Is Frederick, MD Tap Water Safe to Drink?
Yes, Frederick tap water is safe to drink. Hardness is low at 69 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Frederick Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Frederick Compares
Frederick's water is 50% softer than the national average of 138 PPM - ranking in the bottom 64% for hardness nationwide. Most homes here do not need a softener. Within Maryland, it ranks #6 of 15 cities (3% above the state average of 67 PPM). Among cities (50k-100k), Frederick ranks #184 of 258 for hardness.
What Frederick's Water Means for Your Home
Hardness: 69 PPM - Low Concern
Frederick's water is moderately hard at 69 PPM. You'll see some spotting on glassware and a film on shower doors over time, but it's not the kind of hardness that demands a full softener. A salt-free conditioner is worth considering if you have a tankless water heater or high-end fixtures.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Frederick's water has TTHMs at 49 ppb and HAA5 at 24.2 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Frederick's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 49 ppb (61% of the legal limit, but 326x the EWG guideline) and HAA5 at 24.2 ppb (40% of the legal limit, but 242x 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.
Chromium-6 was detected at 0.201 ppb, which is 10x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. 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) | 69 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 84 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 3.3 ppt | — | No total limit | Detected |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 3 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1.2 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 1.61 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommendations for Frederick Homes
Quick Fix for Chlorine: Shower Filter
At 1.2 mg/L chlorine, many Frederick residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in Frederick
City-wide data is a solid starting point, but your specific tap might differ based on plumbing age, distance from the treatment plant, or seasonal changes.
Free option: Request City of Frederick Water's annual Consumer Confidence Report for official city-level data.
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About Frederick's Water Supply
Water Utility: City of Frederick Water
Water Source: Monocacy River watershed (Surface Water)
Population Served: 74,911
Hardness: 69 PPM (4 grains per gallon)
Frederick's drinking water comes from surface sources — Monocacy River watershed. 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 75,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request City of Frederick Water'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 City of Frederick Water in Frederick, MD, including ZIP codes:
21701, 21702, 21703, 21704, 21705, 21709, 21710, 21714, 21716, 21717, 21718, 21727, 21754, 21755, 21757, 21758, 21759, 21762, 21769, 21770, 21771, 21774, 21775, 21776, 21777, 21778, 21788, 21791, 21792, 21793, 21798
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Frederick to Other Maryland Cities
Frequently Asked Questions About Frederick Water
Is Frederick tap water safe to drink?
Where does Frederick's water come from?
Do I need a water softener in Frederick?
What is the hardness of Frederick water in grains per gallon?
What are disinfection byproducts in Frederick's water?
Is chromium-6 in Frederick's water?
Why does Frederick water taste like chlorine?
Can I drink Frederick 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 Frederick Homeowners Actually Buy
Common purchases for homes with 69 PPM water.
Affiliate disclosure: we may earn a commission. Selection based on Frederick's water data.