Water Quality

We provide clean, safe, award-winning drinking water that meets or exceeds all state and federal regulatory requirements. It is continually tested during the treatment process and throughout our water distribution system to ensure quality and safety.

Our lab performs thousands of water analyses per month. A summary of each year's water quality testing is provided in our annual water quality report, also known as the Consumer Confidence Report (CCR). This report is published each May and posted on this page.

Partnership For Safe WaterPartnership for Safe Water logo

We joined the Partnership in 1995, received the Directors Award in 2004, the Five Year Directors Award in 2008, and the 10 Year Directors Award in 2013.

The Partnership is a voluntary program for water utilities that commit to treating water beyond what's required by regulations. Sponsored by the US Environmental Protection Agency, the American Water Works Association, and other water organizations, the program focuses on helping surface water treatment plants optimize operations—specifically filtration. 

More than 200 utilities nationwide participate in the program, which has four phases of achievement: collection of turbidity data (a measure of the cloudiness of water), a self-assessment evaluation, and a peer review.

Area Wide Optimization Program (AWOP)

On the state level, the Department of Health and Environmental Control (SCDHEC) sponsors a program similar to the national Partnership program.

The Area Wide Optimization Program, or AWOP, and the goal is to support utilities in improving disinfection and particle removal for the benefit of public health.

Every year, DHEC recognizes water plants that go beyond the requirements of EPA regulations for drinking water. We were awarded this recognition in 2003 and again in 2007 for the performance of our Hanahan Water Treatment Plant.

Request A Water Quality Test

If you have a water quality concern or would like to request a water quality test, please call our Customer Service department at 843-727-6800 or send us an email.

Lead Testing

We reduce the corrosiveness of our water during the treatment process, which prevents lead from old plumbing from leaching into your water. However, if your home has old plumbing and/or solder, and you would like to test your water for lead, we offer testing free of charge. Just pick up a testing kit at our downtown or north area office locations. Learn more about lead and drinking water.

Drinking Water Fluoridation (

Position Statement


Adopted by the Board of Commissioners October 24, 2017

The Charleston Water System (CWS) supports the recommendations of the World Health Organization, American Medical Association, Canadian Medical Association, Centers for Disease Control and Prevention (CDC), American Dental Association, Canadian Dental Association, South Carolina Dental Association and other professional organizations in the medical community, for the proper fluoridation of public water supplies as a public health benefit. We also support regular scrutiny of the most current peer reviewed research on fluoride and the positions of the medical and dental community.

We adjust the naturally occurring level of fluoride in our drinking water in a responsible, effective, and reliable manner that includes monitoring and controlling fluoride levels as mandated by state and/or federal laws, regulations and recommendations. We carefully monitor and adjust potable water to achieve the scientifically recommended concentration of fluoride for protection against dental caries, which is 0.7 parts per million. Our annual cost for this program is about $110,000, which equates to $0.25 per person across the approximately 450,000 people in our water service area.

The CWS participates in the fluoridation of water under the guidance of the South Carolina Department of Health and Environmental Control (SCDHEC), Oral Health Division. SCDHEC coordinates their program in conjunction with the CDC and the U.S. Department of Health and Human Services.

If there are questions regarding these programs, please contact:
Division of Oral Health
2100 Bull Street, Columbia, S.C. 29201
P: (803) 898-9577
F: (803) 898-2065