2007
Drinking Water Quality Report
Colstrip Montana

We're pleased to present to you this year's Annual Water Quality Report. This report is designed to inform you about the quality of water and services we deliver to you every day. Our constant goal is to provide you with a safe and dependable supply of drinking water. We want you to understand the efforts we make to continually improve the water treatment process and protect our water resources. We are committed to ensuring the quality of your water. I'm pleased to report that our drinking water is safe and meets federal and state requirements.

Water Source and Treatment

PPL Montana pumps water from the Yellowstone River six miles west of Forsyth to Castle Rock Lake. Our system draws water from Castle Rock Lake and is treated at The Colstrip Water Treatment Plant.

The water plant is a variable declining rate direct filtration facility. It is designed for raw water to gravity flow from Castle Rock Lake through an in-line mechanical mixer. It mixes aluminum chlorhydrate (coagulant), activated carbon and/or potassium permanganate (removes taste and odor), and fluoride with the raw water flow stream, then through a static mixer where a nonionic polymer is applied as a filter aid, and into an open distribution channel at the head of four filter bays. In these filters is a dual media of anthracite coal and sand. Filtered water leaving the filter bays enters a weir trough where chlorine is added for disinfection. Water cresting the clearwell weir trough falls into the clearwell and is available for pumping into the Colstrip distribution system through the high service pumps. Colstrip has over 26 miles of distribution system. The high service pumping system is designed to serve three separate pressure zones in the Town of Colstrip. Zone 1 is the lowest part of the town. It is served by two 500,000 gallon reservoirs. Many of the old mains in this part of town have been replaced in the last few years.  Zone 2 is the second highest portion of the distribution system and it is served by a 2,000,000 gallon reservoir in the northern portion of Colstrip. Because of a declining population in this area, this reservoir is maintained at 1,200,000 to achieve better turnover. Zone 2 was recently expanded west of the highway to homes and businesses at the Colstrip Commerce Circle.  Zone 3 is served by a 650,000 gallon reservoir in the southwestern part of the town west of the highway. Six high service pumps serve these three pressure zones.

Water from the clearwell is also used for backwashing the filters. The backwash is sequenced and controlled by a SCADA system located in the control room. The SCADA (supervisory control and data acquisition) system also monitors and records the function of all treatment processes, reservoir levels, the wastewater treatment plant and sewage lift stations.

There are turbidity meters on all filters and the clearwell that are recording continuously the clarity of the water. We have online chlorine and fluoride analyzers which monitor and record residuals leaving our treatment plant on a daily basis. We test chlorine residuals daily in our distribution system. We also test for total coliform bacteria (i.e. e-coli) monthly from 3 different sites in our distribution. We are sampling quarterly from the distribution to comply with the Disinfection By-Products Rule. We also sample yearly to comply with Phase II and Phase IV of the Surface Water Drinking Act. All of our outside testing is done by Energy Laboratories of Billings except the total coliforms, which are done by Aquatec Laboratories of Lewistown. Both labs are certified.

In 2007 we installed an Onsite Hypochlorite Generating System which uses common rock salt to produce a mild bleach solution which is now used for disinfection.  The addition of this system has allowed us to completely remove the hazards of using and storing ton cylinders of chlorine.

Water Contaminants

The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity. 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 storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming.
• 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, and can also come from gas stations, urban stormwater runoff, and septic systems.
• Radioactive Contaminants, which can be naturally-occurring or the result of oil and gas production and mining activities.

 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. More information about contaminants and potential health effects can be obtained by calling EPA.s Safe Drinking Water Hotline, 1-800-426-4791.

 In order to ensure that tap water is safe to drink, the Environmental Protection Agency (EPA) prescribes regulations which limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water which must provide the same protection for public health. MCL's are set at very stringent levels. To understand the possible health effects described for many regulated constituents, a person would have to drink 2 liters of water every day at the MCL level for a lifetime to have a one-in-a-million chance of having the described health effect.

 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/Centers for Disease Control and Prevention (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline, 1-800-426-4791.

 The EPA requires monitoring of over 80 drinking water contaminants. Only those listed in the following table were detected in your drinking water. The table shows the test results for calendar year 2007. As authorized by the EPA, monitoring requirements for certain contaminants are less often than once a year because the concentrations of these contaminants are not expected to vary significantly from year to year.

 As you will see by the following table, our system had no violations of the water quality standards. We’re proud that your drinking water meets or exceeds all Federal and State requirements. We have learned through our monitoring and testing that some constituents have been detected. The EPA has determined that your water IS SAFE at these levels.

Important Terms

Table of Detected Contaminants

Key to Table:

AL = Action Level

MCL = Maximum Contaminant Level

MCLG = Maximum Contaminant Level Goal

ppm = parts per million, or milligrams per liter (mg/l)

ppb = parts per billion, or micrograms per liter (ug/l)

ND = No Detect

NR = Not Regulated

N/A = Not Applicable

NTU = Nephelometric Turbidity Units

TTHMs = Total Trihalomethanes

pCi/l = picocuries per liter (a measure of radioactivity)

 Below is a table of other constituents. Although not regulated, they are provided for the informational purposes of our customers.

Listed Below are contaminants that were tested for but were not detected in 2007

Benzene
Bromobenzene
Bromoform
Bromomethane
n-Butylbenzene
sec-Butylbenzene
tert-Butylbenzene
Carbon tetrachloride
1,2-Dichloroethane
Chlorobenzene
Chloroethane
Chloromethane
2-Chlorotoluene
4-Chlorotoluene
1,2-Dibromo-3-chloropropane
Dibromomethane
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Dichlorodifluoromethane
1,1-Dichloroethane
1,2-Dibromoethane
1,1-Dichloroethene
cis-1,2-Dichloroethene
trans-1,2-Dichloroethene
1,2-Dichloropropane
1,3-Dichloropropane
2,2-Dichloropropane
1,1-Dichloropropene
cis-1,3-Dichloropropene
trans-1,3-Dichloropropene
Ethylbenzene
Hexachlorobutadiene
Isopropylbenzene
p-lsopropyltoluene
Methyl tert-butyl ether (MTBE)
Methylene chloride
Naphthalene
n-Propylbenzene
Styrene
1,1,1,2- Tetrachloroethane
1,1,2,2- Tetrachloroethane
Tetrachloroethene
Toluene
1,2,3- Trichlorobenzene
Iron
1,2,4- Trichlorobenzene
1,1.1- Trichloroethane
1,1,2- Trichloroethane
Trichloroethene
Trichlorof1uoromethane
1.2,3- Trichloropropane
1,2.4- Trimethylbenzene
1,3,5- Trimethylbenzene
Vinyl chloride
m+p-Xylenes
o-Xylene
Xylenes, Total
2,4,5- TP (Silvex)
2,4-D
2,4-DB
3-Hydroxycarbofuran
Alachlor
Aldicarb
Aldicarb sulfone
Aldicarb sulfoxide
Aldrin
Antimony
Atrazine
Barium
Baygon   
Benzo(a)pyrene
Beryllium
di(2-ethylhexyl)Adipate
di(2-ethylhexyl)Phthalate
Butachlor
Cadmium
Carbaryl
Carbofuran
Chlordane
Chromium
Dalapon
Dicamba
Dichlorprop
Dieldrin
Dinoseb
Endrin
gamma-BHC (Lindane)
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexaclorocyclopentadiene
Mercury
Methomyl
Methoxychlor
Metolachlor
Metribuzin
Nickel
Oxamyl
Pentachlorophenol
Propachlo
Selenium
Simazine
Thallium
Toxaphene