(BOISE) The Idaho Conservation League released its first report on groundwater in the Eastern Snake Plain Aquifer (ESPA), which reveals declining water quality as a result of increasing pollutants, primarily nitrogen and phosphorus.

The ESPA supplies drinking water to more than 300,000 Idahoans, but is increasingly contaminated by human activity, fueled in large part by the rapid growth of the industrialized dairy industry. Each year, the estimated 417,000 dairy cows in the Magic Valley produce manure equivalent to 12 million people, or nearly one-and-a-half times the population of New York City. 

“That manure has to go somewhere,” said Josh Johnson, conservation associate in ICL’s Ketchum office. “Combine that animal waste with the fertilizer that’s used on the Snake River Plain and it’s too much for typical crops to absorb. The rest is free to drain into the aquifer or the river.”

Johnson added, “Although recharge could be a way for polluted water to enter the aquifer, the root cause of that pollution is still likely excess nitrogen and phosphorus from large industrialized dairy operations and irrigated agriculture.”

 ICL’s report also drew the following conclusions regarding groundwater quality in the ESPA:

  • More than 2/3s of sampled wells have concentrations above natural background levels for nitrate, and, in some areas, exceed state/federal water quality standards.
  • Limited phosphorus data indicates contamination is increasing and has the potential to exacerbate existing pollutant problems in the Snake River.
  • Evidence strongly indicates that nitrate and phosphorus concentrations will continue to increase in the coming decades.
  • These water quality issues will increasingly have more severe implications for Idaho’s ability to meet water quality standards, manage population growth and protect the health of Idahoans.

ICL was founded to be a strong voice for clean water. The current state of the Snake River (referred to as “Idaho’s sewer system”) is emblematic of the water quality issues seen statewide. In some areas, it is now unsafe to swim in or eat fish from the Snake River, due to a combination of overallocation of the river’s water and pollution discharge from factories, municipalities, dairies and farm fields. While working to protect waters across the state, ICL has embarked on a campaign to restore the health of the Snake River.