Groundwater Capture System Upgrade and O&M

Project Profile

  • Project Location : Pennsylvania
  • Client Industry : Contractor / Consultant
  • Owner Industry : Utilities / Power
  • Gwtt Scope : Operations & Maintenance
  • Contract Value : $500K
  • Project Duration : 34 Months
  • Contaminants : Diesel, LNAPL
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Key Project Details

  • Troubleshoot and repair the poorly performing groundwater capture system.
  • The primary contaminant of concern was LNAPL from an underground storage tank leak.
  • The groundwater extraction system consisted of eight groundwater wells protected by a pre-cast concrete vault.
  • GWTT installed heat tracing and insulation on portions of the exterior/exposed treatment system piping.
  • The customer was so pleased with these results that GWTT was asked to install another two-well system.

PROJECT CHALLENGES

  • Poorly operating system required optimization and upgrades while continuing to operate at partial output.
  • Upgrades had to be done on an active project site.
  • Limited laydown area for equipment replacement and system reconfiguration.

Project Narrative

GWTT was selected to provide Operation & Maintenance (O&M) services for an existing groundwater capture system located in Pennsylvania. The customer asked GWTT to troubleshoot and repair the poorly performing groundwater capture system. There was concern that the groundwater plume could encroach into the Delaware River, a potential outcome the client wanted to mitigate. The primary contaminant of concern was diesel (LNAPL), which ended up in the plume due to an underground storage tank leak. The groundwater/diesel was pretreated with a small oil/water separator (OWS) which transferred the treated effluent water into the site’s large OWS. The product from the small OWS was piped into a 500-gal product holding tank.

GWTT was able to begin work on the project site immediately, as all personnel were already trained and certified to meet all site-specific safety and operational training requirements.

The groundwater extraction system consisted of eight groundwater wells protected with 4’ x 4’ x 3’ deep pre-cast concrete vaults. The pumps used were small air diaphragm pumps with a 10 GPM capability. Under the previous operator, the system had only generated about 15 gallons of product per month. After a system assessment, GWTT replaced all of the air diaphragm pumps with QED top-loading pumps. After the upgrade, the system captured 100 gallons of product in the first 24 hours of operation. The customer was so pleased with these results that GWTT was asked to install another two-well system on the outer edge of the plume. Additionally, as part of a subsequent client request, GWTT installed heat tracing and insulation on portions of the exterior/exposed treatment system piping.