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WaterVerge

Water quality report · updated Jul 2026

Is Clio, SC Tap Water Safe to Drink?

Graded A-, with 4 unresolved violations on record. See what was cited — and what it means for your tap. What to do ↓

0 contaminants over a legal limit
0.8 ppb lead, 90th percentile · low
4 unresolved violations
788 people served by 1 water system

PWSID SC3410002 · moderate data confidence · local government utility

Reviewed by WaterVerge Editorial Team · Last updated July 2026
A 88.9 / 100

#58 of 195South Carolina cities
How we grade →

01The verdict: is Clio water safe?

Clio's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (88.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 788 residents using groundwater (wells).

The concern

4 unresolved violations on record

EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.

See what was cited ↓
The good news

Lead is well under the limit

90th-percentile lead is 0.8 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.

See the trend ↓
Keep watching

A flood-prone service area

10 federal disaster declarations on record. After severe weather, watch for boil-water advisories.

See the risk factors ↓

Clio's drinking water received a grade of A- (88.9 out of 100), indicating good water quality. The city's 1 water system serves approximately 788 residents using groundwater.

Lead levels were measured at 0.8 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 8 violations on record, including 1 health-based violation. 4 remain unresolved.

Clio ranks #58 out of 195 cities in South Carolina for water quality, placing it mid-range in the state. Clio relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. As a small community water system, Clio may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

How the 88.9/100 breaks down Methodology →
ViolationsHistorical violation record including health-based and monitoring violations.
43.9 / 45A
Lead & CopperLead at 0.8 ppb (90th percentile).
20 / 20A
ContaminantsPFAS + legacy contaminant analysis.
17 / 20B
ComplianceMonitoring and reporting compliance with EPA regulations.
3 / 10F
Source RiskWater source: Groundwater.
5 / 5A

02What's in Clio's water

Every contaminant flagged in Clio, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.

1 detection · sorted by % of legal limit
Over the limit Elevated — watch Within limits
0 50% LEGAL LIMIT 150%
1 contaminant tested under EPA SDWIS, LCR and UCMR programs · 1 detected · not yet tested for PFAS under UCMR 5

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.8 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

03Clio's ten-year track record

Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 8 violations on record, including 1 health-based violation. 4 remain unresolved.

9 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.

2 monitoring & paperwork
UpdateWater quality data updatedLatest EPA compliance and testing data incorporated into Clio's water quality assessment. Grade: A- (88.9/100).
DisasterHURRICANE IDALIAFederal disaster declaration (FEMA DR-3597). Hurricane event — may have impacted local water infrastructure.
DisasterHURRICANE IANFederal disaster declaration (FEMA DR-4677). Hurricane event — may have impacted local water infrastructure.
Violation1 drinking water violation recordedContaminants: Revised Total Coliform Rule.Resolved
Violation1 drinking water violation recordedContaminants: Chlorine.Resolved
Violation1 drinking water violation recordedContaminants: Stage 2 Disinfectants and Disinfection Byproducts Rule.Open
Lead, 90th percentileppb · lower is better
05101520EPA action level · 15 ppb1994 — 10 ppb1995 — 0 ppb1996 — 5 ppb1997 — 5 ppb2001 — 2 ppb2010 — 0 ppb2013 — 0 ppb2019 — 0.48 ppb2022 — 1.6 ppb2025 — 0.80 ppb100.80199419962001201320222025

Down 9.2 ppb since 1994. Latest reading: 0.80 ppb (2025) — 5% of the action level. Sampled at higher-risk homes (90th percentile).

04Where Clio's water comes from

Clio's drinking water is drawn from underground aquifers through wells.

Source

Groundwater

Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.

Treatment

Local treatment

Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.

Distribution

1 system

1 water system, operated under local government ownership.

Delivery

788 people

Residents served across Clio's service area.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 788 people through 1 water system.

System namePWSIDPopulationSource
CLIO TOWN OF (SC3410002) SC3410002 788 Groundwater

Water bodies near Clio

Crooked Crk Bl N Marlboro · river

These water bodies shape the regional watershed and can indirectly affect groundwater quality.

05Pressure on Clio's watershed

Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.

Industrial discharge

Present — monitored

1 facility within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.

MARLEY ENGINEERED PRODUCTS 0 lb · 8.0 mi

Flood & storm history

Recurring — declared disasters

10 federal disaster declarations on record for Marlboro County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.

HURRICANE IDALIA Aug 2023 · DR-3597
HURRICANE IAN Nov 2022 · DR-4677
HURRICANE IAN Sep 2022 · DR-3585

Drought

D3 — extreme drought

Marlboro County is in D3 (extreme drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.

Current streak at D2+ severity23 wks
Weeks at D2+ in the last 5 years23 wks
Months in D2+ over the last 30 years16.0%

06How Clio compares

Scores for nearby South Carolina cities on one line, with the average marked.

Greenville
92.1 · A
Clio (this city)
88.9 · A-
Okatie
83.8 · B+
Charleston
82.8 · B+
Conway
67.5 · C+
Columbia
37.1 · F

dashed line = South Carolina average (77/100)

Clio scores 88.9/100above the South Carolina average of 77/100. It outscores 7 of 10 nearby cities. Full South Carolina rankings →

Marlboro water quality rankings
Compare all cities in the county — grades, violations, and contaminant data side by side.

07What to do at home

Steps matched to what testing actually found in Clio's water — not generic advice.

Extra protection

A basic carbon filter still helps

Clio's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.

Compare tested filters →
Know your report

Read your utility's annual report

Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.

How to read a CCR →
Stay informed

Watch for Clio alerts

This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.

All water alerts →

Frequently asked questions

Is Clio, SC tap water safe to drink?

Clio's water quality earned a grade of A- (88.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #58 out of 195 cities tested in South Carolina.

What contaminants are in Clio's water?

Lead was measured at 0.8 ppb (90th percentile). 8 violations are on record.

How is Clio's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Clio?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Clio's water come from?

Clio's water is sourced from Groundwater. The city has 1 water system serving approximately 788 residents.

What health violations has Clio's water system had?

Clio has 1 health-based violation on record. The most recent violation was recorded in December 2020. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.

Is Clio's groundwater at risk of contamination?

Clio uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 8 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Clio's water compare to other cities?

Clio ranks #58 out of 195 cities in South Carolina (better than 70% of state cities) and #3171 out of 15382 cities nationally (79th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Clio's small water system affect quality?

Clio's system serves approximately 788 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 8 violations on record.

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About Clio, SC: Clio is a town in Marlboro County, South Carolina, United States. As of the 2020 census, Clio had a population of 608. Marlboro School of Discovery was a magnet school in Clio, South Carolina and was part of the Marlboro County School District. Median household income $32,847 · median age 52.4 · 68.8% homeowners · 11% college educated. Wikipedia → Service area: 1 ZIP code across Marlboro.
Show ZIP codes 29525
Sources: EPA SDWIS & ECHO · UCMR 3–5 · Lead & Copper Rule samples · EPA TRI · U.S. Drought Monitor · FEMA declarations. Data last updated Jul 2026. Analysis by the WaterVerge Editorial Team · methodology.