Following completion of construction of the Fire & EMS Headquarters in 2017, the two on-site infiltration basins and sediment forebays were unable to dewater through infiltration, resulting in permanent pools of water in the basins. As a result, less storage was available during storm events and stormwater periodically overtopped the basin in the northwest corner of the site, discharging onto adjacent properties. Owners of the adjacent properties to the west of the site also reported an increase in water on these properties since the completion of construction. To minimize discharge onto the adjacent properties and to maximize storage available during storm events, Fire & EMS staff used submersible pumps to dewater the basins, pumping the water into catch basins located in Paxton Street and Main Street.
In 2020, the Town hired Vanasse Hangen Brustlin, Inc. (VHB) to perform extensive testing and review of the existing stormwater system, which determined that the above issues result from high groundwater and impermeable soils below the basins. Following these determinations, VHB was contracted by the Town to redesign the existing on-site stormwater system to eliminate the standing water. The design concept, which the Select Board and area residents expressed their support for, included the following:
- Raising the bottom of the on-site stormwater basins to bring them above seasonal high groundwater
- Lateral expansion of on-site stormwater basins to make up for the storage lost in item 1 above
- Designing the basins as detention basins (to slow the water leaving the site), including a new pipe discharging from the site through a new drainage easement on #22 Warren Ave
- Installation of a drainage trunkline on Warren Ave and Gleason Way, discharging through new easements on #5 Gleason Way and #14 Harberton Dr
- Discharge will be over 100' from the wetland(s) in the area and will include a riprap apron and level spreader to dissipate energy and prevent erosion
Permitting though Leicester Conservation Commission and Leicester Planning Board was completed in Spring/Summer 2021. The construction contract was awarded to N. Cibotti, Inc. out of Braintree, MA. Construction of the designed improvement commenced in Fall 2021, with work being completed in May 2022.