HomeMy WebLinkAbout2024 Annual Water Quality ReportSUMMER2025
EDITION
The City of Tigard provides clean, safe, dependable drinking water to the residents of Durham, King City, two-thirds of Tigard, and Tigard Water District.
Inside:
Tigard Water Source Information ..2
Tigard Water Service Area Map ....2
The Purpose of this Report ............3
Learn More About Your Water .......3
Information on
Detected Substances .....................3
Water Quality Analysis Results ..4-5
Lead… Are You at Risk?..................6
Source Water Assessment .............6
Definitions .......................................6
Drinking Water Contaminants .......7
Immuno-Compromised Notice .....7
Cryptosporidium ............................7
Frequently Asked Questions .........8
Your Water Bill?
Utility Billing ..........503-718-2460
Water Quality?
Jennifer Joe...........503-718-2599
jennifer@tigard-or.gov
Water Conservation?
Jennifer Joe...........503-718-2599
jennifer@tigard-or.gov
Backflow Prevention?
Hung Nguyen ........503-718-2603
hung@tigard-or.gov
Water Emergencies?
Public Works ..........503-718-2591
After-Hours Water Emergencies?
On-Call Service ......503-639-1554
General Inquiries?
Public Works ...........503-718-2591
Questions?
2024 ANNUAL WATER QUALITY REPORT
The City of Tigard maintains almost 300 miles of
water distribution mains throughout the Tigard
Water Service Area (TWSA). Connecting these water
mains to individual customers is the water service
line. A service line is defined as the pipe(s), fittings,
and meter located between the water main and a
customer’s building inlet.
In the TWSA, the segment of service line between
the water main and water meter is owned and
maintained by the City of Tigard, and the segment
of service line between the water meter and
building entrance is owned and maintained by the
customer as shown in the diagram above. Water
service lines can be made of different materials,
including plastic, galvanized steel, copper, or lead.
The City of Tigard manages an ongoing Water
Service Line Inventory project throughout the
Tigard Water Service Area as part of a proactive
effort to confirm that there are no lead materials
in use in our water system. This project meets
new federal requirements set forth in the US
Environmental Protection Agency Lead and Copper
Rule Revisions to identify service line materials
in water systems by October 2024. Identifying
lead service lines and replacing them, if found, is
important to protecting public health.
PUBLIC
Service Line & Water Meter
Responsibility of City of Tigard
PRIVATE
Service Line
Responsibility of Property Owner
Water Meter
Water
Main
YOUR
Water
Service Line
Water
Service Line
Water
Service Line
To create this inventory, the City of Tigard Water
Department used the following resources and
methods to determine that all service lines within
the Tigard Water Service Area are non-lead:
•Tigard Water Dept.service line material records;
•Oregon state law and plumbing code that do not
allow lead as a pipe material;
•Oregon Health Authority determination that
service lines with a diameter of two inches or
greater are non-lead; and
•Physical inspection of a random selection
of service lines within the TWSA that had
an unknown pipe material, statistically
demonstrating that there are no lead service
lines in the TWSA.
Since the probability of finding lead service
lines was already very low because of regional
construction practices and prior lead bans, Tigard’s
approach was designed to be cost-effective and
efficient with minimal impact on customers. Tigard
has completed its water service line inventory and
has confirmed that there are no lead service lines
within the Tigard Water Service Area.
Questions about the service line inventory?
Contact Ross Horton at ross.horton@tigard-or.gov.
Lead Service Line Inventory – What is it and how does it affect you?
2 | 2024 Water Quality Report • City of Tigard Water Division
S O U R C E I N F O R M A T I O N
Where Does Tigard’s Water Come From?
In 2024, Tigard’s drinking
water system delivered water
from the Lake Oswego-Tigard
Water Treatment Plant with
a supplemental supply from
groundwater wells.
Lake Oswego-Tigard Water
Treatment Plant
The Lake Oswego–Tigard Treatment Plant
withdraws water from the Clackamas River
Basin which encompasses nearly 940 square
miles. Drawn from the Clackamas River, the
pumped water moves through a pipeline
buried beneath the Willamette River to the
Lake Oswego – Tigard Water Treatment Plant
located in West Linn.
Who are our other partners?
In addition to our partnership with Lake
Oswego, Tigard is also a member of the
Regional Water Providers Consortium and the
Clackamas River Water Providers.
The Regional Water Providers Consortium
provides leadership in the planning,
management, stewardship, and resiliency of
drinking water in the Portland metropolitan
region. They are comprised of members
located in the Clackamas, Columbia,
Multnomah, Washington, and Yamhill
Counties. Find out more about the Consortium
and its work in water conservation, emergency
preparedness, and regional coordination at
regionalh2o.org.
The Clackamas River Water Providers is a
coalition of the municipal water providers
that get their drinking water from the
Clackamas River who are working together
on water resource issues. The purpose of
the organization is to fund and coordinate
efforts regarding source water protection
and public outreach and education around
watershed issues, drinking water, and water
conservation, so that we can preserve the
Clackamas River as a high-quality drinking
water source and minimize future drinking
water treatment costs while being good
stewards of the river. For more information,
visit clackamasproviders.org.
How is your
drinking water treated?
The Lake Oswego-Tigard Treatment Plant
uses a conventional treatment process which
includes ballasted flocculation, intermediate
ozone, and biological filtration.
Ballasted Flocculation uses
micro-sand and a coagulant to settle
dirt, sediment and contaminants out of
the water.
Ozone is then added to remove unpleasant
taste and odor compounds and to provide
advanced treatment.
Biological Filtration through a deep bed of
granular activated carbon and silica sand
removes any remaining tiny microbes and
contaminants, such as cryptosporidium.
Beneficial biological activity removes
organic molecules that can produce
disinfection byproducts.
Filtered water is then disinfected using
small amounts of chlorine and the pH is
adjusted with caustic soda to prevent
corrosion of household plumbing.
Groundwater
During periods of high water demand, Tigard
supplements its supply with water from three
city-owned aquifer storage and recovery
wells, and a native groundwater well. All
groundwater sources are disinfected using
small amounts of chlorine.
Have a
question about
this report?
Contact Environmental Program
Coordinator Jennifer Joe at
503-71 8-2599 or
jennifer@tigard-or.gov.
Habla Espanol?
Este informe contiene información
importante acerca de su agua
potable. Haga que alguien lo
traduzca para usted, o hable con
alguien que lo entienda.
2024 Water Quality Report • City of Tigard Water Division | 3
The following list of chemicals and compounds
are what we test for on a regular basis. Most
chemicals are measured in parts per billion (ppb)
or parts per million (ppm).
Volatile Organic Compound: (21 compounds)
manmade chemical compounds such as
cleaning fluids, degreasers and plastics.
Information on Detected Substances
In 2024, water delivered to the TWSA met all regulatory requirements. More than 90 contaminants
are regularly sampled, both before and after the water is treated, to ensure it meets the more than
120 water quality standards for drinking water set by the Environmental Protection Agency (EPA) and
the State of Oregon. If a known health-related contaminant is not listed in this report, it was not
detected in the drinking water.
Barium and Copper are naturally
occurring elements that can dissolve in the
groundwater supply.
Chlorine is added to maintain disinfection
requirements throughout the water
distribution system.
Chromium is found in discharge from
steel and pulp mills and is a naturally
occurring element. Chronic exposure to
chromium, in excess of the MCL, can cause
allergic dermatitis.
Disinfection Byproducts - Haloacetic
Acids (HAA) and Total Trihalomethanes
(THM) form through chemical reactions
between chlorine and naturally occurring
organic matter in the water. The careful
Unregulated water quality standards are
established as guidelines to assist public water
systems in managing drinking water for aesthetic
considerations such as taste, color, and odor.
These contaminants do not present a risk to
human health.
Calcium, Chloride, Iron, Magnesium,
Manganese, Silica, Sodium and Sulfate are
formed through the erosion of natural deposits
and may be added to water during treatment.
The City of Tigard is responsible for
providing a clean, safe, dependable
supply of drinking water to over
60,000 residents in the Tigard Water
Service Area (TWSA). This service
area includes the cities of Durham,
King City, two-thirds of Tigard and the
Tigard Water District. Each entity has
representation on the Water Advisory
Board. The board offers expert
guidance to the Tigard City Council on
water-related matters.
This report summarizes Tigard’s
2024 water quality data. Additional
information is included to inform,
educate and update consumers on
water issues affecting the community.
Want to learn more
about your water?
If so, the Water Advisory Board
invites you to attend meetings on
the second Wednesday at 5:30 p.m.
on even number months. Meetings
are held at the Tigard Public Works
Building located at 8777
SW Burnham Street, Tigard.
The Partnership Committee is
a four-person advisory group
with members from the City of
Tigard and City of Lake Oswego
City Councils. The Committee
provides oversight on issues
and topics of Partnership water
operations, budgets and requests.
Individual members will deliver
information and recommendations
to their respective City Councils
as necessary. Meetings are held
every quarter rotating between
Tigard and Lake Oswego locations
on Monday at 5:30 pm. Visit
lotigardwater.org for a schedule
and more information.
WATER SYSTEM INFORMATION
The Purpose of
This Report
To learn about the health effects of contaminants, visit the Oregon Health Authority website at:
bit.ly/DrinkingWaterContaminants
Regulated Contaminants
Detected Unregulated (Secondary) Contaminants
Synthetic Organic Compounds:
(30 compounds) manmade chemicals,
including insecticides and herbicides.
Inorganic Compounds: (16 compounds)
naturally occurring minerals and chemicals
that are released into water through erosion
and leaching of mineral deposits.
What Else Do We Look For In Our Water?
control of the disinfection process keeps
byproduct levels to a minimum, while
maintaining the required levels of chlorine.
Nitrate and Nitrite form through the
erosion of natural deposits, agricultural
activity and leaching of septic tanks.
Total Coliform Bacteria are naturally
present in the environment and may
indicate other potentially harmful bacteria
may be present. Chlorine is added to the
drinking water supply to kill these bacteria.
Turbidity is a measure of the amount of
sediment suspended in the water. This
sediment can interfere with disinfection
and provide a medium for microbial growth.
Large storm events can result in
increased turbidity in the raw water.
Federal standards regulate contaminants to protect drinking water quality.
Tigard and its water supply partners test for more than 200 regulated and unregulated contaminants.
Contaminant MCL MCLG TWSA Results
LOW Range HIGH
Violation?
Yes / No
Major Sources
in Drinking Water
MICROBIOLOGICAL CONTAMINANTS
Fecal Coliform and E.Coli
Bacteria
A routine sample and a repeat sample are total
coliform positive and one
is also E. coli positive
0 0% of samples with detectable
E. coli or fecal coliform bacteria No Human and animal
fecal waste
Total Coliform Bacteria Must not detect coliform bacteria in more than 5% of samples per month 0 0% of samples with detectable
total coliform bacteria No Naturally present in
the environment
Turbidity (NTU)5 N/A 0.03 0.16 No Erosion of
natural deposits
DISINFECTION RESIDUAL
Total Chlorine Residual Run-
ning Monthly Average (ppm)4 4 0.89 1.07 No Additive used to
disinfect waterTotal Chlorine Residual at
Any One Site (ppm)NA NA 0.16 1.21 No
DISINFECTION BYPRODUCTS - HALOACETIC ACIDS
Haloacetic Acids Running
Annual Average (ppm)0.060 NA 0.0061 0.0070 No Byproduct of drinking
water disinfectionHaloacetic Acids at Any One
Site (ppm)NA NA 0.0040 0.0090 No
DISINFECTION BYPRODUCTS - TOTAL TRIHALOMETHANES
Total Trihalomethanes Run-
ning Annual Average (ppm)0.080 NA 0.0092 0.0119 No Byproduct of drinking
water disinfectionTotal Trihalomethanes at
Any One Site (ppm)NA NA 0.0079 0.0190 No
INORGANICS CONTAMINANTS
Barium (ppb)2,000 2,000 2.3 3.3 No
Erosion of natural deposits
Copper (ppb)1,300 1,300 ND 3.5 No
Chromium - total (ppb)100 100 ND 3.0 No
Nitrate as Nitrogen (ppm)10 10 0.07 0.19 No
Nitrite as Nitrogen (ppm)1 1 0.07 0.19 No
UNREGULATED AND SECONDARY (REGULATIONS PROVIDE ADVISORY LIMITS ONLY)
Calcium (ppm)No Standard No Standard 4.9 6.2 No
Erosion of natural deposits
Chloride (ppm)250 250 2.5 2.6 No
4 | 2024 Water Quality Report • City of Tigard Water Division
2024 Water Quality Analysis Results
Contaminant MCL MCLG TWSA Results
LOW Range HIGH
Violation?
Yes / No
Major Sources
in Drinking Water
UNREGULATED AND SECONDARY (REGULATIONS PROVIDE ADVISORY LIMITS ONLY)
Calcium (ppm)No Standard No Standard 4.9 6.2 No
Erosion of natural deposits
Chloride (ppm)250 250 2.5 2.6 No
Iron (ppm)0.30 0.30 0.05 0.30 No
Magnesium (ppm)No Standard No Standard 1.5 2.1 No
Manganese (ppm)0.05 0.05 0.0024 0.0077 No
Silica (ppm)No Standard No Standard 19 24 No
Sodium (ppm)No Standard No Standard 5.9 7.2 No
Sulfate (ppm)250 250 5.8 9.8 No
Contaminant 90th
Percentile
Number of Sites Exceed-
ing the Action Level MCLG Lead and Copper
Rule Exceedance
Action Level
Reached Typical Source
Copper (ppm) * 0.03
0 samples (out of 34)
exceeded the copper action
level of 1.3 ppm
1.3
More than 10% of the
homes tested have
levels above 1.3 ppm
No Corrosion of
household and
commercial plumbingLead (ppb) *0.9
0 samples (out of 34)
exceeded the lead action
level of 15 ppb
15
More than 10% of the
homes tested have
levels above 15 ppb
No
2024 Water Quality Report • City of Tigard Water Division | 5
*Samples were taken in 2023. The City of Tigard is currently under reduced monitoring and are required to sample every three years. This is the most
recent data available and was done in compliance with regulations set forth by the regulating agencies.
2024 Water Quality Analysis Results
The 1996 Safe Drinking Water Act (SDWA) amendments require
that once every five years, the Environmental Protection
Agency (EPA) issues a new list of no more than 30 unregulated
contaminants to be monitored by public water systems. The
fifth Unregulated Contaminant Monitoring Rule (UCMR5) was
published on December 27, 2021. UCMR5 requires sample
collection for 30 chemical contaminants between 2023 and 2025.
The data collected under UCMR5 improves understanding of the
prevalence and amount of 29 per- and polyfluoroalkyl substances
(PFAS) and lithium in the nation’s drinking water systems.
What are the public health benefits of the UCMR program?
The UCMR program provides the EPA and other interested
parties with nationally representative data on the occurrence of
particular contaminants in drinking water, the number of people
potentially being exposed, and an estimate of the levels of that
exposure. In accordance with the SDWA, the EPA will consider the
occurrence data from UCMR5 and other sources, along with the
peer reviewed health effects assessments, to support a regulatory
determination on whether to initiate the process to develop a
national primary drinking water regulation.
Were PFAS or lithium found in the Tigard Water Service Area’s
drinking water?
No. The results from three rounds of testing concluded there are
no detectible levels of PFAS or lithium found in the water coming
from the Clackamas River or our groundwater sources. One more
round of testing will be completed in 2025 and results from that
will be in next year’s Water Quality Report.
For more information, visit epa.gov/dwucmr or call 1-800-426-4791
for the Safe Drinking Water Hotline.
Fifth Unregulated Contaminant Monitoring Rule
6 | 2024 Water Quality Report • City of Tigard Water Division
Action Level (AL)
The concentration of a contaminant, which, if exceeded,
triggers treatment or other requirements that a water system
must follow.
Maximum Contaminant Level (MCL)
The highest level of a contaminant that is allowed in drinking
water. MCLs are set as close to the MCLGs 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 addition of a disinfectant is
necessary for control of microbial contaminants.
Non-Detected (ND)
Not detected at or above the MDL.
Not Applicable (NA)
Not applicable for the specified contaminant.
Nephelometric Turbidity Units (NTUs)
Turbidity is a measure of how clear the water looks. Turbidity
can interfere with disinfection and provide a medium for
microbial growth.
Parts per Million (ppm) or Milligrams per Liter (mg/L)
A unit measurement describing the level of detected
contaminants that is one part by weight of analyte to one
million parts by weight of the water sample. One part per
million corresponds to one penny in $10,000 or approximately
one minute in two years. One part per million is equal to
1,000 parts per billion.
Parts per Billion (ppb) or Mircograms per Liter (µg/L)
A unit measurement describing the level of detected
contaminants that is one part by weight of analyte to
one billion parts by weight of the water sample. One part
per billion corresponds to one penny in $10,000,000 or
approximately one minute in 2,000 years.
Picocurie per Liter (pCi/L)
Picocurie is a measurement of radioactivity.
Treatment Technique (TT)
A required process intended to reduce the level of a
contaminant in drinking water.
Lead in the Drinking Water…Are You at Risk?
If present, elevated levels of lead can cause serious health problems,
especially for pregnant women and young children. Lead in drinking
water is primarily from materials and components associated with service
lines and home plumbing. The City of Tigard is responsible for providing
high-quality drinking water, but cannot control the variety of materials
used in plumbing components. When your water has been sitting for
several hours, you can minimize the potential for lead exposure by
flushing your tap for 30 seconds to 2 minutes before using water for
drinking or cooking. If you are concerned about lead in your water, you
may wish to have your water tested. Information on lead in drinking
water, testing methods and steps you can take to minimize exposure is
available from the Safe Drinking Water Hotline (800-426-4791) or
www.epa.gov/safewater/lead.
DEFINITIONS
In 2005, the Oregon Health Authority and the Department of
Environmental Quality conducted a source water assessment
for the aquifer storage and recovery wells and the native
groundwater well serving the Tigard Waster Service Area (TWSA).
In 2019, the report was evaluated and updated in conjunction
with other Clackamas River water providers. The purpose of the
assessment was to identify potential sources of direct and indirect
contamination in areas surrounding our wells. To view the reports,
contact Environmental Program Coordinator Jennifer Joe at
503-718-2599 or jennifer@tigard-or.gov
TWSA
2024 Water Quality Report • City of Tigard Water Division | 7
SPECIAL NOTICE FOR
IMMUNO-COMPROMISED PERSONS
Some people may be more vulnerable to contaminants in drinking
water than the general population. Immuno-compromised persons
such as persons with cancer undergoing chemotherapy, persons
who have undergone organ transplants, people with HIV/AIDS or
other immune system disorders, some elderly, and infants can
be particularly at-risk from infections. These people should seek
advice about drinking water from their health-care providers.
Environmental Protection Agency and Centers for Disease Control
and Prevention guidelines on appropriate means to lessen
the risk of infection by Cryptosporidium and other microbial
contaminants are available from the Safe Drinking Water Hotline
(800-426-4791).
In order to ensure that tap water is
safe to drink, the US Environmental
Protection Agency (EPA) sets
regulatory limits on the amounts
of certain contaminants in water
provided by public water systems.
The Food and Drug Administration
(FDA) sets limits on contaminants in
bottled water, which must provide the
same protection for public health.
The sources of drinking water (both tap water and bottled water)
include rivers, lakes, streams, ponds, reservoirs, springs, and wells.
As water travels over the surface of the land or through the ground, it
dissolves naturally occurring minerals and, in some cases, radioactive
material, and can pick up substances resulting from the presence of
animals or from human activity.
Drinking water, including bottled water, may contain small amounts of
some contaminants. However, the presence of contaminants does not
necessarily indicate that the water poses a health risk.
Contaminants that may be present in source water include:
Is a micro-organism (protozoan) naturally present in surface
water supplies throughout the world. Surface water supplies are
particularly vulnerable if they receive runoff or pollution from
human or animal wastes.
Since wildlife inhabit the Clackamas River Watersheds, managing
agencies regularly monitor for Cryptosporidium. Occasionally, this
monitoring detects low levels of Cryptosporidium.
New national standards further reduce the risks of illness
from Cryptosporidium. Symptoms of infection include nausea,
abdominal cramps and diarrhea.
Most healthy individuals are
able to overcome the
disease within a few
weeks. However,
immuno-
compromised
people have
more difficulty
and are at
greater risk
of developing
severe, life
threatening illnesses.
Immuno-compromised
individuals are encouraged
to consult their doctor regarding
appropriate precautions to avoid infection.
Cryptosporidium must be ingested for it to cause disease and may
be spread through means other than drinking water.
CRYPTOSPORIDIUMCRYPTOSPORIDIUM
Microbial Contaminants, such as viruses and
bacteria, which may come from wildlife or septic
systems.
Inorganic Contaminants, such as salts
and metals. Can occur naturally or result from
urban stormwater runoff, industrial or domestic
wastewater discharges or farming.
Pesticides and Herbicides, May come from
a variety of sources such as farming, urban
stormwater runoff and home or business use.
Organic Chemical Contaminants, such as
synthetic and volatile organic chemicals. These
are byproducts of industrial processes, and
may come from gas stations, urban stormwater
runoff and septic systems.
Radioactive Contaminants, which can occur
naturally.
More information about contaminants and potential health
effects is available from the EPA’s Safe Drinking Water Hotline
800-426-4791.
What the EPA Says About
Drinking Water
Contaminants
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* * * * * * ECRWSS
POSTAL CUSTOMER
PRESRT STD
U.S. POSTAGE
P A I D
PORTLAND, OR
PERMIT # 1350
City of Tigard
PUBLIC WORKS DEPARTMENT
13125 SW Hall Blvd.
Tigard, OR 97223
This report was printed on recycled paper with environmentally friendly inks. Please remember to recycle.
8 | 2024 Water Quality Report • City of Tigard Water Division
Is fluoride added to our drinking water?
No. The Lake Oswego-Tigard Treatment
Plant does not add fluoride to the water,
but naturally occurring trace amounts
may be present when serving water
from seasonal groundwater sources (see
the Water Quality Analysis Results table
for more information about the current
year). You may want to consult with
your dentist about fluoride treatment to
help prevent tooth decay, especially for
young children.
Is our water soft or hard?
Our water is very soft. Most of the year
the hardness ranges from 3-8 parts
per million (ppm), or approximately ¼
to ½ a grain of hardness per gallon.
During the summer and in times of
emergency, some customers receive a
blend of groundwater from our aquifer
storage and recovery wells and native
groundwater well. The water from these
wells has a hardness of approximately
60 ppm (about 5 grains per gallon),
which is deemed moderately hard.
H2O
FrequentlyAsked Questions
Tigard is planning a cost-
effective, emergency-ready,
and modern Police and
Public Works Facility. We
are asking the community
to support this project with a bond vote
in May 2026. For more information scan
the QR code or visit www.tigard-or.gov/
BuildingaBetterTigard
TIGARDBUILDING A BETTER