Scottsdale Water
PO Box 25089
8787 E Hualapai Drive
Scottsdale, AZ 85255

ScottsdaleAZ.gov/Water
480-312-5650
Water Quality: 480-312-8732

2025

Water
Quality
Report

About This Report
At Scottsdale Water, we are committed to bringing our vision of Water
Sustainability through Stewardship, Innovation, and People to life every day. Our
goal is simple: to provide you with safe, reliable drinking water at an affordable
price, paired with exceptional service. This annual report highlights our dedication
to that mission.
Water is a vital resource, particularly as our community faces an
unprecedented drought. Beyond ensuring that your water is safe, we are
equally focused on maintaining a sustainable and secure water supply, both for
today and for the future.
Scottsdale Water operates one of the most innovative and technologically
advanced water recycling facilities in the nation. Thanks to forward-thinking
aquifer recharge programs, strategic planning, and smart investments, Scottsdale
became the first city in Arizona to achieve safe yield—putting more water into the
aquifer than we extract—and has consistently done so since 2006, nearly 20 years
ahead of the state-mandated deadline.
I encourage you to read through this report and learn more about the work and
dedication behind providing safe, reliable, and affordable drinking water every day.
Kevin Rose • Scottsdale Water acting Senior Director

DEFINITIONS AND ABBREVIATIONS
Contaminant – Any physical, chemical, biological or
radiological substance or matter in the water.
Maximum Contaminant Level Goal (MCLG) – 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 Contaminant Level (MCL) – The highest level of a
contaminant allowed by the EPA in drinking water. MCLs are
set as close to MCLGs as feasible using the best available
treatment technology.
Maximum Residual Disinfectant Level (MRDL) – The highest
level of a disinfectant (chlorine) allowed in drinking water.
There is convincing scientific evidence that addition of
a disinfectant is necessary for the control of microbial
contaminants.
Maximum Residual Disinfectant Level Goal (MRDLG) –
The level of 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.
Treatment Technique (TT) – A required process intended to
reduce the level of a contaminant in drinking water.
Action Level (AL) – The concentration of a contaminant, which,
if exceeded, triggers treatment or other requirements that a
water provider must follow.
Part Per Million (ppm) / Part Per Billion (ppb) – Equivalent
to mg/L and µg/L respectively, describe the levels of detected
substances.
Picocuries Per Liter (pCi/L) – A measure of the radioactivity
in a liter of water.
Non-detectable (ND) – The substance was analyzed but not
detected.
Not Applicable (NA) – A regulatory limit does not exist. S

A NOTE FROM THE EPA
To ensure the water from your tap is safe to drink, the
Environmental Protection Agency issues regulations
limiting the amount of certain impurities allowed in drinking
water and the water treatment process. You can expect all
drinking water, including bottled water (which is regulated
by the Food and Drug Administration), to contain at least
small amounts of some contaminants. It’s important to
know the presence or detection of impurities does not
necessarily indicate a health risk.
Scottsdale’s drinking water sources include rivers, lakes,
reservoirs and wells. As water travels over the surface of the
land or through the ground, it dissolves naturally occurring
materials and can pick up substances from human or
animal activity. Possible contaminants may include:
• Microbial contaminants including viruses, bacteria and
parasites, which may come from sewage treatment
plants, septic systems, agricultural or livestock
operations and wildlife.
• Inorganic contaminants such as minerals, salts and
metals, which can be naturally occurring or result
from urban stormwater runoff, industrial or domestic
wastewater discharges, oil and gas production, mining
or farming.
• Radiochemical contaminants, which occur naturally
or result from oil and gas production and mining
activities.
• Pesticides and herbicides that may come from
agriculture, stormwater runoff and residential uses.
• Organic chemical contaminants including synthetic and
volatile organic compounds, which are byproducts of
industrial processes and petroleum production, and
also can come from gas stations, stormwater runoff
and septic systems. S

Water Supply and Treatment
Prior to the 1980s, Scottsdale was 100 percent reliant on
groundwater for its water supply. Today, 90 percent of our
total water supply comes from renewable surface water
sources and recycled water, helping us ensure a long-term
water supply for future generations.
Depending on the time of year, the weather and customer
demand, you may receive water from a single source or from
a combination of sources. S
Water from Lake Mead is treated at the Scottsdale CAP Plant.

SURFACE WATER

GROUNDWATER

RECYCLED WATER

Scottsdale’s main surface water
supply comes from the Colorado
River. It is transported through the
Central Arizona Project canal to the
CAP Water Treatment Plant at the
Scottsdale Water Campus in northern
Scottsdale.

A small portion of Scottsdale’s water
supply also comes from aquifers deep10%
below ground. The city has 21 active
12%
wells and operates several groundwater
treatment facilities, including the Central
Groundwater Treatment Facility and the
North Indian Bend Wash Granular Activated
Carbon Treatment Facility, which treat
groundwater from the North Indian Bend
Wash Superfund site.

The Advanced Water Treatment Plant
at the Scottsdale Water Campus is
one of the largest and most advanced
water recycling facilities in the world.
The plant treats water from Scottsdale
businesses and homes to ultrapure
standards that exceed federal drinking
78%
water
regulations. That water is then
used for turf irrigation and to replenish
our local aquifers.

Both facilities were built by private
companies that were deemed potentially
responsible for contaminating the
groundwater with Trichloroethylene. These
companies pay operating and maintenance
costs of the facilities. The groundwater
is treated to levels that exceed federal
and state drinking water standards, with
regulatory oversight by the EPA, ADEQ and
Maricopa County. S

Since 1998, the state-of-the-art facility
has enabled Scottsdale to inject over
70 billion gallons of water into our area
aquifers in an effort to safeguard the
city’s long-term water supply, while
ensuring the exceptional water quality
of our local aquifers. To put this number
in perspective, that's enough water to
fill the Arizona Cardinals' State Farm
Stadium 120 times. S

The CAP Plant, which can treat up to
70 million gallons of water per day,
is actually three distinct facilities in
one. CAP I and II use a conventional
water treatment process, which
includes pretreatment, coagulation/
flocculation, sedimentation, filtration
and disinfection. Water at CAP III is
treated with ultrafiltration membrane
technology and disinfection. The CAP
Plant uses granular activated carbon
to improve taste and odor and treat
for disinfection byproducts.
We also receive surface water from
the Verde and Salt rivers watersheds,
which is transported by the Salt
River Project to the Chaparral Water
Treatment Plant located near the
intersection of Hayden Road and
East McDonald Drive. The Chaparral
WTP uses ultrafiltration membranes
and granular activated carbon and
has a treatment capacity of 27
million gallons a day. S

Scottsdale's Water Portfolio for 2024
Groundwater - 5%
Recycled - 9%
Salt River Project - 14%
Central Arizona Project - 72%

SOURCE WATER ASSESSMENT PROGRAM
In 2004, Scottsdale worked with the Arizona Department of
Environmental Quality to finalize an assessment on the wells and
surface water sources we use to provide you with drinking water.
This assessment looked at potential risks to our water sources,
which include gas stations, landfills, dry cleaners, agricultural
fields and wastewater treatment plants.
The CAP
Water Treatment
Plants arethat
located
at the
The
assessment
concluded
most
of Scottsdale’s
Scottsdale Water Campus in north Scottsdale.
groundwater
wells have low to medium risk, with the exception
of the wells linked to the North Indian Bend Wash Superfund

Site. The water produced by these wells has a high risk of
contamination, but is treated to meet or surpass drinking water
standards and monitored closely by the city, ADEQ and the EPA.
All surface water sources are considered high risk due to their
exposure to open air. These risks are addressed by the EPA
through its increased monitoring requirements for surface water
sources. The complete assessment is available at
azdeq.gov/environ/water/dw/swap.html or by calling Scottsdale
Water at 480-312-8732. S

Ensuring long-term
water supplies
Since 2022, the Colorado River system has been in
official shortage – meaning less water for the state of
Arizona through the Central Arizona Project (CAP).
There has been a significant amount of news coverage
about the drought and water cuts. The city is still
able to meet demand for residents and businesses,
while preparing for further cuts in coming years. The
governance structure of how and when we are in
shortage is currently controlled through the 2007 Interim
Guidelines. This set of guidelines is set to expire at the
end of 2026.
The U.S. Bureau of Reclamation intent is “to develop a
robust set of operating guidelines for Lake Powell and
Lake Mead that provide for the sustainable management
of the Colorado River system and its resources under a
wide range of potential future system conditions due to a
changing climate”. This is a critical time in our state for
future planning efforts.

Water retention basins at the CAP plant at the Water Campus.

• E
 xpanding our recycled water systems and entering
into conversations for regional programs.
• Increasing aquifer storage and recovery abilities.
• E
 xpanding the Automatic Meter Infrastructure
network and WaterSmart customer portal to assist
customers to better understand and more efficiently
manage their water.

In the face of this uncertainty, coupled with a potential for
higher levels of shortage triggers and reduction amounts,
this becomes a time for serious planning and action.

• I dentifying steps and technology that could be
used to improve the city’s water conservation and
efficiency efforts.

Scottsdale was the first city in Arizona to declare stage
one of its Drought Management Plan and has since
grown many conservation initiatives (some by as much
as 400%) and continue efforts on infrastructure planning.
Scottsdale is responding in the following ways:

• D
 iversifying the city's water portfolio so the city is not
as susceptible to water variances with one source
Ensuring a resilient water supply requires several levels
of investment that can build a more robust supply in the
face of the uncertainty on the Colorado system. S

HIGHLY PURIFED, RECYCLED WATER
Long-term water sustainability takes planning, innovation, and resources. Since 2019, when Scottsdale was granted
the first direct potable reuse permit in Arizona, Scottsdale Water has been preparing for full-scale execution of the
highly purified, recycled water by using this water for taste testing and beer making. Now, given the current water
shortages on the Colorado River, Scottsdale Water is planning to integrate this purified water into the Scottsdale water
blend as early as 2029. By using state-of-the-art purification processes such as ozonation, membrane ultrafiltration,
reverse osmosis, and ultraviolet photolysis, water will be treated to meet all state and federal drinking water standards
to create a final product that results in a safe, clean water that has been proven more pure than bottled water. S

WATER HARDNESS
As water makes its way to treatment plants or through aquifers, it
picks up naturally occurring minerals that make the water “hard”
and can also affect taste and other characteristics. Hardness is
not a primary water quality standard and is not considered to be
a health concern. Scottsdale is committed to providing you with
the cleanest and safest drinking water possible, at an affordable
price. We could implement additional treatment processes to
address hardness, but this would not be cost effective, especially
since the majority of residential water consumption is for outdoor
use. There are varying levels of water hardness throughout
Scottsdale as shown in the table to the right. S

Approximate Hardness Levels
Boundary

Hardness
(Grains per
Gallon)

Hardness
(mg/L or
ppm)

South of Indian School Road

13 - 15

230-260

Indian School Road to Chaparral Road

13 - 17

215-285

North of Chaparral Road

13 - 17

230-290

2024 Compliance Monitoring Results
Scottsdale performs tests for an assortment of contaminants at
locations throughout the city. We test samples from eight entry points
to the distribution system that represent the treated source water and
at 150 locations throughout the distribution system to ensure the water
entering your home or business remains safe and reliable.
We test for over 100 substances, but only the substances detected in
the water are listed in this report. The results shown are from testing
performed in 2024 unless otherwise noted.
A few substances are discussed in detail below. For more
information about other substances or a complete list of all testing,
please contact us at 480-312-8732 or visit the EPA’s website,
epa.gov/dwstandardsregulations. S

The water quality lab, constructed in late 1990s, will undergo a
large expansion and renovation in 2026, which will further enhance
scientists' abilities to confirm treatment and compliance with all
regulatory standards.

Arsenic is a naturally occurring mineral commonly found in water
due to leaching from rocks and soil. The maximum contaminant
level for arsenic allowed in drinking water is 10 ppb (parts per
billion), based on a running annual average.

of these disinfection byproducts, granular activated carbon is
used during the water treatment process to reduce levels of
organic matter and subsequently reduce DBP levels.

While your drinking water meets or surpasses EPA’s standard for
arsenic, it does contain low levels of arsenic. EPA is continually
researching the health effects of low levels of arsenic, which has
been known to cause cancer in humans at high concentrations
and is linked to other health effects such as skin damage
and circulatory problems. In 2024, the highest level of arsenic
measured in Scottsdale’s drinking water was 8.4 ppb.

Cryptosporidium is a pathogen found in surface water throughout
the United States and can be spread through other methods
besides drinking water. Ingestion may cause a gastrointestinal
illness. During periodic monitoring conducted in 2017,
Cryptosporidium was not detected in our source waters. If
present, this organism is removed during treatment through the
use of multimedia filtration. S

Nitrate is an inorganic substance that is monitored due to run off
from fertilizer use. Nitrate in drinking water at levels greater than
10 ppm (parts per million) is considered a health risk for infants
younger than six months of age. (Nitrate levels above 10 ppm in
drinking water can cause blue baby syndrome.) Nitrate levels in
surface water supplies may rise quickly for short periods of time
due to rainfall or agricultural activity. If you are caring for an infant
you should seek advice from your health care provider. In 2024,
the highest nitrate level detected in Scottsdale’s drinking water
was 4.9 ppm.
Turbidity is a measure of clarity in the water and is reported as
Nephelometric Turbidity Units. Turbidity is caused by a variety of
substances including sand, dirt and algae. Water is measured for
turbidity to determine the effectiveness of the water treatment
process. Scottsdale measures turbidity continuously at its
surface water treatment plants.
Microbiological Testing is performed monthly at over 150 sites
within the distribution system for Total Coliform and E. coli
bacteria in order to verify the integrity of the distribution system
as well as our water sources.
Chlorine is used as a disinfectant to ensure the treated water
remains safe at all times. We continually monitor chlorine levels
throughout the system to ensure that safe and adequate levels
are maintained. Scottsdale’s goal is to have a chlorine residual
between 0.5 and 1.5 ppm in our drinking water system.
Byproducts of using chlorine as a disinfectant are
trihalomethanes and haloacetic acids. These are formed as a
result of a chemical reaction between chlorine and naturally
occurring organic matter in the water. To minimize the formation

Additional Monitoring

Lead and copper are typically found in drinking water because of
materials and components found in service lines and home plumbing. If
present, elevated levels of lead can cause health problems, especially
for pregnant women and young children. Scottsdale is committed to
providing high quality drinking water, but cannot control the variety of
materials used in plumbing components. When water has been sitting
for several hours, you can minimize the potential for lead exposure
by flushing the tap for 30 seconds to 2 minutes before using water for
drinking or cooking. If concerned about lead in your water, you can
have your water tested. Information on lead in drinking water, testing
methods, and steps to minimize exposure is available from the Safe
Drinking Water Hotline (800-426-4791) or at epa.gov/safewater/lead.
The most recent testing for lead and copper was performed in 2023.
Lead and copper levels reported in the table are from water faucets
inside 50 Scottsdale homes built before the lead ban.
Residents participating in the lead and copper program are notified
of their results. If the lead concentration exceeds 15 ppb, the home is
retested and the homeowner is contacted for follow-up guidance on
ways to lessen the risk of exposure to lead from drinking water.
To address lead in drinking water, public water systems were required
to develop and maintain an inventory of service line materials by Oct
16, 2024. Developing an inventory and identifying the location of lead
service lines (LSL) is the first step for beginning LSL replacement and
protecting public health.
To date, we've discovered no lead service lines. The lead service
inventory may be viewed at: https://www.scottsdaleaz.gov/water/
water-quality/drinking-water. Contact us for more information about
the inventory or lead sampling that's been done.
To further protect our customer’s from lead in drinking water, Scottsdale
uses caution when changing to a new water source or changing an
existing treatment process. Additional monitoring is performed to
ensure the water is not corrosive to home plumbing. S

Results for Regulated Contaminants
Highest
Amount
Detected

System
Average

Highest
Running
Annual
Average1

Likely Source in Drinking Water

Substance

Unit

MCL

MCLG

Lowest
Amount
Detected

Arsenic

ppb

10

0

1.1

8.4

4.1

8.4

Leaching of natural deposits

Barium

ppb

2,000

2,000

23

152

79

N/A

Leaching of natural deposits

Chromium

ppb

100

100

ND

26.9

9.2

N/A

Leaching of natural deposits

Fluoride

ppm

4

4

0.3

0.4

0.4

N/A

Leaching of natural deposits

Nickel

ppb

N/A

100

ND

1

1

N/A

Leaching of natural deposits

Nitrate

ppm

10

10

0.2

4.9

1.3

3.4

Leaching of natural deposits and septic
systems; Runoff from fertilizer use

Selenium

ppb

50

50

1.7

2.8

2.3

N/A

Leaching of natural deposits; Discharge from
petroleum refineries and mining

Alpha Emitters 2

pCi/L

15

0

ND

2.3

0.5

N/A

Leaching of natural deposits

Uranium

ppb

30

0

ND

14

4.2

N/A

Leaching of natural deposits

ppm

TT

N/A

1.3

2.2

1.7

N/A

Naturally present in the environment

2

Total Organic Carbon

Substance

Unit

MCL

TT
Requirement

Highest
Measurement

Treatment Technique
Comparison

Likely Source in Drinking
Water

Turbidity

NTU

1

95% less than 0.3 NTU

0.27

100% less than 0.3 NTU

Soil runoff

Substance

Unit

MCL

MCLG

Lowest
Amount
Detected

Highest
Amount
Detected 1

Average

Total Coliform

%

5 (monthly)

0

0

0.6

0.2

Naturally present in the environment

Chlorine

ppm

4 (MRDL)

4 (MRDLG)

0

1.5

0.65

Water additive used to control microbial
growth

Total Trihalomethanes
(TTHMs)

ppb

80

N/A

20.1

54.6

52.8 3

Byproduct of drinking water disinfection

Haloacetic Acids

ppb

60

N/A

3.8

13.0

10.2 3

Byproduct of drinking water disinfection

Likely Source in Drinking Water

Substance

Unit

AL

MCLG

90th Percentile
Value

# of Homes
Greater than
AL

Levels in
Treated
Water

System Average
Levels in Treated
Water

Likely Source in Drinking Water

Lead 4

ppb

15

0

2.0

1 out of 50

ND

ND

Corrosion of household plumbing

ppb

1,300

N/A

170

0 out of 50

ND - 2.8

1.6

Corrosion of household plumbing

Copper
1.
2.
3.
4.

4

Highest average at a single sample location
Includes 2020, 2023 & 2024 Sampling Data
Reported value is the highest locational running annual average (LRAA) calculated on a quarterly basis.
Lead and Copper Standard: 90% of homes tested must have lead and copper levels below the alert level (AL). LCR data collected in 2023.

Attention Immuno-Compromised Citizens:
If you are a person with a compromised immune system
(i.e. undergoing chemotherapy, have had an organ transplant
or have HIV/AIDS or other immune system disorders) you
may be particularly at risk of infections and more vulnerable
to contaminants in drinking water. Some elderly persons and
infants may also have increased risk. You are encouraged

to seek advice about drinking water from your health care
provider. More information including ways to lessen the risk
of infection from microbial contaminants and potential health
effects can be obtained by calling the EPA’s Safe Drinking
Water Hotline (800-426-4791). S

Results for Unregulated Contaminants
Substance

Unit

MCL

MCLG

Lowest
Amount
Detected

Highest
Amount
Detected

Alkalinity

ppm

NA

NA

111

250

Aluminum

ppm

NA

NA

ND

0.10

Calcium

ppm

NA

NA

45

88

Chloride

ppm

NA

NA

35

170

Iron

ppm

NA

NA

ND

0.04

Magnesium

ppm

NA

NA

23

37

Manganese

ppm

NA

NA

ND

0.0024

Std. Unit

NA

NA

7.0

8.2

Sodium

ppm

NA

NA

46

112

Sulfate

ppm

NA

NA

20

253

oC

NA

NA

14

33

oF

NA

NA

59

91

Total Dissolved Solids

ppm

NA

NA

325

710

Zinc

ppm

NA

NA

ND

0.056

pH

Temperature

Scientists at the water quality lab test water from more
than 150 locations monthly to ensure the safety of the
water supply.

RESULTS FOR UNREGULATED CONTAMINANT MONITORING RULE

In an ongoing effort to improve the safety of drinking water, the Unregulated Contaminant Monitoring Rule (UCMR), part of the Safe
Drinking Water Act, requires the EPA and water systems to assess the occurrence of unregulated contaminants in drinking water
across the country. A new list of contaminants is issued about every five years and can contain up to 30 contaminants. The EPA uses
this occurrence data along with health effects studies to determine if additional regulations are needed to protect public health.
Monitoring is performed at every location where source water enters the distribution system and some contaminants are also
measured at points within the distribution system, where the water is consumed. The table below shows results of the most recent
testing conducted in 2020. S
Substance

Unit

MCL

MCLG

Lowest
Amount
Detected

Highest
Amount
Detected

Average

Likely Source in Drinking Water

Manganese

ppb

N/A

N/A

0.0

3.3

0.61

Leaching of natural deposits

Germanium

ppb

N/A

N/A

0

0.44

0.024

Leaching of natural deposits

Total Organic Carbon1

ppm

N/A

N/A

3.2

5.1

4.1

Decaying natural organic matter

Bromide

ppm

N/A

N/A

0.057

0.12

0.08

Natural and industrial sources

ppb

N/A

N/A

5.3

13

9.5

Byproduct of drinking water disinfection

ppb

N/A

N/A

8.8

17.0

13.7

Byproduct of drinking water disinfection

ppb

N/A

N/A

11

26

20.0

Byproduct of drinking water disinfection

HAA5

1

2

HAA6Br
HAA92

2

1. Halo Acetic Acid Indicator measured in source water
2. Halo Acetic Acid (HAA) Group

ADDITIONAL WATER INFORMATION RESOURCES
U.S. EPA’s Safe Drinking Water Hotline
800-426-4791, epa.gov/safewater
Arizona Department of Environmental Quality
602-771-2300, azdeq.gov/environ/water/dw
Maricopa County Environmental Services Department
602-506-6666, maricopa.gov/EnvSvc/WaterWaste

Water-related topics may be discussed at City Council meetings
or other public forums and we welcome your attendance. Meeting
notices and City Council agendas are posted on the city’s website at
ScottsdaleAZ.gov, search “Council Agendas.”
Este informe contiene informacion muy importante sobre su agua
potable. Si desea una copia de este informe en español o tiene
alguna pregunta sobre el, por favor llame a 480-312-8711. S

Outreach and Education
TIER 3 PUBLIC NOTICE
When water systems violate a drinking water
standard that does not have a direct impact
on human health (for example, failing to take a
required sample on time) the water supplier has
up to a year to provide a notice of this situation
to its customers.
We are required to monitor the wells for a fecal
indicator like E. coli bacteria within 24 hours
when there is a total coliform bacteria positive
sample result in the distribution system. We
had a total coliform positive sample result
on October 17, 2024, we did not take a fecal
indicator source sample as required under the
Ground Water Rule and, therefore, cannot be
sure of the quality of our drinking water during
that time. A groundwater source associated
with this sample station was running at the time
but was not collected. Training was provided to
staff to prevent similar violations in the future.
Repeat samples in the distribution system were
collected within 24 hours and all absent for
total coliform and E. coli bacteria. This event
was not an emergency and not a health threat.
Consumers do not need to take any action.
For more information, please contact
Scottsdale Water at (480) 312-8732 or 8787 E.
Hualapai Dr. Scottsdale, AZ 85255.
Please share this information with all the other
people who drink this water, especially those
who may not have received this notice directly
(for example, people in apartments, nursing
homes, schools, and businesses). You can do
this by posting this notice in a public place or
distributing copies by hand or mail. S

ScottsdaleAZ.gov/Water
480-312-5650
Water Quality: 480-312-8732

CITIZENS WATER ACADEMY
Are you curious about how Scottsdale gets its water? Do
you want to know more in depth about water as a whole?
Scottsdale offers a Water Citizen Academy to residents.
This free program offers an inside look at Scottsdale's water
utility - one of the most advanced municipal water systems
in the country! The multi-week course explains all facets of
Scottsdale Water's planning and policies and takes you inside
its state-of-the-art facilities and daily operations. Registration
for Fall 2025's academy will open in August. S

For more information, visit ScottsdaleAZ.gov and search “Water Academy.”

WATER TRAILER AT LOCAL EVENTS
Scottsdale Water is proud to offer free water at city events
to educate the community on the safety and reliability of its
water. This program also informs citizens and visitors on best
water conservation practices and how to be better stewards
of this precious resource. S