Oregon Public Broadcasting

A colorless, odorless poison is seeping into the water and sickening families in eastern Washington's Yakima Valley.

Many private wells there are contaminated with nitrates. The compound can reduce your blood's ability to carry oxygen. In high concentrations, nitrates are especially dangerous for babies.

The federal government has launched an investigation to find the source of this contamination. But it's the poorest families who are most at risk.

Anna King / Northwest News Network

Sandy Halstead, of the Environmental Protection Agency, and a summer intern, listen to the concerns of a homeowner in the Yakima Valley. Many private wells in the Eastern Washington agricultural area are polluted with nitrates.

Anita Rojas just finished serving dinner to her three growing boys.

The sweet-natured boys line up at the sink to dutifully wash their dishes. Rojas admits she boiled the fresh corn they ate in water that might make her family sick. But Rojas says there's only so much bottled water she can buy.

Anita Rojas: "It is really hard because I work all the time. Sometimes the kids go through a lot of water. Sometimes I get home and they say, 'Mom! We've run out of water.' I have to run to the store to get water."

Rojas says at $1.50 a gallon, bottled water is a drain on her one-income budget. She spends as much as $150 a month to bring in clean water for cooking, drinking and brushing teeth.

Anita Rojas: "And it's too bad because living out here you think the water is safe out in the country. But here we are. It's sad that our water has to be like this."

Rojas isn't alone. There are an estimated 1800 wells in the Yakima Valley contaminated with nitrates. And it's not the only place in the Northwest with poisoned wells.

The Environmental Protection Agency is concerned about nitrates in well water in agricultural areas across Washington, Oregon and Idaho.

Where is this contamination coming from? Sandy Halstead is trying to find out.

Anna King / Northwest News Network

Janeth Lopez, 35, and her children are safe because their well tested negative for high levels of nitrates. Communicating the problem of a colorless, odorless poison to families in the Yakima Valley is a difficult task for federal and state government officials. Many families don't speak English, or are living in poverty. The Environmental Protection Agency is testing hundreds of wells in the Yakima Valley to get a better idea of where the nitrates are coming from.

Sandy Halstead: "And do you know where the well is, the head?"

Halstead uses a bit of Spanish and just plain guts to get through many situations here in the Yakima Valley. She works for the EPA and is leading the federal study on the groundwater here. She creeps down a rickety set of stairs.

Sandy Halstead: "Also looking for black widows. They are very popular in these old well houses."

What Halstead and her colleagues are trying to do with these samples is sort of like water CSI. Forensics can determine if nitrates are coming from say a hop farm, dairy or septic tank.

She says the prime suspects are large cattle operations or other types of farms, old abandoned or uncased wells, and failing septic systems. Halstead says overall, the problem likely comes from a mix of those things.

The state of Washington set aside $400,000 to help install purification systems. That will help roughly about 500 homes. But Halstead knows that's not enough, especially for the rural poor.

Water purification for one kitchen faucet can cost about $800

Sandy Halstead: "There have been nights that I've haven't been able to sleep. Because I think of some of these families and I don't really have a good solution for them. It's pretty difficult."

Here's another difficulty: Private wells are in a regulatory black hole. Neither the federal, nor the state government, have control over them.

That's meant the problem has persisted for decades with no agency taking responsibility for it.

Helen Reddout has been sounding the alarm about this for more than 10 years. The retired science teacher says studies are great -- she can rattle off a list of them. But she wants to see serious enforcement and remediation this time

Helen Reddout: "What happens is we'll have a study. And the people that aren't living with this say, 'Oh they have some new regulations so the people are being taken care of.' Well it's not so."

Meanwhile, Yakima Valley farmers, especially dairies and large cattle feeding operations, say they shouldn't catch all the blame.

Jay Gordon, heads the Washington Dairy Federation. He says the new EPA study will help locate exactly where the contamination is coming from.

Jay Gordon: "We suspect that it's not only dairies, but it's fertilizer on agriculture, golf courses but also residential use as well as septic tanks. Then everyone needs to step up and do their part, and we are no different."

State and federal regulators say they're waiting for the study results before making any decisions on cleanup or enforcement.

The EPA's study should be complete this coming February.

Top officials there say even if the pollution stops today, some of the Yakima Valley's drinking water will be too contaminated to drink for decades.