An Enbridge report submitted to federal regulators states just four gallons of crude oil reached groundwater at the site of an Enbridge spill in Jefferson County. A valve failure caused 69,000 gallons of oil to leak from the company’s Line 6 pipeline.
Enbridge submitted the report to the Pipeline and Hazardous Materials Safety Administration, or PHMSA, on Jan. 10. The company found 0.1 barrels of crude oil, or 4.2 gallons, reached groundwater due to the spill discovered Nov. 11 on Enbridge’s Line 6.
WPR previously reported a valve leak caused by a degraded gasket that had loosened over time released 1,650 barrels or roughly 69,000 gallons. The release happened at Enbridge’s Cambridge pump station in the town of Oakland between Milwaukee and Madison.
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The valve was installed in 1973, which the company cited as a contributing factor in the spill. At the time, tools that measure whether the right amount of force is used when tightening fasteners were not readily available or used. The gasket also had no inner ring.
Enbridge brought underground connections up to the company’s current standards during the site cleanup, but the company is also reviewing other sites with equipment installed during the early 1970s.
“Based on the findings of these exploratory reviews, further investigations may take place at other locations,” the report states.
The report also states that the company’s leak detection did not activate alarms because the rate and duration of the release was “lower than the detectable threshold of the active alarm systems.”
The report said the leak likely occurred over an extended period of time. It was identified by Enbridge personnel on the morning of Nov. 11. The Line 6 pump station was shut down eight minutes later and restarted after repairs at 5 p.m. the next day.
Enbridge estimates around 960 barrels, or roughly 40,000 gallons, has been recovered from the spill.
“Enbridge has already begun proactive investigation of other flanged connections of the same vintage and materials. In our report submitted to PHMSA it notes investigation activities to date show product impacts are confined to the facility, localized near the release site, and that no potable water wells or surface water features have been impacted,” Enbridge spokesperson Juli Kellner said in a statement.
Based on data provided, the Wisconsin Department of Natural Resources confirmed that sampling of monitoring wells on site continues to show the spill has been confined to Enbridge’s property. That’s according to Trevor Nobile, field operations director with the DNR’s remediation and redevelopment program.
“They will continue to conduct their site investigation (and) evaluate remedial actions and next steps as far as the cleanup,” Nobile said.
Nobile said the DNR conducted a site visit on Jan. 7 and held a community meeting in the town of Oakland last week.
This week, Enbridge is planning to conduct sampling of a private well and a round of groundwater sampling at four onsite monitoring wells. Those wells will be monitored for compounds of crude oil, including volatile organic compounds. The pump station’s drinking water well will also be sampled along with a dozen onsite monitoring wells that include locations along the outer edge of Enbridge’s property.
The estimated cost of the incident is nearly $1.3 million for emergency response, repairs and cleanup costs.
The spill has heightened safety concerns as Enbridge seeks to reroute its Line 5 pipeline around the Bad River tribe’s reservation. The project would cross 186 waterways and disturb around 101 acres of wetlands.
On Monday, Capitol Police arrested one individual and escorted three others out of the DNR’s offices in Madison during a Line 5 protest. Protesters were calling on the agency to revoke permits for the project and shut down the pipeline.
Enbridge previously violated permits and water quality standards when it built parallel pipelines across 14 counties in 2007 and 2008. In 2008, the Wisconsin Department of Justice reached a $1.1 million settlement for more than 100 environmental violations that caused harm to wetlands and waterways.
Editor’s note: An earlier version of this story stated that federal regulators had released a final report on findings regarding the Enbridge spill in Jefferson County. It’s been updated to reflect that the company submitted the report to the federal Pipeline and Hazardous Materials Safety Administration.
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