Stormwater Treatment Design and Implementation

The 2017 permit (revised in 2018) implemented stricter benchmarks for various constituents and added additional monitoring and compliance requirements. GSI has helped design modifications to several of the site’s stormwater conveyance systems to lower concentrations of metals in stormwater discharges below the updated NPDES benchmarks. Treatment technologies implemented at the facility have included settling and infiltration basins, downspout filtration, catch basin inserts, and storm piping modifications to limit solids migration to downstream filter vaults. The implemented treatment technologies have been successful in keeping concentrations of metals below the NPDES benchmarks. In 2018, as part of a larger remediation project, GSI helped regrade a portion of the facility to promote infiltration and limit discharges to areas with contaminated sediments.

GSI’s work involved:

• Designing modifications to the site’s stormwater conveyance systems.
• Implementing treatment technologies to help better manage stormwater, including settling and infiltration basins, downspout filtration, catch basin inserts, and storm piping modifications to limit solids migration to downstream filter vaults.