Some frustrated residents and anti-fracking activists are finding new names to call the Pennsylvania Department of Environmental Protection (DEP) -- "Don't Expect Protection," "Department of Energy Production" -- according to Dana Dolney of ShaleTest, a nonprofit that provides free air and water quality testing for low-income residents near natural gas wells.
The department is taking heat for providing what critics see as incomplete water quality test results to property owners who are concerned about pollution from nearby fracking operations. Withholding such information, the critics say, could endanger residents' health.
"Based on what is happening in the Marcellus Shale, we saw a huge desperate need for this kind of testing," Dolney said. "We wouldn't have to do what we do if it wasn't for the failures of the DEP."
The DEP and natural gas companies are defending the testing methods, asserting that the contaminants most likely to be associated with fossil fuel extraction are included in what is shared with the DEP and, subsequently, with homeowners.
Still, critics suggest the purported "filtering" of testing data is just one of the ways people are left in the dark about the assortment of heavy metals and other toxic contaminants that may be in their air and water as a result of drilling, hydraulic fracturing and other phases of natural gas production. Recent studies have identified more than 600 chemicals used throughout the process of natural gas production, and often left undisclosed by companies. Additionally, natural but equally hazardous substances can be released from the wells.
"The disclosing of chemicals used by the industry remains seriously incomplete. Couple that with the incomplete reports on water tests and it aggravates a situation where landowners don't have a full picture of what is going on," said Kate Sinding, a senior attorney with the Natural Resources Defense Council.
David Headley, of Smithfield, Penn., is one of those that's been getting incomplete information about contaminates in his water.
In April 2010, four years after the first natural gas well was drilled near his home, the DEP tested Headley's drinking water and reported low levels of barium, strontium and manganese.
"We were told the water was safe to drink," David Headley said. "But we had an infant in the house, and a pre-teen. We weren't about to let them drink it."
The test results were labeled with the now-controversial Pennsylvania DEP code 942, which tells the testing lab to send back just a subset of results. Among 24 heavy metals tested, for example, results of just eight are ultimately verified and reported. Aluminum, silicon, titanium and lithium are among the excluded metals.
"A number of those other metals could be present," said Tony Ingraffea, professor of Civil and Environmental Engineering at Cornell University. "I know for a fact that lithium has been found in drinking water tests done on families who have complained due to nearby drilling or fracking."
Travis Windle, spokesperson for the Marcellus Shale Coalition called the accusations of manipulated test results "baseless claims." And Pennsylvania DEP spokesman Kevin Sunday told The Huffington Post that the "biggest indicators of drilling" are barium, strontium and potassium -- all included with code 942. The agency, he explained, bypasses the costly and time-intensive quality control steps for the 16 less relevant metals.
Sunday added that the agency sometimes uses a newer code, 946, which provides a slightly longer list of contaminants, including aluminum and lithium.
It's not entirely clear what contaminants a test should be looking to find. No federal laws require natural gas companies to disclose the chemicals they use in their operations, a byproduct of the so-called "Halliburton loophole," a Bush-era energy bill that exempts natural gas drilling from the Safe Drinking Water Act.
Some states have enacted their own disclosure legislation on fracking fluids -- the material blasted into bedrock to release natural gas -- but many have loopholes.
Pennsylvania's Act 13, for example, includes disclosure exemptions for any chemicals brought up naturally from the shale, formed as a reaction, or are otherwise "incidental." There are also exclusions for trade secrets.
In September, an investigation by EnergyWire found that 65 percent of disclosures made by oil and gas companies leave out information about one or more fracking chemicals that the companies claim to be confidential.
Physicians, according to a provision in Act 13, can access this exempted information if it is relevant to a patient's care, but they must first sign a confidentiality agreement stating that they won't share the information with anyone -- not even their patients.
Thanks to databases such as FracFocus and a recent project by the nonprofit SkyTruth, the information that is publicly disclosed is becoming easier to find. None of these public records, however, include information on the chemicals used during the drilling of the well or in other aspects of the operations.
The EPA, too, is focusing their current research on how fracking could affect drinking water sources -- from water acquisition to treatment and disposal of the wastewater. As the agency told HuffPost, while they "are not looking at transport or drilling, the scope of the study does include spills of chemicals used on site to formulate fluids for hydraulic fracturing."
That means the study will miss at least one likely contamination source: "Whatever is in the drilling mud fluid comes into contact with underground sources of drinking water," according Cornell's Ingraffea.
Theo Colborn, an expert in toxic chemicals and president of the Endocrine Disruption Exchange, said that fracking fluid is just one component of the huge pollution problem stemming from natural gas production.
Around wells in rural Colorado, her team recently detected high concentrations of contaminants in the air, including methylene chloride, a toxic solvent not disclosed by industry but reported by residents and gas field workers as being stored on well pads for cleaning purposes. The levels of the contaminant peaked before the fracking phase even began.
As for David Headley, ShaleTest recently looked at the air quality around his home and detected high levels of many toxic chemicals, including acetone and carbon tetrachloride.
Between contamination of the air, ground and water, Headley said he still doesn't know what chemicals his family may have been exposed to over the past few years. He added that such a lack of information has hindered the ability of doctors to pinpoint the cause of his son's stomach cramps as well as the skin rashes and chronic coughs affecting his whole family.
It makes the future look "scary," he said.
WATCH: Well Venting Near David Headley's Home:
This article has been updated to include comments from the EPA.