In a story published last week, Bloomberg News reviewed hundreds of legal and regulatory documents to uncover a trail of court cases involving claims of people who said they become ill because of fracking. Nearly all of the cases have been sealed from public view. Per Bloomberg News:

In cases from Wyoming to Arkansas, Pennsylvania to Texas, drillers have agreed to cash settlements or property buyouts with people who say hydraulic fracturing, also known as fracking, ruined their water, according to a review by Bloomberg News of hundreds of regulatory and legal filings. In most cases homeowners must agree to keep quiet.

The strategy keeps data from regulators, policymakers, the news media and health researchers, and makes it difficult to challenge the industry’s claim that fracking has never tainted anyone’s water.

There’s clear potential here for local follow up. Among the cases cited by Bloomberg, for example, is that of a woman from Silt, CO, who “believed gas drilling near her home…was to blame for a tumor she developed” and whose “complaint and the existence, though not details, of a settlement and non-disclosure pact were disclosed in filings with the oil and gas commission.”

Correction: This article originally gave incorrect information about ownership of The Gazette in Colorado Springs. Until last year The Gazette was owned by Freedom Communications, Inc.; it is now owned by Clarity Media. CJR regrets the error.

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Joel Campbell is CJR's correspondent for Utah, Colorado, Arizona, and New Mexico. An associate journalism professor at Brigham Young University, he is the past Freedom of Information chairman for the Society of Professional Journalists and was awarded the Honorary Publisher Award by the Utah Press Association for his advocacy work on behalf of journalists in the Utah Legislature. Follow him on Twitter @joelcampbell.