Private water well screening set for May 4 and 5 in Marfa 

MARFA — The Texas Well Owner Network is hosting a water well screening May 4 in Marfa to give area residents the opportunity to have their well water screened. A meeting will follow on May 5 to explain the results. 

The Well Informed water sample drop-off will be on Tuesday, May 4 from 8:30–10 a.m. at the Texas A&M AgriLife Extension Service office for Presidio County, or the Presidio County Underground Water Conservation District Office, both located at 300 N. Highland St. A meeting explaining screening results will be delivered to participants at 10 a.m. Wednesday, May 5, at the Alpine Civic Center, 100 N. 13 St., Alpine. 

The screening is presented by AgriLife Extension and Texas Water Resources Institute, or TWRI, in partnership with the AgriLife Extension office in Presidio County and the Presidio County Underground Water Conservation District. 

John Smith, AgriLife Extension program specialist – College Station, said area residents wanting to have their well water screened should pick up a sample bag, bottle and instructions from the AgriLife Extension office or underground water conservation district office. 

“It is very important that only sampling bags and bottles from the AgriLife Extension office be used and all instructions for proper sampling are followed to ensure accurate results,” Smith said. 

The samples must be turned in by 10 a.m. on Tuesday, May 4. The cost for each sample is $10. 

Smith said private water wells should be tested annually. Samples will be screened for contaminants, including total coliform bacteria, E. coli, nitrate-nitrogen, arsenic and salinity. 

Smith said research shows the presence of E. coli bacteria in water indicates that waste from humans or warm-blooded animals may have contaminated the water. Water contaminated with E. coli is more likely to also have pathogens present that can cause diarrhea, cramps, nausea or other symptoms. 

The presence of nitrate-nitrogen in well water is also a concern. 

“Water with nitrate-nitrogen at levels of 10 parts per million is considered unsafe for human consumption,” Smith said. “These nitrate levels above 10 parts per million can disrupt the ability of blood to carry oxygen throughout the body, resulting in a condition called methemoglobinemia. Infants less than 6 months of age and young livestock are most susceptible.” 

Salinity as measured by total dissolved solids will also be determined for each sample, he said. Water with high levels may leave deposits and have a salty taste. Using water with high levels for irrigation may damage soil or plants. 


Long-term consumption of arsenic in water, Smith said, increases the risk of skin cancer and cancer in the liver, bladder and lungs. In addition, chronic exposure to arsenic may lead to gastrointestinal irritation and cardiovascular disease. 

Smith said it is extremely important for those submitting samples to be at the Wednesday, May 5, meeting to receive results, learn corrective measures for identified problems and improve their understanding of private well management. 

For more information, please contact the AgriLife Extension office in Presidio County at 432- 729-4746 or the Presidio County Underground Water Conservation District at 432-295-2568. 

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