Weston ZBA Schedules Final Hearings as 40B Dispute Over Groundwater Nears Deadline

WESTON — May 24, 2022 — Weston's ZBA heard sharp expert disagreement over groundwater modeling and downstream phosphorus loading for a proposed 200-unit 40B development at 518 South Avenue. Board Chair Jane Carlson opened the May 24 session by asking Town Counsel Jonathan Witten to rebut a letter from applicant's attorney Sarah Toronto Flores of Nutter McClennan and Fish, which argued the board had exceeded its Chapter 40B authority by examining stormwater and wastewater matters; Witten called the claim "absurd and insulting" and advised the board to proceed as before. Peer reviewers Matt Davis and Michael Mobile identified what Mobile called a "fatal issue" — a disconnect between the HydroCAD and ModFlow models in which groundwater was predicted to rise above infiltration chamber levels for up to 40 hours at a time, negating assumed infiltration rates. Neighborhood consultant Scott Horsley presented a phosphorus loading analysis showing the site's per-acre contribution to Nonsuch Pond would be roughly six times the watershed average, while the River School submitted a letter noting that more than 350 children use the pond and Bogle Brook each summer. The board voted 3-0 to continue to June 7 and provisionally set June 20 for waiver-list discussions, with a hard June 30 hearing-close deadline.