HomeMy WebLinkAbout2022 Annual Water Quality ReportSUMMER2023
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
Learn More About Your Water .......2
The Purpose of this Report ............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
For more information visit www.tigard-or.gov/water
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?
Lake Oswego · TigardWater Partnership
sharing water · connecting communities
Lake Oswego · TigardWater Partnership
sharing water · connecting communities
water provider
staff
members
primary
water sources
pump stations reservoirs
miles of pipe
fire hydrants
million
gallons
storage
capacity
1 3
11
6 14
A snapshot of what it takes to bring drinking water
from its source to your home or business in Tigard, Oregon.
sq. miles
13.7
in the TWSA Clackamas River, ASR and
Ground Water Wells
homes & businesses served
Year the oldest section
of the water system in
Tigard was installed
LARGEST 10 MILLION GALLONS
SMALLEST 200,000 GALLONS
SMALLEST DIAMETER 4 INCHES
LARGEST DIAMETER 36 INCHES
269.29
2,259 20,500
27
2022 ANNUAL WATER QUALITY REPORT
1950
2 | 2022 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 2022, 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.
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 two
city-owned aquifer storage and recovery
wells, and a native groundwater well. All
groundwater sources are disinfected using
small amounts of chlorine.
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, Oregon
metropolitan region. They are comprised of 25
members which are located in the Clackamas,
Columbia, Multnomah, Washington, and
Yamhill Counties. This year, the Consortium
and its members are celebrating 25 years of
service. 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.
Want to learn
more about your
water?
If so, you have a couple of ways
to participate. The Water Advisory
Board (WAB) invites you to attend
their meetings. They are held on the
second Wednesday of evenly numbered
months. Email jennifer@tigard-or.gov
for more information about when and
where you can attend.
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, on Mondays at
5:30 p.m. Visit lotigardwater.org for
more information.
2022 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 2022, 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 is a naturally occurring element that
can dissolve in the groundwater supply.
Chlorine is added to maintain disinfection
requirements throughout the water
distribution system.
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
control of the disinfection process keeps
byproduct levels to a minimum, while
maintaining the required levels of chlorine.
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.
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
2022 water quality data. Additional
information is included to inform,
educate and update consumers
on water issues affecting the
community.
Have a question about
this report?
Contact Environmental Program
Coordinator Jennifer Joe at
503-718-2599 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.
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
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.
Chloride, Potassium, Silica, Sodium and
Sulfate are formed through the erosion
of natural deposits and may be added to
water during treatment.
Dichlorodifluoromethane is a human-
made chemical, commonly known as
Freon-12, that has been phased out of
common use because it damages the
ozone layer in the atmosphere.
Regulated Contaminants
Detected Unregulated Contaminants
Radon is a naturally occurring radioactive
gas that cannot be seen, tasted, or smelled.
Radon can be detected at very low levels
in the groundwater supply. Based on the
historical levels of radon in groundwater
combined with the limited amount of
groundwater used, it is unlikely to have
negative health effects from radon in the
water. Find more information about radon
from the EPA at epa.gov/radon.
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?
2022 WATER QUALITY ANALYSIS RESULTS
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 fe-
cal 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)
Cannot exceed 5 NTU
more than 2 times in 12
months
TT
0.3 in 95%
of samples
Highest single measurement:
0.0132 No Soil runoff
DISINFECTION RESIDUAL
Total Chlorine Residual Run-
ning Annual Average (ppm)4 4 0.85 1.00 No Additive used to
disinfect waterTotal Chlorine Residual at
Any One Site (ppm)NA NA 0.41 1.19 No
DISINFECTION BYPRODUCTS - HALOACETIC ACIDS
Haloacetic Acids Running
Annual Average (ppm)0.060 NA 0.0049 0.0063 No Byproduct of drinking
water disinfectionHaloacetic Acids at Any One
Site (ppm)NA NA 0.0027 0.0310 No
DISINFECTION BYPRODUCTS - TOTAL TRIHALOMETHANES
Total Trihalomethanes Run-
ning Annual Average (ppm)0.080 NA 0.0150 0.0108 No Byproduct of drinking
water disinfectionTotal Trihalomethanes at
Any One Site (ppm)NA NA 0.0053 0.0310 No
The definitions for the vocabulary listed above are available on page 6.
4 | 2022 Water Quality Report • City of Tigard Water Division
Contaminant MCL MCLG TWSA Results
LOW Range HIGH
Violation?
Yes / No
Major Sources
in Drinking Water
INORGANICS CONTAMINANTS
Barium (ppb)2,000 2,000 3.15 4.35 No
Erosion of natural depositsNitrate as Nitrogen (ppm)10 10 0.16 0.51 No
Nitrite as Nitrogen (ppm)1 1 0.138 0.139 No
RADIONUCLIDES
Radon (pCi/L)No Standard No Standard 167 198 No Erosion of natural deposits
UNREGULATED AND SECONDARY (REGULATIONS PROVIDE ADVISORY LIMITS ONLY)
Chloride (ppm)250 250 3.0 5.1 No Erosion of natural deposits
Dichlorodifluoromethane
(ppm)No Standard No Standard 0.0029 0.0094 No Industrial waste deposits
Potassium (ppm)No Standard No Standard 0.7 1.4 No
Erosion of natural deposits
Silica (ppm)No Standard No Standard 12 19 No
Sodium (ppm)No Standard No Standard 4.8 6.0 No
Sulfate (ppm)250 250 3.0 8.0 No
Contaminant 90th
Percentile
Number of Sites
Exceeding
the Action Level
MCLG Lead and Copper
Rule Exceedance
Action Level
Reached Typical Source
Copper (ppm) 0.0
0 samples (out of 34) exceed-
ed 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)0.0
0 samples (out of 34) ex-
ceeded the lead action level
of 15 ppb
15*
More than 10% of the
homes tested have
levels above 15 ppb
No
2022 Water Quality Report • City of Tigard Water Division | 5
2022 WATER QUALITY ANALYSIS RESULTS
* Samples were taken in 2020. 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 set forth by the regulating agencies.
6 | 2022 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).
The purpose of the assessment was to identify potential sources
of direct and indirect contamination in areas surrounding these
wells. The assessment identified 50 potential contaminant
sources (natural and manmade) that may affect the water
quality if managed improperly. To view the assessment, contact
Environmental Program Coordinator Jennifer Joe at
503-718-2599 or jennifer@tigard-or.gov.
TWSA
2022 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.
Because of this natural part of water’s cycle, 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.
CRYPTOSPORIDIUM
Microbial Contaminants, such
as viruses and bacteria, which
may come from wildlife or
septic systems.
Inorganic Contaminants,
such as salts and metals,
which can occur naturally or
result from urban stormwater
runoff, industrial or domestic
wastewater discharges or
farming.
Pesticides and Herbicides,
which may come from a variety
of sources such as farming,
urban stormwater runoff and
home or business use.
Organic Chemical
Contaminants,
including synthetic and
volatile organic chemicals,
which 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
* * * * * * 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 | 2022 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 (none
was detected in 2022). 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 Frequently
Asked Questions
How can I get my water tested?
Contact Tigard Public Works at
503-718-2591 for information about a
free lead-in-water testing kit. For
more extensive testing, private
laboratories can test your tap water
for a fee. Not all labs are accredited to
test for all contaminants. For
information about accredited labs, call
the Oregon Health Authority, Oregon
Environmental Laboratory Accreditation
Program at 503-693-4122.