Consumer Confidence Report

The Consumer Confidence Report (CCR) is an annual water quality report that all public water systems are required to publish. This requirement is based on the 1996 Amendments to the Safe Drinking Water Act and the right-to-know provisions of that Act. Each customer of the City of Cheyenne Board of Public Utilities (BOPU) has the opportunity to review the CCR annually or at any time on this website. The CCR is designed to help you make informed choices about the water you drink and to know what contaminants, if any, are in your drinking water.

2025 Consumer Confidence Report

The City of Cheyenne Board of Public Utilities (BOPU) is proud to provide this 2025 Consumer Confidence Report (CCR), also known as an annual drinking water quality report. This CCR summarizes water quality from January 1 through December 31, 2025.

The BOPU prepares this report each year in accordance with the Safe Drinking Water Act. Read about the Safe Drinking Water Act online at www.epa.gov/sdwa . The CCR includes a summary of source water information, detected contaminants, compliance with Federal, State, and local regulations and standards, and educational information about Cheyenne’s water system. The purpose of the CCR is to improve public health by providing information that assists consumers with making educated decisions regarding any potential health risks pertaining to the quality, treatment, and management of their drinking water. If you have any questions about this CCR, call the Water and Wastewater Quality Control Supervisor at (307) 637-0870.

Este reporte contiene información importante acerca de su agua potable. Por asistencia traduciendo este reporte en español o si tiene unas preguntas de acerca al reporte por favor de llamar a nuestro representante de servicio al cliente. El número de teléfono es: (307) 637-6460.

If you are unable to access or read this document due to visual impairment or other disability, assistance is available. Please contact us at (307) 637-6460, and we will be happy to provide the information in an alternative format or offer any support you may need to ensure accessibility.

How does Cheyenne’s water compare to drinking water standards?

The BOPU is proud to report that Cheyenne's drinking water meets or exceeds (is better than) federal requirements.

The BOPU's Water Treatment Division monitors water quality 24 hours a day, 7 days a week, using in-line instruments. Operators also confirm instrument readings with daily sampling and lab analyses. Lab staff monitor water quality throughout Cheyenne weekly. While some parameters were detected in water samples, there were no violations of either National Primary Drinking Water Regulations or National Secondary Drinking Water Standards. To learn more about federal drinking water regulations or standards, visit www.epa.gov/dwreginfo. The tables below in the Results Section of this report show the most recent water quality data (from January 1, 2025, through December 31, 2025).

Where does Cheyenne's water come from?

Cheyenne's water comes from both surface water and groundwater sources. A Source Water Assessment and Protection report was completed in 2004. You can read the report online at www.cheyennebopu.org/files/assets/bopu/divisions-documents/admin/water-conservation/2004-source-water-assessments_final-report.pdf(PDF, 548KB).

Cheyenne’s water sources include…

Douglas Creek

Most of Cheyenne’s surface water is collected from Douglas Creek. Douglas Creek is a tributary of the North Platte River and is located about 75 miles west of Cheyenne in the Medicine Bow Mountains (also called the Snowy Range). The Medicine Bow Mountains form the eastern boundary of the North Platte River Watershed in southeast Wyoming.

The BOPU collects water from Douglas Creek by storing it in Rob Roy Reservoir. When the BOPU stores water in Rob Roy Reservoir, that water is removed from the North Platte River. The BOPU replaces the water removed from the North Platte River with water from another source. That source is within the Little Snake River Watershed. This exchange is driven by the allocation of water rights for these rivers.

The Little Snake River is located in the Sierra Madre Mountains. The Sierra Madre Mountains form the western boundary of the North Platte River Watershed in southeast Wyoming. The Little Snake River is located approximately 110 miles west of Cheyenne, west of the Continental Divide. A series of collection structures, pipelines, and a conveyance tunnel collect water from tributaries to the Little Snake River and transport the water under the Continental Divide to Hog Park Reservoir. Water from Hog Park Reservoir can be released into the North Platte River and can be recaptured in Seminoe Reservoir. The BOPU uses water from both Hog Park and Seminoe Reservoirs as trade water in the North Platte River. When the BOPU collects water at Rob Roy Reservoir, the BOPU releases the same amount of water from either Hog Park Reservoir or Seminoe Reservoir.

Two pipelines deliver water from Rob Roy Reservoir to Cheyenne. The pipelines carry water down the Medicine Bow Mountains, across the Laramie River Valley, and over the Laramie Mountains then deliver the water to Granite Springs Reservoir and Crystal Lake Reservoir. Because water enters the pipelines at around 9,000 feet in elevation in the Medicine Bow Mountains and cross the Laramie Mountains at around 8,000 feet, the pipelines are able to deliver water across two mountain ranges by gravity without any need for pumping.

The Little Snake River is a tributary to the Colorado River. Interstate agreements between Wyoming, Arizona, California, Colorado, New Mexico, Nevada, and Utah determine how much water each state gets to use from the Colorado River Watershed. These agreements rely on water stored in reservoirs to distribute water between the states. After decades of drought, reservoir storage in the Colorado River is declining and may reach critically low levels. If reservoir storage continues to decline, some water users in Wyoming (including the City of Cheyenne) may not be able to collect water from sources that are in the Colorado River system. This would reduce Cheyenne’s water supply by approximately half. For more information about Wyoming and the Colorado River, visit the Wyoming State Engineer’s Colorado River Working Group online at https://seo.wyo.gov/interstate-streams/colorado-river-working-group.

Crow Creek

Surface water is also collected from the Crow Creek Watershed. Crow Creek Watershed is located about 30 miles west of Cheyenne in the Laramie Mountains near the Vedauwoo Recreation Area. Water from Crow Creek is stored in North Crow Reservoir (North Crow Creek), Granite Springs and Crystal Lake Reservoirs (Middle Crow Creek) and South Crow Diversion Structure (South Crow Creek).

Water stored in Crystal Lake Reservoir, Lower North Crow Reservoir, and South Crow Diversion Structure can be delivered to Cheyenne’s R.L. Sherard Water Treatment Plant by pipelines.

Since 2002, water from Lower North Crow Reservoir and South Crow Diversion Structure have been used to maintain water levels in lakes such as Lake Absarracca, Kiwanis Lake, and Sloans Lake. Because of the drought and water shortages in the Colorado River system, this water may be needed for drinking water. The BOPU is conducting a study to determine if water from North Crow Reservoir and South Crow Diversion Structure can be treated at the R.L. Sherard Water Treatment Plant. The study specifically looks at how using water from these sources could impact water quality and how the water’s chemistry might interact with pipes in the distribution system and in customers’ homes. The study is expected to be completed by December 31, 2027.

Groundwater

Cheyenne owns and operates about 36 wells in four well fields (Bell, Borie, Federal, and Happy Jack). These wellfields are located west and northwest of Cheyenne. The wells pump from the High Plains (Ogallala and White River) Aquifers.

In 2020, the BOPU completed a study on the ratio of surface water to groundwater in Cheyenne’s drinking water. Prior to the study, the BOPU created a blend of 75 percent surface water and 25 percent groundwater. This blend had been established in the 1990’s to increase pH and alkalinity in Cheyenne’s drinking water. The higher pH (around a 7.6 standard units or SU) and higher alkalinity (around 66 parts per million or ppm) helps prevent corrosion in Cheyenne’s distribution system and in customer’s homes and businesses. After three decades of 25 percent groundwater blend, BOPU staff had noticed that ground water levels west of Cheyenne were decreasing. The BOPU conducted this study to see if the new water treatment plant, constructed in 2002, could maintain water quality with less groundwater. If less groundwater could be used, the BOPU could allow groundwater levels to recover west of Cheyenne.

The study concluded that because the water treatment plant can adjust finished drinking water pH and alkalinity, operators could reduce the amount of groundwater in the blend from 25 percent to 15 percent and still maintain water quality. This allows operators to use local aquifers more sustainably. Since making this change in the ratio of surface water to groundwater, water levels in the aquifers west of Cheyenne have started to rise in several wells despite being in a drought. This suggests that the aquifers west of Cheyenne are improving.

Learn more about Cheyenne's water.

We encourage our customers to learn about Cheyenne's water system and the Safe Drinking Water Act. Our water protects our health, provides fire protection, provides a natural resource for businesses, and provides for our way of life. Our water is vital to our future. Visit our website at www.cheyennebopu.org/Water/Water-Supply for additional information about our water system. Some examples of the information available at that site include...

• A description of where Cheyenne’s water comes from.
• Information about water quality such as hardness, clarity, fluoride, and other useful water quality parameters that aren’t included in this report.

What is the BOPU doing to manage water sustainably?

Cheyenne is in the high plains. We are surrounded by short-grass prairie with vegetation that is adapted to long periods without water. In Southeast Wyoming, water is a limited resource. Here are some ways the BOPU is managing water resources sustainably:

Help our customers use less water.

BOPU has a water conservation program that sets watering schedules and rules, assists customers in identifying leaks, and determines bill structures that encourage efficient water use. Additionally, the BOPU runs the program OUR Water (Outreach for Upgrades and Repairs) that provides customers with high efficiency indoor fixtures and other water saving tools, including toilet components to eradicate leaks. For more information, visit www.cheyennebopu.org/Cheyennes-Water/Water-Conservation.

Make water do twice the work.

Once water goes down the drain, it will be used again. The BOPU reclaims wastewater at Cheyenne’s water reclamation facilities. The BOPU renamed the wastewater treatment plants to water reclamation facilities because the treatment processes used at the facilities reclaim water making it safe to use again. Some of this water is recycled and piped back into Cheyenne to water parks and athletic fields. Water that isn’t recycled is returned to Crow Creek where it is used by livestock, wildlife, aquatic species, and other users downstream.

Produce power from water.

In 2023, the BOPU completed construction on a hydroelectric generation facility. The hydroelectric generator produces power from water flowing to the water treatment plant. Water flowing to the treatment plant comes from Crystal Reservoir which is over 500 feet higher in elevation than the treatment plant. Because of this elevation change, water enters that plant at pressures around 210 pounds per square inch. The generator uses this flowing water and pressure to spin a turbine that produces electricity.

Producing power from water flows to the water treatment plant allowed the water treatment plant to become energy efficient. In 2025, the hydroelectric generator produced an average of 315 kilowatts (kW) per day during winter months and up to 832 kW per day during summer months. Of this amount, the water treatment plant used an average of 163 kW per day. The rest is sold to Black Hills Energy and used by electrical customers in the Cheyenne area. In total, the hydroelectric generator produced over 4.039 million kilowatt hours (kWh) and sold 2.627 million kWh to the grid. In 2025, the water treatment plant used power from the grid for only 20 hours. Those 20 hours occurred mostly during maintenance on the hydroelectric generator.

Producing power from water flowing to the water treatment plant also allows the plant to become a safer place to work and safer neighbor to Cheyenne. Historically, the water treatment plant used chlorine gas to disinfect water. If the chlorine gas escaped the chemical feed systems at the plant, the gas could harm employees by damaging eyes, skin, and respiratory systems. The water treatment plant is located uphill and west of Cheyenne. If chlorine gas escaped the plant, it would flow downhill and, with Wyoming’s westerly winds, be pushed towards Cheyenne. As Cheyenne grows to the west, the chlorine gas will have less room to dissipate before reaching residents. While the water treatment plant had safety monitoring and chlorine neutralizing systems in place to prevent and respond to chlorine leaks; removing the chlorine storage and having the ability to make sodium hypochlorite as needed eliminates the need to store large amounts of dangerous chemicals at the water treatment plant. Because the hydroelectric generation system produces ample power, the BOPU can economically replace the chlorine gas disinfection system with an onsite-sodium-hypochlorite-generation disinfection system.

Sodium hypochlorite is powerful water disinfectant but safer to handle and store than chlorine gas. Sodium Hypochlorite is produced from salt water using electricity. The electricity breaks the bond between the sodium and chlorine atoms in the salt. The sodium and chlorine then bind with the water to form sodium hypochlorite. The hypochlorite is then pumped and added to the water to disinfect the water, killing microbes and bacteria. Using the extra power from the hydroelectric generator to make sodium hypochlorite allows water treatment operators staff to continue to provide safe water while simultaneously improving safety and reducing chemical treatment costs.

Looking for more water.

The BOPU is actively investigating and pursuing additional surface and groundwater sources to prepare for possible reductions in water supply due to Colorado River curtailment. For more information about Colorado River and Cheyenne’s water, see the Cheyenne’s Water Sources section above.

A Note from the EPA About Drinking Water Sources and Regulations

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. Some of the contaminants listed in the water quality results sections below are beneficial in the right concentrations. Examples include chlorine, fluoride, and minerals (alkalinity).

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. To ensure tap water is safe to drink, the EPA regulates the amount of certain contaminants in water from public water systems. The Food and Drug Administration regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

Contaminants that may be present in source water include:

Microbial contaminants, such as viruses and bacteria, may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife. Because Cheyenne’s water sources come from Federal National Forests, State Forests, and land used for ranching activities there are no sewage treatment plants upstream of Cheyenne’s water sources. The most likely sources of microbial contamination for Cheyenne’s water are wildlife, agricultural livestock operations and septic systems.

Inorganic contaminants, such as salts and metals, can be naturally occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming. Because Cheyenne’s water sources come from Federal National Forests, State Forests, and land used for ranching activities, there are no urban storm water runoff or large industrial sources of inorganic contaminants. There are also limited mining and oil/gas production sources for inorganic chemicals. The inorganic contaminants that were detected during water quality analyses such as fluoride are most likely from naturally occurring deposits eroded by storm water and snow melt runoff. Other inorganic contaminants, such as copper and lead, come from customer piping and fixtures. Read more information in the “Should I be concerned about lead in my drinking water” section below after the results tables.

Pesticides and herbicides, which may come from a variety of sources such as agricultural, urban storm water runoff, and residential uses. The organics section in the results below provides a list of pesticides and herbicides that were tested for but not detected in Cheyenne’s water. Because there are no large communities upstream of Cheyenne’s water sources, potential sources of pesticides and herbicides are more likely to come from agricultural and residential uses.

Organic chemical contaminants, including synthetic and volatile organic chemicals which are by-products of industrial process and petroleum production, and can also come from gas stations, urban storm water runoff, and septic systems. The organics section in the results below provides a list of organic chemicals that were tested for but not detected. Because Cheyenne’s water sources come from Federal National Forests, State Forests, and land used for ranching activities, there are few industrial, gas stations, urban storm water runoff sources for organic chemicals. The only organic chemicals detected in Cheyenne’s water are byproducts of water treatment and disinfection. The amount of these chemicals was determined to be below maximum contaminant levels.

Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities. Because Cheyenne’s water sources come from Federal National Forests, State Forests, and land used for ranching activities, there are few oil and gas production or mining activities in watersheds that produce water for Cheyenne. The radioactive contaminants listed in the results section below are most likely from naturally occurring deposits.

Learn more information about contaminants and potential health effects by…

• Calling the EPA's Safe Drinking Water Hotline at 1 (800) 426-4791.
• Visiting the EPA’s website on the Safe Drinking Water Act at www.epa.gov/sdwa.

Definitions

In the tables below, you will find many terms and abbreviations which might not be familiar. To help you better understand these terms, we provided the following definitions.

Action Level (AL) - The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.

Maximum Contaminant Level (MCL) - The "maximum allowed" is the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the Maximum Contaminant Level Goals as feasible using the best available treatment technology.

Maximum Contaminant Level Goal (MCLG) - The "Goal" is the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

Maximum Residual Disinfectant Level (MRDL) - The highest level of disinfectant allowed in drinking water. The addition of disinfectant is necessary for control of microbial contaminants.

Maximum Residual Disinfectant Level Goal (MRDLG) - The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

National Primary Drinking Water Regulations (NPDWR) - Standards including AL, MCL, MRDL, and TT that are established under the Safe Drinking Water Act.

Nephelometric Turbidity Unit (NTU) - Nephelometric Turbidity Unit is a measure of the clarity of water. Turbidity in excess of 5 NTU is just noticeable by the average person.

Non-detect (ND) - Contaminant was not detected in the sample above the analytical method’s reporting limit. This means the amount of the contaminant is below the analytical method’s ability to detect it.

Parts per billion (ppb) or microgram per liter (µg/L) - One part per billion is one drop in a billion drops. Using time as a scale, it is equal to one second in 31.71 years. In finance, it is equal to one penny in $10,000,000.

Parts per million (ppm) or milligram per liter (mg/L) - One part per million is one drop in a million drops. Using time as a scale, it is equal to one second in 11.57 days. In finance, it is equal to one penny in $10,000.

Picocurie per Liter (pCi/L) - Picocurie per liter is a measure of radiation. A picocurie per liter corresponds to 0.037 radioactive disintegrations per second in a liter of air.

RTST  - Sample was taken at the Round Top Storage Tank.

SWTP  - Sample was taken at the Sherard Water Treatment Plant.

Treatment Technique (TT) - A treatment technique is a required process intended to reduce the level of contaminant in drinking water.

Results of water quality analyses identified the following contaminants in Cheyenne’s finished drinking water.

Microbial Contaminants and Turbidity

Contaminant	Violation Yes/No	Level Detected	MCLG	MCL	Likely Source of Contamination/ Comments
Total Coliform Bacteria	No	Presence/Absence Testing	0	Presence of coliform in ≥ 5% of monthly samples	Coliform bacteria is naturally present in the environment. 720 samples were required for regulatory compliance. The BOPU collected 958 samples. Of that number, no sample tested positive for total coliform.
Turbidity	No	100% ≤ 0.08 NTU 95% ≤ 0.04 NTU	N/A	TT 95% < 0.3 NTU	The likely source of turbidity contamination is soil runoff. Turbidity is a measurement of the cloudiness of water caused by suspended particles and is a good indicator of general water quality and the effectiveness of water treatment processes. The maximum allowable filtered water turbidity is 0.3 NTU in 95% of all samples. Cheyenne’s water was much lower with 100% of samples less than 0.08 NTU and 95% of samples were less than 0.04 NTU. Turbidity values are recorded every 4 hours from all filters in operation and values reported monthly to the EPA.

The BOPU tested raw (untreated) water from Crystal Reservoir for Giardia and Cryptosporidium in 2017 but found less than one per liter of sample.

Disinfection Chemicals

Name	Violation Yes/No	Level Detected	MRDLG	MRDL	Likely Source of Contamination/ Comments
Chlorine	No	0.1 to 1.3 ppm	4	4	Chlorine is a drinking water disinfectant that is used to control microbial growth.

Inorganic Contaminants

Contaminant	Violation Yes/No	Level Detected	Unit	MCLG	MCL	Likely Source of Contamination/ Comments
Copper	No	90 percent of results were less than 0.28. No analysis results exceeded the MCL. Results ranged from ND to 0.42.	ppm	1.3	AL=90% <1.3	Sources of copper include corrosion of household plumbing systems; naturally present in the environment; and leaching from wood preservatives. These samples were taken from private residences.
Fluoride	No	RTST: 0.3 SWTP: 0.2	ppm	4	4	Fluoride sources include erosion of natural deposits and water additives that promote strong teeth. The samples reported here were collected as part of inorganic contaminant monitoring required under the Safe Drinking Water Act. Operators also monitor fluoride daily as part of treatment process control. Fluoride concentrations from these analyses averaged 0.5.
Lead	No	90 percent of results were less than 15. Results ranged from ND to 110. Four of the 33 samples taken exceeded the AL.	ppb	0	AL=90% <15	Lead sources include corrosion of household plumbing systems These samples were taken from private residences. The highest result of 110 ppb came from a private residence. Because of this high result, staff retested the same location. The retest had a result of 4 ppb.
Nitrate + Nitrite (as Nitrogen)	No	RTST: 0.49 SWTP: 0.25	ppm	10	10	Nitrate and nitrite sources include runoff from fertilizer use; leaching from septic tanks; sewage; they are naturally present in the environment.

Antimony, Arsenic, Barium, Beryllium, Cadmium, Chromium, Cyanide, Mercury, Nickel, Selenium and Thallium were analyzed for but not detected by certified laboratory analysis.

Asbestos was analyzed in 2022 but not detected by certified laboratory analysis.

Sodium was detected in laboratory analysis (SWTP: 12.3 ppm, RTST: 12.2 ppm). Sodium does not have National Primary Drinking Water Regulation or Secondary Drinking Water Regulation. Sodium comes primarily from water treatment chemicals used to adjust water pH and from the erosion of natural deposits.

Organic Contaminants

Contaminant	Violation Yes/No	Level Detected RTST	Level Detected SWTP	Unit	MCLG	MCL	Likely Source of Contamination/ Comments
Total Trihalomethanes	No	Min=27.8 Max=27.8 Avg=27.8	Min=22.5 Max=42 Avg=30.6	ppb	0	80	Trihalomethanes are a by-product of organics in the water reacting with chlorine. The longer water is exposed to chlorine, the more trihalomethanes form. Sampling sites were representative of higher water age in Cheyenne’s water distribution system. The values reported in this table are from annual averages of each location sampled. Total trihalomethanes are the sum of 4 compounds: Chloroform, Bromoform, Bromodichloromethane, and Dibromochloromethane.
Haloacetic Acid	No	Min=22 Max=22 Avg=22	Min=21 Max=26.5 Avg=23.8	ppb	0	60	Haloacetic acids are a by-product of organics in the water reacting with chlorine. Sampling sites were representative of average water age in Cheyenne’s water distribution system. The values reported in this table are from annual averages of each location sampled. Haloacetic acids are the sum of 5 compounds: Monochloroacetic Acid, Dichloroacetic Acid, Trichloroacetic Acid, Monobromoacetic Acid, and Dibromoacetic Acid.
Total Organic Carbon (TOC)	No	N/A	Raw Water Avg=4.1 Treated Water Avg= <2	ppm	N/A	TT	TOC is organic matter that comes naturally from the environment. TOC provides a medium for the formation of disinfection byproducts such as trihalomethanes and haloacetic acids. TOC was analyzed each month and is used to determine water treatment effectiveness. Removal requirements were met during 2025. The reporting limit for TOC by the independent lab that analyzed the samples is 2 mg/L.

The following semi-volatile organic compounds were analyzed for but not detected by certified independent laboratory analysis:

Alachlor; Aldrin; Aroclor 1016; Aroclor 1221; Aroclor 1232; Aroclor 1242; Aroclor 1248; Aroclor 1254; Aroclor 1260; Atrazine; Benzo(a)pyrene; bis(2-ethylhexyl)Adipate; bis(2-ethylhexyl)Phthalate; Butachlor; Chlordane; Dieldrin; Endrin; gamma-BHC (Lindane); Heptachlor; Heptachlor epoxide; Hexachlorobenzene; Hexachlorocyclopentadiene; Methoxychlor; Metolachlor; Metribuzin; Propachlor; Simazine; Toxaphene, Total PCBs, Endothall.

The following volatile organic compounds were analyzed for but not detected by certified independent laboratory analysis:

Benzene; Bromobenzene; Bromochloromethane; Bromoform; Bromomethane; n-Butylbenzene; sec-Butylbenzene; tert-Butylbenzene; Carbon tetrachloride; 1,2-Dichloroethane; Chlorobenzene; Chloroethane; Chloromethane; 2-Chlorotoluene; 4-Chlorotoluene; Dibromomethane; 1,2-Dichlorobenzene; 1,3-Dichlorobenzene; 1,4-Dichlorobenzene; Dichlorodifluoromethane; 1,1-Dichloroethane; 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-Isopropyltoluene; 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; 1,2,4-Trichlorobenzene; 1,1,1-Trichloroethane; 1,1,2-Trichloroethane; Trichloroethene; Trichlorofluoromethane; 1,2,3-Trichloropropane; 1,2,4-Trimethylbenzene; 1,3,5-Trimethylbenzene; Vinyl chloride; m+p-Xylenes; o-Xylene; Total Xylenes; 1,2-Dibromo-3-Chloropropane, 1,2-Dibromoethane.

The following pesticides and herbicides were analyzed for but not detected by certified independent laboratory analysis:

Aldicarb; Aldicarb sulfone; Aldicarb sulfoxide; Carbaryl; 3-Hydroxycarbofuran; Carbofuran; Methiocarb; Methomyl; Oxamyl; Baygon; Glyphosate; Diquat; 2,4,5-TP (Silvex); 2,4-D; 2,4-DB; Dalapon; Dicamba; Dichloroprop; Dinoseb; Pentachlorophenol; Picloram.

Radionuclides

Contaminant	Violation Yes/No	Level Detected RTST	Level Detected SWTP	Unit	MCLG	MCL	Likely Source of Contamination/ Comments
Gross Alpha	No	-0.1±1.5 (2021)	1.9±1.4 (2022)	pCi/L	None	15	Naturally occurring in the environment.
Radium 226	No	0.07±0.30 (2021)	0.01±0.30 (2022)	pCi/L	None	15	Naturally occurring in the environment.
Radium 228	No	0.60±0.70 (2021)	0.6±0.7 (2022)	pCi/L	None	15	Naturally occurring in the environment.
Uranium	No	0.5 (2021)	0.7 (2022)	ppb	None	30	Naturally occurring in the environment.

 

How do drinking water regulations apply to immunocompromised people?

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised persons, such as people with cancer undergoing chemotherapy, persons who have undergone organ transplants, persons with HIV/AIDS or other immune system disorders, some elderly, and infants can be at particular risk from infection. These people should seek advice about drinking water from their health care provider. EPA/Centers for Disease Control and Prevention guidelines on appropriate means to lessen the risk of infection by Cryptosporidium, and other microbiological contaminants, are available by calling the Safe Drinking Water Hotline at 1 (800) 426-4791 or by visiting the EPA’s webpage at www.epa.gov/safewater.

Should I be concerned about lead in my drinking water?

The EPA has determined that no level of lead in drinking water is safe. Exposure to lead can have serious health effects across all age groups, with pregnant individuals, infants (both formula and breastfed), and young children being particularly vulnerable. In children, lead exposure can decrease IQ and attention span, contribute to learning and behavior problems, or exacerbate existing conditions. Additionally, children born to individuals exposed to lead before or during pregnancy may face increased health risks. For adults, prolonged exposure increases the likelihood of heart disease, high blood pressure, kidney issues, and nervous system complications. Contact your healthcare provider for more information on your risk factors.

What are the sources of Lead in Drinking Water?

The primary source of lead in drinking water is from home plumbing and service lines containing lead components. Homes built before 1989 are the most likely to have plumbing components made of lead. After 1989, lead plumbing components were banned by Federal law (Safe Water Drinking Act amendments of 1986).

What is the BOPU doing to prevent lead exposure?

In the early 1990’s, Cheyenne conducted studies and implemented programs to adjust water pH and alkalinity, preventing lead and copper from leaching from pipes into drinking water. Today, the R.L. Sherard Water Treatment Plant employs dedicated systems to regulate pH and alkalinity. Operators blend treated surface water with groundwater to maintain stability and minimize the risk of lead dissolving from older pipes. The BOPU provides high quality drinking water and is actively investigating, inventorying, and working to remove lead service lines, but cannot control the variety of materials used in plumbing components in private homes. Until 2022, the BOPU did not own or maintain service lines beyond the water main connector. Since then, the BOPU operates as a split ownership utility, meaning it shares responsibility for service lines with property owners. In this arrangement, the BOPU owns and maintains the section of the service line from the water main to and including the curb stop or shutoff, while property owners are responsible for the portion from the curb stop to their home. This structure necessitates collaboration between the BOPU and property owners to effectively identify and mitigate potential lead risks in the service lines.

What is the BOPU doing to identify who has lead service lines?

To comply with the Lead and Copper Rule Revisions (LCRR) and Lead and Copper Rule Improvements (LCRI), BOPU is implementing a structured approach to accurately identify and inventory the materials used in all service lines within our system. Because of the split ownership on service lines, the BOPU has limited historical data on the types of materials used to construct most of the service lines in Cheyenne. Consequently, the initial inventory identified the materials used in most service lines as being unknown.

For service lines that cannot be validated through historical data, BOPU will conduct targeted inspections using methods such as excavating small sections near curb stops to examine both utility and customer-side materials, assessing meter pits for signs of galvanized pipes requiring replacement, and inspecting internal plumbing at points of entry into buildings. These efforts ensure compliance with EPA guidelines while accurately identifying and documenting all service lines in the system.

As staff continue to identify the materials used to construct service lines, staff also update the service line inventory. You can access a map of the service line inventory online at www.cheyennebopu.org/Water/Lead-Service-Line.

In addition to our ongoing investigation and inventory efforts, BOPU is committed to replacing all confirmed utility-side lead service lines by December 2037 in full compliance with EPA LCRI mandates.

Lead Monitoring Efforts

BOPU monitors lead levels in selected older homes through annual water sampling. These homes were chosen based on historical lead service line use or construction periods when lead plumbing was prevalent.

Recent lab results indicate that most homes remain below the EPA’s action level for lead. In 2025, the BOPU worked with 30 customers to sample for lead in water. Three samples exceeded the EPA’s action level of 15 parts per billion (ppb) for lead. All three samples were taken in an area northwest of the intersection of East Pershing Boulevard and Evans Avenue. This area was near some street construction at the time the samples were taken. The BOPU worked with these homeowners to resample drinking water. Two of the three resamples returned values below the EPA’s action level of 15 ppb. The highest result of 110 ppb was among the sites resampled. This resampled result was at 4 ppb. Only one sample continued to be higher than 15 ppb. BOPU Staff notified the homeowners of the results. Including the original samples and the resamples, 33 samples total, the 90th percentile of all the samples taken was calculated at 15 ppb.

How can customers reduce lead exposure in drinking water?

If you are concerned about lead in your drinking water, consider the following actions to minimize exposure:

• Use a certified water filter. Ensure your filter is certified to remove lead by the American National Standards Institute. Follow the manufacturer’s instructions on installation, maintenance, and replacement schedules. Do not use hot water with the filter. www.epa.gov/water-research/consumer-tool-identifying-point-use-and-pitcher-filters-certified-reduce-lead.
• Clean faucet aerators regularly. Sediment, debris, and lead particles can collect in the aerator, potentially introducing lead into your water.
• Use cold water for consumption. Lead dissolves more easily in hot water. Always use cold water for drinking, cooking, and preparing baby formula. Boiling water does not remove lead.
• Flush pipes before use. Homes constructed prior to 1989 may have piping, solder or fixtures that contain lead. The more time water sits in a home’s pipes, solder or fixtures that contain lead, the higher the possibility that lead can dissolve into the water. Run your tap, take a shower, do laundry, or wash dishes before using water for drinking or cooking. Run the water until the water runs cold. This indicates the water is fresh from the main and has not had very much contact time with pipes, solder or fixtures. Customers who have been notified that they have lead service lines or galvanized service lines requiring replacement may need to flush pipes for a longer period.
• Be aware of nearby construction. Construction or maintenance can disturb lead service lines or disturb corrosion in galvanized lines releasing lead that was trapped in the corrosion. This can increase lead levels in drinking water. The BOPU will reach out to customers near construction projects on water and sewer mains prior to starting construction.
• Learn what materials were used in your service line. Visit the BOPU’s website at www.cheyennebopu.org/Water/Lead-Service-Line for an inventory map of known service lines and the materials used in its construction.
• Replace in home fixtures and plumbing that contain lead. Customers can identify and remove lead materials within the home’s plumbing and reduce the risk of exposure. Learn more by visiting the EPA’s online step by step guide on how to find lead pipes in a home at www.epa.gov/ground-water-and-drinking-water/protect-your-tap-quick-check-lead.
• Customers who are concerned about lead in drinking water may wish to have water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at www.epa.gov/safewater/lead. A list of certified testing facilities is available at: www.epa.gov/region8-waterops/certified-drinking-water-laboratories-systems-wyoming-and-tribal-lands-epa-region. Note that a single sample may not capture all potential sources of lead in your plumbing. Lead levels may vary over time. Lead exposure is still possible after tap sampling results do not detect lead in a particular sample. More information on lead sources is available at: www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water#getinto.

Additional resources on lead in drinking water

For more information on reducing lead exposure in drinking water, visit: the EPA’s website on lead at www.epa.gov/lead. You may also visit the BOPU’s website on lead at www.cheyennebopu.org/Water/Lead-Service-Line.

What are perfluoroalkyl and polyfluoroalkyl substances?

Perfluoroalkyl and polyfluoroalkyl substances (PFAS and PFOA) are chemical compounds manufactured and used for decades to repel water, grease, and oil. They are commonly found in products such as firefighting foam, carpets, clothing, nonstick cookware, food packaging, plastic coatings, and dental floss.

The chemicals are known as “forever chemicals” because they don’t break down over time. Research by the Centers for Disease Control and Prevention show most people in the United States have been exposed to some PFAS. Research suggests that exposure to high levels of certain PFAS may lead to health impacts.

The BOPU is working with the US EPA and the State of Wyoming to monitor for PFAS in Cheyenne’s water. So far, there have been no detects of PFAS in Cheyenne’s drinking water.

Tricholorethylene and the Atlas “D” Missile Site

Some wells in the Borie Wellfield pump from aquifers contaminated with trichloroethylene (TCE). The TCE comes from the Atlas “D” Missile Site located on the Belvoir Ranch southwest of Cheyenne. TCE was used at the missile site to clean missiles during the early 1960’s. Since then, a plume of TCE has spread underground reaching municipal wells. The U.S. Army Corps of Engineers (ACOE) constructed a groundwater treatment plant located near Cheyenne’s water treatment plant. This groundwater treatment plant removes TCE from the water produced at the Borie Wellfield. Both the ACOE and the BOPU monitor water quality from the Borie Wellfield before and after treatment. Results from water quality sampling during 2025 from water pumped from the Borie Wellfield averaged 7.9 ppb of TCE. Results from water quality samples taken in 2025 from water treated at the ACOE groundwater treatment plant’s finished drinking water all had results of non-detects for TCE. This means the amount of TCE in the water was below the analytical method’s ability to detect it. The method has a reporting limit for TCE of 0.5 ppb. The maximum contaminant level for TCE in drinking water is 5 ppb. See the Definitions section for more information “ppb”. To learn more about the Atlas “D” Missile Site or the TCE contamination, visit the ACOE Atlas “D” Missile Site 4’s website at www.atlassite4.com.

How is the water system funded?

In the BOPU's ongoing effort to provide a safe and dependable water supply, it is necessary to make improvements to Cheyenne's water system. Water system improvements and maintenance are paid for through water rates charged to BOPU customers. In fiscal year 2025, total operating expenses for the water and sewer departments were approximately $39.754 million. Learn more about how the BOPU invests funds from water and sewer bills by reviewing the 2025 Annual Financial Report online at www.cheyennebopu.org/About-Us/Financial-Reports. This report and the BOPU’s finances are audited annually. The Government Finance Officers Association of the United States and Canada awarded the BOPU with the Certificate of Achievement for Excellence in Financial Reporting for fiscal year 2024 and the 46 years prior. The certificate is the highest form of recognition for financial reporting by state and local governments. The award is for meeting high standards in the BOPU’s annual financial report and for demonstrating a “spirit of full disclosure” with auditors.

BOPU Mission Statement

Sustain Cheyenne’s essential water resources to realize our community’s potential.

BOPU Vision Statement

We will set the standard of excellence in the water and wastewater industry. We will be a leader in service to our customers. We will be responsible stewards in managing and protecting our water resources, the environment, the health and safety of our employees and community.

Contact Us

Questions about this report or concerning your water utility should be directed to:

We want customers to be informed about their water. To learn more about Cheyenne's water system, please attend any of our regularly scheduled BOPU Board Meetings. Board Meetings are held at 3:00 pm on the third Monday of each month and are open to the public. If the third Monday of the month is a holiday, Board Meetings are held on the following Tuesday. More information about Board Meetings is available on our website at: www.cheyennebopu.org/About-Us/Board-Meetings.

Previous Consumer Confidence Reports

Click on the links below to view Consumer Confidence Reports from previous years.

2025 Consumer Confidence Report(PDF, 458KB)
2024 Consumer Confidence Report(PDF, 573KB)
2023 Consumer Confidence Report(PDF, 561KB)
2022 Consumer Confidence Report(PDF, 547KB)
2021 Consumer Confidence Report(PDF, 546KB)
2020 Consumer Confidence Report(PDF, 678KB)
2019 Consumer Confidence Report(PDF, 671KB)
2018 Consumer Confidence Report(PDF, 188KB)
2017 Consumer Confidence Report(PDF, 268KB)
2016 Consumer Confidence Report(PDF, 654KB)
2015 Consumer Confidence Report(PDF, 149KB)
2014 Consumer Confidence Report(PDF, 148KB)
2013 Consumer Confidence Report(PDF, 152KB)
2012 Consumer Confidence Report(PDF, 778KB)