Pipeline Release Site – Walnut Grove, Missouri
Project Description
A major pipeline company contracted Environmental Works, Inc. (EWI) for emergency response cleanup and follow-up site characterization after a release of diesel fuel, gasoline, and jet fuel from an underground pipeline. The release entered the subsurface, traveled downgradient, and resurfaced with seepage of product impacting 19,000 square feet of land. EWI performed free product control and cleanup, recovered 260 gallons of free product, excavated 1,600 tons of petroleum-impacted soil, and containerized 42,500 gallons of petroleum-impacted surface and excavation water. Associated wastes were characterized and properly disposed. This work was completed within 78 days of the release discovery.
The site was subsequently entered into the MDNR Voluntary Cleanup Program (VCP). EWI performed the initial site characterization and a detailed hydrogeological investigation that included:
- Mapping surface karst features (sinkholes, springs, fractures, etc.)
- Photo-lineament interpretation to identify prospective fracture zones
- Geophysical resistivity transects to pinpoint fracture zones
- Stream survey to identify potential groundwater discharge points
- More than 150 soil borings to verify subsurface conditions
- Extensive soil sampling and chemical analysis
- Installation of seven 6-inch diameter, open borehole unconsolidated and bedrock wells up to 70 feet deep
Project Accomplishments
- EWI served as the successful replacement to the initial response contractor who could not meet the challenging technical objectives.
- EWI successfully contained product releases and prevented surface migration to the local creek.
- Successful contaminant delineation despite complicated geologic and hydrogeologic conditions - e.g. sinkholes, horizontal voids and fractures.