LNAPL Recovery / Groundwater Treatment System O&M

Project Profile

  • Project Location : Pennsylvania
  • Client Industry : Contractor / Consultant
  • Owner Industry : Utility
  • Gwtt Scope : Operations & Maintenance
  • Contract Value : $100K
  • Project Duration : 12 Months (Currently In Process)
  • Contaminants : n/a
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Project Narrative

GWTT was contracted to take over operations & maintenance from a prior service provider at a former petroleum processing site in Pennsylvania. GWTT staff worked with the prior provider on a carefully planned and executed transition of operational oversight, including an extensive review of historical system operations data.

The system was designed to mitigate discharges to the Delaware River from groundwater seeps by hydraulically containing the liquid discharge from several previously identified seep areas along the bank of the river.

The objective of the treatment system is to separate any recovered LNAPL and to treat the remaining water for VOCs, oil and grease, MTBE, metals, pesticides, PCBs, Dioxin, and acid/base/neutral organics before discharging into the DELCORA sewer system. The remediation process is composed of 15 vacuum wells and two interceptor/collection trenches. Once extracted, the water goes through an air stripper, an oil/water separator, two transfer tanks, six bag filters, and two 1,000-lb liquid-phase carbon vessels before being discharged into the DELCORA sewer system.

The interceptor/collection trenches currently run intermittently, and the extraction wells are running on the southern end only because there is no oil sheen being observed at the northern end of the system.

The treatment system was designed and programmed to operate continuously with system operators on-site twice weekly to keep up with data collection and reporting, site observations, and routine and preventative treatment system maintenance.