Common water quality problems and their methods of treatment

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Use the following symptoms to determine the possible cause of problems with your water quality – these symptoms can all be felt, smelled, tasted or seen. Watch out… some of the symptoms may indicate serious problem!

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. However if consumed, could lead to kidney/ bladder stones Cation exchange water softener or reverse osmosis.
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.
  • Dissolved hydrogen sulfide gas.
  • Presence of sulfate reducing bacteria in raw water.
Various effects
  • Manganese greensand filter - constant chlorination followed by filtration/ dechlorination.
  • 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
  • Locate and eliminate source of seepage - then heavily chlorinate well.
  • 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.

D. Sense of Sight

Impurity or Contaminant Symptom Cause Health Effects Means of Treatment


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.
  • 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
  • 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.
  • Over 10 ppm Fe+ chlorination with sufficient retention tank time for full oxidation followed by filtration/ dechlorination.
  • In warm climates residual aerator and filtration will substantially reduce iron content.
  • 2. Precipitate iron (water will not clear when drawn).
Various effects
  • Up to 10 ppm iron removed by manganese greensand filter, if pH 6.7 or higher, or;
  • Manganese treated, non-hydrous aluminum silicate filter where pH of 6.8 or higher and oxygen is 15% of total iron content.
  • 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
  • Adsorption via special macro-porous Type I anion exchange resin regenerated with salt (NaCl) up to 3.0 ppm.
  • Manganese greensand or manganese treated sodium alumino-silicate under proper set of conditions.
Milky water Cloudiness of water when drawn.
  • Some precipitant sludge created during heating of water.
  • High degree of air in water from poorly functioning pump.
  • Excessive coagulant-feed being carried through filter.
  • Various effects

  • Aesthetic only

  • Various effects
  • Blow down domestic or commercial hot water heater tank periodically.
  • Water will usually clear quickly upon standing.
  • 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
  • Excessive salt content.
  • High temperature drying creates chloride concentration accelerating corrosion.
Various effects
  • Use other chloride resistant metals.
  • Reduce total dissolved solids by reverse osmosis.

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