2006Water Quality Report

City of Henderson

� 2006 Water Quality report �2006 Water Quality report

2006Why am I receiving a Water Quality Report?Safe, clean water is important to all of us. The City of Henderson is dedicated to providing you with high quality water and sewer service.

The purpose of this Water Quality Report is to:

u Provide you with information about your drinking water

u Present water quality data from the year 2005

u Comply with U.S. Environmental Protection Agency (EPA) requirements for reporting to customers

u Provide helpful information regarding drought and water conservation

The City of Henderson is proud of the quality of its water supply, which meets or surpasses all federal and state water quality requirements.

If you have any questions regarding your water quality or about information presented in this report, please call us at 267-5900 or visit our Web site at www.cityofhenderson.com/utilities.

� 2006 Water Quality report

Water Quality Report

ContentsWater Quality Facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

A Message for You . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Water Source and Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Understanding Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Year 2005 Water Quality Data . . . . . . . . . . . . . . . . . . . . . . . . . .8

Henderson Department of Utility Services . . . . . . . . . . . . . . . .10

Water Quality FactsOur water is safe

The water we drink in the City of Henderson comes from the Colorado River via Lake Mead, which is one of the highest quality water sources in the United States.

Our drinking water meets or surpasses all water quality standards

Our drinking water meets or surpasses all state and federal requirements for drinking water as outlined in the Federal Safe Drinking Water Act.

How would I know if our drinking water became unsafe?

We would notify you. The City and the Nevada Bureau of Health Protection Services closely monitor the results of hundreds of water quality tests performed on our drinking water each month. In the event of a violation of any health standards or Maximum Contaminant Level (MCL), the City is required by law to notify the public.

Our water treatment facilities are secure

The water treatment facilities that serve our community are kept secure and are accessible only to authorized water treatment personnel.

Where can I learn more?There are several sources of additional information on water quality, including the EPA Safe Drinking Water Hotline at 800-426-4791, the City of Henderson Department of Utility Services at 267-5900, or the Clark County Health District at www.cchd.org.

A Message for YouDear Henderson Resident,

Safe, clean drinking water is one of life’s most basic needs, and our ability to provide, treat and deliver this water to our citizens is one of our most important responsibilities. We are pleased to provide you with this report, which gives you important information about the water you use every day.

During the year 2005, Henderson treated and delivered over 24 billion gallons of water to our residents, and conducted thousands of water quality tests to ensure that your water was clean and safe when it arrived at your home or business.

Along with other agencies in our State and region, Henderson is working to ensure that we have the water resources necessary to provide for our needs for many years into the future.

We’ll continue to use the very best in water treatment technology and processes to treat your drinking water, to ensure you have this life-giving resource when you need it. We also hope you’ll take every opportunity to conserve water.

We hope you find this report helpful and informative. We’re dedicated to protecting and delivering high-quality water to you and your family, and we hope you’ll join us in conserving this precious resource.

Mayor Jim Gibson (center) Councilmen (left to right) Jack K. Clark, Steven D. Kirk,

Amanda M. Cyphers and Andy A. Hafen

� 2006 Water Quality report �2006 Water Quality report

Lake Mead Alfred Merritt Smith Water Treatment Plant

River Mountains Treatment and Transmission

Facility

SNWA Intakes

City of Henderson Water Treatment Facility

BWC Intake

Water Source and Assessment Surface Water Source AssessmentThe surface water source assessment includes an analysis of the current water-quality data at the intakes and the vulnerability of the intakes to potential contaminating activities located within the Las Vegas Valley watershed. The vulnerability analysis includes the time of travel from potential contaminating activities to the intake, physical barrier effectiveness of the watershed, the risk associated with the potential contaminating activities and evaluation of historical water-quality data prior to treatment. It is noteworthy that this study represents an initial survey of the drinking water intakes’ vulnerability and is based on land use in the watershed rather than an analysis of the drinking water. Even before undergoing treatment, water quality at the intakes is within state and federal drinking water standards except for microbiological contaminants naturally found in all surface waters.

The vulnerability analysis of land use shows that the potential contaminating activities with the highest vulnerability rating include septic systems, golf courses/parks, storm channels, gasoline stations, auto repair

shops, construction and wastewater treatment plant discharges. Based on water-quality data (prior to treatment) and the results of the vulnerability analysis of potential contaminating activities, the drinking water intake is at a moderate level of risk for volatile organic (VOC), synthetic organic (SOC), microbiological and radiological contaminants and at a high level of risk for inorganic (IOC) contaminants. All of the Las Vegas Valley governmental agencies coordinate their watershed management programs to minimize the vulnerability risk to Lake Mead. The findings of the source water assessment will be used to enhance those programs.

The treated water delivered by the City of Henderson meets or surpasses all state and federal drinking water standards.

For additional information, please contact the Nevada Division of Environmental Protection at (775) 687-9520.

Where does my water come from?All of the water we use in the City of Henderson comes from the Colorado River and its tributaries. It begins as snow in the Colorado

Rockies, which melts and travels down the Colorado River, through the Grand Canyon and into Lake Mead.

Where and how is it treated?At Saddle Island in Lake Mead, there are three water intakes: two underwater intakes from the Southern Nevada Water Authority (SNWA) and one intake tower owned and operated by Basic Water Company (BWC). The SNWA intakes deliver water to the Alfred Merritt Smith Water Treatment Facility and River Mountains Water Treatment Facility, which treat the

water and then pump it to member agencies of the SNWA. The majority of Henderson’s residents receive their water from the SNWA, but some of our citizens receive their water from the City of Henderson Water Treatment Facility on Water Street in downtown Henderson (see the large photo on the facing page).

At each of these facilities, the water is treated to meet extremely high standards before being sent to homes and businesses throughout our service area.

What about taste and hardness?

As the water makes its journey through canyons, rivers and reservoirs, it picks up natural elements like calcium and magnesium that give our water its hardness and taste.

Customers often ask what the hardness of the water is in either grains per gallon or parts per million in order to set water softeners. Our water averages 326 mg/L of CaCo3 (Calcium Carbonate). Usually water softener manufacturers ask for the hardness in grains per gallon (gpg). 1 gpg = 17.12 mg/L. Therefore, 326 mg/L divided by 17.12 mg/L equals 19 grains per gallon of hardness.

The Colorado River System

� 2006 Water Quality report �2006 Water Quality report

Understanding Water QualityWhy is there anything in my water?

A contaminant is any substance that is not H20. All drinking water—including bottled water—can reasonably be expected to contain at least small amounts of some contaminants. Listed on the following pages are the contaminants detected in Henderson’s drinking water from 1/1/05 through 12/31/05.

Sources of drinking water (both tap 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. Water can also pick up substances resulting from the presence of animals or human activity. Contaminants that may be present in source water include:

Microbial contaminants, such as viruses and bacteria, which may come from septic systems, agricultural livestock operations, wastewater treatment plants and wildlife.

Inorganic contaminants, such as salts and metals, that can be naturally occurring or result from urban storm water runoff, industrial or domestic

wastewater discharges, oil and gas production, mining or farming.

Pesticides, herbicides and fungicides, which may come from a variety of sources such as agriculture, urban runoff, and residential uses.

Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.

Organic chemical contaminants, including synthetic and volatile organic chemicals, that are by-products of industrial processes and petroleum production, and can also come from gas stations, urban storm runoff and septic systems.

Important Health InformationSome people may be more vulnerable to contaminants in the 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. These people should seek advice about drinking water from their health care provider. EPA/Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and Giardia and other microbial contaminants are available from the EPA’s Safe Drinking Water Hotline at 800-426-4791.

Our Contaminant Watch ListIn order to ensure that tap water is safe to drink, the EPA and Nevada Division of Environmental Protection (NDEP) prescribe regulations which limit the amount of certain contaminants in the water provided by the public water system. The City of Henderson’s water treatment facility treats water according to these regulations.

Although the City’s water supply is tested for all of the contaminants required by law, the following have recently been of interest to the general public:

Cryptosporidium is a microscopic organism that, if ingested, can cause fever and gastrointestinal symptoms. Crypto is made harmless or removed from water through a successful treatment combination of filtration, sedimentation and disinfection using ultraviolet light and ozone. Our water treatment facilities carefully monitor our water for the presence of this organism.

MTBE is a chemical agent used in gasoline to reduce smog. Methyl tertiary butyl ether has become a major environmental concern throughout the nation after being detected in groundwater supplies. The City of Henderson does not rely on groundwater, but has carefully tested for this compound and has not detected it in our water supply.

Turbidity is a measurement that refers to the clarity of the water and has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses and parasites that can cause symptoms such as nausea, cramps, diarrhea and associated headaches. In 2005, all of the samples tested were below 0.5 NTU, well below the action level (AL, see page 8).

Arsenic is a naturally-occurring element that can enter a water source from the erosion of natural deposits. Some people who drink water containing arsenic in excess of the Maximum Contaminant Level (MCL) over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer. No samples exceeded 6 ppb, well below the proposed EPA limit of 10 ppb.

Perchlorate, a man-made salt consisting of chloride and oxygen, has been detected at low levels in untreated and treated water. Scientists have traced the salt’s origin to shallow groundwater entering the Las Vegas Wash. Although there are no State of Nevada or federal limits for perchlorate in drinking water, Southern Nevada’s water agencies are closely monitoring efforts by the Nevada Division of Environmental Protection to intercept and remove perchlorate at its source.

2005Water Quality DataYear Regulated ContaminantsCity of Henderson

Water Treatment PlantAlfred Merritt Smith

Water Treatment FacilityRiver Mountains

Water Treatment Facility

Substance MCL Range Average Range Average Range Average MCLG Potential Source of Contaminant

Gross Alpha Activity 1� pCi/L � pCi/L � pCi/L ND ND �.� pCi/L �.� pCi/L 0 pCi/L Erosion of natural deposits

Gross Beta Activity1 �0 pCi/L �.� pCi/L �.� pCi/L �.1 pCi/L �.1 pCi/L ND ND 0 pCi/L Decay of man-made and natural deposits

Arsenic2 �0 ppb ND–� ppb 1 ppb ND–� ppb 0.� ppb �–� ppb � ppb 0 ppb Erosion of natural deposits

Barium � ppm 0.1�–0.1� ppm 0.1� ppm 0.1�–0.1� ppm 0.1� ppm 0.1�–0.1� ppm 0.1� ppm � ppm Erosion of natural deposits

Bromate 10 ppb ND ND ND–10 ppb �.1 ppb ND–10 ppb �.� ppb 0 ppb By-product of drinking water disinfection

Chromium 100 ppb ND ND ND–� ppb 1.� ppb ND–�.� ppb 1.1 ppb 100 ppb Erosion of natural deposits

Fluoride � ppm 0.�9–0.99 ppm 0.8� ppm 0.��–0.89 ppm 0.8� ppm 0.��–0.9� ppm 0.8� ppm � ppm Erosion of natural deposits, water additive

Nitrate 10 ppm 0.�9–0.�� ppm 0.�� ppm 0.��–0.�� ppm 0.�� ppm 0.�8–0.�� ppm 0.�� ppm 10 ppm Runoff from fertilizer, leaching from septic tanks, erosion

Free Chlorine Residual3 � ppm 0.19–1.� ppm 0.9� ppm 0.��–1.88 ppm 1.�� ppm 0.��–1.88 ppm 1.�� ppm � ppm By-product of drinking water

disinfection

Copper4 1.� ppm� (AL) 0.0�–1.� ppm 0.8� ppm

(90th percentile) N/A N/A 1.� ppm (AL)

Corrosion of household plumbing systems

Lead4 1� ppb� (AL) ND–� ppb ND (90th

percentile) N/A N/A 0 ppb (AL) Corrosion of household plumbing systems

Total Trihalomethanes 80 ppb �8–�� ppb �9 ppb 1�–�0 ppb �� ppb 1�–�0 ppb �� ppb N/A By-product of drinking water

disinfection

Haloacetic Acids �0 ppb 1�–�8 ppb �0 ppb 1�–�1 ppb 19 ppb 1�–�1 ppb 19 ppb N/A By-product of drinking water disinfection

Radium � pCi/L 0.�� pCi/L 0.�� pCi/L �.�9 pCi/L �.�9 pCi/L 0.89 pCi/L 0.89 pCi/L 0 pCi/L Erosion of natural deposits

Uranium �0 ppb �.9 ppb �.9 ppb �.� ppb �.� ppb �.� ppb �.� ppb 0 ppb Erosion of natural deposits

Total Coliform �% positive

0–0.�% positive 0.1�% positive 0% 0% 0%

positive Bacterial growth

Maximum Turbidity & Date Found

Min % Monthly Samples <0.�

NTU

Maximum Turbidity & Date Found

Min % Monthly Samples <0.�

NTU

Maximum Turbidity & Date Found

Min % Monthly Samples <0.�

NTU

Turbidity6 TT 0.�� NTU (Dec 1�) 9�.8% 0.0�� NTU

(Jan 1�) 100% 0.0�� NTU (Jan �1) 100% N/A Soil runoff

Unregulated Contaminants7

City of Henderson Water Treatment Plant

Alfred Merritt Smith Water Treatment Facility

River Mountains Water Treatment Facility

Sulfate N/A ��0–�90 ppm �80 ppm ��0–�90 ppm ��� ppm ��0–�80 ppm ��� ppm NR Mineral and nutrient

Perchlorate N/A �.8–9.� ppb �.1 ppb ND–�.� ppb �.� ppb ND–�.� ppb � ppb NR Rocket fuel production

Listed below are the contaminants detected in Henderson’s drinking water from 1/1/2005 through 12/31/2005. All regulated contaminants were below allowed levels.

Terms, Definitions & Abbreviations

Maximum Contaminant Level (MCL)

The highest level of contaminant allowed in drinking water. MCLs are set as close to the MCLG as feasible using the best available treatment technology.

Maximum Contaminant Level Goal (MCLG)

The level of 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 a disinfectant allowed in drinking water. There is convincing evidence that the addition of a 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 contamination.

N/A Not Applicable, or no MCL or MCLG established.

ND Not Detected in our drinking water.

Parts per million (ppm)

Or milligrams per liter. A measure of the concentration of a substance roughly equal to 1 inch in 1� miles.

Parts per billion (ppb)

Or micrograms per liter. A measure of the concentration of a substance roughly equal to one inch in 1�,000 miles.

PicoCuries per Liter (pCi/L)

A measure of radioactivity in water. Low levels of radiation occur naturally in many water systems, including the Colorado River, the source of our water.

Nephelometric Turbidity Units (NTU)

A measure of the clarity of water. Turbidity of � NTU is just barely noticeable to the average person.

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

Treatment Technology (TT)

A required process intended to reduce the level of a contaminant in drinking water.

Disinfection by-product

A substance created by the chemicals or processes used to destroy potentially harmful microorganisms.

8 2006 Water Quality report 92006 Water Quality report

How do I read these tables?The tables on these pages list contaminants which: 1) have associated Primary Maximum Contaminant Levels (MCLs) that are regulated and 2) were detected by the City of Henderson, Alfred Merritt Smith or River Mountains water quality laboratories.

A contaminant is any substance other than the hydrogen or oxygen molecules that make up the chemical formula of water (H2O). Drinking water—including bottled water—may reasonably be expected to contain at least small amounts of some contaminants. Contaminants do not pose a health risk when they are present at levels below the MCL.

Regulations require us to monitor for certain contaminants (like lead and copper) less than once per year because the concentrations of these contaminants are not expected to vary significantly from year to year. Some of the data, though representative of current water quality, are more than one year old.

1) The EPA considers �0 pCi/L to be the level of concern for beta particles. Actual MCL for beta particles is � mrem/year.�) 10 ppb as of January ��, �00��) Regulated by MRDL, with the goal stated as MRDLG. The value is the highest quarterly running annual average reported in �00�.�) Copper & Lead testing are required every � years. Data are from the most recent testing done in accordance with regulations.�) Action Level–90% of samples must be below this level.6) 95% of all samples taken after filtration each month must be less than 0.3 NTU. Maximum turbidity cannot exceed 1.0 NTU�) For a complete list of unregulated contaminants that we tested for, please call the Department of Utility Services at ���-�900.

10 2006 Water Quality report 112006 Water Quality report

City of Henderson Department of Utility Services

The City of Henderson is the only full-service city in Southern Nevada providing water and sewer services to its citizens. The Department of Utility Services is responsible for all facets of water, wastewater, and reclaimed water services for the Henderson community. The Department provides treatment and delivery of drinking water, collection and

reclamation of wastewater, laboratory testing services, utility infrastructure planning and management, customer and billing services, as well as educational programs for our residents.

The Department’s mission is clear, “to provide vital water and wastewater services to our citizens while protecting the environment, health and prosperity of our community.” During the last several years of drought, this mission has included protecting Southern Nevada’s precious water resources through diligent conservation efforts.

Water Conservation in Southern NevadaThe vast majority of the water we use in Southern Nevada originates in the Colorado Rocky Mountains. The quantity of water available to the seven states that rely on this source is dependent on the amount of snow that falls on the Western slopes of the mountain range, then melts and eventually forms the Colorado River. While the effect of the worst drought in recorded history appears to be diminishing, we cannot relax our conservation efforts if we want to protect our future water resources. Water conservation has become a necessary way of life in our desert environment, but need not affect our quality of life here in Henderson.

Nearly two-thirds of our water is used to irrigate outdoor landscaping. The most significant step you can take towards water conservation is to remove your lawn and replace it with water efficient desert landscaping. Through a simple turf conversion, you can save 55 gallons of water a year for every square foot of grass you replace. You may find the additional benefits of replacing your lawn just as noteworthy, such as a more colorful and interesting landscape that requires less maintenance. Acacia Demonstration Gardens is a wonderful source of inspiration for plants that will work well in your yard. To learn more about the Demonstration Gardens visit www.cityofhenderson.com/parks.

During 2005, Henderson residents and businesses converted more than 2.46 million square feet of turf to desert appropriate landscaping, for a total water savings of 135.5 million gallons. That’s enough water to fill 1,524 Olympic-sized swimming pools. Thank you, Henderson, for your continuing efforts to protect the future of our precious water resources.

Drought AlertSouthern Nevada will remain in Drought Alert through 2006. All water customers must water their landscaping according to an assigned watering group. Visit the drought and conservation page at www.cityofhenderson.com/utilities to determine your watering group and assigned watering days.

Henderson Water Reclamation Facility

Henderson has the ability to reclaim wastewater, or water used inside your home or business, for reuse in specific situations such as landscape irrigation. On an average day, more than 20 million gallons of wastewater is collected and sent to the City of Henderson’s Water Reclamation Facility. Rain water and water that is used outdoors is collected by the City’s storm drain system and diverted directly to the Las Vegas Wash, bypassing the water reclamation process. That is why our conservation efforts are primarily focused on reducing outdoor water use through watering restrictions; this water cannot be reclaimed or reused.

Henderson’s wastewater treatment process is one of the best in the country, with effluent quality in the top seven percent nation-wide. The reason our wastewater is cleaned and treated to such a high standard is because it is reused. The City has three uses for treated wastewater: return to the environment by way of the Las Vegas Wash, delivery to the City’s extensive water reclamation system, and discharge to the ponds at the Bird Viewing Preserve.

Water returned to the environment through the Las Vegas Wash earns “return flow credits,” allowing us to draw additional drinking water from Lake Mead above and beyond our yearly allocation of 300,000 acre feet, in an amount equal to what is returned. In 2005, Southern Nevada earned 210,000 acre feet in return flow credits, increasing our available drinking water resources by 70%.

The City reuses about 31% of its treated wastewater for landscape irrigation at Henderson golf courses, medians along Boulder Highway, and a local cemetery. Reclaimed water is also used on construction sites.

Henderson Water Treatment PlantThe City of Henderson is the only city in Southern Nevada to operate its own Water Treatment Plant. “Raw” or untreated water from Lake Mead is delivered to the treatment plant, which removes impurities and disinfects the water as if flows by gravity through several treatment processes. One step in the process is ultraviolet disinfection, a superior method of water treatment that relies on an environmentally friendly light source to render any microorganisms found in the water harmless. Henderson’s drinking water is tested daily, and meets or surpasses all state and federal drinking water standards. Our drinking water meets even higher standards than those imposed on bottled waters.

The Water Treatment Plant supplies 15% of the Henderson community’s drinking water; the remaining 85% is supplied by the Southern Nevada Water System. On an average day, the City treats and delivers 65 million gallons of water to residents and businesses.

Henderson is fortunate to have one of the highest quality drinking water sources in the nation, the Colorado River. The water has a “hard” taste due to the natural minerals collected as the snow on the Western slopes of the Colorado Rockies melts and collects to form the river, but is otherwise relatively free from contaminants.

More InformationIf you have questions about water quality, drought and conservation in Southern Nevada, or educational programs offered by the City of Henderson, you may contact the Customer Care Center at 267-5900 or via email at cohutil@cityofhenderson.com.

PRSRT STD US Postage

PAIDPermit 438

Las Vegas, NV

The City of HendersonJames B. Gibson, Mayor

City CouncilJack K. Clark

Amanda M. CyphersAndy A. HafenSteven D. Kirk

Philip D. Speight, City ManagerMark T. Calhoun, Assistant City ManagerMary Kay Peck, Assistant City Manager

Dennis B. Porter, Director of Utility Services

City of Henderson240 Water street

Po Box 95050Henderson, nV 89015

Published June 2006Este reporte contiene información importante sobre la calidad del agua en su comunidad. Tradúzcalo o hable con alguien que lo entiende bien. Si necesita ayuda con esto, llame nuestro Centro del Cuidado del Cliente en 267-2500 para la ayuda..

2006Water Quality Report

Department of Utility ServicesCustomer Care Center(702) 267-5900www.cityofhenderson.com/utilities

Department of Utility Services

This report is being sent to you by the City of Henderson to comply with federal Environmental Protection Agency requirements.