Discovery and Initial Steps
The spill was discovered in mid-April as the snow melted (see Figure 1). A 55-gallon drum of motor oil in a parking lot near the Tech Centre property was damaged by a snowplow during the winter. Some 30 gallons of spilled oil was carried off the pavement along with the melting snow. A rainstorm further aggravated the situation.
The company that provided the snow plowing offered to immediately come in and dig out all of the contaminated soil and stone, take it to a local landfill, and replace it with fresh new material. The offer was put on hold while we sought legal and other professional advice. We were informed that because we discovered the contamination and it was on our property, we were responsible for immediate containment to minimize environmental impact. We were also responsible for addressing possible downstream contamination.
A local civil engineering and environmental firm was hired to assess the spill. Their observation showed “visual and olfactory evidence of petroleum contamination.” That initial observation was verified by a core sampling. It was recommended that wood chips and hay bales be layered on the visible spill areas in an attempt to contain it (see Figure 2). The engineering firm added a ten-foot absorbent boom to the containment efforts. They were also required to inform the Wisconsin Department of Natural Resources Regional Spills Coordinator.
The Wisconsin Department of Natural Resources was the only public agency that had to be involved with the incident. Numerous photographs were taken of the site, including aerial photographs. An early concern was that the oil had leaked into a ditch containing surface water (see Figure 3). Whether the oil had contaminated any groundwater was unknown until weeks later.
A couple weeks after the initial observation, it was agreed that the snow plowing company that first made the offer to remove the spill would be allowed to do so, but only under the guidance and direction of the civil engineering and environmental firm.
Excavation began in May. Due to the electrical and telecommunications underground conflicts, it all had to be dug out by hand (see Figure 4). Nearly six tons of soil were excavated, loaded, and sent to a qualified landfill. The depth of the excavation varied, but it was no deeper than 6". By late May, the spill was entirely contained. By early June, all affected soil was removed. This had to be confirmed by another round of soil samples.
The final 13-page report by the civil engineering and environmental firm, in color and spiral bound, contained the entire testimony since the firm was hired. An appendix included all the photos, lab analysis charts, and statements from everyone involved. The firm’s final observation was summed up in the statement: “Given the amount of oil released and the amount of contaminated material hauled away, the environment has been restored to the extent practicable.”
The excavated area had to be backfilled with clean topsoil and seeded. The snow plowing company handled all the expenses for the spill cleanup, except for the initial core sampling that I-CAR had authorized on its own.
One of the last steps was receiving a final signoff from the Wisconsin Department of Natural Resources Regional Spills Coordinator. That two-page report did not come until weeks after the final engineering report was printed and delivered. The DNR report stated that the spill was cleaned up to the extent practicable, and no further cleanup is needed. The groundwater was not contaminated. The spill had not migrated into the drainage ditch. It was also noted that no citations had to be issued in connection with the spill. Final landscaping of the area could then begin. The final cost to I-CAR was much less than what we had feared.
Suggestions for a Similar Issue
In case a facility encounters a similar issue, we can only suggest being forthright with the environmental authorities. It will do no good to try and hide the incident or ignore the issue. Contact the local agency and ask, “What do I need to do about an outdoor oil spill?” Similar to a vehicle owner involved in their first collision, a facility owner doesn’t know what to do when an accident occurs.
We took the initiative to contact the local engineering firm to do a core sample. We then asked the firm what do we do next? Their advice was to take every effort to contain the spill. Being upfront about the incident is always the best approach.
The affair required us to collaborate with legal, engineering, and environmental firms that we had little or no contact with previously. As it turned out, the spill did not contaminate surrounding groundwater. It was contained and cleaned up in a relatively short time. We hope this story of our experience will help whatever contaminant spill situation you may encounter.