CHESTER COUNTY, Tenn. (WKRN) — Hundreds of thousands of gallons of crude oil reportedly leaked in Henderson last month.

A release stated that on June 29, Energy Transfer Partner’s Mid Valley Pipeline ruptured after a secondary party damaged the transmission pipeline.

What was initially estimated to be 21,000 gallons, turned out to be 201,600 gallons there were discharged into the surrounding area, including Horse Creek. This is the second-largest recorded crude oil spill in Tennessee since 1986, according to the Pipeline and Hazardous Materials Safety Administration.

The Chester County Emergency Management Agency allegedly stated that a worker operating a mower hit the pipeline, suggesting that it may have been exposed or close to the surface. However, operators are not required to maintain a depth of cover over their pipelines.

“Safety regulators need to require operators to maintain a safe depth of cover on all their pipelines, especially those that could impact our treasured sources of water,” Pipeline Safety Trust Executive Director Bill Caram said in the release.

Horse Creek is currently dammed as crews work to clear the area.