Tetra Tech & Adventus deploy In-Situ Groundwater Remediation of Heavy Metals at an Active Manufacturing Facility.
1966 to the present: Manufacturing of various automotive components
1966 to1984: Operation of chromium plating
1983: Release of metal plating rinse water
1983 to 1989: Excavation of soil and operation of 4 groundwater recovery wells
2006: Completion of investigation and remediation feasibility study
2007 to present: Implementation of selected remedial technology
Conclusions & Lessons Learned:
1. Quickly reduced groundwater conditions resulted in the immobilization of heavy metals.
2. Naturally occurring arsenic and iron oxyhydroxide have the potential to be temporarily mobilized.
3. Some geochemical reactions occur over a long period of time; therefore, performance monitoring will continue.
4. High pressure exerted on the subsurface caused the injected mixture to migrate to the surface when the injection tooling was removed.
5. Mixture would also migrate to surface from nearby location
6. Adjacent locations were not injected on during the same day.
7. Drilling rods and tooling were left in the ground overnight to allow pressure to dissipate.
8. Use of water flush to clean out tooling.
9. Determine radius of influence early in project.
10. Have replacement parts on hand for tooling/pump.
11. Long term performance monitoring needed.
12. Work directly with facility personnel to gain access.