Waters of the Palouse River and its tributaries are required by the federal EPA's Clean Water Act to meet certain surfce water quality standards. Both Washington and Idaho have also adopted their own additional water quality standards to protect public health and welfare, enhance water quality, and protect biological integrity.

Some of the key parameters evaluated to determine the quality of streamflows within the Palouse Basin, where agriculture is the predominant land use, include Total Maximum Daily Load (TMDL), water temperature, bacteria, nutrients, and turbidity. From these parameters, additional inferences can be made based on their relationship with other parameters.

Recent studies have found that levels of fecal coliform bacteria, pH, dissolved oxygen, temperature, and ammonia are of concern within the North Fork and South Fork Palouse River drainages. You can link to these studies from our Digital Resources page (look under "Available Reports").

UI students measure stream temperature and pH along Paradise Creek [J. Fairley]

Groundwater quality, as discussed here, refers to the quality of drinking water from a public health perspective. Because of their use in fertilizers and agricultural practices, common parameters evaluated to determine groundwater quality are nitrates and, to a lesser degree, pesticides. High nitrate concentrations may also indicate leaching from septic tanks and sewage, and thus may be potential indicators of other types of contamination.

Given that the Palouse Basin is dominated by non-irrigated agriculture, results from numerous studies (see Phase II - Level 1 Technical Assessment for the Palouse Basin, Sec 7.3.2) show generally low nitrate and pesticide concentrations in groundwater samples. With few exceptions (shallow wells or those lacking well-head protection), groundwater within the Palouse Basin meets water quality standards for drinking water.