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Water

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1. Does Charleston have a shortage of water?

No, we are fortunate to have an abundant water supply, even during a drought.

2. Does Charleston's water contain fluoride?

Yes, our source water includes naturally occurring fluoride (approximately 0.15 mg/L), and we adjust the level to approximately 0.7 mg/L during the treatment process. 

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:

SCDHEC
Division of Oral Health
2100 Bull Street, Columbia, S.C. 29201
P: (803) 898-9577
F: (803) 898-2065

3. How is the water disinfected?

We use chlorine dioxide and chloramines (a compound formed by combining ammonia and chlorine) to protect against harmful microorganisms.

Chloramines are more stable than chlorine in the water distribution system, and chloramine residuals help maintain consistent water quality. The amount of disinfectant is carefully measured to the lowest level needed to keep the water free of disease-causing organisms. Learn more about the water treatment process.

4. I live in an older home, should I be concerned about lead pipes contaminating my water?

Charleston Water System prevents the corrosion of lead plumbing into water by adjusting the properties of our water. We add a corrosion inhibitor during the treatment process, which forms a molecular barrier between the pipe and the water inside.

The results of our lead testing are well below the USEPA’s limit of 15 parts per billion (ppb). Lead testing results are included in our most recent water quality report.

As an extra precaution, customers can minimize the potential for lead exposure by flushing out water that has been sitting in your home’s plumbing for several hours or more. Just let your water run for up to two minutes before using it for cooking or drinking.

Charleston Water System offers free lead tests. Testing kits are available at our office locations: 103 St. Philip St., Downtown, and 6330 Murray Drive, Hanahan, Customer Service Center.

5. Is it okay to use the hot water tap for cooking or drinking?

No. Always use the cold water faucet for drinking and cooking.

Hot water from the tap comes from your water heater, which may contain impurities. Also, if you have plumbing with lead solder or brass fixtures (which contain lead), the lead is more likely to leach into hot water than cold water. Instead of using the hot water tap, heat cold water on the stove or in the microwave.

6. Is my water safe to drink or is bottled water or filtered water safer?

Yes, Charleston Water System tap water meets or exceeds all drinking water standards and is safe to drink. Bottled or filtered water is also high quality, but it is much more expensive than tap water.

7. Is tap water safe for use in aquariums?

No. We use chloramines (a combination of chlorine and ammonia) to disinfect drinking water which are harmful to fish and other aquatic life. There are a number of products available at pet stores to remove chloramines from your fish tank.

Our tap water is safe for dog, cats, and other non-aquatic pets.

8. My dishwasher leaves water spots on my glasses. What can I do to prevent this?

Water spots on dishes are caused by minerals in the water left behind when water evaporates. To prevent this, use a rinsing agent in your dishwasher, which improves the sheeting action of water and helps to prevent spotting.

Also, be sure to use the proper amount of dishwashing detergent. Using too little may not get your dishes clean, and using too much can cause etching (which is tiny scratches on the surface of the glass that cannot be removed).

The optimal amount of detergent depends on the hardness of water (amount of minerals in the water). Our water's hardness level is about 58.4 ppm, or 3.4 gpg. Check your dishwasher's manual for the recommended amount of detergent to use.

9. My water tastes / smells funny. Does this mean it's not safe to drink? What should I do?

There are a variety of factors that can impact the taste or smell of tap water but not change the quality of the water. In Charleston Water's case, algae in our surface water, when put through the treatment process, can give off harmless compounds that may cause the water to taste “earthy” or “musty.” In most cases, taste and odor are purely aesthetic concerns, and are not reliable indicators of water quality.

10. Should I be concerned about Cryptosporidium or Giardia?

No. We monitor our source water for both, and there is a very low occurrence of these pathogenic organisms.

In addition, our treatment plant has multiple barriers of protection, such as enhanced chemical coagulation, filtration, disinfection, and careful monitoring of turbidity to ensure the optimum removal of these organisms. However, for people with compromised immune systems, the EPA and CDC offer the following advisory statement:

"Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with HIV/AIDS or other immune system disorders, persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, some elderly and some infants can be particularly at risk from infections.

These people should seek advice from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline at 1-800-426-4791."

11. Should I be concerned about the sodium level of Charleston Water System water?

No. Our water has a very low sodium level (10mg/1 or less). This is substantially lower than most well water supplies and many bottled water brands.

12. Sometimes my water has a milky white appearance, why?

This is caused by air dissolved in water. Let the water stand in a glass, and the air bubbles will rise to the top and the water will become clear.

13. What is a Boil Water Advisory?

If the public water system becomes contaminated or a situation allows the possibility of contamination (such as a water main break or loss of system pressure), we will issue a Boil Water Advisory.

The SC Department of Health and Environmental Control (SCDHEC) requires the issuance of a Boil Water Advisory under certain conditions, such as widespread loss of system pressure or a large water main break.

If an advisory is issued, we will notify customers in a variety of ways, depending on the area affected. During an advisory, customers should bring water to a vigorous boil for at least one minute and let it cool before using for cooking or drinking. This will kill any bacteria that may be in the water.

Learn more about boil water advisories

14. What is the pH of Charleston's water?

The pH of water is a measure of the water's acidity on a scale of 0 (acidic) to 14 (basic), with a pH of 7 being neutral. The pH of Charleston's water is adjusted to around 8.3. This helps stabilize the disinfectant and to reduce the corrosion of pipes and plumbing materials.

15. What is hardness and how hard is Charleston's water?

Water hardness is a measure of dissolved minerals in water, specifically calcium and magnesium. Soft water has little or no dissolved minerals. Hard water has higher mineral content that can cause scaling in plumbing and soap scum residue in bathrooms.

Charleston Water System has moderately soft water. Our lab measures hardness in parts per million (ppm), but it can also be expressed in grains per gallon (gpg). The average hardness level of our water is 58.4 ppm, or 3.4 gpg, as shown in this chart.

Some dishwashers and washing machines have hardness-related settings or recommend how much detergent to use based on your water's hardness.

16. Where does Charleston Water System water come from?

We treat water from the Edisto River and the Bushy Park Reservoir, both of which are surface water sources. The water is treated at our Hanahan Water Treatment Plant, which is permitted to treat up to 115.4 million gallons per day (mgd).

17. Why does my water sometimes appear rusty?

Discolored water can sometimes occur as a result of fire hydrant testing, valve testing, or work on a nearby water main.

A change in the direction or velocity of water flow water can cause the iron compounds that accumulate in water mains to become suspended in the water, resulting in a discolored appearance.

Typically, our crews will open a nearby fire hydrant to flush out this discolored water before it reaches customers' taps. If you experience discolored water, flush your plumbing by turning on a faucet until the water runs clear. If it persists, call us at (843) 727-6800.