The Pennsylvania Department of Environmental Protection released a list of 243 cases across two dozen counties confirming to residents that their private water had been impacted by gas drilling, known as fracking.

The list contains links to copies of letters sent over the last decade following up on civilian reports of water contamination. Some letters replied to three-year-old complaints, like one sent earlier this year to a Stevens Township resident in Bradford County informing the resident that there was excessive levels of manganese and iron in their water and confirmed that the well water, “went dry while Southwestern Energy Production Company was drilling the vertical section of the [redacted] gas well.”

Another letter from 2013 reported that “the presence of combustible gas” in a Forks Township resident’s water exceeded “the lower explosive limit of 5 percent for methane gas.” The department recommended installing a vent but added, “it is not possible to completely eliminate the hazards of having natural gas in your water supply by simple venting your well.”

So far, the largest fine the DEP enforced was $4.15 million against Range Resources in September brought on by leaks of hazardous flow-back fluid that sunk into soil and groundwater during the hydraulic fracturing process. The fine is less than 0.5 percent of the company’s yearly revenue of $907 million.

In July, the state’s Auditor General Eugene DePasquale released a report that found the DEP had failed to regulate the expanding gas industry. With few resources, the department relied on companies to self-regulate and took longer than the maximum of 45 days to respond to civilian complaints in a majority of cases.