Town Center Subbasin Study Report - Bellingham Massachusetts

Proposed Designs for Drainage Area O24: Municipal CenterO24 Municipal Center: Infiltration TrenchStormwater Control Description:An infiltration trench will be constructed to capture,treat, and infiltrate runoff from the driveway andparking lot behind the Municipal center building.Currently, this runoff is all collected by a single catchbasin in the rear lot which will remain and act as abypass of the infiltration trench for larger storm events.Infiltration TrenchO24 Municipal Center: Infiltration TrenchAA’Drainage Area (acres) 0.68Impervious Area (acres) 0.68Estimated Infiltration Rate (in./hr) 4.46Target Phosphorus Removal 79.5%Water Quality Depth (in.) 0.48Water Quality Volume (ft3) 1,130±Stormwater control Surface Area (ft2) 820±Estimated Construction Cost $7,840Plan and section details can be found in Appendix C.22