Background
There are multiple sources of nitrate contamination in the LUBGWMA, resulting in varying levels of nitrate in groundwater throughout the area. A 2011 analysis by DEQ, ODA, and OSU Extension identified the following primary estimated sources of contamination: about 70% from irrigated farmland, about 13% from large dairy and cattle farms (confined animal feeding operations or CAFOs), about 8% from animal pastures, about 5% from food processing facilities that reuse wastewater to irrigate fields, and about 5% from residential onsite septic systems and other sources.