| 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.
|