The investigation is the latest to target the state's environmental regulators. Last week, the agency came under fire after revelations that it had improperly carried out fracking-related air studies in 2010 and 2011.
The congressional inquiry is expected to expand to other states before the end of the year, mirroring a growing concern over the disposal of massive amounts of waste generated by fracking.
Among other concerns, Cartwright wants to determine whether Pennsylvania is adhering to the federal Clean Air Act, which mandates protection from airborne contaminants.
Cartwright cites a 2011 minority staff report of the House Energy and Commerce Committee. It identified 29 chemicals found in fracking waste that are possible human carcinogens, and are regulated under both the Clean Air Act and the Safe Drinking Water Act for their risks to human health.
An investigation published earlier this month by the Center found that in most states where fracking is taking place, air emissions from oil and gas waste are among the least regulated, least monitored and least understood components in the extraction-and-production cycle.
This lack of understanding can be traced to decisions Congress and the U.S. Environmental Protection Agency made decades ago, when oil and gas producers successfully lobbied to get most of their waste exempted from federal hazardous waste regulations.
The exemption was granted in 1988 even though an EPA study from a year earlier concluded that 23 percent of the waste samples the agency had collected contained one or more toxic compounds – at levels 100 times higher than those considered safe for humans.
But that same EPA study also recommended granting the exemption because the authors determined that the expense of disposing of so much hazardous waste would likely slow domestic energy production and there weren't enough hazardous waste sites to handle the waste.
Cartwright cites a report from earlier this year by the Pennsylvania auditor general that concludes the state's system for oversight of fracking waste "is not an effective monitoring tool" and "is not proactive in discouraging improper, even illegal, disposal of waste."
The DEP has taken strong action against two waste handlers in the state in the last two months. In September, the agency issued a $4.15 million fine to operator Range Resources for four leaky impoundments. Earlier this month, the DEP announced it was pursuing an even larger fine of $4.5 million to EQT Production Co. for a major 2012 impoundment leak.
According to Davitt Woodell, president and CEO of the environmental advocacy group Pennsylvania Environmental Council, this is a "signal that the DEP will step up and enforce" its existing waste regulations.
Still, Woodell says, even stronger rules are needed—and the DEP knows this. That's why the agency is drafting stronger measures, such as requiring that all large open-air waste pits have double liners and leak protection systems in place.
Cartwright's committee is seeking answers by November 12 to more than a dozen questions about Pennsylvania's process for monitoring the handling and disposal of fracking waste.
Among the answers Cartwright wants from Pennsylvania's environmental regulators are:
A description of the state's inspection procedures of oil and gas waste disposal facilities with respect to protecting human health and the environment from contamination.
An explanation of the reporting requirements for producers, transporters and disposal site operators that handle fracking waste.
An explanation of the process for receiving and investigating complaints regarding fracking waste handling or disposal.
Details on how state regulators monitor the accuracy of reporting and compliance with reporting and certification requirements for the handling and disposal of fracking waste
The number of inspections or investigations of disposal facilities receiving fracking waste.