Editor's Note: This story was originally posted Nov. 18 and has been updated with new information on lead testing in homes around Asheville.
Asheville residents have drinkable tap water for the first time in more than seven weeks after flooding and landslides during Hurricane Helene destroyed critical infrastructure.
Water Resources spokesperson Clay Chandler said the city tested 120 water samples this weekend, and the results showed no bacteria in the water, paving the way for the boil water notice to be lifted.
Here are answers to frequently asked questions about safety, system repairs, and more.
Is Asheville's water safe to drink, bathe, and cook with?
The water is now safe for consumption and hygiene, Chandler said.
The city, he said, has been flushing the system of untreated water for about 10 days.
No raw, or untreated water, has been in the system since November 9, and crews will disassemble the raw water pipeline over the weekend.
"The return to potable water was gradual," Assistant City Manager Ben Woody said at the briefing on Nov. 19. "We feel confident about the return to that treated water to our distribution system."
The municipal water system is "heavily regulated" by state and federal authorities, he said.
"We would not have lifted the boil water notice if we didn't feel confident that we are delivering the highest quality drinking water to our customers in Asheville," Woody said.
What about the risk of lead in the water?
Although recent water testing confirms there’s no lead in the city of Asheville’s water supply, if you live in a home built before the mid-1980s, you can lower possible risks by flushing your pipes for at least 30 seconds, officials said on Dec. 9.
In mid-November, city officials said there was no finding of lead in the source water at North Fork. There were some findings of lead at local elementary schools.
The city typically takes preventative measures to deter corrosion that can cause lead to leach into the water, but the damage from Hurricane Helene interfered with the process.
For about 19 days after the storm, the city was unable to put zinc orthophosphate, a substance put into municipal water regularly to inhibit corrosion in pipes, into the system at North Fork. The piping configuration did not allow for the treatment, Chandler said.
Corrosion deterrence measures continued at the Mills River facility after the storm. The city resumed anticorrosive treatment at North Fork beginning Oct. 30, according to the city.
It can take anywhere from one to three months for the anticorrosive mechanism to take effect, Water Resources Compliance Manager Brenna Cook said.
Homes built before the mid-1980's are at higher risk of lead leaching from pipes. Water that sits for 4 to 6 hours are at higher risk as well.
EPA guidance identifies this flushing process as a short-term solution for removing lead or copper from water.
The city will continue to test for lead in the system, Woody said. The testing is conducted by an outside firm, and results take 4-6 weeks.
Residents can request a free lead testing test by calling 828-259-5962 or emailing leadprevention@ashevillenc.gov. Find more on the lead issues here.
What about at-home testing?
If a customer wants to pay for independent testing, the state Department of Health and Human Services lists certified labs, Cook said on Nov 19.
Cook cautioned customers not to use at-home tests ordered online.
But what about the turbidity?
The storm churned up the turbidity, or cloudiness caused by sediment, at the North Fork Reservoir. Turbidity is measured in nephelometric turbidity units (ntu).
In typical circumstances, water resources officials look for turbidity of less than 2 ntu. The storm left the reservoir with levels above 90 ntu.
The filtration system at North Fork is not designed to handle water with high turbidity levels. Officials initially said the turbidity level would need to drop to less than 2 ntu in order to be filtered by the system.
But in late October, water resources began pushing water through the system, even though turbidity levels remained in the low-20s and high teens.
As of November 18, the turbidity level dropped to 14.5 ntu.
The filters were able to handle water with higher levels of turbidity than experts originally estimated.
Water in the system is back to pre-storm levels of .1 ntu.
And what about the flushing?
The system was able to be flushed starting at the end of October with the return of treated water to the system, Chandler said.
"We didn't have to do it at the volume we thought we were going to. We have been opening hydrants here and there as this process has been ongoing and that has proven sufficient to turn the system over," he said at a briefing on Nov. 18.
"All the raw water initially put in the system has been replaced with treated water," Chandler said.
Are there special instructions now that potable water returned?
Icemakers and water heaters that may have been turned off may be turned back on, Chandler said, but it is important that customers check with their manufacturers for restart instructions if appliances have been inactive for an extended period of time.
On Nov. 19, Cook advised customers to make ice three times before using it.
How did we get here?
Hurricane Helene devastated infrastructure across Western North Carolina. In Asheville, the storm wrecked the water system, leaving residents without any water for several weeks.
About two weeks after the storm, nonpotable water returned to the taps, but potable water remained a challenge.
Last week, Water Resources also identified lead issues in some Asheville schools' water supplies. The issue is a result of pipes in the school system, and no lead was found in water samples from the source at North Fork.
What was the problem at North Fork?
Typically, about 80% of the city's water system's customers are served with water from the North Fork Reservoir.
Once one of the most pristine water sources in the country, North Fork was turned upside down by Hurricane Helene.
In addition, one of the main lines at North Fork was damaged in the storm. Water resources had to construct a new bypass line in order to get the system up and running again.
But isn't Mills River working?
Yes. Mills River produces about 3.5 million gallons of water per day.
Demand for the entire water system in Asheville is typically 20-25 million gallons per day.
How was the issue addressed?
The first plan was to treat the water with two substances: (1) aluminum sulfate and (2) caustic soda.
Is aluminum sulfate (Al₂(SO₄)₃) safe?
Yes. "A lot of water treatment facilities will have aluminum sulfate," Alan D. Steinman, professor at Grand Valley State University's Annis Water Resources Institute, told BPR.
"Alum treatment has been done on hundreds, if not thousands, of lakes around the world," he said.
Most drinking water treatment plants apply alum as the last step of their treatment process," lake management consultant and Lake Advocates co-founder Dick Osgood told BPR.
What is the second plan?
The second plan, announced at the end of October, is for the U.S. Army Corps of Engineers (USACE) to build mobile filtration systems at the North Fork facility.
The units will provide filtration of about 15 million gallons of water a day. The USACE buildout is expected to take 35 days, and the project remains on track, Chandler said on Nov. 15.
Why didn't they do the additional filtration system earlier?
Until late October, the USACE and other experts were not sure the units would be able to handle the volume of water required by the system, Chandler said.
What does rain do?
A heavy rain with wind could churn up more turbidity, but a "normal, straight down rain" helps the sediment settle, Chandler said.
What level of chlorination is the city using?
Previously, the city was hyperchlorinating, Chandler said. "That's the only thing we're adding to it before pushing it out into the system."
Immediately after the storm, the city chlorinated the water at eight parts per million, but reduced to six parts per million.
Decisions about chlorination levels are made in conjunction with the Environmental Protection Agency (EPA) and the North Carolina Department of Environmental Quality (DEQ).
On Nov. 18, Chandler said the chlorination level returned to the normal level of about two parts per million.
What kind of testing is the city doing on the water?
The city tests daily for bacteria and metals.
The boil water notice issued previously in Asheville was not due to bacteria, but rather from increased sediment in the water.
The EPA sets two different standards for different aspects of drinking water:
1. Primary Maximum Contaminant Limits: These are regulated under state and federal laws and include elements like Coliform bacteria and E. Coli.
"No more no more than 5% of your bacterial test can come back positive for choliform. Anything more than 5% and that's when the trigger kicks in and you're under boil water notice," Chandler said.
2. National Secondary Drinking Water Regulations: This includes elements like iron, manganese and aluminum. The EPA provided exceptions on some of the levels in the immediate aftermath of the storm, Chandler said.
All test results from the sampling during the weekend of Nov. 15 returned negative.
Test results are publicly available here.
Why is the water brown or yellow?
Despite the chlorination, the sediment in the water made it appear cloudy.
"If your water is brown, that's the iron. If your water is yellow, that's the manganese and the aluminum that's naturally occurring," Chandler said.
Why did the city call or text me every day with the same information?
State and federal regulations require the communication of a boil water notice to customers. The city will be assessed on how it communicated the messages to customers, Chandler said, so officials opted for daily voicemails, texts and emails to make sure they informed as many residents as possible.
What about my bill? Do I have to pay for the nonpotable water?
No. Chandler told BPR the department would not charge for the period without potable water.
The department must check water meters since the lifting of the boil water notice in order to resume billing. About 30% of the city's meters can be checked remotely, he said. Water resources staff will check water the remaining 70% of meters to resume residential billing.
This story was updated to reflect daily water use and to include questions and answers about lead testing.
