U.S. Water News Online
KANSAS CITY, Mo. — Future water supplies from the High Plains aquifer could be in jeopardy if large amounts of water are pumped out of it and if farmers continue using chemicals on land above the vast underground reservoir, the U.S. Geological Survey said in a report.
While the aquifer's water quality is good, there will have to be “some substantial changes” in how the aquifer is used “if we want to extend the life of it,” said Jason Gurdak, lead author of the study.
Gurdak said prolonged irrigation pumping of the aquifer, also known as the Ogallala, and use of fertilizers on crops in the region could lead to higher contaminant concentrations.
The aquifer is the most heavily used groundwater resource in the United States, supplying water to Kansas, Colorado, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming. Most of the water is used for irrigation, but about 2 million people also depend on it for drinking water.
“There is a concern over the ongoing sustainability of this resource,” Gurdak said. “People around the world know about the Ogallala; they know it's the poster child for water resources that are being challenged because of use.”
For the study, which was presented recently at the summer meeting of the Western States Water Council in Park City, Utah, the USGS analyzed water samples taken between 1999 and 2004 from private wells, public supply wells, irrigation wells and shallow monitoring wells for more than 180 chemical compounds and physical properties.
The report said more than 85 percent of the 370 wells used for drinking met federal drinking-water standards.
But the contaminant nitrate was greater than the federal drinking-water standard of 10 parts per million in about 6 percent of the drinking-water wells, the report said. Nitrate can naturally occur, but it is also a byproduct of fertilizer and manure.
Most of the contaminants that exceeded drinking-water standards were naturally occurring, like arsenic, dissolved solids, fluoride, iron and manganese, the report said. None of the pesticides detected exceeded drinking-water standards.
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