Dairy Nitrate Study Insights

Data Collected at Four Washington State Dairies Show the Operations are a Source of Nitrates in the Groundwater,but Also Point to Steps the Dairies Can Take to Reduce the Pollution

Data collected at four Lower Yakima Valley dairies show the operations are a source of nitrates in the groundwater but also point to steps the dairies can take to reduce the pollution, according to the federal Environmental Protection Agency.

Agency staff presented their findings from more than a year of working with dairies at last week's meeting of the committee tasked with developing a plan to clean up the Lower Valley's groundwater, provoking questions and concerns from dairy industry representatives and environmentalists.

It's a highly charged issue because the dairies didn't volunteer for the study — they signed a legal agreement with the EPA to cooperate in 2013 to avoid litigation. Then, an environmental group sued anyway over alleged pollution, based on the EPA's findings. That case is scheduled to go to trial in February.

Nitrates are considered an acute contaminant because they reduce the blood's ability to carry oxygen and can cause serious health problems for infants, pregnant women and adults with certain blood disorders.

Representatives of the dairy industry say the situation unfairly targeted the four dairies and created a situation where other farmers are now afraid to cooperate with the Groundwater Management Area committee, referred to as GWMA.

But Tom Eaton, director of the EPA's Washington Office and member of the GWMA committee, said he hopes the findings help point a path forward.

"We think the data speaks for itself that the dairies are sources of nitrates," he said in an interview before the meeting on Thursday.

"We are just asking the dairies to address their sources, and more broadly in the GWMA, that's what needs to happen to address the problem. If we are going to be able to provide clean, safe drinking water in the long run, that's what it is going to take."

Brendan Monahan, attorney for the dairies — Cow Palace of Granger, George DeRuyter and Son Dairy of Outlook, D&A Dairy of Outlook and Bosma-Liberty Dairy of Zillah — said they dispute the EPA's claim that the data prove that the dairies contributed to excessive nitrates measured in nearby wells. They filed a motion last month asking to exclude the EPA's finding from the legal fight with the Granger-based Community Association for the Restoration of the Environment, or CARE, and the National Center for Food Safety.

But Adam Dolsen, the president of Cow Palace, said that working with the EPA gave the company a welcome chance to demonstrate the measures it takes to be environmentally responsible.

"Instead of trying to fight (the EPA), we reframed it as a way to provide transparency," Dolsen said. "We saw this as an opportunity to show what we are doing and prove people wrong by showing that we are doing things right, in a sustainable way, and that we are a leader in this agricultural community."

Cow Palace milks about 7,000 dairy cows and manages about 1,000 acres of dairy operations and cropland. Combined, the four dairies have about 24,000 cows, which produce about 500,000 tons of manure a year, in an area of about 5 square miles just northeast of Granger.

Under the agreement, Cow Palace and the other dairies installed monitoring wells and irrigation sensors, improved manure management and hired agronomists to sample the soil in their fields. Up next is an evaluation of waste storage lagoons to make sure they are compliant with updated standards.

A recent survey of residential wells within a 1-mile radius of the dairies found that out of 181 homes, 61 percent had nitrate levels over the legal limit of 10 milligrams per liter. That's compared to 12 percent of private wells that are over the limit across the Lower Valley, according to the EPA. Under the consent order, the dairies supplied water treatment systems for all the wells that exceeded the limit.

The initial data showed that as groundwater flows south under the dairies' property, the amount of nitrates found in the water generally increases, although there are a few wells that don't fit the pattern.

Soil samples taken in the fall of 2013 showed that about half the crop fields fertilized with manure had more nitrates than the crops would be able to use, which means the excess is at risk of leeching into the groundwater, especially during the wet weather in winter and early spring, said Eric Winiecki, who manages the EPA's work with these dairies.

Winiecki said that in post-harvest fields with a double crop of silage corn and triticale, the soil had an average of nearly 800 pounds of nitrates per acre in the root zone, which is more than twice the fertilizer recommendation of 300 pounds needed by the next year's crop. The average alfalfa field had 184 pounds per acre in the root zone after harvest.

Scott Stephen, a consulting agronomist working with Cow Palace, said the EPA underestimated annual crop needs somewhat. However, he said he did recommend that the dairy make some cropping changes based on the 2013 data, including reducing or halting manure applications on some fields that showed higher levels of nitrates and switching some fields from triticale and corn to alfalfa, which can extract and use more nutrients from the soil.

Data collected this fall, which the EPA did not have ready to present, already show that the nitrates in the fields are going down, Stephen said.

"What we are seeing now is that the removal (by crops) is exceeding the application to the fields, but it's always an ongoing balance," Stephen said.

Dolsen said it is in his company's best interest to make sure the nutrients are in balance as well, because they see manure not as a waste, but as a valuable fertilizer.

"Basically, it's a sustainable approach. Our cow poop is turned into compost used around the state for crops like wine grapes and hop fields, and some of the liquid nutrients go on our fields to grow the crops that are fed to our cows," Dolsen said.

Another step Cow Palace has taken to reduce the potential for nitrates to leach into the groundwater is to carefully manage irrigation so that there's not too much water draining through the soil and carrying the nitrates with it, Stephen said.

The new moisture sensors will prevent over-watering.

All of the efforts that Cow Palace and the other dairies have taken represent a significant investment, Dolsen said, from paying experts like Stephen and installing dozens of $1,600 moisture sensors. But, he added that it's also making Cow Palace a better operation and a leader in the industry.

The EPA plans to continue monitoring groundwater and soil with the dairies for eight years. If no downward trend in nitrates is observed, the dairies have agreed to take additional steps.

Representatives of the dairy industry responded to the EPA's presentation on Thursday with critical questions about why the study didn't use control wells in other areas or look at other potential sources of nitrates, such as septic systems.

Eaton, the EPA's representative on the GWMA responded by saying that while the GWMA's responsibility is to look at all sources of nitrates in the Valley and evaluate them, the EPA's collaboration with these four dairies was just designed to focus on how the dairies might be contributing and what could be done about it.

A previous EPA study estimated that livestock operations were responsible for 65 percent of the nitrogen applied to land in Yakima County, along with 30 percent from crop fertilizer and 3 percent from septic systems.

Environmentalists at the meeting questioned why the EPA was willing to give the dairies eight years to demonstrate improvement and how it was possible that the dairies were allowed to operate if only one of 41 waste lagoons was compliant with federal standards.

Winiecki responded by saying that most of the lagoons were constructed before the current standards took effect and that upcoming testing will show if lagoons have problems that need to be fixed.

He also said it's unreasonable to expect the groundwater to show rapid improvement.

"Measures taken today might not show up in the aquifer for years, but it's good to get started," he said. "The approach here is to monitor and implement some actions we think will be effective and then see if they do have an effect."

Source: Yakima Herald

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