Weston ZBA continues 518 South Ave 40B hearing as experts attack modeling

WESTON — January 31, 2022 — Abutter experts tell Weston ZBA the 518 South Avenue 40B project does not demonstrate a working design. At the Jan. 31 continued hearing on the 200-unit comprehensive permit at 510, 518 and 540 South Ave., hydrologist Michael Mobile said the applicant's own MODFLOW model predicts groundwater breakout above the wetland and rising into stormwater infiltration chambers. Wetlands expert Scott Horsley said the proposed 33,000 gallons-per-day discharge enters a stream with a 7Q10 base flow of about 3,800 gallons — a nine-to-one ratio — and that the project recharges 19,049 cubic feet of stormwater against a required 8,364. Engineer John Chessia listed setback failures including 5 feet to a soil absorption system where 50 feet are required: "If it doesn't comply, I don't see how you can approve it." The board voted 3-0 to continue to Feb. 17 and March 8.