Frequently Asked Questions

Yes, basically. Nearly all wipes labeled as “flushable” are now truly flushable thanks to our class action lawsuit against wipes manufacturers and retailers! 

ALL "Flushable" wipes will truly be flushable by late 2025, and these remaining brands are very close to the flushability standard now.

Simply look at the label on the package:

• If it says "Flushable," then it is flushable. 
• If it says "Do Not Flush," then do not flush.

No. Wastewater treatment plants aren’t designed to remove pharmaceuticals, so flushing introduces them directly into the environment - the Charleston Harbor in our case.

The Food and Drug Administration (FDA) recommends disposing of expired medications in the trash. To prevent tampering, take the medicine out of its original container and mix with coffee grounds or kitty litter in a plastic bag or other container.

Grease hardens as it cools. Even when mixed with hot water, the grease will separate out and settle in plumbing systems and sewer lines. Over time, grease accumulation can severely reduce the capacity of a pipe or block it completely, sometimes resulting in sewer back-ups or overflows.

Dispose of fats, oils, and grease by pouring it into a container and putting it in the trash.

Visit the Wastewater-Collection-and-Treatment page for a video and overview of the treatment process.

“Activated sludge” is a mass of microorganisms that digest organic material in wastewater. The microorganisms clean the wastewater by digesting organic materials and other contaminants. Wastewater remains in aeration basins for about three hours to allow time for the microorganisms to grow and consume the bacteria.

Contact a Backflow Tester from our List of Approved Backflow Testers and schedule a test. Provide a copy of the letter to your Tester. After completing the test, the Tester will submit the results to Charleston Water System.

Compliance with our backflow requirements is the responsibility of the water account holder. If you are renting a home or commercial space, your landlord or property management company may agree to take care of the backflow installation and/or annual testing, but it is the ultimately the account holder's responsibility.

We recommend contacting a licensed plumber. You can install it yourself, but it must be installed according to our specifications, and we will inspect it after installation. If you hire someone to install it, provide him with a copy of the letter and installation guidelines enclosed in the letter. Once it's installed, you or the installer should contact us to request an inspection. If it passes inspection, the final step is to have it tested by a tester from our List of Approved Backflow Testers.

Backflow prevention assemblies have internal seals, springs, and moving parts that are susceptible to wear and failure. Annual testing ensures they are functioning properly and protecting our public water system.

No, they are independent private contractors. Charleston Water System does not install or test backflow preventers. We only inspect them. We do require backflow tests to be performed by Testers on our List of Approved Backflow Testers.

Contact our Cross-Connection Control Program by calling (843) 727-7148 or send us an email.

No, we're fortunate to have an abundant water supply, even during drought conditions.

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

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.

Charleston Water System prevents lead from corroding from lead pipes and plumbing into your drinking water water by adjusting the properties of our water. We add a food-grade corrosion inhibitor called orthophosphate during our water treatment process to form a barrier between the pipe and the water inside. As a direct result, our lead testing results have been far below the EPA’s limit of 10 parts per billion (ppb) since 1994.

Customers with lead pipes or plumbing can further minimize exposure by flushing out water that has been sitting in your plumbing for several hours or more. Just let your water run for up to two minutes before using it for cooking or drinking.

We offer free lead tests, which are available at our office locations:
- 103 St. Philip St., Downtown Charleston
- 6330 Murray Drive, Hanahan

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

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. And people too, of course...

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 dish detergent. Too little may not get your dishes clean, and 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.

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

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.

This is caused by tiny air bubbles in the water.

Solution:  Let the water stand in a glass to allow air bubbles to rise to the top and disappear.

If there's a CHANCE that our water has become contaminated with bacteria, we will issue a precautionary Boil Water Advisory. The SC Department of Environmental Services (SCDES) requires a Boil Water Advisory under certain conditions, such as loss of system pressure following a 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.

We treat water from the Bushy Park Reservoir and the Edisto River, both of which are surface water sources. We blend these sources and our water typically consists of 90% Bushy Park and 10% Edisto. All water is treated at our Hanahan Water Treatment Plant, which is permitted to treat up to 115.4 million gallons per day (mgd), making this plant the largest in South Carolina.

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 customer taps. If you experience discolored water, flush your plumbing by turning on a cold water faucet until the water runs clear. If it persists, call us at (843) 727-6800.

Contact the Purchasing department to request a Vendor Application form. Completing and returning the form will guarantee placement on the bidder’s mailing list.

The total cost to install a ¾” domestic irrigation meter is $535. That includes a $500 tap fee, which covers the cost to install and connect the new meter, and a $35 account origination fee. This fee is nonrefundable or transferable. It’s important to note that irrigation accounts require you to install a backflow prevention device and have it tested annually by an approved tester. A certified plumber or contractor can install a backflow preventer for you. The cost will depend on the type of device required and the installation labor.

Commercial accounts are charged both a tap and impact fee based on meter size. In most cases, an irrigation meter can be very cost effective because commercial accounts are charged wastewater based on 100% of their water use fees. Tap and Impact Fees cover the cost for the Charleston Water System distribution system to install and connect the new meter. A $35 account origination fee is also charged for creation of the new account. This fee is nonrefundable and nontransferable. It is important to note that irrigation accounts require installation of a backflow prevention device. These devices must be tested annually by an approved tester. A plumber or contractor can install a backflow preventer for you. The cost will be determined by the type of device required and the installation labor. Annual testing fees vary, so it’s a good idea to call around for pricing, but be sure to use a Charleston Water System approved tester.

Your savings depends on where you live and your water use. Most customers see a payback on the up-front cost of installing the irrigation meter in 4 to 5 years.
For a savings and payback period estimate, call (843) 727-6800, or email us.

*One important thing to consider is how getting an irrigation meter will affect your domestic sewer bill if you live in a single family home. You won’t pay any sewer charges for water used through an irrigation meter, but your sewer bill for your residential account will increase slightly because your domestic sewer charges will be calculated based on 100% of your domestic water usage instead of 95%.

Complete the Application For Service form. If you have any questions, contact us at 843-727-6800 or email us.

It typically takes eight weeks from the time you apply and pay for an irrigation account to the time it is installed.

Additionally, our backflow requirements must be met before we will activate the irrigation service. We require irrigation accounts to have a backflow prevention assembly in order to protect our water system against contamination from backflow.

We do not install or test backflow preventers. Customers are responsible for installing backflow preventers in accordance with our requirements and having them tested annually. For more information: Backflow requirements for residential customers 

Charleston Water System will install the new meter box and meter. The customer is responsible for connecting their water service line on their property to the new meter (we recommend hiring a qualified plumber, landscaper, or contractor to do this). We do not install irrigation systems or  required backflow preventers.

Please contact our Customer Service Department at (843) 727-6800 or via email.

If you find a water leak and repair it, you may be eligible for an adjustment on the sewer portion of your bill. We only offer sewer adjustments because water from a leak typically does not enter the sewer system. We require proof of repair before granting a leak adjustment, and customers are eligible for one leak adjustment every three years.

Use the link below to submit a leak adjustment request, or call our Customer Service Department at (843) 727-6800.

Customers who fill a pool are eligible for an adjustment to the associated sewer charges once every five years. 

Customer Service (843) 727-6800 or send an email.

Yes! Sign up for AutoPay or complete the form on the back of your bill.

Sewer bills are based on water consumption and include a monthly minimum bill plus a volume charge for billable sewer usage above 2 Ccf (1,496 gallons).

Your water bill includes a monthly minimum charge plus a unit volume charge for water consumption above 2 Ccf (1,496 gallons).

The primary drivers of rate increases are the need to fund new and replacement infrastructure, and comply with new regulations. Many of our water mains, sewer lines, and treatment facilities are 50-100+ years old and have reached the end of their service life.

Replacing this aging infrastructure is necessary to maintain the level of service we all expect, but the cost is high.

We fund infrastructure by issuing revenue bonds and raising rates to repay the debt. Retained earnings and impact fee revenue provide some funding, but not enough to meet the needs. The cost of wide-scale infrastructure replacement and it’s impact on water and sewer rates is a challenge faced by utilities across the country.

Our water and sewer rate structures both include a minimum bill, which is a monthly charge for service availability and up to 2 Ccf (1,496 gallons) of water consumption.

The minimum bill is designed to recover the costs associated with making service available, including costs related to metering and billing and infrastructure. The water minimum bill also pays for the costs associated with providing water for fire protection, one of our key functions.

These costs remain constant regardless of whether you use any water in a billing period.

It is a separate water meter that is only used for irrigation. Because water used for irrigating does not flow into the sewer system, irrigation accounts are not billed for sewer.

If you frequently water your lawn or garden, or add water to a pool, you may want to consider applying for an irrigation meter.

Automated Meter Reading, or AMR, allows meters to be read automatically via a radio signal transmitted to a laptop in a CWS vehicle as it drives around town. Benefits include more precise meter reads and dramatically improved efficiency during meter reading.

Charleston Water System will waive the monthly sewer charge for new homes under construction until one of the following occurs:

• Actual sewer usage begins
• A certificate of occupancy is issued
• The maximum time period of 4 months has passed.

Upon receipt of a monthly bill, the homeowner should strike though the sewer charges, write the words “home under construction, Attention: Billing Dept.” and return with payment.

We have a statutory responsibility to provide water and sewer service in Charleston. Over the years, our Board of Commissioners has extended our services to other municipalities. This expansion increases risk, cost, and operational challenges, so we bill customers in these areas at a higher rate.

Frequent Q&A

• All of my neighbors around me pay Inside-City rates, and it doesn’t cost you more to serve me, so why charge me Outside-City rates? 

  Rates are based on municipality, and it’s not prudent to consider each customer’s physical location when developing a rate model.

• Are Outside-City rates a ploy to make people annex into the city of Charleston?
  No. Our rate structure is an industry-standard model that provides equity for all users. The City mentions our rates as a benefit of annexation as marketing.

• How can I tell if a property pays an Inside-City or Outside-City rate?
  Inside-City customers have a green garbage can.

Please see our service area map.

Please see our tap and impact fee schedule.

Water pressure varies by area, and water system design calculations must be based on the results of flow testing. We will perform a flow test upon request for a fee.

Request a flow test: Hydrostatic Flow Test Request Form.

These filters improve the aesthetics of water (improve taste and odor) but do not remove harmful bacteria. Learn about the your filter by contacting the manufacturer or NSF International, an independent testing group (Ph: 1-800-673-8010). If in doubt, boil your water or use bottled water.

An advisory or notice remains in effect until test samples show the water is safe to drink. Testing for bacteria requires 16 hours to complete.

We repeal a precautionary advisory or notice when we confirm the water is safe to drink. Stay tuned to local media for updates. We will also post updates on this website and place an automated message on the Customer Service phone system at (843) 727-6800.

• If untreated water reaches the distribution system
• Loss of pressure in the entire distribution system or a significant portion of the system
• A water main break where dirt and debris have entered the distribution piping
• Prior to a hurricane making landfall (in this situation, the advisory would be issued by DHEC)

• When test samples indicate the presence of total coliform bacteria

A Boil Water Advisory (BWA) is a precautionary public statement advising customers to boil tap water before consuming it. They’re issued when an event has occurred allowing the possibility for the water distribution system to become contaminated. An advisory does not mean that the water is contaminated, but rather that it could be contaminated. Since the water quality is unknown, customers should assume the water is unsafe to drink and take the appropriate precautions. An advisory is different from a Boil Water Notice, which is issued when contamination is confirmed in the water system. During a notice, all customers must boil their water before consuming it or use bottled water.

• Run all cold water faucets in your home for one minute
• To flush automatic ice makers, make three batches of ice and discard
• Run water softeners through a regeneration cycle
• Run drinking water fountains for one minute
• Run water coolers with direct water connections for five minutes.

No,

If a hurricane is about to impact our service area, then the Charleston Water System may, after consultation with SCDHEC, issue a Boil Water Advisory as a precautionary measure.

After the storm:

- We look for damage to our system and make any repairs as quickly as possible.

- If tests show the water is safe to drink, we lift the Boil Water Advisory.

- If tests indicate bacterial contamination, we issue a Boil Water Notice.

- Stay tuned to media reports for instructions.