Pinnacle Engineering was hired by an industrial coatings company to collect soil samples from inside a secondary containment area where corrosion in the plant floor exposed drainage pipes that lay adjacent to operating production lines at the plant. Following visual inspections to assess the integrity of the drainage pipes and to evaluate drainage in this area of the plant, Pinnacle conducted sampling of subsurface soils which indicated impacts to soil with industrial metals, including Chromium+6. The glacial sediments on which the facility was built, have high background concentrations of the same metal compounds used in the production processes for the facility’s coating operations.
Pinnacle recommended institutional and physical controls to eliminate the discharge of plant waters through the corrosion in the plant floor such that the facility could continue operations under its existing discharge permit. The Minnesota Pollution Control Agency (MPCA) was notified and recommended that the client enter its Voluntary Investigation and Cleanup (VIC) program while Pinnacle simultaneously developed a Phase II subsurface investigation to determine the nature and extent of impacts of metals beneath the plant. Pinnacle and facility staff established a schedule for decommissioning the active production line, and completed the entire investigation and replaced the tank line and containment area without disruption to the facility’s operation.
Although soils beneath the facility and in background locations exceeded Minnesota soil reference values (SRVs) and soil leaching values (SLVs) and groundwater exceeded Minnesota Health Risk Limits (HRLs), Pinnacle established that the impacts of the waste water release from the facility were insignificant and did not adversely affect the soil and groundwater environments. This investigation was expedited, and the report completed and submitted, before the client’s VIC enrollment was complete. The MPCA notified the client that no additional work was necessary (other than floor repairs), and Pinnacle assisted the client in attaining an MPCA “no further action” determination and filing an Affidavit of Hazardous Substances to be recorded with the property title.