GZA assisted a client when it acquired an active steel forging plant on a 17-acre site, operational since the 1940s, that was under an Administrative Consent Order to address impacted groundwater and soil. The site is on the banks of the Rockaway River and surrounded by wetlands; therefore, extensive permitting was anticipated.
GZA conducted a Preliminary Assessment (PA) and a Remedial Investigation (RI) to identify Areas of Concern (AOCs) which included an unlined pond and channel that received process wastewater and stormwater; a defunct oil/water separator; a former waste drum storage area with PCB-impacted soil, two areas of LNAPL and a chlorinated plume that extends from the site to off-site wetlands. GZA determined which AOCs required active remediation vs. management under institutional/ engineering controls. An Ecological Risk Assessment was conducted to investigate the release of site contaminants to Environmentally Sensitive Natural Resources (ESNR) including wetlands and the river. GZA designed and implemented remedial actions to address LNAPL, petroleum-impacted soil in the former oil/water separator area and petroleum-impacted sediment in the unlined channel. Prior to remediating the channel, GZA evaluated the site’s process wastewater/stormwater collection systems and designed and received regulatory approval to redirect flows to the municipal sewer collection system for treatment. Remediation of impacted sediment from the ponds involved excavation and off-site disposal, and GZA designed a wetland restoration of the ponds and channels. Necessary wetlands and flood hazard permits were obtained for remediation work. Sampling for potential perfluoroalkyl substances (PFAS) was prompted by the historical storage of firefighting foam on the site; results indicated that PFAS in groundwater was not present above applicable standards.
GZA developed a robust response to complex environmental and ecological concerns at the site, prioritized and sequenced the investigation and remedial design efforts for compliance and cost-effectiveness.