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About the Authority
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If you and I were to conduct a sidewalk poll on the most important concern the average women or man
might have regarding water pollution, it's a safe bet that it would be assurance that the water flowing from
their kitchen or bathroom faucet was safe to drink. Such a public concern stems from the recognition that
human health is directly threatened by impure drinking water. There exists today a growing realization that
the quality of drinking water is linked to the quality of our environment as a whole, inasmuch as air
pollution, leachates from landfills, sewage, toxic chemicals, etc., all can invade water supplies. Water
sources from ground water aquifers can be affected by storm water runoffs, pollution discharges to lakes or
rivers being contaminated by way of industrial effluent discharges to raw sewage affecting any point source
water supply.
Municipal officials were tasked to institute various methods for drinking water treatment, primarily
filtration and chlorination that largely succeeded in eliminating the serious water-related epidemic diseases
of the past. Nethertheless, the organisms that cause typhoid, cholera, dysentery, and other gastrointestinal
ailments are still in our midst, ready to make their presence known whenever a breakdown in water
treatment processes affords such pathogens to penetrate our technology lines of defense.
Unlike sewage treatment, which is intended to reduce levels of wastewater contamination to the point
where the effluent can be returned to a stream without provoking serious health or ecological damage,
drinking water treatment theoretically should entirely remove all contaminants in the water, or at least
reduce to acceptable levels. All drinking water, regardless of its source, should be treated prior to
consumption, since it can never be safely assumed that such water is totally free from contamination.
Although the precise details of drinking water treatment vary from plant to plant, depending largely on the
actual quality of the local raw water supply (i.e. water from surface water sources that are polluted would
require more extensive treatment than does well water drawn from a high quality uncontaminated aquifer),
the basic steps in the process can be described as follows:
- Sedimentation incoming raw water is detained in a quiet pond or tank for a period of time to
allow suspended materials to settle out.
- Coagulation alum (hydrated aluminum sulfate) is added to the water to cause smaller suspended
solids to form flocs which than precipitate to the bottom of the holding tank or pond.
- Filtration water passes through beds of uncontaminated sands, crushed anthracite coal, or
diatomaceous earth further reducing many bacterial cells and protozoans.
- Disinfection most commonly with chlorine (ozone, bromine, iodine or ultraviolet light) when
used with preceding steps.
In many water treatment plants, particularly those utilizing well water, preliminary pretreatment also
includes aerating the water to remove iron and dissolved gases such as hydrogen sulfide (rotten egg smell)
which impart objectionable tastes and odor to water. The current tools for removing iron may also include
water contact with a permanganate sand bed and chlorine in the operation. As to where we live, water may
contain excessive amounts of calcium or magnesium salts. These minerals cause the water to be hard.
Lime, soda ash is added to the water or the Ion Exchange process is used to soften the water. Activated
Carbon bed exchange filters are quite often used as dependent on the initial water source to remove organic
contaminates at a process point before reaching the user. To further ensure that the treatment process is
working properly, laboratory testing should be carried out on a regular basis. Municipalities are required to
have testing performed for certain parameters as per the 1974 Safe Drinking Water Act. Discloser of their
findings on those special tests is provided for view from the municipalities that service your home or
business.
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