By Erica Gies
Pennsylvania rivers that supply drinking water continued to show high levels of the salt bromide earlier this year, a telltale sign that they were still receiving inadequately treated wastewater from natural gas hydraulic fracturing, or fracking, operations. The levels surprised officials, who thought they’d solved the pollution problem by requesting that drilling companies stop using municipal treatment plants for disposal.
Since then, bromide levels have decreased, but industry sources say the practice of treatment plant disposal in Northeastern states continues.
While activists and scientific studies have focused heavily on potential groundwater contamination caused by fracked wells, the disposal of fracking wastewater may be a greater pollution threat.
Gas companies use an average of 5 million gallons of water per “frack” to crack apart underground bedrock and release natural gas. Into that water they mix chemicals – biocides to kill bacteria, scale inhibitors to keep pipes clear, and lubricants to ensure smooth machinery operation. They also add proppants – tiny particles of sand, quartz or ceramics to hold underground fractures open, allowing gas to flow up to the surface.
The problem is that some of these contaminated fluids flow back to the surface too, along with added contaminants picked up deep underground, such as naturally occurring salts and radioactive elements.
Companies dispose of this frack wastewater differently depending on region, though each method is problematic. In most of the country, injection wells are used to pump waste deep underground. In the Northeast, wastewater is disposed of in three ways: It is trucked to Ohio and dumped down injection wells; processed at municipal sewage treatment facilities and then piped into local rivers; or treated onsite and reused in fracking.
At first blush, treating frack water at municipal treatment plants may seem like a good solution. However, these plants were designed to treat sewage, not the radioactive compounds in frack water, which can pass straight through into local waters.
Another problem: when the salt in frack water is combined with the chlorine used at some water treatment plants, it forms chemicals called trihalomethanes that increase the risk of bladder and other cancers with long-term exposure. Not only that, the chemicals in frack water can kill the beneficial bacteria used in sewage treatment plants, making the treatment process less effective.
Worse still, many Northeast municipal sewage systems also process storm water. So every time there is a hard rain, large volumes of runoff force the shutdown of sewage treatment plants, allowing high volumes of untreated raw sewage, and possibly frack wastewater, to gush into waterways.
Another disposal approach is for gas companies to treat wastewater onsite and reuse the water in future fracks. However, this can be energy intensive and costly. Gas companies also sometimes sell the byproduct – a super salty waste called brine that contains heavy metals and other pollutants – to state transportation departments like those in Pennsylvania and West Virginia to melt highway snow in winter and suppress dust in summer. This use conveys salts and chemicals to waterways, and should be discontinued.
Unfortunately, pumping the waste into injection wells deep underground may not be the answer either. More than 150,000 active injection wells underlying 32 states now absorb 2 billion gallons of waste fluid daily, a process that the EPA supports for the disposal of polluted water from the oil and gas, chemical, agricultural, and pharmaceutical industries as a strategy to protect soils and surface water from contamination.
But these injection wells, mostly old oil and gas drill holes, have no container at the bottom to trap waste. An investigative report by ProPublica found that thousands of them are leaking, bringing chemicals and waste to the surface or into shallow aquifers.
Costs to clean water tainted by fracking – whether injected underground, treated and dumped or reused – are currently being externalized by oil and gas companies, with cities and states, and ultimately us – the taxpayers – picking up the tab. Toothless federal and state laws and industry exemptions to environmental laws, have so far failed to address the problem.
People tout natural gas as a cheap fuel, but that is faulty logic that fails to add in water cleanup costs. When proper accounting is done, we may discover that natural gas is simply not cost-effective – or environmentally friendly – and that it is time for the U.S. to pursue other energy options.
Freelance reporter Erica Gies has been published by The New York Times, Forbes.com, The International Herald Tribune, Wired News, Grist, and E/The Environmental Magazine. To comment write to firstname.lastname@example.org ©BRP 2012.