Signs of Common Water Quality Problems

Taken from: Manual of Individual and Non-Public Water Supply Systems
(EPA 570/9-91-004 / May 1991) APPENDIX E: Identification by Human Senses

Note: This information has been taken principally from a paper titled "Sensitivity: A Key Water Conditioning Skill" by Wes McGowan. The paper was published in Water Technology, September/October 1982.

The following chart is intended to serve as a general guide for consumers in determining the cause of problems with their water that can be felt, smelled, tasted, or seen. In some cases, these symptoms may indicate a serious problem -- in others, only the taste and smell of tap water (its aesthetics) may be affected, not its safety. For each symptom, EPA has indicated the likely cause, and the possible health effects (or whether the concern is aesthetic only) based on the likely cause. EPA cannot guarantee, however, the exact cause of any water quality problem.

If the symptoms indicate a potential health problem, test the water to determine what contaminants are present. Check with your state laboratory certification officer to find a certified laboratory near you to do your own testing, or read your annual water quality report to see the results of testing conducted by your supplier.

Once you know for sure what contaminants are in your water, you can find out if the contaminant is one that EPA sets a drinking water standard for due to its potential health effects.

A. Sense of Feeling

Impurity or Contaminant	Symptom	Cause	Health Effects	Means of Treatment
Hard Water	Soap curd, and scum in wash basins & bathtub. Whitish scale deposits in pipes, water heater & tea kettle.	Calcium (limestone) and magnesium salts.	Aesthetic only	Cation exchange water softener.
Grittiness	Abrasive texture to water when washing or residual left in sink.	Excessively fine sand, silt in water.	Various -- sand could trap contaminants	Sand trap in ultra-filtration.

B. Sense of Smell

Impurity or Contaminant	Symptom	Cause	Health Effects	Means of Treatment
Odor	Musty, earthy or wood smell.	Generally, harmless organic matter.	Aesthetic only	Activated carbon filter.
	Chlorine smell.	Excessive chlorination.	Could occur from formation of disinfection byproducts	Dechlorinate with activated carbon filter.
	Rotten egg odor - tarnished silverware.	1. Dissolved hydrogen sulfide gas. 2. Presence of sulfate reducing bacteria in raw water.	Various effects	1. Manganese greensand filter - constant chlorination followed by filtration/ dechlorination. 2. Constant chlorination followed by activated carbon filter.
	Hot water, rotten egg odor.	Action of magnesium rod in hot water heater.	Various Effects	Remove magnesium rod from heater.
	Detergent odor, water foams when drawn.	Seepage of septic discharge into underground water supply.	Disease-causing microorganisms may be present	1. Locate and eliminate source of seepage - then heavily chlorinate well. 2. Activated carbon filter will adsorb limited amount.
	Gasoline or oil (hydro-carbon) smell.	Leak in fuel oil tank or gasoline tank seeping into water supply.	Fuel components may be toxic or carcinogenic	No residential treatment. Locate and eliminate seepage.
	Methane gas.	Naturally occurring caused by decaying organics.	Various effects	Aeration system and repump.
	Phenol smell (chemical odor).	Industrial waste seeping into surface or ground water supplies.	Various -- compounds may be carcinogenic	Activated carbon filter will adsorb short-term.

C. Sense of Taste

Impurity or Contaminant

Symptom

Cause

Health Effects

Means of Treatment

Taste

Salty or brackish.

High sodium content.

Aesthetic only

1. Deionize drinking water only with disposable mixed bed - anion/cation resins; or

2. Reverse osmosis; or

3. Home distillation system.

Alkali taste.

High dissolved mineral containing alkalinity. (Stained aluminum cookware.)

Aesthetic only

Reduce by reverse osmosis.

Metallic taste.

1. Very low pH water (3.0-5.5).

2. Heavy iron concentration in water above 3.0 ppm Fe.

3. Leaching of lead and copper

Various -- depends on cause

1. Correct with calcite type filter (see Acid Water).

2. (See Iron Water).

D. Sense of Sight

Impurity or Contaminant	Symptom	Cause	Health Effects	Means of Treatment
Turbidity	Dirt, salt, clay.	Suspended matter in surface water pond, stream or lake.	Turbid water may contain disease causing microorganisms	"Calcite" or Neutralize (media) type filter - up to 50 ppm
	Sand grit, silt or clay substances.	Well sand from new well or defective well screen.	Turbid water may contain disease causing microorganisms	Sand trap and/or new well screen
	Rust in water.	Acid water causing iron "pick-up."	Turbid water may contain disease causing microorganisms	Neutralizing calcite filter to correct low pH acidity and remove precipitated iron
	Gray string-like fiber.	Organic mater in raw water algae, etc.	Turbid water may contain disease causing microorganisms	Constant chlorination followed by activated carbon filter to dechlorinate.
Acid water	Green stains on sinks and silver, porcelain bathroom fixtures. Blue-green cast to water.	Water which has high carbon dioxide content (pH below 6.8) reacting with brass and copper pipes and fittings.	Could lead to health effects if acid water causes leaching of lead and copper	1. Neutralizing calcite filter down to pH of 5.5, or 2. Calcite/ Magnesia - oxide mix (5 to 1) for higher flow rate and to correct very low pH water. 3. Soda ash chemical feed followed by filtration.
Discolored water red, "Iron" water	Brown-red stains on sinks and other porcelain bathroom fixtures. Water turns brown-red in cooking or upon heating. Clothing becomes discolored.	1. Dissolved iron in influent (more than 0.3 ppm Fe+) water appears clear when first drawn at cold water faucet. Above 0.3 ppm Fe causes staining.	Various effects	1. Can remove 0.5 ppm of Fe+ for every grain/gal of hardness to 10 ppm with water softener and minimum pH of 6.7. 2. Over 10 ppm Fe+ chlorination with sufficient retention tank time for full oxidation followed by filtration/ dechlorination. 3. In warm climates residual aerator and filtration will substantially reduce iron content.
		2. Precipitate iron (water will not clear when drawn).	Various effects	1. Up to 10 ppm iron removed by manganese greensand filter, if pH 6.7 or higher, or; 2. Manganese treated, non-hydrous aluminum silicate filter where pH of 6.8 or higher and oxygen is 15% of total iron content. 3. Downflow water softener with good backwash, up to 1.0 ppm Fe. Above 1 ppm to 10 ppm use calcite filter followed by downflow water softener. Calcite media type filter to remove precipitated iron.
	Brownish cast does not precipitate.	Iron pick-up from old pipe with water having a pH below 6.8. Organic (bacterial) iron.	Various effects	1. Treat well to destroy iron bacteria with solution of hydrochloric acid then constant chlorination followed by activated carbon media filtration and dechlorination. 2. Potassium permanganate chemical feed followed by filtration.
	Reddish color in water sample after standing 24 hours.	Colloidal iron.	Various effects	Constant chlorination followed by activated carbon media filter dechlorination.
Yellow water	Yellowish cast to water after softening and/or filtering.	Tannins (humic acids) in water from peaty soil and decaying vegetation.	Various effects	1. Adsorption via special macro-porous Type I anion exchange resin regenerated with salt (NaCl) up to 3.0 ppm. 2. Manganese greensand or manganese treated sodium alumino-silicate under proper set of conditions.
Milky water	Cloudiness of water when drawn.	1. Some precipitant sludge created during heating of water. 2. High degree of air in water from poorly functioning pump. 3. Excessive coagulant-feed being carried through filter.	1. Various effects 2. Aesthetic only 3. Various effects	1. Blow down domestic or commercial hot water heater tank periodically. 2. Water will usually clear quickly upon standing. 3. Reduce coagulant quantity being fed, service filters properly.
Very high chloride content in water	Blackening and pitting of stainless steel sinks and stainless ware in commercial dishwashers	1. Excessive salt content. 2. High temperature drying creates chloride concentration accelerating corrosion.	Various effects	1. Use other chloride resistant metals. 2. Reduce total dissolved solids by reverse osmosis.

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