A video shows drilling mud discharged into a wetland area along the Tuscarawas River south of the town of Navarre. The affected area is 1,000 feet long and 500 feet wide. (Ohio EPA)

The director of the Ohio Environmental Protection Agency on Monday blasted the pipeline company Energy Transfer Partners for a “pattern” of 18 spills of drilling materials and said that the size of the biggest spill could reach 5 million gallons, more than double original estimates.

Craig Butler, the Ohio EPA director, said that his agency has imposed about $400,000 in fines on Energy Transfer Partners, the same company that was recently embroiled in controversy over its Dakota Access crude oil pipeline.

Butler said the company had brushed off his complaints, claiming the state EPA lacked the authority to interfere with its plans for the construction of a natural gas pipeline called Rover.

Butler, a 27-year veteran of the Ohio EPA, said that the company’s response was “dismissive,” “exceptionally disappointing” and unlike any other response he has seen from a company.

While drilling mud used to cool and lubricate drilling equipment is not toxic, the biggest spill has poured fluid the consistency of a milkshake a couple of feet deep in a previously pristine wetland and would “kill just about everything in that wetland,” Butler said. The company is trying to remove the material by vacuum and even by hand, Butler said.

Energy Transfer Partners, whose Dakota Access pipeline ignited weeks of protests by Native Americans and environmentalists, is now building a $4.2 billion natural gas pipeline that would link the shale gas-rich regions of Appalachia to Michigan and Ontario, Canada. The company received a permit from the Federal Energy Regulatory Commission (FERC) on Feb. 2 and has told investors that the first stage of the pipeline will be complete by July.

The Rover project is the first of two pipelines Energy Transfer Partners planned to build across Ohio.  “As of yet I’m not convinced that they’re not more focused on getting the lines in rather than doing it safely, protecting the environment and public health,” Butler said. He said he had appealed to the FERC for support.

A spokesman for the company said that Butler had “mischaracterized” what had been taking place and that the state regulators “have no jurisdiction to fine us.” He said that the leaks, which he said were “inadvertent releases that come up through natural fissures in the soil and rock,” were “anticipated in the permit” from the FERC. “Periodically this comes up,” he added.

Butler’s comments raised the confrontation between the state EPA and Energy Transfer Partners that began in April when the company notified the agency that it had twice discharged drilling fluids in pristine Ohio wetlands and that the larger of the spills covered an area the size of 8½ football fields.

Energy Transfer Partners said at the time that the larger spill just south of Navarre, Ohio, could be as much as 2 million gallons.

But Butler said that was now the lower end of his range of estimates. The upper end, 5 million gallons, would make the volume of drilling mud nearly half as great as the volume of crude oil spilled by the Exxon Valdez accident off Alaska in 1989.

“We have no idea where they came up with those figures,” the Energy Transfer Partners spokesman said.

Energy Transfer Partners also said in its filings that on April 14, it had spilled 50,000 gallons of the same fluids, affecting a smaller area of 30,000 square feet near Mifflin Township, more than 100 miles away. Butler said there was no change in that estimate.

But Butler said that one of the other 16 spills had affected drinking water supplies and that a municipality had adjusted its filtration systems to protect drinking water. The last of the 16 spills was reported Monday; about 200 gallons of drilling slurry leaked into the Conotton Creek, affecting about half a mile of the waterway about 50 miles south of Akron.

The spills generally take place while Energy Transfer Partners is drilling 60 to 70 feet below waterways to avoid contamination, but the company has said that drilling mud can seep, or gush, to the surface through fissures in the soil.

The Ohio EPA director also said the agency had given Energy Transfer Partners permission to hire contractors to do limited burning of brush and trees to clear a right of way for the Rover pipeline. But he said that the contractors had “disregarded” the permit’s guidelines and that smoke had affected residential areas.

Butler said he arranged a meeting with Energy Transfer Partners executives to say “how upset Ohio was” and to arrange new response plans but that the company said it would continue to operate. It has not paid any of the fines imposed by Ohio’s EPA.

“We agree that the drilling mud is not toxic,” Butler said, “but if you take millions of gallons of bentonite clay and put it in the middle of a category 3, superior-quality wetland like they did, it has a deadly effect on that wetland and chokes out the organisms in that wetland. And it can take significant time and money to reestablish that wetland.”

An earlier version of this article incorrectly said that drinking water supplies had been affected in two municipalities instead of one.