Is Mount Pleasant, SC Tap Water Safe to Drink?
Mount Pleasant tap water is legally compliant, but one contaminant exceeds health guidelines. Specifically: PFAS above EPA limits (PFOA: 4.87 ppt, PFOS: 6.63 ppt — limit is 4 ppt each). A point-of-use filter is recommended for drinking and cooking water.
Hardness Scale: Where Mount Pleasant Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Mount Pleasant Compares
Mount Pleasant's water is 75% softer than the national average of 138 PPM - ranking in the bottom 79% for hardness nationwide. Most homes here do not need a softener. Within South Carolina, it ranks #10 of 16 cities (8% below the state average of 38 PPM). Among cities (50k-100k), Mount Pleasant ranks #219 of 258 for hardness.
What Mount Pleasant's Water Means for Your Home
Hardness: 35 PPM - Low Concern
Mount Pleasant's water is slightly hard at 35 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. Mount Pleasant is softer than 79% of US cities. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Forever chemicals (PFAS) are worth watching here. Mount Pleasant has PFOA at 4.87 ppt and PFOS at 6.63 ppt, exceeding the EPA's 2024 limit of 4 ppt per compound. PFAS are synthetic compounds that accumulate in your body over time. A certified carbon filter or reverse osmosis system with NSF P473 certification is the most effective protection. See the regulatory timeline.
What's in the Treatment Process
Mount Pleasant's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 6.96 ppb (9% of the legal limit, but 46x the EWG guideline) and HAA5 at 9.6 ppb (16% of the legal limit, but 96x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 35 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 45 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 31.11 ppt | — | No total limit | Detected |
| ↳ PFOA | 4.87 ppt | 0 ppt | 4 ppt (2024) | ⚠ Exceeds |
| ↳ PFOS | 6.63 ppt | 0 ppt | 4 ppt (2024) | ⚠ Exceeds |
| Lead | 1.1 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 0.4 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 0.0122 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommended Filter for Mount Pleasant
PFAS exceed EPA limits (PFOA: 4.87 ppt, PFOS: 6.63 ppt — limit: 4 ppt each). A certified filter reduces these contaminants effectively.
How to Test Your Water in Mount Pleasant
With PFAS at 31.11 ppt in Mount Pleasant's supply, confirming your home's specific levels is especially important. PFAS vary by neighborhood and can concentrate differently depending on your position in the distribution system.
Free option: Request Charleston Water System's annual Consumer Confidence Report for official city-level data.
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About Mount Pleasant's Water Supply
Water Utility: Charleston Water System
Water Source: Cooper River via Charleston CPW (Surface Water)
Population Served: 91,500
Hardness: 35 PPM (2 grains per gallon)
Mount Pleasant's drinking water comes from surface sources — Cooper River via Charleston CPW. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 92,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Charleston Water System's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by Charleston Water System in Mount Pleasant, SC, including ZIP codes:
29429, 29451, 29458, 29464, 29465, 29466
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Mount Pleasant to Other South Carolina Cities
Frequently Asked Questions About Mount Pleasant Water
Is Mount Pleasant tap water safe to drink?
Where does Mount Pleasant's water come from?
Do I need a water softener in Mount Pleasant?
How do I remove PFAS from Mount Pleasant tap water?
What water filter is best for Mount Pleasant?
Is Mount Pleasant water safe for babies and infants?
What are disinfection byproducts in Mount Pleasant's water?
Can I drink Mount Pleasant tap water straight from the faucet?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What Mount Pleasant Homeowners Actually Buy
Prioritized for contaminant reduction for homes with 35 PPM water and PFAS above EPA limits.
Affiliate disclosure: we may earn a commission. Selection based on Mount Pleasant's water data.