Water Color Odor Appearance and Taste

Water Color Odor Appearance and Taste
Your First Evidence of a Problem

COLOR

Is your water safe to drink? Does it smell funny or is it cloudy or off-color? The increase in the reported cases of chemical spills, leaking oil tanks, toxic waste sites, and pesticide use may make you wonder about the quality and safety of your water. what is in your water. Whether you get your water from a public or a privately-owned public water system, or your own well or spring, having a safe source of drinking water is vital to the health of you and your family.

Changes in the appearance, taste, odor, and color may be your first evidence of a problem. Color in water can be caused by a number of contaminants such as iron which changes in the presence of oxygen to yellow or red sediment. Color from iron is referred to as "apparent color" rather than "true color". True color is distinguished from apparent color by filtering the sample.

SOURCE:

The most common source of true color is decaying organic matter such asthe yellowish "tea color" of water in tundra or wet bogs. True color is mostly found in surface water, although ground water may contain some color if the aquifer flows through a layer of buried vegetation, such as from a long buried slough of a river.

Potential Health Hazards:

Color is not a toxic characteristic, but is listed by the EPA as a secondary (aesthetic) parameter affecting the appearance and palatability of the water. When chlorinated, color-causing organic matter may form chlorinated organic compounds such as trihalomethanes. Chloroform is a common trihalomethane, and is along with several others, considered to be a potential carcinogen. For this reason ADEC limits total trihalomethanes(TTHM's) in public water supplies to 0.1 ppm (100 ppb). Color is measured in units based on a platinum-cobalt standard solution which forms a yellow tint and is limited to 15 units in public water supplies.

TREATMENT:

Color can be removed by activated carbon filters, sometimes marketed as taste and odor filters. The activated carbon or charcoal must be replaced after a period of time when its capacity for adsorption of the color is exhausted. Another treatment method is coagulation and sedimentation using alum or other chemicals. This process is normally used only in large plants since its complexity requires the care of a trained water treatment plant operator.

TESTING:

Color analysis is done by visual comparison to a set of platinum-cobalt standards in Nessler tubes. Sample collection is done in a clean rinsed bottle which should be refrigerated if stored for more than a few hours. If the color of the water exceeds 15 color units and the water is being chlorinated, we suggest having the water examined for total trihalomethanes by gas chromatography. This is a more expensive and time consuming analysis, but is extremely sensitive with detection limits down to the ppb level. Sample vials specially designed to eliminate the air space above the sample are required for sampling.Drinking Water Smells, Smelly Water, Taste and Odor Problems Besides the parameters described in this report, the color, appearance, taste, smell, and odor of drinking water is the first clue to the homeowner that there may be a problem with the water. It is important to note that some chemicals, especially organic compounds and bacterial agents, may be at toxic or at pathogenic (i.e., disease causing) levels, without any observable clues to a problem.

Primary treatment method used to handle taste, smell, odor, or color problems may include filtration, filtration through a carbon filter, softening, chlorination and distillation. The type of pretreatment would depend on the concentration and type of contamination and associated water quality.

Taste, Smell, Odor, and Color and Associated Potential Problem

Taste Problems
Salty-brackish
High sodium

Alkali Taste
High hardness, total dissolved solids, high alkalinity

Metallic Taste
Low pH, high metal content, corrosive water A metallic taste can be caused by inorganicchemicals such as iron (at levels over 0.004 mg/l), copper (2-5 mg/l), and

zinc (4-9 mg/l).

Odor / Smell Problems Drinking Water
Rotten-Egg Odor Smell,Musty Odors Smell Earthy, musty, grassy, fishy, vegetable and cucumber Hydrogen sulfide , sulfate-reducing bacteria Softwater reactions in electric water heaters, algal bioproducts algal by-products

Oily Smell Gasoline or oil contamination, possibly nuisance bacteria ethane

Like Gas Smell
Organic decomposition - note natural gas has no odor, but the natural gas delivered to your home has mercaptans (sulfur -compounds) added that create a strong odor to help detect leaks.

Phenolic Smell
Industrial or gasoline contamination

Chemical Smell
Organic chemicals, Industrial

Color

Milky
Precipitation of carbonates excessive air, suspended solids









Blackish Tint Reactions with manganese and possibly iron, IRB/ Slime Bacteria

Yellowish Tint
Presence of humic or fluvic compounds, iron, IRB bacteria









Reddish Tint Presence of Dissolved or precipitated iron, iron, IRB bacteria
(Source: Driscoll, 1986; Lehr, 1980)