A crew of Democratic House members are calling on the EPA to do its damned job — specifically, to investigate potential links between pollution and fracking in three states where groundwater has been mysteriously poisoned.

Rep. Matt Cartwright’s (D-Pa.) letter, sent Tuesday to EPA Administrator Gina McCarthy with signatures from seven other lawmakers, follows the agency’s disturbing decisions to drop three investigations into possible connections between fracking and water contamination.

In mid-2012, the EPA dropped an investigation into water pollution in Dimock, Pa., despite internal warnings from one of the agency’s scientists that methane levels jumped in aquifers following drilling — “perhaps as a result of fracking.” In early 2013, the agency dropped its investigation into water pollution in Parker County, Texas — despite lacking confidence in the quality of water tests conducted by the frackers themselves. And in the middle of last year, the EPA dropped its investigation into water contamination around Pavilion, Wyo. — despite findings in a draft report that fracking chemicals were likely to blame.

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“Each community was grateful when when the EPA stepped in to help deal with their water contamination issues, and disheartened when the EPA dropped their investigations, leaving them with polluted water and little explanation,” the lawmakers wrote in their letter.

“We are writing to urge you to take any and all steps within your power to help these communities. … Members of these communities currently do not have safe, clean drinking water and need EPA’s help to address the ongoing water contamination issues in their homes and get EPA assurance once their water is clean and safe.”