Well Water Tests
What is Tested and Why?
EPA Guidance on Well Water
The Environmental Protection Agency (EPA) provides guidance to ensure the safety and quality of drinking water from private wells. Conduct annual checkups and maintenance to ensure the well is functioning properly and remains free from contaminants.
Arsenic
Limit 0.010 mg/L
Health Concerns:
Skin damage or problems with circulatory systems and may have increased risk of getting cancer. Test more often if detected or in areas with known Arsenic issues
Potential Sources:
Erosion of natural deposits; runoff from orchards; runoff from glass & electronics production wastes
Cadmium
Limit 0.005 mg/L
Health Concerns:
Kidney damage
Potential Sources:
Corrosion of galvanized pipes; erosion of natural deposits; discharge
from metal refineries; runoff from waste batteries and paints
Chloride
Limit 250 mg/L
Health Concerns:
Can affect water taste and odor
Coliform Bacteria
Limit: Absence (0 detectable)
Health Concerns:
Coliforms are bacteria that indicate that other, potentially harmful bacteria may be present. See E.coli Bacteria
Conductivity
Limit 1000 µS/cm
The U.S. Environmental Protection Agency (EPA) recommends that drinking water conductivity should be less than 1000 µS/cm to ensure it is safe and not overly contaminated. Conductivity values outside this range may indicate potential water quality issues that require further investigation.
Copper
Limit: 1.3 mg/L
Health Concerns:
Short-term exposure: Gastrointestinal distress. Long- term exposure: Liver or kidney damage. People with Wilson’s Disease should consult their personal doctor if the amount of copper in their water exceeds the action level
Potential Sources:
Corrosion of household plumbing systems; erosion of natural deposits
E.coli Bacteria
Limit: Absence (0 detectable)
Health Concerns:
E.coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes may cause short term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a special health risk for infants, young children, and people with severely compromised immune systems.
Possible Sources:
Human and animal fecal waste
Fluoride
Limit: 4 mg/L
Health Concerns:
Bone disease (pain and tenderness of the bones); children may get mottled teeth
Possible Sources:
Water additive which promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories
Hardness
Considered to be Soft Water if below 50 mg/L, Hard Water if above 200 mg/L
Health Concerns:
Can affect water taste and odor
Additional Information:
The EPA has not set a legal limit for water hardness, but it provides guidelines for secondary drinking water standards to help manage aesthetic issues like taste and scaling. Many water utilities aim to keep hardness levels low to avoid unpleasant effects, and homeowners often use water softeners to reduce hardness.
Optimum Range: 50 mg/L to 200 mg/L
Heterotrophic plate count (HPC)
Limit: 500 bacterial colonies per milliliter (CFU/mL)
Health Concerns:
HPC has no health effects; it is an analytic method used to measure the variety of bacteria that are common in water. The lower the concentration of bacteria in drinking water, the better maintained the water system is
Possible Sources:
HPC measures a range of bacteria that are naturally present in the environment
Iron
Limit: 0.3 mg/L
Health Concerns:
Can affect water taste and odor
Lead
Limit: 0.015 mg/L
Health Concerns:
Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilities; Adults: Kidney problems; high blood pressure
Possible Sources:
Corrosion of household plumbing systems; erosion of natural deposits
Magnesium
Limits: No MCL values, typical concentrations range from 1 to 100 mg/L
Health Concerns:
EPA provides no MCL, as it is generally considered non-toxic and even beneficial in moderate amounts, often contributing to water hardness, though high levels can affect taste or cause scaling in pipes.
Potential Sources:
Magnesium in well water originates from natural rock and soil dissolution or human sources like fertilizers, road salts, and industrial waste, varying by local geology, water hardness, and pH.
Manganese
Limit: 0.3 mg/L
Health Concerns:
High manganese can cause neurological health risks (especially in infants) above 0.3 mg/L, and aesthetic issues (bitter taste, black staining) above 0.05 mg/L.
Possible Sources:
Common sources include natural rock/soil leaching and human activities like agricultural runoff or industrial waste.
Mercury
Limit 0.002 mg/L
Health Concerns:
Kidney damage
Potential Sources:
Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands
Nitrate
Limit: 10 mg/L
Health Concerns:
Infants below the age of six months who drink water containing nitrate in excess of their MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome
Possible Sources:
Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Nitrite
Limit: 1000 µg/L
Health Concerns:
Infants below the age of six months who drink water containing nitrite or nitrite in excess of their MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome
Possible Sources:
Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Sodium
No Limit unless on low sodium intake diets
Health Concerns:
For those on low-sodium intake diets (<500mg/day) the limit is 20mg/L and can affect health (e.g., hypertension, kidney issues).
For those on a normal diet the suggested acceptable range is 30-60 mg/L, above that It may cause salty taste, plumbing corrosion, and plant damage.
Domestic water softeners can increase sodium levels to more than 300 mg/L in drinking water (NAS 1977).
Possible Sources:
Natural mineral leaching from rocks and soils; human sources like road salt runoff, leaking septic systems, fertilizers, industrial waste, sewage, and water softener backwash.
pH
Limit: 6.5 to 8.5
Health Concerns:
Can affect water taste and odor
