Chemistry professor urges further evaluation of lead levels in Asheville’s drinking water

I am writing as both a chemist and as a resident of Buncombe County, who works in and has a child who attends school in the Asheville City Water Resources distribution area, to urge you to investigate and promote to the public the critical importance of addressing the recent positive test results for lead, and what that means for potentially more widespread prevalence of lead in drinking water across the Asheville City Water distribution system.

Following the catastrophic impacts on the Asheville City Water system, it was shared on news media [for example, Mountain Xpress] and Buncombe County Press Briefings (November 14) that Asheville Water Resources suspended corrosion control treatment (orthophosphate additive) for 19 days, during a time when raw water from the North Fork Reservoir was directly input into City Water distribution lines.  The degree of chlorination was also significantly increased.  Both of these measures were done to address public health concerns from having no access to running water across the water service area, the inability to flush household toilets, and the need for widespread fire suppression.

However, suspending corrosion control has the potential to cause a new problem for Asheville City Water system residents:  the leaching of lead (Pb) into drinking water resulting from changes in the integrity of private plumbing without this corrosion control.  Understanding the impact of changes in water chemistry is important to understanding why suspending suppression control is now a problem.

As has been shared already in the media, 60% of Asheville city residents own homes built before 1988.  Before 1988, lead was commonly used in pipes, faucets, plumbing fixtures, and the solder joints of indoor plumbing [CDC].  In addition, lead is a common material for plumbing service lines connecting homes to water distribution lines.

What has been keeping our older homes, businesses, and schools from having elevated lead in their water is that, over time, pipes and fixtures have developed a thin protective coating that prevents the direct contact of water with the metal (lead, copper, etc).  The orthophosphate corrosion control treatment helps to maintain this protective coating!  (Reference, EPA)

Water chemistry is very complex; changes due to factors like pH, oxygen content, chlorination, temperature, mineral levels, and corrosion control measures can cause chemical reactions that disrupt this protective coating.  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.  (Reference, EPA)

What is unclear is how much damage to this protective layer can be caused by the 19 day lapse in corrosion control (most of the case studies of elevated lead from changes in water chemistry in Washington DC, Flint MI, Greensboro NC etc. 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.

Yet, recent test results of water collected on October 17 and again on October 24, 2024 at area elementary schools (early in the time period without corrosion control and with elevated chlorination) show levels of lead above the action limit at schools where prior lead test results were well below the action limit, and well above the amount of lead recommended for action by the American Academy of Pediatrics.  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.  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.

And although orthophosphate corrosion control has now been resumed across the water system, 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.  (Reference, EPA)

My email message today is to help explain the chemistry reasons behind why the schools had positive tests now for the first time, and why potential damage to private plumbing could be much more widespread than just to those schools that were tested.  And it is a request for you to call for action for wider sharing of information in order to protect the public.

Addressing this problem with consistent and transparent messaging is critically important, especially as the boil water notice has been lifted and residents across Asheville may begin to consume water from their homes.  Widespread compliance of the new addition to the alert to flush for 30 seconds to 2 minutes on a daily basis is insufficient without proper public education of why this is important, how it works, and long-term solutions.

The City of Asheville Water Resources has recently posted information on their website, (including mitigation measures for those schools who have already tested positive, guidance to flush water through pipes before boiling and consuming, encouragement for homeowners to research the composition of their service lines and to test for lead in their water, and for children or pregnant or breastfeeding women who consumed any water since the storm to get tested for lead).  These steps need to be disseminated clearly and transparently to the public to facilitate widespread adoption, as there is a legal responsibility from the EPA Lead and Copper Rule.

We can not risk widespread lead poisoning, especially on top of all that our community has faced in the wake of Helene.  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.

This includes:

A. Widespread testing at the tap (for both lead and copper) of residences and businesses built before 1988 and/or which have lead-containing (or unknown) water service lines.

B.  Clear and effective education and outreach to the public on the following;

• How the integrity of their home plumbing could have been impacted by the recent challenges faced by Asheville City Water and the decisions to suspend corrosion control.  And how the damage is longer-term, and won’t be immediately resolved as we have resumed corrosion control.
• How to determine the type of water service line to your home, from this website https://experience.arcgis.com/experience/ef566666b9f74e9ab65d4616b93fbdf9 or what to do if your service line is unknown.
• The importance of testing the water they drink and cook with – at the tap.  Residents can get a free lead test to test their water ( call 828-259-5962 or email leadprevention@ashevillenc.gov)
• The proper procedures for collecting water samples for testing.  The sampling procedures include several samples:  (1) water that has been sitting stagnant in the fixture (first draw), which indicates lead leaching within the plumbing fixtures.  (2) water after flushing for 30 seconds, which indicates lead leaching from the service line.
• To drink and cook with only bottled water until they get test results.  Boiling water will not remove lead.  And even with the boil water notice now lifted, there is still a need to get water from water distribution sites across the city and county.
• The immediate need for blood tests for lead for anyone that consumed tap water since water service returned in mid October (i.e., those that boiled their water before consumption).  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.
• Information on next steps if water test results return positive for lead, including industry standards for household water filtration systems for removing lead (NSF/ANSI-53 Pb-certified).

The Press Briefings from Thursday, November 14 and Friday, November 15 from Asheville City Water did not effectively communicate the scope of potential problems that residents are facing.  Their focus on the test results of undetectable levels of lead at the water source and how the source of any positive test is from the private side of the water system did not clearly and transparently communicate that elevated lead tests could be a new problem caused by city water flowing into homes without corrosion control.  Additionally, in the Press Briefing from November 18, the boil water notice was lifted and stated that “normal use for consumption and hygiene may resume”.

Further advice was given for customers with homes before 1988 to follow guidance that they have been giving “all along” about flushing water through taps before consuming; and it was shared that elementary school lead results were due to water sitting in the pipes and not from their source water or changes in water chemistry.  These briefings and notices from the ashevillenc.gov website are grossly insufficient, both to address the gravity of this issue and to let the public know that there is the potential for a new problem that they did not have to deal with before.  Their focus on the lack of presence of lead in the distribution system does not clearly and transparently identify new potential risks for their water consumers.  Advice on flushing alone is poor public policy.

I understand that it is very important to not cause a panic.  Yet clear and effective communication, and widespread testing will ensure that there is not a second crisis across Asheville and Buncombe County.  There is no safe level of lead in drinking water.  Please help promote the need for testing home water, blood tests for those who consumed water, and communication on potential impacts to private plumbing systems.

Let me be clear.  While the source of lead that has been measured already in our elementary schools water samples (and any future positive tests results from Asheville residences) is from the plumbing itself and not from the source water, the action of disrupting the water chemistry by lapse in corrosion control is a likely enough cause to warrant further investigation.  Under these circumstances, we can not assume that the lead was only leached from stagnant water in old pipes and not from changes in corrosion control.  And, just because the orthophosphate treatment has started up again, it doesn’t mean that we don’t have to be concerned about long-term damage to our residential & private plumbing infrastructure.

I wouldn’t want to be the one who tells people that their water is safe to drink, without further testing for lead.  A more comprehensive approach and widespread communication to address this issue is needed.

Thank you,

Sally A. Wasileski Schmeltzer, PhD Chemistry

Resources:

About Lead in Drinking Water | Childhood Lead Poisoning Prevention | CDC

Optimal Corrosion Control Treatment Evaluation Technical Recommendations for Primacy Agencies and Public Water Systems, EPA

Measuring the benefit of orthophosphate treatment on lead in drinking water | Journal of Water and Health | IWA Publishing

https://www.youtube.com/watch?v=LC6OJ92-uEI

American Academy of Pediatrics policy statement on Prevention of Childhood Lead Toxicity