Farming, septics harming county's groundwater
Public meeting on groundwater study
El Paso County’s Groundwater Quality Study Committee will hold a public meeting 6-8 p.m. Monday in the Falcon High School cafeteria, 10255 Lambert Road in Falcon.
Members will present information on the recently completed study of groundwater quality in the alluvial aquifer of the Upper Black Squirrel Creek Basin.
Farming and septic systems from new homes could be contributing to high levels of contaminants known as nitrates in groundwater in the Upper Black Squirrel Creek Basin in eastern El Paso County, a new study has found.
The Colorado Geological Survey recently analyzed records of water quality samples from 1954 to 2009, a $53,000 project initiated by county commissioners to help guide land-use decisions in the basin. More than half of the water samples showed nitrate levels of 5 milligrams per liter or higher. That’s below the federal drinking water standard of 10, but the study’s author said it is still higher than it should be given the natural conditions, in the 2 to 3 milligrams per liter range.
“Five is just higher than one would expect in a native groundwater environment. It suggests there are some human influences on the increased concentrations,” said hydrogeologist Ralf Topper.
Nitrates are a by-product of fertilizer, which can get into the aquifer as runoff from farm fields and cattle pens. They can also come from the breakdown of human waste in septic systems.
Nitrate levels in drinking water above 10 milligrams per liter have been linked to methemoglobinemia, or “blue baby syndrome,” in infants under six months old. Researchers found nine water-quality samples taken since 1971 that violated that standard, most recently in 2006.
But, Topper said, the study relied only on previous water-quality tests, and there was a lack of data from the U.S. Highway 24 corridor and Falcon and Peyton areas, where much of the new development has occurred. So he is urging the county to initiate a second study to gather more samples for testing.
Despite the nitrate levels, Topper said, “The overall conclusion was that the groundwater is of good quality, suitable for the beneficial uses that are currently occurring.”
Along with nine water samples above the 10 milligrams per liter federal standards for nitrates, the study identified six above standards for dissolved solids, three for iron, two for pH level and one each for arsenic and sulfate.
Researchers looked at information from 150 water samples collected from 72 wells.
