George Stark, spokesman for Cabot Oil & Gas Co., the Texas gas driller that produced the wastewater at its Susquehanna County well sites, said the contractor that treated its wastewater sent it to the Philadelphia area without Cabot's knowledge.
"As soon as we discovered the water was being sent to the Delaware River basin, the operation ceased," Stark said.
The DRBC did not fine Cabot or PSC Environmental Services L.L.C., the private company that treated the wastewater at its Hatfield plant before discharging it to the township sewer system.
"In our minds, the most important issue was that they stop taking the imported material," said Clarke Rupert, a DRBC spokesman.
But the Delaware Riverkeeper Network, an environmental group that has led efforts to restrict gas-drilling activity in the watershed, said the unauthorized discharges underscored its doubts about the effectiveness of regulators.
In a letter Tuesday to the DRBC, Maya K. van Rossum, the head of the riverkeeper organization, urged the commission to take "swift and strong" enforcement action against the driller.
"Because of this blatant violation of DRBC's rules and regulations, and the precedent that gets set for the future, it is important that the DRBC exercise all due enforcement authority for this violation," van Rossum wrote.
The environmental group learned of the Hatfield Township discharges only after it was contacted recently by a reporter from the Associated Press, which reported the incident this week.
The DRBC said it learned of the discharges in May, after PSC had been treating the wastewater for nearly a year. It sent letters to Cabot and the treatment plant June 1 ordering them to cease, said Rupert.
