Fast Facts
  • There's no lead in our water.
  • We're in compliance with lead regulations (see our data).
  • We're working to create a database of all service lines - both ours and the customer side too. Call us to see if we have data about the service line serving your home (843) 727-6800.
  • No schools are served by lead service lines.
  • We 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 reduce or prevent lead contamination by adjusting the pH / 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 lead service line.

Is lead regulated?

What are the results of CWS lead testing?
Our most recent lead testing (July 2021*) included samples from 50 homes with lead service lines and/or plumbing components:

  • 40 homes - no lead detected
  • 10 homes - trace levels of lead detected; highest was 19 ppb
  • 90th percentile result was 2.1 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 were only required to conduct lead sampling once every three years through 2021. Future sampling will occur annually.

How do I know if I have a lead service line or plumbing?
Some service lines (pipes that carry water from our water mains to homes) and plumbing components are made of lead or have lead components.

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

Lead pipe scratch test
Lead pipe scratch test (appears silver when scratched with a coin).

If you're unsure if you have a lead service line, call us at (843) 727-6800 or email customerservice@charlestoncpw.com.

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

We'll replace our portion of a lead service line (between the water main and water meter) if we find it during field work or at a customer's request.

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

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 3-5 min.