Fluoride
Found naturally in water. While low levels of fluoride are desirable, excessive amounts may stain teeth.
Arsenic
This toxic element is found naturally in soil and bedrock. Ingestion in high amounts can lead to serious health problems.
Chlorides
Small amounts of salt are natural. Higher levels are unnatural and may indicate a faulty water softener, road salt, septic waste or fertilizer contamination.
Lead
Houses built before 1985 may contain lead pipes or lead-based solder. Lead can cause serious health problems in young children.
Hydrogen Sulfide
A gas dissolved in water. It is easily detected by its rotten egg odor.
Coliform Bacteria
A natural part of the microbiology of soils, insects, and warm-blooded animals, coliform bacteria is the primary indicator for the presence of disease-causing organisms in water.
Manganese
A metal found in rock, which does not occur naturally in its pure form. It is often accompanied by iron and hydrogen sulfide and causes black stains. Evidence of manganese staining is typically found in the dishwasher.
Iron
Not considered hazardous to health, but when the level of iron exceeds 0.3 mg/l water may leave behind red, brown, or yellow stains on laundry, glassware, dishes and fixtures. The water may have a metallic taste and an offensive odor, or even restrict or clog piping and fixtures.
Nitrates
Elevated levels can be an indication of farm chemical or lawn fertilizer contamination, or even septic saturation. Nitrates can pose a serious health risk to infants.
High levels of sulfates can cause odors, leave spots, taste bitter and have a temporary laxative effect.
Hardness
Interferes with cleaning tasks from laundering and dishwashing to bathing and personal grooming. Clothes laundered in hard water may look dingy and feel harsh and scratchy. Dishes and glasses may be spotted when dry. Hard water may leave film on glass shower doors, shower walls, bathtubs, sinks, faucets, etc. Hair washed in hard water may feel sticky and look dull. These deposits also collect in household plumbing lines, water heaters and appliances, reducing their efficiency.