02/06/2025 CONSERVATION COMMISSION Minutes

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Documents provided: Cape &Islands Engineering,Inc.,Request to Amend Order of Conditions 043-3209; 01/06/25 Plan"Site&Septic Upgrade Plan" (no increase in flow); 01/09/25 Plan"Landscape Plan'Sean Papich Landscape Architecture NO[ 3-3327 362 Monomoscoy Road, Todd A. West ➢ Representative: Cape and Islands Engineering, Inc Proposed Dock Project Overview • The plan involves removing an existing dock and constructing a new one in the center of the lot • The new dock will use a vibratory hammer for pile installation without cutting over the salt marsh • The proposed pier offers improvements, including greater separation, through-flow grating, and better substrate clearance. Environmental Considerations and Design Details • Division of Marine Fisheries (DMF)raised concerns about separation from the salt marsh • The engineer proposed increasing the separation to 6 ft to provide a 5:1 ratio • The design includes larger vent pile spacing to minimize the impact on the salt marsh • Only one set of piles in the salt marsh is being removed and one set is being proposed • The new dock location (center of the lot)meets Chapter 91 requirements for the 25 ft setback from the property line • Proposed 10-12-inch piles with vibratory hammer removal of existing pilings • The engineer agreed to revegetate the salt marsh areas where the existing structure is removed. Technical Specifications and Regulatory Requirements • The water depth at the existing float is 1.6 ft, while the proposed new float will be in 2.2 ft of depth • Chapter 91 (DEP)requires a setback of 25 ft from the property lines for the new structure • The existing dock predates the enforcement of current Chapter 91 regulations • Two dolphin piles (tie-off piles) are included in the design to assist with navigation in strong currents • The float will be removed and stored off-site during the winter months • Through-flow decking is proposed for the entire structure • The existing structure has 6 piles, while the proposed structure will have 20 piles in total. Mitigation Measures and Environmental Impact • An engineer calculated a net zero impact in the salt marsh (2 piles removed, 2 proposed) • Land under ocean impact would increase from 1.1 to 5.4 square feet. • The applicant initially preferred paying the mitigation fee rather than planting • The commission noted that the shellfish constable was assessing no shellfish mitigation fee 6