1. Annual Drinking
Water Quality
Report
Spring 2015
Cool, clear
water tastes
so good! It’s
important to
know that
it’s clean and
safe, too.
Take a look
inside to see
how we take
care of your
water!

2. 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 possible using the best
available treatment technology.
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 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.
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.
NTU: Nephelometric Turbidity Unit: Turbidity is
a measurement of water clarity. Materials that cause turbidity
include clay, silt, bacteria and viruses.
TT: Treatment Technique: A required process intended
to reduce the level of a contaminant in drinking water.
GLOSSARY OF TERMS
FOR TEST RESULTS
What can you do to prevent drinking water
contamination? Do you have an irrigation or fire
sprinkler system? Be sure to test your backflow
assembly annually.
A backflow prevention assembly protects our drinking
water supplies from contamination due to backflow,
which can draw soil, pet waste, fertilizers and pesticides
into the public drinking water supply.
Your backflow assembly is your primary defense that
protects you from a potential contamination incident
that could affect the health of your family and neighbors.
Annual testing can help determine if the assembly is still
functioning properly. If a backflow assembly fails a test, it
could be due to broken or malfunctioning parts.
For more information, call Chic Nessly, the District’s Cross
Connection Control Specialist, at (425) 295-3213, or email
him at chic.nessly@spwsd.org.
“This water tastes great!
Let’s protect it.”
Prevent Drinking Water Contamination!
ppm: Parts per million, or milligrams per liter (mg/l). Compare
with one cent in $10,000. One ppm = 1,000 ppb.
ppb: Parts per billion, or micrograms per liter (µg/l). Compare
with one cent in $10 million.
TTHM: Total Trihalomethanes: By-products of
drinking water disinfection.
HAA5: Haloacetic acids: The five haloacetic acids are
also water disinfection by-products.
ND: Not Detected. NA: Not Applicable.
2

3. Underground you will find a treasure that is worth more
than gold - clean water, necessary for our very survival!
It seeps between the spaces of layers of gravel and sand,
sometimes hundreds of feet deep. How do we get it
from way down there to your tap?
From below to above and beyond!
Imagine drinking water through a straw. Our well pumps
operate on a similar principle. These hard-working
machines can pull water from depths of a thousand feet!
Although this water source is clean, we treat it to remove
any lingering bacteria and viruses. We then store it in
our tanks so that when you turn on the tap, clean water
is always there.
Get into the zone.
This groundwater circulates in two separate zones.
If you live south of the Redmond-Fall City Road in
Sammamish or Issaquah, you get your water from the
Plateau Zone. This zone includes two separate aquifer
systems, the Plateau Aquifer and the Lower Issaquah
Valley Aquifer (LIVA). We use eight wells to draw from
the Plateau Aquifer and three wells to pump from
the LIVA. If you live north of the Redmond Fall-City
Road, you are in the Cascade View
Zone, which includes an area of
unincorporated King County. We
have three wells working there to
bring water to you.
Did you know? We share a joint tank with the Northeast Sammamish Sewer and Water District
(NESSWD.) If you live north of NE 8th Street, you may receive some of your water from NESSWD’s
sources. Please contact NESSWD at (425) 868-1144 for a copy of their water quality report.
Here are your water quality test results from the groundwater supply:
Detected
Substance
Unit MCL MCLG Average Range Likely Sources
Nitrate ppm 10 10 0.95 0.2 - 2.2
Runoff from fertilizer use,
leaching from septic tanks,
sewage, erosion of natural
deposits
Arsenic ppb 10 0 3.5 1 - 6
Erosion of natural deposits.
Includes 2012 and 2013 data.
Fluoride ppm 4 4 0.75 0.67 - 0.83
Water additive which
promotes strong teeth
TTHM ppb 80 NA 13.5 5.8 - 19
By-products of drinking water
disinfection
HAA5 ppb 60 NA 5.58 4.0 - 7.7
Chlorine ppm MRDL = 4 MRDLG = 4 0.40 0.28 - 0.49
3
Buried Treasure: Your Groundwater

4. Up in the mountains east of North Bend lies a 90,000
acre wilderness. Seattle Public Utilities serves as the
caretaker for this marvelous watershed resource.
Melting snow feeds mountain streams that flow to clear,
cold lakes. Your water is carefully cleaned and treated to
remove any impurities. We then blend this wealth from
the mountains with our groundwater so it is ready for
you at your home!
Here are your water quality test results from the surface water supply:
EPA’S Allowable
Limits
Levels in Cedar Water Levels in Tolt Water
Detected
Compounds
Units MCLG MCL Average Range Average Range Typical Sources
Raw Water
Total Organic
Carbon
ppm NA TT 0.9 0.4 - 1.9 1.3 1.1 - 1.7
Naturally present in the
environment
Cryptosporidium* #/100L NA NA ND ND ND ND
Naturally present in the
environment
Finished Water
Turbidity NTU NA TT 0.4 0.2 - 1.6 0.07 0.05 - 0.28 Soil runoff
Barium ppb 2000 2000 1.4 (one sample) 1.2 (one sample) Erosion of natural deposits
Bromate ppb 0 10 ND ND 0.2 ND - 1.5
By-product of drinking water
disinfection
Fluoride ppm 4 4 0.8 0.7 - 0.8 0.8 0.7 - 0.9
Water additive that promotes
strong teeth
Nitrate ppm 10 10 0.02 (one sample) 0.11 (one sample) Erosion of natural deposits
Cryptosporidium*: Cryptosporidium was not detected in any samples from the Cedar or Tolt (3 samples each supply).
Another precious realm is the Tolt River
Watershed, located in the foothills of the
Cascades east of Carnation. Seattle is also the
steward of this area of 13,000 acres of protected
forests, lakes and streams. The Tolt Treatment
Plant is a state of the art facility that assures that
you will always have clean water at your tap.
4
Mountain Wealth: Your Surface Water
Cedar River Watershed
Tolt Watershed
Cascade Water
Alliance manages
contracts with Seattle
Public Utilities for
wholesale water
purchases from these
sources.

5. Water comes from many sources, including rivers, lakes, streams,
ponds, reservoirs, springs and groundwater wells. As water travels
over the land surface or through the ground, it dissolves naturally
occurring minerals and can pick up impurities resulting from the
presence of animals or human activity. Substances that may be
present in source water include:
Microbial contaminants, such as viruses and bacteria, which may
come from sewage treatment plants, septic systems, agricultural
livestock operations, and wildlife.
Inorganic elements, such as 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.
Pesticides and herbicides, which may come from a variety of
sources, including “weed and feed” products you might use on your
lawn.
Organic chemical substances, including synthetic and volatile
organic chemicals, which are by-products of industrial processes and
petroleum production, and can also come from gas stations, urban
stormwater runoff and septic systems.
All drinking water, including bottled water, will likely contain at least
small amounts of these materials but this doesn’t necessarily mean
that the water poses a health risk. To ensure that your tap water is safe to drink, the United States Environmental
Protection Agency (EPA) adopts regulations setting the water quality standards for public water systems. The U.S. Food
and Drug Administration regulates impurities in bottled water and provides the same level of public health protection
for bottled water as the EPA does for tap water. The Environmental Protection Agency and Centers for Disease Control
both have guidelines on what we all can do to protect our water quality.
5
You can get more information about water impurities and potential health effects by calling the EPA’s Safe Drinking
Water Hotline at 1-800-426-4791 or see their website at www.epa.gov/safewater.
What the EPA would like you to know...
Some people may be more vulnerable to
contaminants in drinking water than the general
population, such as people with compromised
immune systems. This could include the following:
• You have cancer and are undergoing
chemotherapy.
• You have undergone an organ transplant.
• You have HIV or AIDS or other immune system
disorders.
• Some elderly persons may be affected.
• Infants can also be at risk from infections.
These people and their caregivers should seek advice
about drinking water from their health care providers.
ARE YOU AT RISK?

6. Here are the lead and copper water quality test results (2013 data):
Detected
Substance
Unit MCLG Action Level (AL)
90th
Percentile
Value
Highest
Detected
Level
Range of
Detections
Likely Sources
Lead ppb 0 15 2 40 1 - 40
Corrosion of household
plumbing systems
Copper ppm 1.3 1.3 0.10 0.16 0.003 - 0.16
Corrosion of household
plumbing systems
How do lead and copper get into our drinking water? We do not have
lead or copper in our source water. It comes primarily from the materials
and components that make up the service lines in your home plumbing. The
Department of Health did not require us to test for lead and copper in 2014,
so we are providing you with our 2013 test results.
What is an action level? The EPA has set an action level instead of a maximum
contaminant level for both lead and copper. If water testing indicates that
we have exceeded the action level of a substance, then we must treat the
water to remove lead and copper or follow other requirements. We have
installed corrosion control facilities on many of our wells to comply with the
requirements of the Lead and Copper Rule. This treatment approach has
successfully reduced lead and copper issues in our distribution system.
What did you find regarding lead? Lead was detected in 9 out of 30 homes
during the August 2013 testing. The lead action level is exceeded if the
concentration of lead in more than 10 percent of the tap water samples
(known as the 90th percentile value) is greater than the lead action level of
15 parts per billion (ppb). The 90th percentile value of the 30 District samples
was 2 ppb, so we are in compliance for lead.
Are elevated levels of lead a concern? If present, elevated levels of lead
can cause serious health problems, especially for pregnant women and young
children.Weareresponsibleforprovidingyouwithhighqualitydrinkingwater,
but we can’t control the variety of materials used in plumbing components.
When your water has been sitting for several hours, you can flush your tap for
30 seconds to 2 minutes before using water for drinking and cooking, which
may help clear the lead out of your water. 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 lead
exposure are available from the Safe Drinking Water Hotline at 1-800-426-
4791 or at www.epa.gov/safewater/lead.
How about copper? Copper was detected in 28 out of 30 homes during the
August 2013 testing. The copper action level is exceeded if the concentration
of copper in more than 10 percent of the tap water samples (90th percentile)
is greater than 1.3 parts per million (ppm). The 90th percentile value of the
30 District samples was only 0.10 ppm. The level for all homes was below the
action level for copper, and none of the samples exceeded the copper action
level, so we are currently in compliance for copper.
6
Watching our Lead and Copper

7. We reach out to our customers.
The Sammamish Plateau Water and Sewer District sponsored a number of public outreach
events in 2014, including the SAMMI Awards, the Sammamish Disaster Preparedness Fair,
Fourth on the Plateau, Sammamish Days and the Sustainable Sammamish Festival. We also
participated in school science fairs and the Sammamish Watershed Festival, a two-day water
education event that reached over 700 students.
7
How are we using water efficiently?
We track our leaks.
By law, we must maintain our
distribution system leakage at
10% or less for a rolling three
year average. The District’s 2014
leakage percentage was 8.04%,
and the rolling three year average
was 6.87%, which is within state
Department of Health standards.
SPWSD Distribution System Leakage for 2014
Category Total (in millions of gallons)
Water Production and Purchases 1,765
Authorized Consumption 1,623
Distribution System Leakage (DSL) 142
We set goals.
In order to meet state water use efficiency regulations, we worked in partnership with
the Cascade Water Alliance to set a water conservation goal that covers the 2014-2019
time frame. The goal is to save 0.6 million gallons per day (mgd) on an average annual
basis, and 1.0 mgd peak season, at full implementation of the program by 2020.
We conduct programs.
Cascade provides water efficiency programs and services on behalf of its members, including
the District. With these tools, you, our customers, are using water wisely! Here’s what
Cascade provided in 2014:
>> Showerhead and aerator installation at commercial accounts
>> Cascade Gardener classes for our residential customers
>> Irrigation system upgrade rebates for business and HOAs
>> Water education programs in area schools
>> Training for landscapers and parks staff on efficient irrigation management
>> Toilet leak detection dye strips mailed to all single family homes
>> WaterSense labeled new homes program for builders
>> Commercial and multifamily irrigation audit program (District)
We monitor our progress.
These programs and service resulted in a savings of 178,459 gallons per day, or
29.7% of Cascade’s six year goal. We want to thank our customers for helping
us make progress towards our goal!

8. PRSRTSTD
USPOSTAGE
PAID
SEATTLEWA
PERMIT315
Learnmoreaboutyour
drinkingwaterinside!
Sammamish Plateau
Water and Sewer District
1510 - 228th Ave. SE
Sammamish, WA 98075
24 HOUR LINE: (425) 392-6256
www.spwsd.org
John Anderson
Water Superintendent
john.anderson@spwsd.org
Washington State Department of
Health
Division of Drinking Water
(360) 236-3100
www.doh.wa.gov/ehp/dw
NEED HELP?
HAVE A WATER EMERGENCY?
Call us anytime!
US Environmental Protection Agency
(EPA)
Safe Drinking Water Hotline:
1-800-426-4791
www.epa.gov/safewater