Well owners who drink water from a private well should have the water tested at least once a year to make sure that it is safe to drink. The Texas Well Owner Network (TWON) recommends that well owners test their water at least annually for bacteria, nitrates and contaminants of local concern, such as arsenic.
Coliform bacteria are a large group of many kinds of bacteria, including fecal coliform bacteria, which occur naturally in the intestines of warm-blooded animals. The group also includes non-fecal coliform bacteria. One species of fecal coliform bacteria is Escherichia coli (E. coli). If E. coli or other fecal coliform bacteria are in well water, the water has come into contact with human or animal waste and could cause disease.
Private well owners can have their water tested at their county health department or a local lab. To find a drinking water laboratory, call the local health department or select from a list of National Environmental Laboratory Accreditation Program (NELAC) certified drinking water laboratories. For help determining tests for your specific area or interpreting the test results, ask the lab that conducted the test or your county health department.
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