EPA Releases Reports on St. Louis Remediation
Below are links to a number of EPA reports related to on-going remediation in St. Louis. More detailed descriptions of each report will be posted in coming weeks.
MW-19 Investigation Work Plan link below. This investigation is to evaluate if an additional DNAPL/groundwater collection trench is required. This investigation will begin April 4, 2022.
https://semspub.epa.gov/work/05/973779.pdf
Upgradient Slurry Wall Investigation. This investigation is a continuation of the ongoing upgradient slurry wall investigation. This investigation will begin April 4, 2022.
https://semspub.epa.gov/work/05/973666.pdf
Bathometric Survey of Pine River. This investigation will provide information needed for the design of the downgradient vertical barrier wall. This investigation will begin April 4, 2022.
https://semspub.epa.gov/work/05/973667.pdf
Feasibility Study for OU3. I am currently working on the Proposed Plan for OU3 and will keep you updated when the document will likely be released.
https://semspub.epa.gov/work/05/973689.pdf
Perimeter Drain Pre-design Investigation. This investigation work plan is to get design information for the route of the perimeter drain which will drain the shallow outwash unit to an elevation below the Pine River. This work plan is underdevelopment. Drilling will determine likely waste disposal requirements for the excavated soils and provide geotechnical information for the design. This should be released to the public by the end of April 2022. The work will begin as soon as the report is approved since we will have a drill rig on-site.
Updating the existing groundwater flow model using data obtained since 2016. The model will be used to evaluate the upgradient slurry wall and assist in the design of the perimeter drain. The work on updating the model will begin after the work plan is approved and this will require an update of the quality assurance project plan. I expect this work to begin by July 1, 2022 but it depends on review by our Quality Assurance Department. Additional groundwater data may need to be obtained.
Treatability Study for Potential Source Area 3. This investigation work plan is to determine which oxidant will be needed to treat DDT and HBB in groundwater. This work plan is underdevelopment and I expect this work to begin in the summer of 2022.
Downgradient Vertical Barrier Wall Design. Preliminary design work will begin after the completion of the bathometric survey is complete. Since this work has just received funding I have not talked with Jacobs about timing but we would like to begin this construction in 2024 or sooner.
Excavation of Potential Source Areas 1 and 2. We hope to give a notice to proceed on June 1, 2022 and would expect excavation to begin by the fall of 2022 but this is subject to change.
Operable unit 4 carbon amendment study. We expect to continue the Year Phase 2 sampling beginning in April 2022 and are in the planning stages for additional ecological sampling on floodplain. The ecological work is in the development stage and has not received additional funding.
https://semspub.epa.gov/work/05/965279.pdf
Operable Unit 4 Remedial Investigation. Additional sampling and ecological work is planned for summer of 2022 and planning to expand this work is underway with Jacobs. New ecological work has not been funded.