We're in compliance with lead regulations and offer free lead testing upon request. 

How does lead get into drinking water?
Lead does not occur naturally in water. It comes from lead pipes or plumbing materials. Although lead pipes and solder are banned, homes built before 1986 may still have lead plumbing.

What keeps lead out of drinking water?
We prevent lead contamination by reducing the corrosiveness of our water and by adding orthophosphate during water treatment, which forms a thin protective coating inside pipes.

Lead Service Line - Orthophosphate Lining
The orthophosphate coating is visible inside this old lead service line.

Is lead regulated?
Yes, the US EPA's Lead and Copper Rule requires utilities to test drinking water from a sampling of homes that have lead service lines or plumbing. Lead levels must be below 15 parts per billion (ppb) for 90% of the samples tested -- this is called the 90th percentile result. If a utility exceeds that 15 ppb level, then further action is required, including public notification/education.

Does CWS meet lead regulations?
Yes, our lead levels are well below the 15 ppb action level.
History of CWS compliance with the Lead and Copper Rule (PDF)

What are the results of CWS's lead testing?

Results of our most recent lead testing (August 2018*) included samples from 51 homes with lead service lines and/or plumbing components:

  • 33 homes - no lead detected
  • 17 homes - trace levels of lead detected; highest was 11 ppb
  • 90th percentile result was 2.3 ppb, which is well below the 15 ppb action level

*Because our lead levels have remained consistently low as a result of our corrosion control measures, we are required to conduct lead sampling once every three years. Future sampling will occur in 2021, 2024, etc.

How do I know if I have a lead service line or plumbing?
Our water mains are not made of lead, but some service lines (small pipes that carry water from our water mains to homes) and plumbing components are made of lead.

Homes built before 1932 may have a lead service line, and those built before 1986 may have lead plumbing components.

Lead pipes have a dull gray appearance. The scratch test is an easy way to identify lead. Use a coin to scratch the pipe surface. If the scratch appears bright silver, it’s lead. 
Lead pipe scratch test
Lead pipe scratch test. Lead appears bright silver when scratched with a coin.

If you're unsure whether you have a lead service line, call us at 843-727-6800 or email customerservice@charlestoncpw.com for more information.

If I have a lead service line, will you replace it?

We will replace our portion of a lead service line, which is located between the water main and the water meter, if we discover it during the course of field work or at a customer's request. 

We do not replace the customers' portion of the service line, which is located between the water meter and the home, as this is part of a customer's private plumbing system.

How can I reduce my risk of lead exposure if I think I have lead plumbing?

  • Use cold water for cooking, drinking, and mixing infant formula. Lead is less likely to corrode into cold water.
  • If water sits in your pipes for an extended period of time, such as overnight, while you're at work, or when you're on vacation, flush your plumbing by letting cold water run for 1-2 min.
Will Charleston Water System test my water for lead?
Yes, we provide free lead testing upon request. Call (843) 727-6800 to request a testing kit or visit one of our Customer Service locations.