| 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.
|
