An investigation of four states’ records on drilling-related complaints has revealed that pollution was confirmed in many of the cases, although the way states report the issues varies greatly. The Associated Press (AP) examined hundreds of complaints about well water contamination due to oil and gas drilling in a “review that casts doubt on industry suggestions that such problems rarely happen.”

The oil and gas industry refuses to admit that oil and gas drilling processes cause problems including the pollution of water tables, despite documented evidence to the contrary. An AP investigation of drilling-related complaints in four states, however, found that hundreds of complaints are received each year.

The AP looked at records for four states: Pennsylvania, Ohio West Virginia, and Texas and found that the way states chose to handle and report complaints could impact public perception of the problem. According to the report, “the lack of detail in some state reports could help fuel public confusion and mistrust.”

In 2013, Pennsylvania received 398 complaints of pollution of private water wells due to oil and gas drilling. More than 100 cases of pollution have been confirmed over the past few years. According to the AP, the Pennsylvania Department of Environmental Protection “aggressively fought” efforts by new agencies to obtain information related to pollution complaints.

Texas had the most complete data of any of the four states. On a list of 2,000 complaints, 62 alleged possible well water contamination from oil and gas drilling, but a Texas Railroad Commission spokeswoman told the AP that Texas regulators have not confirmed a single case of drilling-related water contamination during the past 10 years.

While Pennsylvania, one of the most heavily-fracked states in the US, provided very little information to the AP, Texas provided an extensive spreadsheet of all oil and gas-related complaints from the past two years.

The raw number of complaints provided by the state of Pennsylvania “Doesn’t tell you anything,” said Rob Jackson, a Duke University scientist who has studied drilling-related contamination. “Right or wrong, many people in the public feel like DEP is stonewalling some of these investigations.”

Scott Anderson, an oil and gas drilling expert with the Environmental Defense Fund in Texas, believes that if the industry and regulatory agencies have nothing to hide, “they should be willing to let the facts speak for themselves,” and said that a lack of transparency fuels public mistrust.

Although public awareness of the dangers associated with fracking is increasing, many still deny that the process is dangerous. Yet, in states across the country, residents have reported contamination of their land and water due to proximity to drilling operations. Many times, despite coming forward with their claims of contamination, individuals are forced to settle with drilling companies in order to pay for fresh water supplies or relocation.

Alisha is a writer and researcher with Ring of Fire. You can follow her on Twitter @childoftheearth.