ÌÇÐÄvlog¹ÙÍø

Plant Statistics
Public Water System ID	310683
Resident Population Served	1600 persons/day
Non-Resident Population Served	3000 persons/day
Total Population Served	4600 persons/day

 

Finished Water Quality
Temperature	50 - 56 degrees F.
Iron	0.01 mg/l
Manganese	0.0 mg/l
Silica	30 mg/l
Hardness	280 - 300 mg/l as CaCO3
pH	7.3 - 7.6
Turbidity	.07 - .09 NTU (Nephelometric Turbidity Units)
Free Chlorine Residual	0.35 - 0.66 mg/l (on Campus)
Fluoride	0.19 mg/l (naturally occurring)
Benzene	less than 0.002 ppb or ug/l (below detection limit)
TTHM	44 ug/l or ppb
Lead	.005 mg/l (action limit = 0.015 mg/l)
Copper	.508 mg/l (action limit = 1.3 mg/l)
Nitrate	1.93 mg/l MCL = 10 mg/l

 

Other Treatment Problems

Crenothrix (Bacterial Iron - a nuisance bacteria, not harmful)
Hydrogen Sulfide (H₂S)

Othorthophosphate added to control corrosion

Definitions

• mg/l = Milligrams per liter, same as parts per million (ppm)
• ug/l = Micrograms per liter, also expressed as parts per billion (ppb)
• MCL = Maximum contaminant level is the highest level of a contaminant allowed in drinking water
• TTHM = Total Trihalomethanes
• NTU = Nephelometric Turbidity Units is a standard measurement of cloudiness in water, more sensitive than even the human eye can see. We monitor turbidity because it is a good indicator of the effectiveness of our water filtration system. High turbidity can hinder the effectiveness of disinfectants

On December 6, 1974 the Safe Drinking Water Act (SDWA) was signed into law. The purpose of the law is to assure that the nation's water supply systems serving the public meet minimum national standards for the protection of public health. The SDWA covers all public water systems with piped water for human consumption with at least 15 service connections or a system that regularly serves at least 25 individuals.

The SDWA directed the U.S. Environmental Protection Agency (EPA) to establish national drinking water standards. These standards limit the amount of certain contaminants provided by public water. Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water. All drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk.

The water delivered to you must meet strict rules of purity. In the Water Quality Reports, you see the MCL's expressed in parts per billion. Have you ever heard the expression, "to win the publisher clearing house sweepstakes is a one chance in a million? Nearly everyone has difficulty understanding what one in a million actually means. In the drinking water industry we take the concept of one in a million very seriously, since this is how we measure very small traces of chemicals or contaminants in water. When we test and measure the level of contaminants in water, we record and report the results in terms of - parts per million, or milligrams per liter, written as ppm or mg/l respectively. A smaller unit of detection we regularly use is parts per billion, or micrograms per liter, written as ppb or \xb5g/l.

One part per million, or one milligram per liter, would be equal to putting ONE drop of water into 10 gallons of water. One part per billion, or one microgram per liter, would be equal to adding one drop of water to a 10,000 gallon swimming pool. (A part per billion is 1,000 times smaller than a part per million.)

To better understand the possible health effects that are described below for regulated contaminants, a person would have to drink 2 liters, (a little more than two quarts), of water every day at the Maximum Concentration Level (MCL) for a lifetime, (which at present is about 70 to 80 years), to have a "one in a million chance" of having the described health effect.

Arsenic - Some people who drink water containing arsenic in excess of the MCL (50 parts per billion) over many years could experience skin damage or problems with their circulatory system and may have an increased risk of getting cancer.

Barium - Some people who drink water containing barium in excess of the MCL (2000 parts per billion) over many years could experience an increase in their blood pressure.

Benzene - Some people who drink water containing benzene in excess of the MCL (5 parts per billion) over many years could experience anemia or a decrease in blood platelets, and may have an increased risk of getting cancer.

Chromium - Some people who drink water containing chromium well in excess of the MCL (100 parts per billion) over many years could experience allergic dermatitis.
COPPER: Copper is an essential nutrient, but some people who drink water containing copper in excess of the action level (1300 parts per billion) over a relatively short amount of time could experience gastrointestinal distress. Some people who drink water containing copper in excess of the action level over many years could suffer liver or kidney damage. People with Wilson's Disease should consult their personal doctor.

Lead - Infants and children who drink water containing lead in excess of the action level (15 parts per billion) could experience delays in their physical or mental development. Children could show slight deficits in attention span and learning abilities. Adults who drink this water over many years could develop kidney problems or high blood pressure.

Nitrate - Infants below the age of six months who drink water containing nitrate in excess of the MCL (10,000 parts per billion) could become seriously ill and, if untreated may die. Symptoms include shortness of breath and bluebaby syndrome.

Total Trihalomethanes - Some people who drink water containing TTHM's in excess of the MCL (80 parts per billion) over many years may experience problems with their liver, kidneys, or central nervous systems, and may have an increased risk of getting cancer.

Iron-related or iron-precipitating bacteria (Crenothrix) are a diverse group of microorganisms widely distributed in nature. They are found in fresh and salt waters, in soils, and on desert rock surfaces. Iron bacteria do not normally cause diseases to humans or animals, but rather, they are a nuisance microorganism.

These bacteria are capable of transforming iron and sometimes manganese to an insoluble form that can cause severe fouling or plugging which reduce flows in pipes and plumbing fixtures, in well pumps, treatment plants, and distribution systems. If your home is supplied by well water, most likely you have, and are, seeing, firsthand, the results of what is meant by this bacteria being a "nuisance" microorganism.

These bacteria are the ones responsible for making that reddish-orange, slimy-looking deposit inside the flush water holding tank on the back of your toilet. These bacteria do not need light or air to proliferate or multiply. They flourish and they obtain energy by the oxidation of dissolved iron in the water from the ferrous to the ferric state. The ferric form is precipitated as ferric hydroxide (Fe(OH)₃).

When the temperature rises in their environment, like what happens to the water sitting overnight in the toilet tank rising to room temperature, or if air or oxidants are added to their environment, they tend to grow much faster and in greater quantities. What you are seeing in your toilet tank is the result of the iron bacteria converting soluble iron, from a liquid state (Fe²⁺), to the insoluble form, (tiny rusty flecks), many times referred to as "red water" (ferric iron (Fe³⁺)). It is in this stage that iron, and manganese, become deposited on the outside of the bacteria cell sheaths and the slimes they produce.

PLEASE, don't be afraid of the water! As mentioned earlier in this article, the bacteria are not harmful, they just look bad and sometimes add an iron taste to your water. Many persons have just come to accept them as part of the Alaskan way of life, as they truly are, pesky little microorganisms. 

Getting back on track, the bacteria cell sheaths and slimes become encrusted with iron and manganese and it is then that you begin seeing the prominent red-orange color. This bacteria is the cause of various clogging and fouling problems with sand filters, iron filters, water softeners, pumps, even the piping. In a water treatment plant these bacteria can and do interfere with the filtration process and can also cause problems in the distribution systems. 

Because these bacteria can cause taste and odor problems, frothing or foaming problems, can foul or plug dishwashers, washing machines, toilets, tubs and stain clothing, sinks and tubs, we work diligently to remove every trace of these bacteria before the water ever leaves the final filtration process of the water treatment plant. Any of the "rusty" or "dirty" looking water that does occasionally come out of the faucets and taps on campus is caused by other problems occurring in the distribution mains, as well as the "Taste and color" problems you experience on campus.

Arsenic	Chlorine	Fuel Oils	Nitrate
Barium	Chromium	Iron and Manganese	Turbidity
Benzene	Fluoride	Lead	Zinc