The federal Environmental Protection Agency admits it didn’t get it right the first time when it reported that dairies were a likely pollution source for Lower Valley water wells, and as a result it took a verbal hit from the dairy industry and its supporters. The EPA is trying again with the hope that its next effort will definitively discern why the wells have such high nitrate levels.

The Yakima Herald-Republic first identified the pollution problem in its 2008 series, “Hidden wells, dirty water,” which detailed regulatory inaction despite studies showing that 20 percent of private wells have nitrate concentrations that exceed federal standards. Many families of decidedly modest means rely on the wells for drinking water; nitrates can cause health problems in infants, the elderly and those whose immune systems are compromised. Nitrates also can signal the presence of bacteria and other contaminants.

The EPA, which said it felt public pressure to release the data after two years of research and several postponements, acknowledged shortcomings when it released the report in September. Researchers sampled 26 residential wells but didn’t know their depth or their quality of construction; wells lacking proper linings are subject to contamination from any number of sources. The EPA agreed with dairy owners’ claims that this compromised the data.

In early December, the EPA set out to drill between nine and 13 wells near five dairies that have been singled out as the likely causes of groundwater pollution. The wells were dug both uphill and downhill of the dairies and varied between 30 feet and 250 feet deep. Dairy owners say better information should come from the new wells; technicians were to collect samples until the end of December.

In the meantime, dairy supporters and critics should hold their fire. Quick to criticize the EPA were Yakima County commissioners, who stated in a letter to the EPA: “If the intent of the study is to draw a direct correlation to the dairies based upon scientific information, we believe it failed to do so simply because of the study’s stated limitations and questionable assumptions.”

We understand commissioners’ concern about how EPA findings could affect the operation of dairies, which are a major economic force in the Yakima Valley. But the commissioners’ letter creates an awkward situation for Commissioner Rand Elliott, who holds a sensitive and important post in chairing the Lower Valley Groundwater Advisory Committee.

The panel consists of a broad-based group of community and industry representatives who will try to develop a plan to reduce nitrate contamination. This issue finds county commission constituents on all sides, including dairies, dairy critics and residents who simply want safe drinking water. Elliott’s role is to build a consensus among disparate and occasionally disputatious sides, and the commissioners’ strong words could compromise his credibility if he is viewed as tilting too far in favor of the industry.

Dairy critics also have their issues with the EPA, arguing that dairies should pick up the tab for the study and saying they would hold off on legal action if the EPA issues fines against dairies. Such actions would carry weight only with the sort of convincing evidence that may or may not come from the second study; for example, the September report also said runoff from irrigated crops or faulty septic systems could be pollution sources.

A lot rides on the second report, assuming it does pass technical scrutiny. It could bring news that the dairy industry doesn’t want to hear. It could disappoint dairy critics by not uncovering a smoking gun that points directly to the dairies. Either way, all sides need to prepare to live by the report’s findings and whatever actions may result from it, provided the follow-up is done correctly.

• Members of the Yakima Herald-Republic editorial board are Sharon J. Prill, Bob Crider, Frank Purdy and Karen Troianello.