About 88 percent of Nebraska residents rely on groundwater to provide their drinking water.
State and national agencies impose specific regulations.
On the positive side, stronger water-purification capability and improved fertilizer practices in some parts of the state have helped reduce the number of occasions where nitrate levels are above the safe-drinking threshold, requiring local water systems to take remedial action.
In some parts of the state, the nitrate concentration in groundwater has risen to troubling levels.
The Little Blue NRD in southeast Nebraska has designated eight “water quality management areas” to address nitrate concerns.
Some examples: » In the Little Blue NRD, 75 percent of reporting ag producers are applying more nitrogen than recommended by specialists at the University of Nebraska-Lincoln.
» In some parts of the Little Blue NRD, nitrate levels “exceed the maximum contaminant level of 10 ppm (parts per million)” considered the safe limit for drinking water.
» In the 756-square-mile area of northeast Nebraska covered by the four-NRD cooperative plan, average nitrate concentrations since 1980 “have increased, with some areas (having) three times the levels safe for drinking water,” the NRDs report.
The natural resources districts, the university, DEQ, the Nebraska Environmental Trust and federal agencies provide technical or financial help to agricultural producers to reduce nitrates and other water-quality concerns.
Conservation steps include adjusted application levels or schedules, avoidance of overwatering, use of cover crops, decommissioning of old wells, proper maintenance of septic systems and wetland restoration.