WATER WORRIES: Farmers, regulators struggle to address nitrate contamination

September 22, 2022
WATER WORRIES: Farmers, regulators struggle to address nitrate contamination

BOARDMAN — It started last January with a multimillion-dollar fine levied by the Oregon Department of Environmental Quality against the Port of Morrow.

The port, situated along the Columbia River in northeastern Oregon, has for years collected nitrogen-rich wastewater from food processors and other businesses at its industrial park near Boardman and used it to irrigate neighboring farmland under a permit from DEQ.

Between 2018 and 2021, regulators found the port violated its water quality permit more than 1,000 times by regularly over-applying the recycled water on fields growing crops such as corn, potatoes and onions.

DEQ initially fined the port $1.3 million and later increased it to $2.1 million after finding additional violations. Fearing potential health risks to the area’s residents, Morrow County commissions declared a local state of emergency.

The episode — overloading of groundwater with nitrates — brings to light an issue that is neither new to agriculture nor unique to only that part of Oregon.

Nitrogen from fertilizer, compost or manure is critical for farmers, who apply it to their fields, but too much can have unintended consequences. Crops can only absorb so much of it, allowing excess nutrients to leach down into groundwater.

Combined with oxygen, the nitrogen becomes what is known as a nitrate, a colorless, odorless compound that experts say can cause serious health problems if consumed in excess.

Though some nitrates occur naturally, the over-application of fertilizer or wastewater by farmers has been identified as a major source of nitrates beyond what the Environmental Protection Agency considers safe for drinking water.

In Morrow County, attempts to regulate contamination have so far netted frustratingly slow progress.

“To date, there’s been a ton of time and resources spent pointing the finger at whose fault this is,” said J.R. Cook, founder and director of the Northeast Oregon Water Association, known as NOWA. “We’re all at fault. Now, what’s the solution?”

Understanding LUBGWMA

The basis for issuing such a large fine to the port lies in its location.

DEQ designated the Lower Umatilla Basin Groundwater Management Area, which goes by the imposing acronym of LUBGWMA, in 1990. The area straddles northern Morrow and Umatilla counties and includes the cities of Hermiston, Umatilla, Echo, Stanfield, Boardman and Irrigon.

The Oregon Health Authority estimates approximately 4,500 domestic wells are in the area providing water for about 12,000 people.

State officials may declare a “groundwater management area” when levels of groundwater nitrates surpass 7 milligrams per liter. That’s 70% of the EPA’s limit for safe drinking water.

While contamination levels in the LUBGWMA vary, many wells have tested above the limit, hence the emergency declaration in Morrow County, DEQ spokeswoman Laura Gleim said.

A test of 132 wells sampled in the area shows 44% exceeded the safe drinking water standard for nitrates, including 14 wells that registered 40 to 60 milligrams per liter. Three wells had more than 60 milligrams per liter — more than six times the maximum allowable concentration.

Erica Heartquist, spokeswoman for the Oregon Health Authority, said drinking water with high levels of nitrates can contribute to several health problems in adults, such as respiratory infections, thyroid dysfunction, spontaneous abortions and some cancers.

The agency, however, does not have the level of detailed information necessary to determine whether any resident’s illness has been caused by exposure to nitrates in drinking water.

In infants, consuming nitrates can cause methemoglobinemia, or “blue baby syndrome,” which occurs when an inadequate amount of oxygen enters the blood.

Methemoglobinemia is not a “reportable condition” for health care providers, though according to OHA, a search of diagnostic codes in health care claims and hospitalization discharge, emergency department and urgent care clinic data found no records of it over the last 10 years.

That search, however, is an inexact science, Heartquist cautioned, and even if the level of exposure is not enough to cause methemoglobinemia, high levels of nitrates in drinking water can still be harmful.

Sources of nitrates

Nitrogen-based fertilizer used on irrigated agricultural land is the source of almost 70% of the nitrogen that has leached into the groundwater, according to research by DEQ, the state Department of Agriculture and Oregon State University Extension Service.

About 12.2% comes from using liquid manure from confined animal feeding operations, such as dairies, to fertilize crops.

Eight percent comes from livestock pastures, and 4.6% is from applying wastewater for irrigation.

In the port’s case, it obtained much of its wastewater from food processors making products such as french fries, frozen onions, cheese and mint oil. Not only is nitrogen found naturally in the crops themselves, but is also in the soil and fertilizers that gets washed off the vegetables during processing, DEQ’s Gleim said.

Recycled water is important for farmers in the basin, where it rains 9 inches per year.

Valuable resource

The nutrients in water reused for irrigation reduce the use of commercial fertilizer that would otherwise generate up to 12,000 tons of carbon dioxide annually, according to NOWA. It also reduces the pressure on badly stressed aquifers.

“It allows industry to continue to grow,” said Jake Madison, a fourth-generation farmer and president of Madison Ranches in Echo, Ore. He uses wastewater from the port to irrigate 2,800 acres of cropland. “It’s a great sustainability story, from the reuse of a scarce natural resource in the area.”

Avoiding nitrate contamination means growers must apply the right amount of nitrogen at the right time.

Too much, and the plants may not be able to use it all.

Apply it before or during wet weather, and the risk of nitrates leaching below the root zone increases.

Either way, it could end up in the groundwater below.

A committee of government, industry and environmental representatives has recommended voluntary measures aimed at curbing nitrates in the LUBGWMA.

Still, 30 years later, data show nitrate concentrations “are going up more than they’re going down,” the committee reported in its 2020 action plan.

Shannon Davis, DEQ Eastern Region administrator, said the agency “could have been doing a much better job than we’ve done to date” regulating permitted facilities. The priority, she said, is issuing strong and consistently enforced permits.

With DEQ, the Port of Morrow is now amending its permit to ensure it does not exceed prescribed rates for land application.

“We owe it to the state of Oregon and the people out there to do the best we can cleaning up and protecting the groundwater,” Davis said.

Legacy of contamination

Cook, with NOWA, said that while DEQ emphasizes stronger permits for operators, it has neglected to address remediation of “legacy” pollutants — nitrates that have accumulated underground over past generations.

Nitrate contamination in the LUBGWMA appears to be in shallow aquifers that aren’t connected to the floodplain, Cook said. That makes it extremely difficult to remove.

“The water that’s in there does not go anywhere,” he explained. “The only way you get it out is to dilute it over time, or pump it out and put it onto fields.”

Cook helped create NOWA in 2013 to address water quality and quantity in the basin. His organization has led calls for more funding from the state to better understand the area’s geology and hydrology, create a more robust well-testing network and implement recommendations outlined in the LUBGWMA committee’s action plan.

“Until there’s action, until there’s a program, it’s all talk,” Cook said.

Madison described legacy nitrates as “great-great grandpa’s contamination.” He said farming practices have come a long way since then, with producers using less nitrogen today to grow more food, depending on the crop.

Applying too much nitrogen can hamper both crop quality and the farm’s bottom line, Madison said. That adds incentive to adopt best management practices. But until the legacy nitrates are dealt with, he worries contamination will persist.

“We’ve got to try to figure out a way to get that water out and do something useful with it,” he said.

A larger problem

Groundwater nitrates extend beyond the Umatilla Basin and across the Pacific Northwest and U.S.

The LUBGWMA is one of three groundwater management areas in Oregon. The other two are in northern Malheur County and the southern Willamette Valley.

In Washington, the state Department of Ecology undertook its Nitrate Prioritization Project in 2014, mapping groundwater areas identified as most vulnerable to contamination. Candidates for “priority areas” are found statewide, from dryland farming areas in the east to the Puget Sound lowlands in the west.

Colleen Keltz, a spokeswoman for Ecology’s Water Quality Program, highlighted the Lower Yakima Valley Groundwater Management Area, where she said about 75 residents have well water that does not meet the EPA’s safe drinking water standard.

The Idaho Department of Environmental Quality maintains a ranking of groundwater nitrate priority areas. It will be updated in 2024.

The current list cites “increasing” nitrate trends in areas of south-central and western Idaho, including Mountain Home, Minidoka, Fort Hall and northeast Canyon County.

“Pretty much, wherever you see there’s nitrate priority areas, there’s development and human activity,” said Ed Hagan, groundwater bureau chief for Idaho DEQ. “I think level of activity is a factor, but it’s also the hydrogeological conditions.”

Abigail Tomasek, a soil water quality specialist for Oregon State University Extension Service, said nitrates are also a major problem in the Midwest, and are a leading cause of the “dead zone” offshore in the Gulf of Mexico.

“It’s not an issue exclusive to the Pacific Northwest,” Tomasek said.

What can be done

To prevent nitrates from irrigated agriculture leaching into groundwater, Tomasek outlined what she called the four “R’s” — right place, right time, right source and right rate.

Right place refers to crop and soil type. Nitrates leach more rapidly in sandy soils than fine-textured soils.

Different crops also have different abilities to absorb nitrogen in the ground. For example, crops such as alfalfa and canola have deep root systems, exceeding 5 feet, and are better at absorbing nutrients from deeper in the soil profile.

By contrast, potatoes and onions generally have shallower, more dense root systems.

“It’s particularly an issue when you have shallow-rooted crops in sandy soils,” Tomasek said. “If you have deeper-rooted crops, it can scavenge that nitrogen.”OSU has published guidelines for the appropriate rates of fertilizer application for various crops.

Timing of application also plays a role. Fertilizing before a rainstorm can accelerate the movement of nitrates through the soil profile.

Once nitrogen reaches the aquifer, it is extremely difficult to remove. Tomasek said. For those with contaminated wells, she said residents can buy reverse osmosis filters or ion exchange systems to treat their water, though they can be expensive.

Chrissy Lucas-Woodruff, outreach program coordinator for OSU Extension in the Willamette Valley, has spent the last 15 years working with small-scale farmers, landowners and new residents to educate them about nitrates, and to test their wells.

She said the biggest contributors to nitrates in the area are agriculture, failing septic systems and manure piles. Her hope is that more positions like hers can be filled statewide, allowing for greater awareness of the problem.

“As a domestic well owner and landowner or renter, you have to be proactive in this,” Lucas-Woodruff said. “You should be paying attention to what’s going on with your own water quality. It’s nothing you can see, smell or taste.”

Need for collaboration

While there are differences of opinion, all sides appear to agree that close collaboration is needed for meaningful reductions in groundwater nitrate concentrations.

Crafting an effective water reuse and land application policy will require government agencies, businesses and the agricultural community to work together, said Davis, the DEQ regional administrator for Eastern Oregon.

Madison, the ranch owner, said land application of wastewater remains valuable because it helps conserve limited water resources in an arid part of the state.

“DEQ needs to understand, as a region, we’re not here to pollute the groundwater and make a mess out of things. We’re trying really hard to be responsible farmers,” Madison said.

-George Plaven

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