This system was not included in federal PFAS monitoring
FYI▾
Should I be concerned?
This system serves fewer than 3,300 people and was not required to participate in EPA UCMR5 testing. Absence of data is not the same as absence of contamination.
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A naturally occurring element found in rock and soil. Gets into drinking water through erosion of natural deposits or runoff from industrial and agricultural sources.
Why it matters
Long-term exposure is linked to increased risk of skin, bladder, and lung cancer. There is no safe level for arsenic — the MCL of 10 µg/L balances health protection with treatment feasibility.
What to do
If your water is near or above the limit, a reverse osmosis filter certified to NSF/ANSI 58 removes over 90% of arsenic. Point-of-use filters at the kitchen tap are effective and affordable.
What the research says
Multiple peer-reviewed studies have found congenital heart defects including atrial septal defects at concentrations as low as 0.0005 mg/L — 20x below the US federal limit.
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A naturally occurring metal found in mineral deposits. Enters water through erosion of natural deposits or discharge from drilling and metal refining operations.
Why it matters
At high levels, barium can cause increased blood pressure. Levels well below the MCL of 2 mg/L are not a health concern.
What to do
No action needed at typical detection levels. Barium is rarely found near its MCL in treated drinking water.
Fluoride▸
0.32 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
Naturally occurring mineral, also added to many water systems to prevent tooth decay. The MCL (4 mg/L) is much higher than the typical added amount (0.7 mg/L).
Why it matters
At levels near the MCL, long-term exposure can cause skeletal fluorosis (bone pain and tenderness). The secondary standard of 2 mg/L triggers a required public notice about dental fluorosis risk in children.
What to do
Levels below 2 mg/L are within the range considered safe. If above 2 mg/L, children under 9 may be at risk for dental fluorosis — talk to your pediatric dentist.
What the research says
Multiple peer-reviewed studies have found lower IQ in children and potential thyroid disruption at concentrations as low as 1.5 mg/L — 3x below the US federal limit.
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A screening test that measures total alpha radiation from all radioactive elements in water — including radium, uranium, and radon.
Why it matters
The MCL of 15 pCi/L protects against long-term cancer risk from radiation exposure.
What to do
No action needed at typical detection levels. If near the MCL, reverse osmosis and ion exchange filters can reduce radioactive contaminants.
Disinfectants — MRDL
Chlorine▸
1.15 mg/L
Reference: MRDL
Federal Maximum Residual Disinfectant Level. Legally enforceable EPA limit on residual disinfectant concentration in distributed water.
What is it?
Added intentionally to kill bacteria and viruses. A chlorine residual in your tap water means the disinfection is still active through the distribution system — this is by design.
Why it matters
The MRDL of 4 mg/L is the maximum allowed. Typical levels are 0.5–2 mg/L. Chlorine at normal levels is not a health concern — the disease risk from untreated water is far greater.
What to do
If you don't like the taste, let water sit in an open pitcher for 30 minutes or use an activated carbon filter. Both remove chlorine taste and odor.
WHO recommendation
Manganese▸
0.01 mg/L
Reference: WHO guideline
World Health Organization drinking-water guideline. International guidance, not legally enforced in the US.
What is it?
A naturally occurring metal that enters water through eroding rocks and soils, and occasionally from industrial sources. Common in groundwater, especially in some regions of the Midwest and Northeast.
Why it matters
Manganese is essential in small amounts but a developmental neurotoxin at higher exposures. Studies have linked manganese in drinking water to attention and learning difficulties in children, including ADHD, with effects detectable at levels below the EPA's aesthetic standard of 0.05 mg/L. The WHO sets a provisional health-based guideline of 0.08 mg/L; some researchers argue this should be lower. Infants drinking formula made with manganese-rich water may be particularly exposed. EPA's 0.05 mg/L secondary standard exists to prevent black or brown staining on laundry and fixtures — not as a health protection.
What to do
If manganese is at or near WHO's 0.08 mg/L guideline, a reverse osmosis filter certified to NSF/ANSI 58 removes most manganese. Activated carbon and standard pitcher filters do not effectively remove dissolved manganese. For infant formula preparation, parents in areas with detectable manganese may want to use filtered or bottled water — this is what MDH (Minnesota) and several other state health departments now recommend.
What the research says
Multiple peer-reviewed studies have found increased ADHD risk and lower IQ in children, with effects observed in a dose-response pattern from <5 µg/L upward (no clean threshold below which the association disappears) with a dose-response relationship across the range of concentrations found in drinking water.
World Health Organization drinking-water guideline. International guidance, not legally enforced in the US.
What is it?
Naturally present in most water sources. Also increases from road salt, water softeners, and natural mineral deposits.
Why it matters
There is no federal MCL for sodium. The WHO suggests a guideline of 200 mg/L for people on sodium-restricted diets. For most people, sodium in water is a small fraction of dietary intake.
What to do
If you're on a sodium-restricted diet and your water is above 20 mg/L, talk to your doctor. For most people, no action needed.
% of limit
Other measurements
These describe characteristics of the water that aren’t health risks at typical levels — mineral content, taste, hardness, and similar.