Pennsylvania officials fined Chesapeake Energy more than $1 million on Tuesday, the state’s largest fine ever to an oil and gas company. In a statement, the Department of Environmental Protection said Chesapeake’s drilling operations had contaminated water supplies for 16 families in Bradford County.

The announcement came just days after the Pittsburgh Post-Gazette reported that the administration of Gov. Tom Corbett, who took office in January, has issued far fewer environmental fines than its predecessor.

“It is important to me and to this administration that natural gas drillers are stewards of the environment, take very seriously their responsibilities to comply with our regulations, and that their actions do not risk public health and safety or the environment,” DEP Secretary Mike Krancer said in the statement on Tuesday.

The fine also cited Chesapeake for a fire at a well site that injured three workers in February. The announcement didn’t mention the blowout at a Chesapeake well in Bradford County last month. That accident leaked a still-undisclosed amount of brine and hydraulic fracturing fluid onto nearby fields and into a creek. The department issued Chesapeake a notice of violation for that incident and is continuing to investigate.

The DEP said the water contamination in Bradford County, which occurred last year, was caused by failures in the casing and cement that surround gas wells, allowing methane to leak into water wells from shallow gas formations. Chesapeake issued a statement saying the company agreed to pay for water treatment for the affected families. The company also said it has enhanced its casing and cementing designs.

“We have worked in coordination and cooperation with the PADEP from the moment we learned a potential problem existed,” Chesapeake spokesman Brian Grove said in the statement. Grove added that although the company has agreed to settle the matter, it hasn’t admitted that it caused the contamination.

The DEP has been under increasing pressure from critics and the federal government to tighten its oversight of the gas industry. Last month, the department asked drilling companies to voluntarily stop sending their wastewater to treatment facilities that discharge the waste into rivers after only partial treatment. But that move only prompted further federal involvement. Last week the EPA ordered the largest drilling companies in the state to disclose where they plan to put the wastewater, indicating that agency officials saw the state’s voluntary request as inadequate.

“Since there was not a requirement that they notify DEP or EPA of the new disposal methods, we wanted to ensure that we all had this information,” EPA spokeswoman Terri White wrote in an email last week. “We want to track these wastewater activities regularly to ensure the protection of public health and the environment."

The EPA also asked the DEP to improve the way it tests wastewater discharges.

So, is the DEP sending a message with the Chesapeake fine? The department hasn’t returned our request for comment yet, but in the statement Sec. Krancer said, “The water well contamination fine is the largest single penalty DEP has ever assessed against an oil and gas operator, and the Avella tank fire penalty is the highest we could assess under the Oil and Gas Act. Our message to drillers and to the public is clear.”