Inform well owners of the possibility of contamination of their wells, the causes of and methods for prevention and clean up.
Over 1,000,000 private water wells in Texas provide water to citizens in rural areas and increasingly, to those living on small acreages at the burgeoning rural-urban interface. Public drinking water supplies are generally of good quality and are monitored through requirements of the federal Safe Drinking Water Act; however, private well owners are independently responsible for monitoring the quality of their wells and frequently at greater risk for exposure to compromised water quality. Although not used for consumptive purposes, numerous irrigation wells extract irrigation waters from the same groundwater resources as private drinking wells and can serve as good indicators of drinking water quality in nearby domestic water supplies. Management and protection of private, domestic and irrigation water sources are under the control of the landowner, and therefore, depend primarily on education rather than regulation.
The U.S. Geological Survey (DeSimone et al. 2009) recently reported that nitrate was the most commonly detected contaminant in private wells derived from man-made sources at concentrations greater than the EPA Maximum Contaminant Levels (MCL) for public water supplies. A second finding potentially affecting a greater portion of the population was that total coliform bacteria, a broad group that includes bacteria from soil, water and animal feces, were detected in 34% of sampled wells. The MCLG for coliform bacteria, including Escherichia coli, in drinking water is zero because this group is a predictor of the probable presence of pathogenic bacteria.
These broad findings of the USGS study are similar to those reported in Texas. For 2003-2008, the Texas Water Development Board reported that for the 3,861 private water wells sampled, the percentage of wells exceeding the nitrate MCL varied from 2% to 50% each year, depending on which regions of Texas were targeted for sampling. Additionally, results of well screenings conducted by the Texas AgriLife Extension Service from 2003-2009 indicate that about 33% of private wells in Texas contain fecal coliform bacteria.
TEX*A*Syst is a series of publications developed in 1996 to help rural residents assess the risk of groundwater pollution, and to describe BMPs that can help protect groundwater. The TEX*A*Syst publications were developed roughly 15 years ago and require updating to reflect current laws and regulations guiding private well maintenance and management, and development of improved BMPs for protecting ground water. The two categories of the most common private well pollutants, fecal coliform bacteria and nutrients, also are the most frequent cause of stream impairment or concern in Texas. It is likely that in many cases, local release of fecal coliform bacteria and nutrients is not limited to contamination of the property owner's private well and that these contaminants are transported off-site and contribute to pollutant loadings in surface waterbodies.
To address these issues affecting both surface and groundwater, SCSC, BAEN and TWRI will develop the Texas Well Owner Network (TWON) designed to deliver a science-based, community-responsive education curriculum. The TWON will focus on protecting groundwater quality and aquifer integrity, but also will complement the successful Texas Watershed Stewards program by emphasizing BMPs addressing potential contamination of surface water by sources also contaminating private domestic and irrigation wells and jeopardizing aquifer integrity. The TWON will train Texans regarding water quality and BMPs for protecting their wells and surface waters, which will avert off-site transport of contaminants (bacteria and nutrients) to surface waters, prevent contamination of underlying aquifers, and safeguard the health of landowners and their families. As a result, this program will support on-going watershed protection planning efforts being conducted by TSSWCB and others by expanding the reach of these programs to additional audiences and resulting in greater implementation of BMPs for water quality improvement and protection.