The city of Asheville stressed that its distribution pipes do not contain lead, and it has no detectable lead in its main reservoir. (Photo: Starr Sariego for the Asheville Watchdog)
This report was first published by Asheville Watchdog.
Two independent chemistry experts say lead could be more widespread in Asheville’s drinking water following Tropical Storm Helene than the city has suggested and both call for more public education and testing.
Sally Wasileski, chair of the UNC Asheville chemistry department, and Abigail Cantor, a chemical engineer and president of Process Research Solutions, LLC, which consults on municipal water issues, said they recommend residents of homes built in or before 1988, when lead was banned in new plumbing, use bottled water until they test their water.
“We cannot risk widespread lead poisoning, especially on top of all that our community has faced in the wake of Helene,” Wasileski wrote in a letter to the media and larger community in November. “We need a broad investigation of the lead levels at the tap of residences, schools, and businesses who source their water from Asheville City Water.”
Cantor, who lives in Madison, Wisconsin, has relatives in Asheville and said she warned them about the risk of lead in the water.
“I’ve told them not to drink the water yet, until I test their water,” Cantor said.
Wasileski and Cantor reached out to Asheville Watchdog independently of each other and stressed a measured approach and the need to base decisions on test results.
“I understand that it is very important to not cause a panic,” Wasileski wrote in her letter. “Yet clear and effective communication, and widespread testing will ensure that there is not a second crisis across Asheville and Buncombe County.”
Asheville Water Resources Department spokesperson Clay Chandler said city water is safe to drink.
“The water meets EPA drinking water standards and is acceptable for consumption,” Chandler said.
“If a customer is pregnant, nursing, or has children under 6 years of age, and has concerns about lead exposure, they’re free to use bottled water for consumption or install a filter certified by the National Sanitation Foundation to reduce lead,” Chandler said.
The city also stressed that its distribution pipes do not contain lead, and it has no detectable lead in its main reservoir.
James Pinckney, an EPA spokesperson, said the agency continues to work closely with Asheville and the North Carolina Department of Environmental Quality on their response efforts, “including their plans to test and report on lead.
“The city has not violated the Safe Drinking Water Act’s Lead and Copper Rule at this time, and they are voluntarily conducting investigative lead sampling in the system post-hurricane to evaluate the aftereffects that the hurricane has had on the system and ensure the safety of the residents,” Pinckney said.
Lead is a powerful neurotoxin that can cause developmental problems in children. No level is safe in a water system.
Since the city announced Nov. 14 the presence of lead in the water of seven schools, it has received more than 5,000 requests for home lead testing kits. It takes four to six weeks to receive the results.
Lead levels rise in pipes when water has been sitting for a while. The city has stressed the importance of flushing residential plumbing lines for 30 seconds to two minutes to help remove lead.
Lead mitigation halted for 19 days
The city normally treats for lead with zinc orthophosphate and sodium bicarbonate. The minerals coat the insides of pipes, with the zinc material absorbing the lead and keeping it from reacting with water; the bicarbonate helps with pH levels.
The corrosion control treatment prevents lead, used in solder in pipes in homes and buildings built in 1988 or before, from leaching into the water. Some older homes also have lead pipe service lines. The city has said about 60 percent of Asheville homes were built in 1988 or earlier.
The Asheville Water Resources Department said in mid-November that it had stopped the treatment for 19 days in October as it worked to restore water following Helene.
The treatment was suspended because sedimentation at North Fork Reservoir, the city’s main water source, was unusually high and the city was using a bypass line to get water out. Treatment resumed Oct. 30, but it can take a month or more to become effective again, the city said.
The city returned non-potable water to most customers by mid-October but told them to use bottled water for consumption — unless they had no access to it, in which case they could boil the tap water for at least a minute before consuming. Boiling water does not remove lead, which has no taste or smell.
Water Resources received initial lead test results Nov. 4 and final ones Nov. 8. The city shared those Nov. 14, announcing seven local schools tested positive for lead.
Chandler emphasized that out of 25 sites tested at schools, those seven had detectable lead levels “on the first draw — meaning, water that had been sitting stagnant for multiple weeks was tested straight out of the pipe, with no flushing beforehand.
“After a 30-second flush, six of those fell below detectable levels,” Chandler said.
Water Resources and Dr. Jennifer Mullendore, medical director for Buncombe County’s Department of Health & Human Services, stressed that students were not exposed to lead, and there have been no reports of students with lead in their bloodstream.
The coating in pipes is the key
A key concern for Wasileski and Cantor is the damage or compromise that the protective coating of zinc orthophosphate may have sustained during the water outage and the suspension of treatment.
In her letter, Wasileski noted that water chemistry is complex and “changes due to factors like pH, oxygen content, chlorination, temperature, mineral levels.”
“Any small breaks in this protective coating would now enable water to come in direct contact with lead metal in the pipes and fixtures, and cause this lead to corrode and leach into the water flowing into and through home plumbing,” Wasileski said, citing EPA information. “What is unclear is how much damage to this protective layer can be caused by the 19-day lapse in corrosion control.”
Wasileski did note that most case studies of elevated lead levels “are from plumbing damage over longer periods of time.
“Even in these cases, the extent of lead corrosion was highly variable as the protective coating of some fixtures and pipes had more breaks (and leached more lead) than others,” Wasileski wrote.
The city’s positive results for lead, she noted, were “well above the amount of lead recommended for action by the American Academy of Pediatrics.Â
“The new lead test results indicate the likelihood of damage to the protective coatings in these schools’ plumbing and fixtures, or damage to their water service lines,” Wasileski wrote. “In addition to the risk of lead in water at these schools, these results also indicate the potential for more widespread damage to plumbing in residences and businesses across the city.”
The risk of exposure, Wasileski said, remains because “it is well known that the time it takes to regenerate this protective layer once corrosion control has resumed is highly variable and can take years to form.” She cited an EPA document in her letter.
Chandler, citing guidance from the EPA, said coating regeneration takes 30 to 90 days.
Cantor, who has been a consulting engineer since 1981 and has specialized in distribution system water quality since 1991, said she agreed with Wasileski’s call for more lead testing in water and for people via blood tests. She’d also like to see better communication and a recommendation that people in older homes not drink tap water until they test for lead.
While zinc orthophosphate can form a protective film on the pipe walls that will slow down or stop further corrosion of the pipe, Cantor said, “if pipe walls are already obscured with chemical scales and biofilms, that protective layer cannot form properly.”
She says this applies to all pipes in a water system, whether city-owned or privately owned, although most significant sources of lead occur in private plumbing.
Water in municipal systems is a mixture of chemicals, microorganisms, minerals and organic matter that interact with biofilms and chemicals on pipe surfaces. Biofilms emit secretions and chemical byproducts that can alter the water chemistry in the distribution system, leading to corrosion of pipe metal.
Cantor said the interactions can cause problems with water quality, including lead and copper release.
Another factor to consider, Cantor said, is that federal regulations require measuring total lead concentration in water — the dissolved lead plus lead in particulate form. But the orthophosphate treatment controls only the dissolved lead concentration.
If the lead is in particulate form, it has been released from pipe accumulations, not from metal corrosion directly.
“It is from release of pipe wall accumulations where the lead has been trapped,” Cantor said. “Orthophosphate will not remedy that situation. Orthophosphate is irrelevant to controlling particulate lead.”
That’s why thorough flushing is key, Cantor said. She recommends the city engage in a program of intense water main flushing throughout the system, and that it continues with the zinc orthophosphate program, as it does offer some protection. Customers should also intensely flush their own homes.
Asheville’s water likely sat in pipes for days or weeks, and that “great stagnation of water,” followed by the introduction of partially treated water, likely “disturbed pipe wall accumulations and released trapped particulate lead in residences and larger buildings such as schools,” Cantor said.
Chandler said predicting how much the city’s corrosion control was compromised is not possible.
“The potential exists that the corrosion control layer did begin to break down,” Chandler said. “The testing performed at the city and county elementary schools, participating child care facilities, private schools and the private residence show a potential for breakdown, but since only seven of 25 sites tested showed a detection — and only one showed a detection after a 30-second flush — it does not point toward a complete breakdown in corrosion control during that 19-day period.”
After Helene washed out the two main transmission lines from North Fork and a backup bypass line, the city focused on restoring service as quickly as possible.
“Once our infrastructure was rebuilt, our sole option was to provide hyperchlorinated raw water for critical fire protection and basic sanitation,” Chandler said, noting the water’s condition necessitated a boil water notice. “Throughout the boil water notice, we recommended bottled water for consumption.”
That guidance came directly from the North Carolina Department of Environmental Quality and the federal EPA, Chandler said.
Before lifting the boil water notice Nov. 18, the city tested water throughout the distribution system, and results showed zinc orthophosphate had reached every part of the system. Under EPA guidance, the city increased the zinc orthophosphate from the normal 2.0 parts per million level to 3.5 ppm “to expedite rebuilding the corrosion control layer,” Chandler said.
North Carolina Department of Environmental Quality spokesperson Josh Kastrinsky said its Public Water Supply section “is aware that Asheville has collected some samples outside of its regular compliance schedule at schools and homes.
“The city is taking another round of samples at Buncombe County schools,” Kastrinsky said. “They are developing a plan to respond to the requests for sampling and reaching out to laboratories to determine capacity. Asheville has been coordinating with EPA on potential sampling options. They should provide sampling results to DEQ, when available.”
Kastrinsky noted that Asheville was on a three-year monitoring schedule and collected 50 samples between June and July of this year.
“None of the samples were above the action level for lead or copper,” Kastrinsky said, noting that one sample was at the lead action level of .015 mg per liter. “At this time, Asheville is in compliance with the federal Lead and Copper Rule and has not been issued any citations or warnings related to lead.”
The importance of flushing pipes
Corrosion control is important, Chandler said, but “the easiest and best way to reduce risk of lead exposure is to flush your system” for 30 seconds to two minutes.
The first step to keeping plumbing clean at the user level is to routinely clean water mains, Cantor said.
The zinc orthophosphate should combine with lead, forming a highly insoluble solid that stays on the pipe and forms a protective layer. But that’s if the pipes are relatively clean.
“What I’ve seen is that pipe walls have so much accumulation of chemical scales and biofilms that the orthophosphate has nowhere to lay down a protective layer,” Cantor said.
She also recommends that homeowners conduct a thorough flushing of their own homes, letting the water run out an outdoor tap first and then running taps on the first floor and then the second. Because plumbing varies from house to house, Cantor declined to give a timeframe on how long to flush.
Wasileski wants to see clearer and more widespread messaging from the city. She recommends widespread testing at the tap for both lead and copper at residences and businesses built before 1988.
She also recommends that residents in these homes use only bottled water until they get lead test results back and advocates immediate blood tests for lead for anyone that consumed tap water since water service returned in mid-October.
“And the need is even higher for children, pregnant or breastfeeding women, and especially for any infants who consumed formula prepared from boiled tap water,” Wasileski said.
She recommends checking the type of water service line to your home by visiting the city’s web page on the issue. That page shows the type of pipe used for service lines and if it contains lead.
More information on the lead issue
The City of Asheville’s webpage on lead and copper testing encourages flushing pipes for 30 seconds to two minutes daily.
“According to guidance from the EPA, flushing is a short-term solution that can be used to reduce potential lead and copper presence in drinking water,” the site states. “Depending on pipe materials, lead and copper may be found in water that has sat undisturbed in household plumbing for 4-6 hours.”
Buncombe County also has a page dedicated to lead awareness and the recent testing issues, titled, “Lead Awareness and Your Health: Q&A with Buncombe County’s Medical Director.”
It states: “Out of an abundance of caution, children under 6, pregnant people, and breastfeeding people who have consumed tap water while the City of Asheville water customers were under a Boil Water Notice, and have concerns, should consult their healthcare providers. If they do not have a doctor, they can call the Buncombe County Blood Lead Information Line at 828-250-5205.”
Asheville Watchdog is a nonprofit news team producing stories that matter to Asheville and Buncombe County. Sally Kestin is a Pulitzer Prize-winning investigative reporter. Email skestin@avlwatchdog.org. To show your support for this vital public service go to avlwatchdog.org/donate.