| 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.
|