When Denton utility customers open their January water bill, they can expect to see a notice about the city’s failure to test the drinking water for lead and copper.
Fritz Schwalm, longtime laboratory manager for Denton Water Utilities, said he knows safe drinking water can be an emotionally charged issue. City employees are taking steps to do the required testing and to make sure they don’t ever miss a testing deadline again, he said.
The risk for lead and copper in Denton’s drinking water is considered low, Schwalm said. Periodic testing from 1993 to 2012 showed very low levels of copper and lead in Denton’s drinking water.
The maximum level of lead allowed in drinking water is 0.015 parts per million. Denton had 0.00168 ppm in 2012. The maximum level of copper allowed in drinking water is 1.3 ppm. Denton had 0.456 ppm in 2012.
Even though the utility missed the deadline to test in 2015, “there’s no reason to expect a change in the water,” Schwalm said.
Denton gets its drinking water from Ray Roberts Lake and Lewisville Lake. The city’s treatment keeps the water slightly alkaline, greatly reducing the risk of lead and copper leaching from old pipes, he said.
The Environmental Protection Agency wrote rules in 1991 to help address the problem of copper and lead leaching from old pipes.
Lead in drinking water can harm the brain, kidneys and red blood cells. Lead can be particularly harmful to pregnant women and young children because of the damage it can cause to brain cells.
Copper in drinking water can distress the stomach and intestines, damage the liver or kidneys and complicate Wilson’s disease, an inherited disorder in which excessive amounts of copper accumulate in the body.
To find out if a public water supply is corroding old pipes, the EPA requires testing of the tap water in people’s homes. How often, and where, a supplier tests depends on the system, Schwalm said.
In Denton’s case, lead and copper testing is required only every three years.
But nearly every public water supply is required to test in the summer. Warmer temperatures increase the risk of lead and copper leaching from old pipes, Schwalm said.
In other words, testing in the winter could miss a problem.
As a result, Denton’s lab won’t be sampling for lead and copper again until summer, he said.
The lab has a list of Denton homeowners who have collected samples in the past and are willing to do so again. In previous years, the city has collected 50 samples, but next summer it plans to collect 100, he said.
City employees cannot collect the samples, Schwalm said. They provide homeowners with instructions and a kit to collect the sample. To make sure the individual homeowner collects the best sample possible, the water must sit in the tap undisturbed for at least six hours and the homeowner must collect immediately upon turning on the tap.
The city’s failure to complete the job last summer was a “perfect storm” of circumstances that included changes at the state level, at other designated labs and in the city’s water department, Schwalm said. But water department employees are taking responsibility for their part.
“These things happen, but we don’t feel good about it,” Schwalm said.
The water department and the city lab monitor for other contaminants on prescribed schedules, too. Monitoring for “higher risk” contaminants, such as bacteria, occurs daily, for example.
Schwalm is writing a procedural plan to make sure the city starts gathering the lead and copper samples on time to complete the job.
If compliance with that testing requirement ultimately becomes his responsibility at the city laboratory, Schwalm said he’s OK with that.
He volunteered to take the calls from concerned customers, saying he also hopes to find more Denton homeowners willing to sample.
“I’m glad I’m the contact person,” Schwalm said.
The notices are tentatively scheduled to be distributed from Jan. 7 through Feb. 3. For more information, call Schwalm at 940-349-8615.