This story has been corrected to remove this sentence: “Because of fire suppressants used during the initial spill emergency, it is likely that the groundwater contains toxic perfluorinated compounds, or PFAS, according to previous statements by DEQ.” Colonial responded and said the suppressants did not contain PFAS.
Colonial Pipeline has omitted key information about potential soil, air and surface water contamination from its comprehensive assessment of the Huntersville gasoline spill, the nation’s largest since 1997, according to state regulators.
These data gaps prompted the NC Department of Environmental Quality today to issue a Notice of Continuing Violation the company regarding the Aug. 14, 2020, spill, which released at least 1.2 million gallons of gasoline, according to recent estimates, in a nature preserve and near a residential neighborhood. That figure does not include “contact water,” which is not gasoline, but water that has come into contact with petroleum products.
While gasoline has not been detected in private drinking water wells, as a precaution the company has connected several households to public water systems and purchased three homes close to the spill site.
The groundwater is also widely contaminated with chemicals found in petroleum products: benzene, a known carcinogen; as well as xylene, toluene and ethylbenzene.
Ethylbenzene exposure has also been linked to cancer, according to federal health officials. Depending on the dose and length of exposure, all four chemicals can harm the neurological system.
“We will continue to hold Colonial Pipeline accountable for its actions and response to the largest gasoline spill in North Carolina’s history,” said Division of Waste Management Director Michael Scott in a prepared statement.
“The Comprehensive Site Assessment lacks critical information necessary to determine the full extent of the impacts of this event. This information is crucial for the protection of public health and the environment.”
In a prepared statement, a Colonial Pipeline spokesperson said the company has already submitted some of the information. “From the beginning of this incident, Colonial Pipeline Company has cooperated and coordinated with state and federal regulators as well as Mecklenburg County officials, with regular on-site meetings and updates,” the statement read.
“We continue to provide detailed information as required and as requested regarding ongoing recovery and remediation efforts, including proactive and voluntary activities at the site and on our pipelines. We are reviewing NCDEQ’s most recent request, which includes activities that are already underway, and some information requests that have already been previously submitted, and we will work diligently to respond to the department’s additional requests.”
DEQ spokeswoman said that although Colonial did provide some information previously, it was either deemed insufficient or was omitted from the Comprehensive Site Assessment.
DEQ originally cited Colonial last September with a Notice of Violation and required the company to submit a comprehensive site assessment to determine the extent of the contamination.
That assessment, submitted Jan. 20, lacks information that would be used to fully understand the extent of the contamination. For example, there is no data on air monitoring at the site, according to today’s notice.
Mecklenburg County, where Huntersville is located, operates its own air quality program. The county’s air quality division could not be immediately reached to see if it had monitoring data.
State regulators also requested that Colonial account for water supply wells southeast of the spill, even beyond the original 2,000-foot boundary. Additional soil sampling data is required, DEQ wrote, and noted that the “potential impacts to the bedrock” have not been fully assessed.
DEQ also has directed Colonial Pipeline to extend residential private well sampling 500 feet beyond the edge of the current boundary. This includes six additional wells, which will be sampled once every six months. The company also must monitor water quality in nearby springs.
The Notice of Continuing Violation identifies 22 corrective actions that Colonial must complete by April 26. Some are highly technical and involve record keeping. Others would give regulators and community members a clearer idea of the depth and breadth of the contamination plume:
- Install at least 12 deep wells to fully define the depth of the contamination;
- Describe the contamination present in excavated soil and its permanent disposal location;
- Provide a report that identifies the potential for vapor intrusion in residences, buildings and utility conduits;
- Provide a detailed summary about air and noise monitoring sampling efforts; and
- Provide additional information about nearby surface water features, particularly neighboring springs.