Subsurface infiltration system

Green provided civil engineering and landscape architecture services for the design of a new police station.

The project consisted of a new 3-story building with an ADA accessible public parking area for five spots and a separate secured parking lot for forty-nine private spots that can be accessed via Condor Street. A new timber fence sound barrier separates the site from the adjacent DPW property. The existing site within the limit of work was entirely developed and discharged runoff from the stie via overland flow directly into the Chelsea River with little to no treatment. The proposed site was designed to improve water quality runoff from the site and avoid permanent direct impacts to the Chelsea River. The proposed stormwater mitigation system was designed using catch basins, proprietary structures and subsurface infiltration chambers to treat the runoff and further reduce flow before discharging to the Chelsea River. The proposed project resulted in significant improvement to stormwater runoff while also minimizing impacts to the Chelsea River.

Additionally, the civil design included new utilities for the building and a subsurface infiltration system to mitigate stormwater runoff.

Permitting for the new building included preparing a Site Plan Application for Boston Water Sewer Commission (BWSC) for the proposed sewer, drain and water utilities as well as a Notice of Intent (NOI) to the Boston Conservation Commission, including design of a stormwater management report that met both State and BWSC stormwater requirements. As part of the NOI, a draft Stormwater Pollution Prevention Plan (SWPPP) that met the requirements of the EPA NPDES Construction General Permit was also prepared.