Water Quality Report

2009 Water Quality Report

The information on this page is from the annual Columbia Water and Light Water Quality Report published each spring for the previous year's testing results. The content is created under guidelines set forth by the Environmental Protection Agency for the Consumer Confidence Report.

Columbia's Water Exceeds Standards

Columbia’s water is tested more frequently and more thoroughly than is required by law. The well water is monitored for any possibility of contamination. More than 4,000 tests are run each year on samples from 40 locations throughout Columbia.

This water quality report is a requirement of the Environmental Protection Agency’s Safe Drinking Water Act. This report lists only those substances found in measurable quantities in Columbia’s drinking water. Of the 83 regulated substances tested for, only 9 substances were found. Not listed in this report are the many contaminants for which the water was tested but none was detected.

In 2009, the water we supplied to our customers met all water quality standards set by the U.S. Environmental Protection Agency and the Missouri Department of Natural Resources. Columbia Water & Light completed the change of the water disinfection process to use chloramine as a secondary disinfectant. This is a common disinfectant that has been used for the last 90 years. The change in secondary disinfectant has reduced the trihalomethanes in the distribution system by more than half. The water continues to be disinfected with chlorine, then ammonium sulfate is added to form the chloramine and slow the formation of trihalomethanes. There are approximately two milligrams of ammonium sulfate added per liter of water. For comparison, this would be similar to adding six grains of table salt to a one gallon container of water. The water continues to be safe to drink. Customers who are undergoing dialysis or have pet fish will need to remove the chloramine prior to use in dialysis equipment or in aquariums.

None of the substances reported in the 2009 Water Quality Report exceed the Maximum Contaminant Levels. The presence of contaminants does not necessarily indicate that the water poses a health risk. Contaminants listed in this document fall under the heading of either Regulated or Unregulated. The EPA makes this distinction based on health risk to humans. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline, 800-426-4791.

All drinking water, including bottled, may reasonably be expected to contain at least small amounts of contaminants. Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised 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 lessen the risk of infection by Cryptosporidium are available from the Safe Drinking Water Hotline, 800-426-4791.

Source of Supply

Columbia's water is pumped from wells that tap a water-filled bed of sand and gravel beneath the farm land bordering the Missouri River just southwest of the city. Long ago, melting glaciers washed sand, gravel and boulders downstream, leaving thick deposits along the course of the river. This geological formation is an alluvium, which, when saturated with water, becomes an alluvial aquifer. Water moving slowly through the aquifer is replenished by a combination of groundwater that flows down from higher elevations and water from the Missouri River that migrates through the formation. In the area surrounding Columbia’s 15 wells, known locally as the “McBaine Bottoms,” 44 billion gallons of water fill the aquifer to within 20 feet of the ground surface. The wells average 110 feet in depth, penetrating the aquifer to near its bottom.

Collectively, the wells can pump about 21,000 gallons of water per minute, or 30 million gallons per day. Groundwater pumped from the wells is piped to the McBaine Water Treatment Plant. The water is naturally of very high quality and free of harmful chemicals and bacteria. However, it does contain dissolved calcium and magnesium that require it to be softened before use. Iron and hydrogen sulfide are also found in the water which can result in the staining of laundry and an unpleasant odor. At the treatment plant, a process called aeration oxidizes the water to reduce these levels.

Softened, filtered water is pumped from the treatment plant to reservoirs at Columbia’s two pump stations. The water is then pumped throughout the city to consumers. A copy of the complete water testing results is available online at www.GoColumbiaMo.com or by calling 874-7325. An assessment of our source water supply is available by contacting Floyd Turner, Manager of Water Operations, at 874-6210.

2009 Water Testing Results

(of substances found in measurable quantities)

Unregulated Substance (units)	Reported Concentration	Range
Chloroform (ug/L)	16.7	10.6 - 25.1
Bromodichloromethane (ug/L)	20.3	11.4 - 25.3
Dibromochloromethane(ug/L)	19.6	11.2 - 24.1
Bromoform (ug/L)	7.4	2.9 - 9.7
Sulfate (mg/L)	80.4*

Regulated Substance (units) and the major source(s) of regulated substance	MCLG	MCL	Reported Concentration
Barium (mg/L) Discharge of drilling wastes; Discharge from metal refineries; Erosion of natural deposits	2	2	0.104
Combined radium (pCi/L) Erosion of natural deposits	0	5	1.4*
Copper (mg/L) Corrosion of household plumbing systems; Erosion of natural deposits; Leaching from wood preservatives	1.3	AL=1.3	0.053 *(1)
Fluoride (mg/L) Water additive that promotes strong teeth; Erosion of natural deposits; Discharge from fertilizer and aluminum factories	4	4	1.01* (2)
Lead (ug/L) Corrosion of household plumbing systems	0	AL=15	2.28 *(3)
Radon (pCi/L) Erosion of natural deposits	0	300 (4)	50.4* (4)
TTHM (ug/L) By-product of drinking water chlorination	0	80	64.0* (5)
HAAs (mg/L) By-product of drinking water chlorination.	0	60	17.6 (6)
	MDRL	MDRLG	Concentration
Chlorine (mg/L) Water additive for disinfection	4	4	1.44(7)

* Indicates data from a previous year's monitoring.

NOTES FROM TABLE
1 Thirty distribution samples were checked for copper. None of the samples exceeded the copper action level. The measurements ranged from 0.002 to 0.152 mg/L.
2 Reported concentration of Fluoride is the average of two samples. The range of measurements is 0.78 to 1.14 mg/L.
3 Thirty distribution samples were checked for lead. No samples exceeded the lead action level. The measurements ranged from 3.91 to undetected.
4 Radon in drinking water at the MCL of 300 pCi/L poses an estimated increased risk of an additional 2 cases of cancer for every 10,000 people exposed. Increased cancer risk for the levels found in our water, 50.4 pCi/L, are undetermined. Additional information is available at the EPA web site: epa.gov/OGWDW.
5 Reported concentration of TTHM is the average of 4 samples from the distribution system. The range of measurements is 36.9 to 75.6 ug/L.
6 Eight samples were checked for the HAAs. The range of the measurements is 11.5 ug/L to 22.1 ug/L.
7 Reported concentration of Chlorine is the average of 1476 samples collected throughout the year at 41 different places in the distribution system. Measured concentration ranged from 0.18 mg/L to 2.5 mg/L.

MDRL -Maximum Disinfectant Residual Level: The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
MDRLG -Maximum Disinfectant Residual Level Goal: The level of a drinking water disinfectant below which there is no known or expected risk to health. MDRLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
MCLG—Maximum Contaminant Level Goal: The level of a contaminant
in drinking water below which there is no known or expected risk to
health.
MCL—Maximum Contaminant Level: The highest level of a contaminant
that is allowed in drinking water.
pCi/L—picocuries per liter: A measure of radioactivity.
mg/L—milligrams per liter or parts per million.
AL—Action Level: The concentration of a contaminant which triggers a
treatment or other requirement which a water system must follow.
ug/L—micrograms per liter.

Columbia Water & Light is a publicly run utility. Any citizen interested in learning more about water quality or wishing to express an opinion regarding our water system can do so by the following means: meetings of the City Council and Water & Light Advisory Board; through the Manager of Water Operations, Floyd Turner, at 874-6210 (875-5533, tty) or fdt@GoColumbiaMo.com.

Download a copy of the complete water testing results (.pdf document)