A new rule on lead and copper for the U.S. drinking water system is under consideration at the Environmental Protection Agency, the first update to these standards in over 30 years.
If finalized as expected this June, the rule will make local water utilities across the country create maps for the public to show where lead is located in underground water systems.
That has officials at Charleston Water System retracing old records that were kept for decades on small paper cards and developing a website to show where lead and copper lines are located. There are about 4,500 known lead service lines in the CWS system and 7,000 lines of unknown material.
Officials at the utility have a basic version of the map already, but don't have a date for when the public will be able to use it.
Sometimes lead lines show up only when work disturbs them.
In water main rehabilitation projects over the last few years, CWS has worked to scrape the inside of and re-line about 29,000 feet of water mains, mostly on the Charleston Peninsula. The most recent phase was still under construction as of mid-May in the area around Warren Street.
Occasionally during the work the water utility found previously unidentified lead distribution lines. None of the mains are made of lead, but some of the pipes that lead to individual homes or businesses may be. About seven were found and replaced during this latest phase of work, CWS spokesman Mike Saia said.
CWS automatically schedules a replacement for lead lines in their system when they find them during work, Director of Water Distribution Kan Oberoi said. If a lead pipe is found between a water meter and a customer's house, however, that's the homeowner's responsibility to replace.
Lead, a highly flexible metal, was the material of choice of many plumbing systems in the first part of the last century. But it is toxic to humans, targeting the nervous system with particularly harmful effects on children whose bodies and brains are still growing.
"Lead can affect almost every organ and system in your body," according to the Centers for Disease Control and Prevention.
The EPA right now allows a small amount of lead in public water systems before action has to be taken, but no amount is safe to consume.
Copper, meanwhile, is an essential element for humans to consume in small amounts, but too much can cause liver or kidney damage or even death, according to the CDC.
The new lead and copper rule will force action to remove or mitigate sources of lead and copper at lower concentrations and mandate water testing in schools and childcare centers. In Charleston, no schools have lead service lines connecting them to the system, according to CWS.
The first version of the lead and copper rule was passed in 1991. When CWS started testing for lead in its water system the next year, it found some of the highest levels anywhere in the country, spokesman Saia said. Levels were as high as 211 parts per billion; the EPA's limit is 15 ppb.
But since 1994, lead levels in Charleston drinking water have been consistently measured below that limit for two reasons. CWS carefully controls the Ph of its water, so the supply is not acidic and less likely to leach metal out of pipes. It also adds orthophosphate, a compound that coats the inside of lines over time so the water running through isn't in direct contact with the material of the pipes.
"We want to make sure that even if you have lead lines in the systems, the lead will not affect the customers, the lead will not transmit to the water," Oberoi said.
CWS also offers free water testing to any customer who wants to sample for lead inside their home. More information is available by calling 843-727-6800.