The sewage-treatment plant in McKeesport, one of nine plants on the Monongahela River that has treated wastewater from drilling operations at the Marcellus Shale, said by some analysts to contain enough natural gas to provide the country's needs for more than 20 years.
Gas drilling a boon to Pa., but at what cost?
Workers at a steel mill and a power plant were the first to notice something strange about the Monongahela River in summer 2008.
The water that U.S. Steel and Allegheny Energy used to power their plants contained so much salty sediment that it was corroding their machinery. Nearby residents saw something odd, too. Dishwashers were malfunctioning, and plates were coming out with spots that couldn't easily be rinsed off.
Pennsylvania's Department of Environmental Protection soon identified the likely cause. The Monongahela, a drinking-water source for 350,000 people, had apparently been contaminated by chemically tainted wastewater from the state's growing natural- gas industry.
The DEP reduced the amount of drilling wastewater that was being discharged into the river and unlocked dams upstream to dilute the contamination.
But questions raised by the incident haven't gone away. And the state budget, signed into law last Friday by Gov. Rendell, allows gas drillers to expand their drilling on state land.
Yesterday, the DEP announced that contamination levels in the Monongahela have spiked again. And the DEP is still investigating whether drilling wastewater contributed to the recent death of 10,000 fish on a 33-mile stretch of Dunkard Creek, which winds through West Virginia and feeds the Monongahela.
A spate of other water-contamination problems have also been linked to gas drilling in Pennsylvania, including methane leaks that have affected drinking water in at least seven counties.
A flood of wastewater
Pennsylvania is at the forefront of the nation's gas-drilling boom, with at least 4,000 new oil and gas wells drilled here last year alone, more than in any other state except Texas. This rapid expansion has forced state regulators to confront a problem that has been largely overlooked during the drilling boom: How will the industry dispose of the enormous amount of wastewater it produces?
Oil and gas wells disgorge about 9 million gallons of wastewater a day in Pennsylvania, according to industry estimates used by the DEP. By 2011 that figure is expected to rise to at least 19 million gallons. That's more than all the state's waterways, combined, can safely absorb, DEP officials say.
"I don't know that even our [water] program people had any idea about the volumes of water that would be used," said Dana Aunkst, who heads the DEP's water program.
Much of the wastewater is the by-product of a drilling process called hydraulic fracturing, or fracking, which pumps at least a million gallons of water per well deep into the earth to break layers of rock and release gas. When the water is sucked back out, it contains natural toxins dredged up during drilling, including cadmium and benzene, which both carry cancer risks. It can also contain small amounts of chemicals added to enhance drilling.
But DEP officials say that one of the most worrisome contaminants in the wastewater is a gritty substance called total dissolved solids, or TDS, a mixture of salt and other minerals that lie deep underground. Drilling wastewater contains so much TDS that it can be five times as salty as seawater.
Large quantities of TDS can clog machinery and affect the color, taste and odor of drinking water - precisely the problems reported along the Monongahela.
Gas-drilling companies dispose of their wastewater in Pennsylvania's municipal sewage plants, which then discharge it into rivers and streams.
The U.S. Environmental Protection Agency warns against this form of treatment, because the plants aren't equipped to remove TDS or any of the chemicals the water may contain. Of even more concern, TDS can disrupt the plants' treatment of ordinary sewage, including human waste.
A lack of capacity
When U.S. Steel and Allegheny Energy complained about the Monongahela's water in 2008, the DEP found almost twice as much TDS as considered safe. What apparently tipped the balance was the drilling wastewater that nine sewage plants were discharging into the river.
Steve Rhoads, president of the Pennsylvania Oil and Gas Association, an industry trade group, argues that most of the TDS had come from abandoned mines, not from drilling wastewater. A study prepared for a different trade group made the same conclusion.
Rhoads also says that Pennsylvania's waterways "are not anywhere near" their capacity to handle TDS and that the DEP's estimate of how much wastewater the industry produces is "completely exaggerated."
