| 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. |