan(s) is an area subject to protection under the Act. Removing, filling, dredging, or altering of the area requires the filing of a Notice of Intent,’ and box 3, to indicate that ‘the work described on referenced plan(s) and document(s) is within an area subject to protection under the Act and will remove, fill, dredge, or alter that area. Therefore, said work requires the filing of a Notice of Intent,’ and box 5, to indicate that the work is subject to the Wetlands Ordinance. Request for Certificate of Compliance, Emerson Way/Oaks Subdivision, DEP File 246-514 Two orders exist for this subdivision. The Commission issued a certificate of compliance in 2021 for an order under the local ordinance only, in 2006. The DEP Order was issued separately, but effectively applies to the same work with the same conditions, for construction of stormwater systems, house lots, and roadways. The Order required that work stay more than 50 feet away from one of the wetland areas, which it has. As part of stormwater O&M requirements, and specified in the project’s covenants, the Conservation Commission is also required to be provided copies of annual inspection and maintenance of the system. Last fall’s inspection has been provided, and the applicant has noted this ongoing responsibility. Work subject to the Order has been completed as proposed, and a certificate can be issued. CITY of NORTHAMPTON PUBLIC HEALTH DEPARTMENT Public Health Director ~ Merridith O’Leary Municipal Building ~ 212 Main Street ~ Northampton, MA 01060 Phone (413)587-1215 ~ Fax (413)587-1221 http://www.northamptonma.gov/245/Health Comments pertaining to: 88 West Farms Road, Septic Repair plan The proposed Eljen Geotextile System design is poorly designed for this site. Based on the topography which has been submitted, more than half of the system will be constructed above existing grade, which will require approximately 5’ of Title 5 sand fill under more than half of the system. It is recommended, although not required, that the configuration of the Eljen modules be changed to reduce the amount of fill needed on the low side of the system. A narrower and longer system configuration is recommended to help with this issue. Rotating the system to be more parallel to the downgradient contours will also improve the design. The comments, made by Health Agent Kaniecki, after observing the soil evaluations on 5/12/2023 indicated the presence of a possible wetland area near the test pit site. No indications of this potential wetland have been shown on the plan. If this design is not cleared by the Conservation Agent, then more information will be required to indicate the system meets the required setbacks to a wetland. Some documentation has not been submitted. The Soil Evaluation Report and the Sieve Analysis Report, from a certified soils laboratory, have not been submitted. The Sieve Analysis was done due to the soil being too saturated with moisture to perform a percolation test. The loading rate used for this design was based on the Sieve Analysis and a copy is needed before the design can be properly reviewed. The plan submitted is missing some required information, as follows: On the soil logs, the existing grade elevation at each test pit is missing, therefore, the estimated seasonal groundwater elevation cannot be confirmed. The test pits shown on the Plan View are not labeled, therefore, it is not clear which soil log belongs to which test pit. The letter designations on the “Invert Elevations and Lengths:” chart do not coincide with all of the letters on the adjacent profile. It will be difficult for an installer to make sense of this design unless it is clear what each component elevation should be. The “System Profile” should contain elevations for each system component and not have to depend on interpreting the various elevations from the graphical scale. The profile also shows the “Breakout Barrier” suspended in mid-air. The DEP design guidance for Impervious Barriers requires the bottom of the barrier to be extended a minimum of 1’ into existing grade. An elevation should be shown for the top of the barrier as well as an elevation for the bottom of the barrier. The guidance also requires that the barrier designer, as part of the “As Built” plan process, must certify that it was properly installed. The plan needs more detailed dimensioning of the proposed Eljen system, such as separation between module runs and the amount of sand between and surrounding the modules. A detail drawing of the Eljen system configuration should be on the plan. J. Gracia, PE 7-17-2023