The dairies north of Sunnyside targeted by the Environmental Protection Agency for groundwater pollution are making progress controlling nitrates, the federal agency said this week.
“The dairies have taken a number of important steps to reduce nitrate pollution to groundwater,” said Lucy Edmondson, director of the EPA’s Washington office, in a telephone interview. “They are making progress, and there is more work to be done.”
Nitrate is a key crop nutrient found in manure and commercial fertilizer that also poses a health risk in drinking water. Unsafe levels of nitrate have been found in wells across the Lower Valley for more than a decade, but the search for solutions remains controversial.
The dairies have taken a number of important steps to reduce nitrate pollution to groundwater.
Lucy Edmondson, director of the EPA’s Washington office
The recently released data showing improved nitrate management stems from a consent order that three dairy operators signed in 2013 to avoid litigation with the EPA.
Tensions have surrounded that consent order since the EPA’s findings were used by environmental groups to sue the dairies — Cow Palace of Granger, George DeRuyter and Son Dairy and D&A Dairy of Outlook, and Bosma-Liberty Dairy of Zillah. In 2015 a federal judge ruled that mismanagement of manure at Cow Palace did cause pollution in violation of solid waste laws and all the dairies agreed to further changes in a settlement.
Calls to the dairies requesting comment were not returned.
Both legal agreements are distinct from ongoing efforts by a committee of state and local officials, farmers and community members tasked with finding a solution to the Lower Valley’s nitrate problem. Known as the Groundwater Management Area committee, GWMA, the group has struggled to find consensus on a path forward, and industry representatives blame the lawsuits for making other farmers afraid to participate.
Edmondson said she hopes the EPA’s findings can help the GWMA as it designs a plan to reduce nitrate pollution across the Lower Valley. But she added that more years of study are needed to see if the steps taken are sufficient.
The data show that careful control of fertilizer and irrigation works to reduce nitrate levels in the soil. In 2013, 20 of the dairies’ 34 fields had high nitrate levels in the soil below crop roots, where it is at risk of moving into the groundwater. In 2015, after the dairies made changes, that fell to just nine fields.
“Prevention is key, because once it is in the groundwater, we can’t get it out,” Edmondson said.
Data collected during that same period don’t show improvement in the groundwater yet, but Edmondson said she expects that will take more time for on-farm changes to show up in the groundwater.
The consent order called for eight years of soil and water monitoring. If groundwater nitrate levels are not improving at the end of the eight years, further measures to protect the groundwater may be required, Edmondson added.