How to Read Your SC Water Quality Report: Consumer Confidence Reports Explained for Coastal Homeowners (2026)

What is a Consumer Confidence Report and who has to send one?

The Consumer Confidence Report requirement was established by the 1996 amendments to the Safe Drinking Water Act. Congress added the requirement because customers had no standard way to learn what their utility found in their water each year. Before 1999, when the rule took effect, water quality data existed but was scattered across regulatory filings that few residents ever accessed.

Every community water system serving more than 25 customers year-round must produce a CCR. In South Carolina, that covers every major municipal utility: Charleston Water System, Beaufort-Jasper Water and Sewer Authority (BJWSA) serving Bluffton and Hilton Head, the Grand Strand Water and Sewer Authority (GSWSA) serving Myrtle Beach and surrounding areas, Mount Pleasant Waterworks, Summerville CPW, and dozens of smaller county and town systems. The full list of South Carolina public water systems and their CCRs is searchable on the EPA CCR database.

The deadline to deliver the CCR to customers is July 1 each year, covering the prior calendar year. Utilities must deliver it directly by mail or electronically, but if they choose electronic delivery they must also send a paper notice telling customers where to find it. Most South Carolina utilities now post the CCR on their website and mail a postcard notifying customers.

The CCR does not apply to private wells. If your home draws water from a private well, no utility monitors or reports your water quality. South Carolina DHEC recommends annual testing for private wells and requires well water testing in certain real estate situations. See our guide on SC DHEC private well testing rules for details specific to South Carolina well owners.

The three main sections of every SC coastal CCR

Every Consumer Confidence Report has the same basic structure, regardless of which utility produced it. Understanding the three sections before you look at the numbers makes the document much easier to interpret.

Source water description. The first section identifies where the utility draws its raw water: a river, reservoir, lake, or aquifer. For most Lowcountry utilities, this means a surface water source (Charleston Water System draws from the Edisto River; BJWSA draws from the Savannah River) or a combination of surface water and groundwater. GSWSA in the Grand Strand blends surface water from its Bull Creek treatment plant with groundwater from the Black Creek Aquifer, which gives its water a distinct mineral profile compared to pure surface water systems. Source identification matters because different source types carry different contaminant risks.

Treatment summary. The second section describes how the utility treats the raw water before distribution: what disinfectants are used, whether coagulation and filtration are applied, and any specialized processes such as activated carbon for taste or granular activated carbon for PFAS. South Carolina surface water utilities are required to filter and disinfect under the Surface Water Treatment Rule. Most coastal SC utilities use chloramine rather than free chlorine as the residual disinfectant. For more on why that matters for your appliances and filtration needs, see our BJWSA chloramine guide for Bluffton and our Charleston Water System guide.

Detected contaminants table. The third and largest section is the table most homeowners want to understand: every regulated contaminant that was detected in the prior year, the concentration found, and how it compares to the EPA limit. This is the section the rest of this guide focuses on.

How to read the detected contaminants table: every column explained

The table typically has six to eight columns. The EPA specifies the minimum required columns, but utilities may add supplemental information. Here is what each column means in plain terms.

Contaminant. The name of the substance measured, sometimes abbreviated. TTHMs stands for total trihalomethanes; HAA5 stands for five haloacetic acids; these are both disinfection byproducts. E. coli refers to fecal bacteria from human or animal waste. Nitrate appears as nitrate or nitrate-N (as nitrogen). PFOA and PFOS are two of the most studied per- and polyfluoroalkyl substances now required to be reported under the EPA PFAS rule finalized in April 2024.

MCLG. Maximum Contaminant Level Goal. This is the EPA's non-enforceable public health target: the concentration at which no known health effects occur, with an adequate safety margin. For carcinogens and microbiological risks, the MCLG is zero because the EPA concludes there is no completely safe level of exposure. You will see zero MCLGs for lead, arsenic, total coliform bacteria, E. coli, and all PFAS compounds required under the 2024 PFAS rule.

MCL or AL. Maximum Contaminant Level (MCL) is the enforceable legal limit. If the detected level exceeds the MCL, the utility is in violation and must notify customers and take corrective action. Action Level (AL) appears instead of MCL for lead and copper, which are regulated differently: if a utility finds that more than 10 percent of sampled homes exceed the action level (15 micrograms per liter for lead, 1.3 milligrams per liter for copper), the utility must take system-wide action. An action level exceedance is not a violation in the traditional sense, but it does require notification and remediation. See our article on the 2024 SC Lead and Copper Rule improvements for how the new rule affects coastal SC homeowners.

Amount detected. The actual concentration found in the utility's water during the testing period, expressed in the same units as the MCL (micrograms per liter, milligrams per liter, or picocuries per liter for radioactive contaminants). Some utilities report a range (lowest to highest detected across the system); others report an average or a running annual average for disinfection byproducts.

Violation. A simple yes or no indicating whether the utility exceeded any regulatory limit during the reporting period. If the violation column shows yes for any parameter, the utility must have already notified you separately, because violation notices are required within 24 hours for acute risks or within 30 days for other violations. A CCR with all no entries in the violation column means the utility met all federal standards for that year.

Likely source. A plain-language note on where the contaminant probably entered the water supply. Common entries for coastal SC: natural deposits of rock and soil (for arsenic, fluoride, and radium), agricultural runoff (nitrate), runoff from urban development (TTHMs and HAA5 precursors), and erosion of natural organic matter (disinfection byproducts in surface water systems).

Common parameters in coastal SC Consumer Confidence Reports

The table below summarizes the regulated contaminants most commonly reported in coastal South Carolina CCRs, with EPA limits and notes on which utilities and source types are most affected. Always verify current detected levels in your utility's most recent CCR. Concentrations vary year to year.

Sources: EPA National Primary Drinking Water Regulations (40 CFR Part 141); EPA PFAS National Primary Drinking Water Rule (April 2024, epa.gov/sdwa/and-pfas-drinking-water); EPA Secondary Drinking Water Standards (40 CFR Part 143). Units: µg/L = micrograms per liter; mg/L = milligrams per liter; pCi/L = picocuries per liter; ng/L = nanograms per liter (equivalent to parts per trillion). Verify current detected levels in your utility's most recent CCR.

What does “detected but below the MCL” actually mean for your health?

Most CCRs in South Carolina show one or more contaminants detected at some concentration but below the enforceable limit, with no violations. This is the normal state for a well-managed water system. Understanding what that means requires separating two concepts: regulatory compliance and individual health risk.

Regulatory compliance means the utility is operating within the law and within the limits the EPA has determined are protective of public health for the general population. However, MCLs are set based on population-level risk assessments and cost-feasibility considerations. For certain contaminants with an MCLG of zero (lead, PFAS, arsenic, E. coli, total coliform), the EPA acknowledges that no level is entirely without risk; the MCL is the lowest level that utilities can reliably achieve given current treatment technology.

For households with higher sensitivity, including infants, pregnant women, and immunocompromised individuals, the EPA recommends additional precautions even when a utility is in full compliance. For example, the EPA advises that pregnant women and infants not drink water with nitrate above 10 mg/L, which is the MCL. But for a household with a newborn, even nitrate slightly below 10 mg/L can be a reason to use filtered water for formula.

Lead is the most important parameter to interpret carefully. Lead at any concentration above zero poses developmental risks to children under six, and the MCLG for lead is zero. If your CCR shows lead detected at, say, 8 µg/L (below the 15 µg/L action level), your utility is in compliance, but lead is present. A certified reverse osmosis system at the drinking tap removes lead to below detectable limits. See our SC Lead and Copper Rule guide for the specific protections the 2024 rule adds.

For PFAS, the EPA set the MCL at 4 ng/L (parts per trillion) for PFOA and PFOS individually, with an MCLG of zero. Detection at any level above zero is now reported. If your CCR shows PFAS detected at 2 ng/L, your utility is compliant, but those compounds are in the water. An NSF/ANSI 58-certified reverse osmosis system removes PFAS to below detectable limits at the drinking faucet. For more context on how the new PFAS rule affects coastal SC utilities, see our article on the EPA PFAS rule and Lowcountry SC.

Which parameters matter most for each coastal SC utility?

The contaminants that are most relevant depend heavily on your utility's water source. Here is a utility-by-utility summary of the parameters coastal SC homeowners are most often asked about. Always verify current figures in your utility's current-year CCR.

Charleston Water System (CWS). Draws from the Edisto River basin. TTHMs and HAA5 are the primary byproducts to watch, as organic matter in Lowcountry river water reacts with the chloramine disinfectant. CWS switched to chloramine years ago specifically to reduce TTHMs. PFAS monitoring has increased following detection studies near JB Charleston. See our full Charleston water quality guide and our article on PFAS in SC drinking water.

Mount Pleasant Waterworks (MTWPW). Supplements Edisto River surface water with Black Creek Aquifer groundwater for portions of its service area. The Black Creek Aquifer blend introduces fluoride, arsenic, and radium that surface water alone would not carry. See our Black Creek and Middendorf Aquifer guide for why these parameters appear in some Mount Pleasant CCR reports.

BJWSA (Bluffton, Beaufort, Hilton Head). Draws from the Savannah River, supplemented by Floridan Aquifer wells. TTHMs and HAA5 are the primary byproducts because the Savannah River carries high dissolved organic matter. Chloramine is the residual disinfectant throughout the system. See our BJWSA Bluffton water quality guide and our Hilton Head water quality guide.

Grand Strand Water and Sewer Authority (GSWSA). Blends surface water from the Bull Creek treatment plant with Black Creek Aquifer groundwater. The Black Creek blend brings fluoride and radium into the GSWSA supply, which is why GSWSA's CCR often shows higher fluoride than surface water-only systems. Hardness is moderate from the groundwater blend. See our GSWSA water quality guide and our Lowcountry utility hardness comparison.

Summerville CPW and suburban Charleston utilities. Summerville draws primarily from the Middendorf Aquifer, the deep confined aquifer beneath Charleston County and Dorchester County. The Middendorf carries high natural hardness (often 5.5 grains per gallon or more at the tap), fluoride, and trace radium. See our Summerville hard water guide for why this utility has some of the hardest water in the Charleston metro.

What to do when your CCR shows an elevated parameter

If a contaminant appears in your CCR at a concentration you want to reduce at your tap, there are a few decision points to work through before choosing a treatment approach.

First, determine whether the concern is at the utility level or the home level. Lead almost always enters drinking water inside the home, either from a lead service line connecting the street main to your home, from lead solder used in plumbing before 1986, or from brass fixtures that contain lead. The utility may deliver water with zero detectable lead, but by the time it sits in your pipes overnight it may pick up lead from your own plumbing. The fix for that is point-of-use treatment at the tap or periodic flushing before using standing water, not a whole-house system.

For contaminants that come from the source or treatment process (TTHMs, HAA5, PFAS, arsenic, fluoride), the choice is between point-of-use treatment at the kitchen tap and whole-house treatment. For drinking water concerns, an under-sink reverse osmosis system certified to NSF/ANSI 58 for the specific contaminants you want to reduce is the most effective approach. RO systems reduce lead, arsenic, fluoride, PFAS, TTHMs, nitrate, and dozens of other compounds at the drinking faucet. See our reverse osmosis guide for how to select and size an RO system for your household.

For chloramine taste, whole-house catalytic carbon filtration addresses the issue at every tap and appliance, not just the drinking faucet. This also reduces TTHMs and HAA5s throughout the home and protects rubber components in appliances and plumbing from chloramine degradation. See our SC coastal whole-house installation guide for what the installation process involves.

If you are not sure which approach makes sense for your water, a free in-home water test gives you an address-specific reading that supplements the utility-wide CCR averages. Utility averages represent conditions at multiple sampling points across a large distribution system; your home may be meaningfully different depending on your distance from the treatment plant, the age of the pipes serving your neighborhood, and the plumbing inside your house. See our guide to choosing the right water treatment system for a decision framework that starts with your actual water test results rather than the utility average.

Private well owners in South Carolina: you do not get a CCR

If your home is on a private well, the CCR framework does not apply. Private wells serve only one household and are classified as individual water systems, not community water systems, so they fall outside the Safe Drinking Water Act's CCR requirement. You are solely responsible for testing your own water quality.

South Carolina DHEC recommends private well owners test annually for total coliform bacteria, E. coli, nitrate, and pH at a minimum. Depending on your county and local geology, additional tests for arsenic, manganese, iron, hardness, and sulfur compounds may be warranted. The SC DHEC environmental portal lists certified laboratories and guidance on collecting samples correctly.

In coastal South Carolina, private well owners face a set of location-specific risks that municipal customers do not. Shallow surficial aquifer wells near blackwater rivers and tidal creeks can pick up tannins and natural organic matter that stain laundry and fixtures. Saltwater intrusion is an active concern for shallow wells on barrier islands and near tidal creeks, particularly as sea level rise extends saltwater further inland. See our guides on saltwater intrusion in coastal SC wells and private well bacteria risk in coastal SC.

South Carolina also requires well water testing in certain real estate transactions for homes on private wells. See our guide on SC DHEC private well testing rules for what is required before closing on a home with a well.