• Site At-a-Glance

    • Ascon Landfill Site

      Location

      Deer Park, Texas

      Regulatory Jurisdiction

      EPA Region 6

      Description
      • Patrick Bayou is a tributary of the Houston Ship Channel (HSC) and is located near Deer Park, Texas.
      • Historical data indicates that sediments are impacted with a range of chemicals include PCBs, PAHs, metals, VOCs and SVOCs.
      • Project Navigator is the Project Coordinator for a multi-party PRP Group at this site.

Patrick Bayou Superfund Site

PNL's Role

PNL is the Project Coordinator for the Patrick Bayou Superfund Site in Deer Park, TX.

Patrick Bayou is a 2.5 mile bayou that drains into the Houston Ship Channel. PNL negotiated the AOC-Settlement Agreement for an RI/FS with US EPA in 2006. It managed selection of the RI/FS contractor and continues to oversee the RI/FS process. Significant specialized efforts were completed to develop a sediment transport model and characterize the sediments at the Site. Adaptive Management Strategies were employed, allowing a pragmatic, phased approach to the project. Upon completion of the RI/FS and selection of a remedy PNL will negotiate the CD/SOW for the RD/RA.

Health and Safety Metrics

  • Approximately 25,000 hours worked without incident.

Technical Milestones

  • The site is currently in the Remedial Investigation/Feasibility study phase.
  • Initial site activities included development of a Preliminary Site Characterization Report and a bathymetry survey.
  • Sediment sampling, radiometric profiling, and additional field investigations have been conducted.
  • A sediment transport model has been developed and will be refined and further calibrated to determine the rates of natural recovery.   The model will be an important risk management tool during the FS.   Preliminary findings indicate the model accurately predicts sediment deposition rates across the site and that Monitored Natural Recovery (MNR) can be forecast based on exponential decay curves. 
  • Use of Adaptive Management Strategies has enhanced project flexibility. In this approach, work is completed and evaluated in a phased and prioritized manner so that the conceptual site models for contaminant sources and distribution, site hydrology, exposure pathways, and risk analyses are continually updated as new information becomes available.
  • In innovated probabilistic risk assessment approach will be utilized at the site.  Sediment sites typically have a high level of uncertainty and this approach will further improve the understanding of the true risk to receptors at the site.  Due to the relative new science involved, PNL has coordinated training in this methodology for the state agency and Natural Resource Trustees.

Stakeholder Relations

  • PNL coordinates with the EPA, TCEQ, state and federal Natural Resource trustees and the City of Deer Park.