Commission tables review of proposed car-collection facility at 16 Trowbridge Drive after tree, erosion and drainage concerns

The Bethel Inland Wetlands Commission on June 22 paused its review of a proposed conversion of the former school at 16 Trowbridge Drive into a private car-collection and storage facility, citing outstanding questions about tree removals, slope stability and drainage.

James Demayo, a professional engineer representing 75 Express CT LLC, walked the commission through a multi-part plan that would add roughly 47,000 square feet of roof area, reduce existing pavement, and increase impervious cover by about 33,976 square feet. He described a large underground infiltration/detention system — "15 rows of 19 units" in his words — and said the design reduces peak runoff, citing specific modeled reductions: "the two-year by 71%, the 10-year by 11%, and the 100-year by 7%." Demayo said the project shifts an existing discharge point eastward and will include a riprap plunge pool at the outlet to limit erosion.

Commissioners and staff focused on three core concerns: whether the culvert and drainage that cross under nearby railroad tracks constitute an intermittent watercourse subject to upland-review protections; the scale and engineering of a proposed retaining wall and patio on a steep slope; and the loss of mature trees in the area the applicant estimated at about 22 trees in the patio area and 26 in the other zone.

"I'm just sad all so many trees are going to be cut down," Commissioner Carolyn Baumgardner said during public and member discussion, urging commissioners to weigh habitat loss. Several members pressed Demayo on construction sequencing and wall design; he told the board that retaining-wall foundations would be designed by geotechnical and structural engineers after local approvals, and that the wall sections could reach double-digit heights in places. Commissioners pressed whether the proposed wall and the excavation required to construct it could destabilize the slope or alter the local groundwater behavior; Demayo said footing depths and drainage details would be determined by a geotechnical investigation and that design features such as footing drains and weep holes would be included to relieve hydrostatic pressure.

Members also asked about operations inside the building—whether car washing or drains were planned—and whether oil/grit separators would be included. Demayo said there were no internal drains in current plans and that any domestic wastewater would go to sewer; he also agreed to add a pre-treatment/sediment or hydrodynamic separator to address the commission and town engineer’s comment.

Railroad coordination was a recurring subject. Commissioners noted that work near or under railroad lines typically requires coordination with Metro-North and the rail owner and that those approvals or restrictions often arrive after local approvals. Demayo acknowledged the risk and said the applicant will consult the railroad once plans are approved to finalize the construction approach.

After extended questioning and with multiple technical items unresolved, Commissioner Carolyn moved and Terry seconded to continue the application. The commission voted to table the 16 Trowbridge Drive site-plan review until its July 27 meeting to allow the applicant to provide additional geotechnical data, detailed retaining-wall cross-sections, clearer tree inventories and any updated drainage calculations.

Next steps: the applicant is expected to supply geotechnical borings and wall cross-sections, a verified tree-count and species list, and finalized stormwater and outlet details for staff and commissioner review prior to July 27.