Leftover paint from large plastic containers converted to hold household garbage was the most plausible source of a yellowish slick in a Martin County creek earlier this month, according to a report released Tuesday.
The discoloration of the creek gained attention outside Kentucky after Erin Brockovich, an environmental activist who was the subject of a popular 2000 movie starring Julia Roberts, posted a picture of the creek on Facebook and promised to investigate.
State investigators ruled out hydraulic fracturing, or fracking, associated with natural-gas wells as a source of the contamination in Rockhouse Creek.
There are no active fracking operations in the area where the creek was affected, and fracking that took place earlier at nearby wells used nitrogen injection, not fluids that would account for the discoloration, the report said.
The Division of Oil & Gas said gas wells in the area had been inspected for soundness and showed no signs of discharge into the creek, according to the report.
Tests on the discolored water did not show high concentrations of substances such as chlorides, meaning water-quality indicators were “inconsistent with degradation” caused by discharges from coal mining or oil and gas drilling, the report said.
The report said the substance in the creek did not cause a fish kill.
Measures of water quality showed little change because of the yellow plume, or returned to prior levels once it cleared the creek, the report said.
Regulators concluded the discharge caused no substantive environmental damage.
Residents said Rockhouse Creek, in the Tomahawk community, ran a bright yellow-green color for an extended period on April 11.
Members of a response team from the state Energy and Environment Cabinet saw a plume of yellow water in the creek about a quarter of a mile long on April 11 and took samples, according to the report.
Officials looked at the possibility the discoloration came from a discharge of antifreeze, or from fluorescent dye used to test septic systems.
However, tests on the discolored water found no glycol, the main component of antifreeze, and no fluorescence, the report said.
When investigators returned to the area, they noticed about 15 houses along the creek where people were using shipping containers as garbage cans.
The containers, made of 275-gallon plastic boxes in metal frames, were used to ship bulk amounts of liquids.
Several residents said the county had recently begun door-to-door garbage service and that they had bought the containers to hold garbage to be picked up.
The report said state employees found that a business in Lawrence County had sold a number of the containers to Martin County residents.
Those containers had held yellow or white highway-marking paint.
The business sold the containers with paint residue in them — several gallons in some cases, the report said.
Tests on the discolored water showed it contained titanium, an ingredient in the paint that had been in the containers. The concentration was consistent with levels provided by the paint manufacturer, the report said.
Investigators believe someone rinsed out one of the repurposed paint containers and the paint ended up in the creek.
The owner of the business that sold the containers, Kelly Music, told the Herald-Leader that state officials told her to let the leftover paint dry and remove it before selling the containers.
Music said she would not sell any more containers until the state gives her approval in writing.
Music said she certainly didn’t intend for the containers to cause an environmental issue.
“We didn’t sell them to be put in a creek,” she said.
State officials looked for the source of the discharge along several miles of Rockhouse Creek and on a tributary called Trace Branch, but did not find a source.
Regulators don’t know if someone intentionally put paint in the creek or whether it was an accident, said Lanny Brannock, a spokesman for the Energy and Environment Cabinet.
The state is continuing to investigate, he said.
It would be a violation of state rules to put paint in the creek on purpose or unintentionally.