1998 report concludes that city's water is safe By David Lias "We are happy to report that in 1998 our water system was in compliance with all federal and state water quality requirements."
This statement, printed in bold capital letters, summarizes a four page report mailed by the city of Vermillion to its citizens late last week.
The report was compiled to inform citizens of the quality of the drinking water provided by the city. Vermillion is required by the U.S. Environmental Protection Agency (EPA) to test its water frequently for the presence and concentrations of over 90 different substances.
The South Dakota Department of Environment and Natural Resources (DENR) reviews the city�s testing data to ensure that Vermillion is providing safe drinking water and is complying with EPA regulations.
The source of the city�s drinking water is ground water from the Lower Vermillion � Missouri Outwash Aquifer. The city has four wells that range from 100 to 120 feet deep. Three wells are located in lower Vermillion between the Vermillion River and the bluff, while the other well is located on South Dakota Street in what is known as Ravine Hill.
The state allows Vermillion to test for some substances less than once per year because the concentrations of these substances do not change frequently. Some of the city�s data, though representative, are more than one year old.
According to the report, antimony, arsenic and nickel are substances that are naturally occurring in an aquifer. In Vermillion�s water, they are found at levels well below the highest level allowed by the EPA.
Some homes in Vermillion may also have lead and copper in their tap water. Those two substances aren�t present in the city�s water supply, however. They are introduced into consumers� homes from home plumbing fixtures.
Nitrate levels in Vermillion�s water in 1998 were below the highest level allowed by the EPA. Vermillion�s water tested at 0.4 mg/L on Dec. 8, 1998. Nitrate in drinking water at levels above 10 mg/L is a health risk for infants younger than six months of age. High nitrate levels can cause blue baby syndrome.
Total trihalomethanes (TTHMs) are chemicals produced by the chlorinating of drinking water. The city monitors for TTHMs on a yearly basis. Vermillion�s TTHMs levels are below the highest level currently allowed by the EPA.
The last test for Vermillion showed no detectable level of trihalomethanes. Some people who drink water containing trihalomethanes in excess of the maximum contaminant level allowed by the government over many years may experience problems with their kidneys, livers, or central nervous systems, and may have an increased risk of getting cancer.
The listing of finished water contaminants, according to the water quality report, shows the level of alpha emitters in Vermillion water to be less than 1. The highest level allowed is 15. The major source of alpha emitters is the erosion of natural deposits.
The level of lead detected in 1998 in the city�s finished water was 1. The highest level allowed is 15. Lead may be introduced to treated water supplies through corrosion of
household plumbing systems and the erosion of natural deposits.
Trihalomethane tested at a level less than 1 in the city�s finished water. The highest THM level allowed is 100. THMs are a byproduct of drinking water chlorination.
The water that is pumped from the aquifer and eventually winds up in Vermillion homes originally came from the earth�s surface, and very slowly seeped down into the aquifer. As water travels over the surface or through the ground, the report states, it dissolves naturally occurring minerals and can pick up substances resulting from the presence of animals or from human activity. Too much of any one substance, either naturally occurring or resulting from human activities can be considered a contaminant.
Contaminants that may be present in source water include:
? Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations and wildlife.
? Inorganic contaminants, such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial or wastewater discharges, or runoff from mining or farming activities
? Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff and residential uses.
? Organic chemical contaminants, including synthetic and volatile organic chemicals which are by-products of industrial processes and petroleum production. This type of contamination can also come from gas stations, urban stormwater runoff and septic systems.
? Radioactive contaminants, which are naturally occurring in some rocks in the Vermillion region.
Vermillion�s water treatment plant subjects the water freshly pumped from the aquifers to several processes to make it safe for human consumption. The water is aerated to remove iron and manganese.
Although the iron and manganese in Vermillion�s water doesn�t pose a health concern, these two naturally occurring substances can cause the water to appear brown or rust-colored, and can stain clothes and plumbing fixtures.
The city uses lime-soda ash softening to lower the hardness of the water. Sodium aluminate is added to settle the lime-soda ash out of the water. Poly-phosphate is added to control iron and manganese within the distribution system.
Carbon dioxide is used to control the pH of the water and the water is then filtered to remove bacteria, viruses and reduce iron and manganese. The water flows from the filters to a storage tank called a clearwell where chlorine is added as a disinfectant to kill bacteria and maintain a residual in the water for protection.
Fluoride is added in the clearwell to strengthen teeth and protect against tooth decay. The city pumps the water from the clearwell to a 1.5 million gallon storage reservoir by the treatment plant and from the reservoir the water is pumped to the city�s two water towers. The water then flows by gravity from the towers to Vermillion homes.
To ensure that tap water is safe to drink, the EPA prescribes regulations that limit the amount of certain contaminants in water provided by public water systems. FDA regulations establish limits for contaminants in bottled water that must provide the same protection for public health.
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 water poses a health risk, the report states. More information about contaminants and potential health effects can be obtained by calling the EPA�s Safe Drinking Water Hotline at 800-426-4791.
The report notes that some people may be more vulnerable to contaminants in drinking water than the general population.
Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly and infants can be particularly at risk from infections.
These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lesson the risk of infection by microbiological contaminants are available from the Safe Drinking Water Hotline.
Citizens with questions or input about Vermillion�s water supply may contact Water Superintendent Vern Hasenbank, 118 Church Street, Vermillion, SD 57069. His phone number is 677-7079.
Citizen input also may be expressed at a Vermillion City Council meeting. The council meets the first and third Mondays of every month at 7:30 p.m. in the council chambers at City Hall.