Howard County Department of Public Works: what's in the water
19 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 Howard County Department of Public Works, 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? Howard County buys its water from Baltimore City (Ashburton and Montebello plants) and WSSC Water (Patuxent plant). Much of western Howard County uses private wells. Check your water bill to confirm your provider.
Everything Howard County Department of Public Works 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.
LeadMetals4 ppb15 ppbAction level2023
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: 4 ppb (90th percentile) · range ND–6.6 · Action level 15 · health goal 0 · violation: No · sampled 2023
PFASIndustrial & farm chemicals · 5 resultsAshburton 2.94 · Patuxent 1.8 · Montebello 1.88 ppt +4 more4 pptMCL2025
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
- Perfluorooctanoic Acid [PFOA]: Ashburton 2.94 · Patuxent 1.8 · Montebello 1.88 ppt (amount detected by supply) · MCL 4 · health goal 0 · violation: No · sampled 2025
- Perfluorooctanesulfonic Acid [PFOS]: Ashburton 3.33 · Patuxent 1.8 · Montebello 1.68 ppt (amount detected by supply) · MCL 4 · health goal 0 · violation: No · sampled 2025
- Perfluorohexanesulfonic Acid [PFHxS]: Ashburton ND · Patuxent 1.6 · Montebello ND ppt (amount detected by supply) · MCL 10 · health goal 10 · violation: No · sampled 2025
- Perfluorobutanesulfonic Acid [PFBS]: Ashburton 1.75 · Patuxent 2 · Montebello 2.21 ppt (amount detected by supply) · violation: No · sampled 2025
- PFHxA, PFBA, PFPeA, PFHpA (unregulated): PFHxA: Ashburton 2.9 · Patuxent 1.9 · Montebello 2.08. PFBA 2.5, PFPeA 2.3, PFHpA 0.6 (Patuxent) ppt (amount detected by supply) · sampled 2025
NitrateNutrientsAshburton 5.81 · Patuxent 1.4 · Montebello 1.57 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: Ashburton 5.81 · Patuxent 1.4 · Montebello 1.57 ppm (amount detected by supply) · range 0.4–5.81 · MCL 10 · health goal 10 · violation: No · sampled 2025
Total TrihalomethanesDisinfection byproducts68 ppb80 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]: 68 ppb (amount detected (howard county)) · range 23–115 · MCL 80 · health goal NA · violation: No · sampled 2025
Haloacetic AcidsDisinfection byproducts31 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]: 31 ppb (amount detected (howard county)) · range ND–32 · MCL 60 · health goal NA · violation: No · sampled 2025
RadiumRadiological0.1 pCi/L5 pCi/LMCL2025
Your body
According to EPA, long-term exposure above the federal limit has been linked to an increased risk of cancer.
Your home & appliances
Radium does not affect plumbing, but it can build up in softener resin and filter media.
What it is
A naturally occurring radioactive element in some rock and soil, found in certain Maryland aquifers. Reports list radium-226, radium-228, or the two combined.
Exactly as reported
- Radium 228: 0.1 pCi/L (amount detected (patuxent supply)) · range 0.1–0.2 · MCL 5 · health goal 0 · violation: No · sampled 2025
Beta/photon emittersRadiological4.4 pCi/L50 pCi/LMCL2025
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: 4.4 pCi/L (amount detected (patuxent supply)) · range ND–4.4 · MCL 50 · health goal 0 · violation: No · sampled 2025
CopperMetals0.1 ppm1.3 ppmAction level2023
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: 0.1 ppm (90th percentile) · range 0.001–0.2 · Action level 1.3 · health goal 1.3 · violation: No · sampled 2023
FluorideMineralsAshburton 0.90 · Patuxent 0.9 · Montebello 1.09 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: Ashburton 0.90 · Patuxent 0.9 · Montebello 1.09 ppm (amount detected by supply) · range 0.07–1.09 · MCL 4 · health goal 4 · violation: No · sampled 2025
ChlorineDisinfectants0.45 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: 0.45 ppm (amount detected (howard county)) · range 0.01–1.12 · Max. disinfectant 4 · health goal 4 · violation: No · sampled 2025
BariumMetalsAshburton 0.0238 · Patuxent 0.04 · Montebello 0.0407 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: Ashburton 0.0238 · Patuxent 0.04 · Montebello 0.0407 ppm (amount detected by supply) · range 0.0199–0.0407 · MCL 2 · health goal 2 · violation: No · sampled 2025
TurbidityWater qualityAshburton 0.12 · Patuxent 0.05 · Montebello 0.22 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
- Turbidity: Ashburton 0.12 · Patuxent 0.05 · Montebello 0.22 NTU (amount detected by supply) · MCL TT · violation: No · sampled 2025
AluminumMetals20 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): 20 ppb (amount detected (patuxent supply)) · range 10–40 · Secondary 200 · violation: No · sampled 2025
ChlorideMinerals43 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): 43 ppm (amount detected (patuxent supply)) · range 35–55 · Secondary 250 · violation: No · sampled 2025
ManganeseMinerals2 ppb50 ppbSecondary2025
Your body
Manganese is a nutrient in small amounts. At higher levels in drinking water, it has been linked in some studies to effects on children’s learning and behavior. EPA has a health advisory level in addition to its cosmetic standard.
Your home & appliances
Manganese causes black or brown stains on fixtures and laundry, a bitter taste, and black sediment in pipes and water heaters.
What it is
A naturally occurring mineral often found with iron in groundwater.
Exactly as reported
- Manganese (secondary): 2 ppb (amount detected (patuxent supply)) · range 3–8 · Secondary 50 · violation: No · sampled 2025Note: Amount and range shown exactly as printed.
SulfateMinerals5.9 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): 5.9 ppm (amount detected (patuxent supply)) · range 4.4–7.1 · Secondary 250 · violation: No · sampled 2025
HardnessMinerals70 ppmNo 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
- Hardness, Total [as CaCO3] (unregulated): 70 ppm (amount detected (patuxent supply)) · range 58–86 · sampled 2025
SodiumMinerals16 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): 16 ppm (amount detected (patuxent supply)) · range 13–22 · sampled 2025
Taste & odor compoundsWater qualityGeosmin 2.9 · 2-MIB 2.2 pptNo federal limit2025
Your body
Geosmin and 2-MIB are considered aesthetic issues, not health risks.
Your home & appliances
They have no effect on plumbing, but they can make water and ice taste earthy.
What it is
Natural compounds made by algae and soil bacteria in rivers and reservoirs that give water an earthy or musty taste. People can notice them at a few parts per trillion.
Exactly as reported
- Geosmin and 2-Methylisoborneol (unregulated): Geosmin 2.9 · 2-MIB 2.2 ppt (amount detected (patuxent supply)) · range 2.0–9.2 · sampled 2025
Source: Howard County Department of Public Works, 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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