City of Frederick: what's in the water
24 contaminants and water quality measures were reported as detected in the Annual Water Quality Report (Reporting Year 2025), covering 2025.
Where this comes from: Every number below is copied from the published Consumer Confidence Report for City of Frederick, hosted by the Maryland Department of the Environment. Some substances aren't tested every year, so the sample date is shown for each result. Values and limits appear as printed.
Is this your water? Parts of these ZIP codes outside city limits are served by Frederick County Division of Water and Sewer Utilities (separate report, not yet included) or private wells. Check your water bill to confirm your provider.
Everything City of Frederick reported
Tap any contaminant to see what it can do to your body and your home & appliances, the exact values from the report, and which systems can help reduce it.
LeadMetals1.6 ppb15 ppbAction level2024
Your body
EPA has set a health goal of zero for lead because no safe level of exposure is known. In children, low-level lead exposure has been linked to lower IQ, learning and attention problems; in adults, to raised blood pressure and kidney effects. Pregnant women and young children are most at risk.
Your home & appliances
Lead itself does not damage plumbing, but its presence is a sign of corrosion: water chemistry that dissolves metal from pipes, solder, and fixtures.
What it is
A metal that usually gets into tap water from lead service lines, lead solder, and older brass fixtures inside buildings, not from the water source itself. Homes built before 1986 are more likely to have lead plumbing.
Exactly as reported
- Lead: 1.6 ppb (90th percentile) · range ND–6.40 · Action level 15 · health goal 0 · violation: No · sampled 2024
PFASIndustrial & farm chemicals · 3 results4.5 ppt +2 moreNo federal limit2025
Your body
Exposure to certain PFAS, such as PFOA and PFOS, has been linked to effects including changes in cholesterol, reduced vaccine response in children, lower birth weight, and increased risk of some cancers (EPA; Fenton et al., 2021). In 2024, EPA set drinking water limits for several PFAS.
Your home & appliances
PFAS do not affect plumbing or appliances.
What it is
Per- and polyfluoroalkyl substances are a large family of man-made chemicals used since the 1940s in non-stick, stain- and water-resistant products and firefighting foams. They break down very slowly in the environment and the body.
Exactly as reported
- PFOS: 4.5 ppt (amount detected) · range ND–4.5 · sampled 2025Note: Listed under unregulated substances. The report notes that the MCLs for these PFAS do not go into effect until 2029 (the PFOS MCL will be 4.0 ppt).
- PFOA: 2.9 ppt (amount detected) · range ND–2.9 · sampled 2025Note: Listed under unregulated substances. The report notes that the MCLs for these PFAS do not go into effect until 2029.
- PFBS, PFHxS, PFHxA, PFPeA: PFBS 3.9 · PFHxS 1.5 · PFHxA 2.4 · PFPeA 3.3 (2024) ppt (amount detected) · sampled 2024–2025
NitrateNutrients1.9 ppm10 ppmMCL2025
Your body
According to EPA, infants under six months who drink water with nitrate above the federal limit could become seriously ill (blue baby syndrome). Research has also examined links between long-term exposure and other health effects.
Your home & appliances
Nitrate does not harm plumbing. It can indicate that surface water or septic waste is reaching a well.
What it is
A form of nitrogen from fertilizer, manure, and septic systems that can soak into groundwater. It is a common concern in farming areas, including much of the Eastern Shore.
Exactly as reported
- Nitrate: 1.9 ppm (amount detected) · range ND–1.9 · MCL 10 · health goal 10 · violation: No · sampled 2025
Total TrihalomethanesDisinfection byproducts · 2 results72.7 ppb +1 more80 ppbMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to liver, kidney, or central nervous system problems and an increased risk of cancer. Studies have associated long-term exposure to chlorination byproducts with bladder cancer.
Your home & appliances
Trihalomethanes do not affect plumbing. They can also be inhaled during hot showers.
What it is
A group of four chemicals (chloroform, bromodichloromethane, dibromochloromethane, bromoform) that form when chlorine reacts with natural organic matter in water. Levels are usually higher at the far ends of a distribution system and in warm months.
Exactly as reported
- Total Trihalomethanes [TTHMs]: 72.7 ppb (amount detected) · range 13.3–102.3 · MCL 80 · health goal NA · violation: No · sampled 2025
- Bromodichloromethane, Chloroform, Dibromochloromethane (unregulated individually): Bromodichloromethane 5.13 · Chloroform 20.1 · Dibromochloromethane 0.61 ppb (amount detected) · range 0.6–20.1 · sampled 2025Note: These are individual trihalomethanes. Together they count toward the TTHM limit of 80 ppb.
Haloacetic AcidsDisinfection byproducts43.2 ppb60 ppbMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to an increased risk of cancer.
Your home & appliances
Haloacetic acids do not affect plumbing.
What it is
Five related chemicals that form when chlorine reacts with natural organic matter in water. Like TTHM, they are tracked at points around the distribution system.
Exactly as reported
- Haloacetic Acids [HAA5]: 43.2 ppb (amount detected) · range 13.8–48.8 · MCL 60 · health goal NA · violation: No · sampled 2025
Gross alpha activityRadiological2.7 pCi/L15 pCi/LMCL2021
Your body
According to EPA, long-term exposure above the federal limit has been linked to an increased risk of cancer.
Your home & appliances
Alpha emitters do not affect plumbing.
What it is
A screening measurement of total alpha radiation in water, mostly from natural uranium, radium, and related elements in rock.
Exactly as reported
- Alpha Emitters: 2.7 pCi/L (amount detected) · range ND–2.7 · MCL 15 · health goal 0 · violation: No · sampled 2021
Beta/photon emittersRadiological7.3 pCi/L50 pCi/LMCL2021
Your body
According to EPA, long-term exposure above the federal limit has been linked to an increased risk of cancer.
Your home & appliances
Beta emitters do not affect plumbing.
What it is
A screening measurement of beta radiation in water, from natural minerals (like potassium-40) and some human-made sources. Water systems compare results to a 50 pCi/L screening level.
Exactly as reported
- Beta/Photon Emitters: 7.3 pCi/L (amount detected) · range ND–7.3 · MCL 50 · health goal 0 · violation: No · sampled 2021
Coliform bacteria & E. coliMicrobes3.8% % of samples5%MCL2025
Your body
According to EPA, germs indicated by E. coli can cause stomach cramps, diarrhea, nausea, and headaches, and may pose a special risk for infants, young children, and people with severely compromised immune systems.
Your home & appliances
Bacteria do not damage plumbing, but in wells they can point to a cracked well cap, a damaged casing, or nearby septic issues.
What it is
Coliforms are bacteria that are common in the environment. Water systems test for them as an indicator: their presence means germs may be able to get into the water. E. coli is a specific type that indicates fecal contamination.
Exactly as reported
- Coliform Bacteria (positive samples): 3.8% % of samples (amount detected) · MCL 5% · health goal 0 · violation: No · sampled 2025
CopperMetals0.123 ppm1.3 ppmAction level2024
Your body
According to EPA, short-term exposure above the action level has been linked to stomach and intestinal upset. Long-term exposure has been linked to liver or kidney damage, and people with Wilson’s disease are more sensitive.
Your home & appliances
Copper in water points to pipe corrosion, which can lead to pinhole leaks over time. It also leaves blue-green stains on sinks, tubs, and fixtures.
What it is
A metal that mostly enters tap water from corrosion of copper pipes and brass fixtures, especially when water is acidic (low pH) or sits in pipes for hours.
Exactly as reported
- Copper: 0.123 ppm (90th percentile) · range ND–0.21 · Action level 1.3 · health goal 1.3 · violation: No · sampled 2024
FluorideMinerals0.74 ppm4 ppmMCL2025
Your body
EPA sets an enforceable limit of 4.0 mg/L and a secondary standard of 2.0 mg/L. According to EPA, long-term exposure above 4.0 mg/L has been linked to bone disease, and children exposed above 2.0 mg/L may develop dental fluorosis (tooth discoloration or pitting). A 2024 federal NTP review examined fluoride exposure above 1.5 mg/L and children’s IQ.
Your home & appliances
Fluoride does not affect plumbing.
What it is
A mineral that occurs naturally in some groundwater and that many public water systems add at low levels to help prevent tooth decay.
Exactly as reported
- Fluoride: 0.74 ppm (amount detected) · range 0.51–0.74 · MCL 4 · health goal 4 · violation: No · sampled 2025
ChlorineDisinfectants1.22 ppm4 ppmMax. disinfectant2025
Your body
According to EPA, people drinking water containing chlorine well in excess of the federal limit could experience eye or nose irritation or stomach discomfort. Disinfection itself is an important public health protection.
Your home & appliances
Chlorine causes the “pool” taste and smell many people notice. Over time it can dry out rubber seals and gaskets in fixtures and appliances.
What it is
Public water systems are required to disinfect water to control germs, and most use chlorine or chloramine. A small amount stays in the water all the way to your tap.
Exactly as reported
- Chlorine: 1.22 ppm (amount detected) · range 0.98–1.22 · Max. disinfectant 4 · health goal 4 · violation: No · sampled 2025
AtrazineIndustrial & farm chemicals0.73 ppb3 ppbMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to cardiovascular system and reproductive problems.
Your home & appliances
Atrazine does not affect plumbing.
What it is
A widely used herbicide on corn and other row crops that can wash into rivers and groundwater after rain.
Exactly as reported
- Atrazine: 0.73 ppb (amount detected) · range ND–0.73 · MCL 3 · health goal 3 · violation: No · sampled 2025
BariumMetals0.038 ppm2 ppmMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to increased blood pressure.
Your home & appliances
Barium can add to the mineral scale that builds up in water heaters and pipes.
What it is
A naturally occurring metal found in many rock formations, plus discharges from drilling and metal refining.
Exactly as reported
- Barium: 0.038 ppm (amount detected) · range ND–0.038 · MCL 2 · health goal 2 · violation: No · sampled 2025
SimazineIndustrial & farm chemicals0.24 ppb4 ppbMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to blood problems.
Your home & appliances
Simazine does not affect plumbing.
What it is
A herbicide related to atrazine, used to control weeds. It can run off into surface water.
Exactly as reported
- Simazine: 0.24 ppb (amount detected) · range ND–0.24 · MCL 4 · health goal 4 · violation: No · sampled 2025
TurbidityWater quality0.26 NTUTTMCL2025
Your body
Turbidity itself has no health effects, but according to EPA, it can interfere with disinfection and give germs a place to grow.
Your home & appliances
Sediment that causes cloudy water can clog faucet aerators, valves, and appliance inlets.
What it is
Turbidity measures how cloudy water is, from suspended particles like silt and clay. Water systems monitor it to show how well their filtration works.
Exactly as reported
- Maximum Turbidity: 0.26 NTU (amount detected) · MCL TT · violation: No · sampled 2025
AluminumMetals0.081 ppb200 ppbSecondary2025
Your body
EPA regulates aluminum only as a secondary (cosmetic) standard, based on color. ATSDR has more on its health effects at higher exposures.
Your home & appliances
At higher levels aluminum can cause water discoloration.
What it is
A common element in soil and rock. Small amounts can remain after some water treatment processes that use aluminum compounds to settle out particles.
Exactly as reported
- Aluminum (secondary): 0.081 ppb (amount detected) · range ND–0.081 · Secondary 200 · violation: No · sampled 2025Note: Shown as printed; the unit column reads ppb.
ChlorideMinerals35.9 ppm250 ppmSecondary2025
Your body
EPA regulates chloride only as a secondary (taste) standard.
Your home & appliances
High chloride gives water a salty taste and can speed up corrosion of metal pipes and water heaters.
What it is
A common salt component from natural deposits, road salt runoff, and saltwater intrusion near the coast.
Exactly as reported
- Chloride (secondary): 35.9 ppm (amount detected) · range 5.2–35.9 · Secondary 250 · violation: No · sampled 2025
IronMinerals290 ppb300 ppbSecondary2025
Your body
EPA treats iron as a cosmetic (secondary) issue rather than a health risk at levels found in drinking water.
Your home & appliances
Iron causes orange-brown stains on sinks, tubs, toilets, and laundry, and a metallic taste. It can also feed iron bacteria and clog pipes, valves, and water treatment equipment.
What it is
A common natural mineral in Maryland groundwater, especially on the Eastern Shore. It can also come from rusting pipes.
Exactly as reported
- Iron (secondary): 290 ppb (amount detected) · range ND–290 · Secondary 300 · violation: No · sampled 2025
SulfateMinerals44.4 ppm250 ppmSecondary2025
Your body
EPA regulates sulfate as a secondary standard. At high levels it can have a laxative effect on people not used to it.
Your home & appliances
High sulfate can give water a bitter taste and contribute to scale.
What it is
A naturally occurring mineral salt in rock and soil, also from some industrial wastes.
Exactly as reported
- Sulfate (secondary): 44.4 ppm (amount detected) · range 2.9–44.4 · Secondary 250 · violation: No · sampled 2025
ZincMetals0.32 ppm5 ppmSecondary2025
Your body
Zinc is an essential nutrient. EPA sets only a secondary (taste) standard for it in drinking water.
Your home & appliances
High zinc can give water a metallic taste and may point to corrosion of galvanized plumbing.
What it is
A naturally occurring metal, also released from galvanized pipes and industrial sources.
Exactly as reported
- Zinc (secondary): 0.32 ppm (amount detected) · range 0.31–0.32 · Secondary 5 · violation: No · sampled 2025
Volatile organic compoundsIndustrial & farm chemicalsChloromethane 2.34 · Bromomethane 0.61 ppbNo federal limit2022–2025
Your body
Health effects vary by chemical. EPA lists the regulated VOCs and their health effects in its national drinking water regulations table.
Your home & appliances
VOCs generally do not affect plumbing. Some can be inhaled during showering.
What it is
Carbon-based chemicals that evaporate easily, from fuels, solvents, industrial processes, and some disinfection reactions. Several are regulated; others are monitored as unregulated.
Exactly as reported
- Chloromethane (2025), Bromomethane (2022) (unregulated): Chloromethane 2.34 · Bromomethane 0.61 ppb (amount detected) · range 1.79–2.34 (chloromethane) · sampled 2022–2025
HardnessMineralsCalcium 39.7 (printed as ppb) · Magnesium 8.4 ppm as printedNo federal limit2025
Your body
Hard water is not considered a health risk. Calcium and magnesium are common dietary minerals.
Your home & appliances
Hard water leaves scale inside water heaters, dishwashers, coffee makers, and pipes, which can reduce efficiency and shorten equipment life. It also leaves spots on glass, crust on faucets and showerheads, and makes soap lather poorly.
What it is
Hardness is the amount of dissolved calcium and magnesium in water, picked up as water moves through limestone and other rock.
Exactly as reported
- Calcium and Magnesium (unregulated): Calcium 39.7 (printed as ppb) · Magnesium 8.4 ppm as printed (amount detected) · range Calcium 6.0–39.7 · Magnesium 0.02–8.4 · sampled 2025Note: Calcium and magnesium are the minerals that make water hard. Units shown as printed.
SodiumMinerals25.7 ppmNo federal limit2025
Your body
Sodium in water is a small part of most people’s daily intake. People on sodium-restricted diets may want to talk to their doctor; EPA guidance mentions 20 mg/L for people on very low-sodium diets.
Your home & appliances
Sodium itself does not usually affect plumbing.
What it is
A naturally occurring element in groundwater. It also comes from road salt, some water treatment chemicals, and water softeners.
Exactly as reported
- Sodium (unregulated): 25.7 ppm (amount detected) · range 1.4–25.7 · sampled 2025
PotassiumMinerals2.8 ppmNo federal limit2025
Your body
Potassium at drinking-water levels is a very small part of normal dietary intake. There is no federal drinking water limit.
Your home & appliances
Potassium does not affect plumbing.
What it is
A naturally occurring mineral and essential nutrient, sometimes reported as an unregulated substance.
Exactly as reported
- Potassium (unregulated): 2.8 ppm (amount detected) · range 0.87–2.8 · sampled 2025
Source: City of Frederick, Annual Water Quality Report (Reporting Year 2025) (published 2026, covering 2025), via the Maryland Department of the Environment. Values appear as printed. Detected doesn't mean unsafe; most results are below federal limits.
The information on this site is for general education only and is not medical advice. Talk with a qualified health professional about health concerns. Water treatment equipment performance depends on the system, its certification, and proper maintenance. Data transcribed 2026-10-24. If you spot a difference from the published report, the published report is correct. Please let us know.
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