In a 72-page report released on Monday, the Susquehanna River Basin Commission concluded that the billions of gallons of water withdrawn by the oil and natural gas industry in Northeast Pennsylvania have had no significant impacts on the quality of the basin’s water resources.

The SRBC, which oversees conservation and monitors oil and gas development in the area, examined its management of water use by producers during the early days of Marcellus Shale development in the region from 2008-2013. The commission said its findings would be used to “inform and direct its future efforts.”

In December 2007, SRBC began investigating water use for unconventional natural gas wells and by June 2008 it was issuing water withdrawal approvals. During the report period, from 2008-2013, the commission said the industry used 13.4 billion gallons of water, mainly drawn from surface water sources. The commission said it approved 222 surface water withdrawals, which accounted for 88% of the total water used by the industry during the period. The rest came from groundwater sources.

“The primary concern related to water needs for hydraulic fracturing has not been conflict between the industry and other human water needs, but rather for impacts to the basin’s aquatic ecosystems,” said SRBC Executive Director Andrew Dehoff.

An aquatic resource survey, the report said, was unable to conclude that “withdrawals are unequivocally” impacting fish and other wildlife communities. Evidence suggests that the water withdrawals generally don’t influence aquatic communities any more than watershed size and land use practices.

Pennsylvania is a member of eight interstate river basin organizations. The Susquehanna River is one of the nation’s largest. Initial water withdrawals from the basin for unconventional wells sparked some of the earliest regulatory reforms in Pennsylvania’s shale era. The DEP called a summit in 2008 to discuss reforms after it was forced to halt water withdrawals when it learned producers not accustomed to the river basin commissions were conducting them without permits or approvals.

During the report period, there were 9,843 unconventional gas wells permitted by the DEP within the river basin. Of those, 3,995 were drilled and another 2,860 were completed. The SRBC found that each well used about 4.3 million gallons of water, 84% of which was comprised of fresh water at each site.

The commission said the industry has generally been in compliance with its regulations. It concluded that the quantity of the basin’s water resources are sufficient to accommodate the industry’s demand for water along with those of other users, saying its monitoring programs “have not detected discernible impacts on the quality of the basin’s water resources.”

“The commission undertook incremental policy and regulatory adaptations to successfully address the potential conflict between the industry and the local aquatic ecosystems for the protection of sensitive habitats and the basin’s finite water resources,” Dehoff said.