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HomeMy WebLinkAboutWQR_2002_Report_FINAL.pdfPlanning/Building/Public Works
City of Renton
1055 South Grady Way
Renton, WA 98055
BULK RATE
U.S. POSTAGE PAID
RENTON, WA
PERMIT NO. 137
ECRWSSPostal Customer
The Earth has been keeping its finite sup-
ply of water constantly in motion by recycling
the same water over and over since the begin-
ning of time. This process of water reuse is
known as the water cycle or the hydrologic
cycle.
A starting point in this cycle is when the
sun’s heat evaporates water from lakes,
streams, oceans, and the earth’s surface into
the atmosphere to form clouds. When the con-
ditions are right, the clouds release this water
as rain or snow. Most of the rain falls into the
oceans, and the rest falls onto land where it
can run off into rivers or lakes or seep (infil-
trate) into the soil. This infiltrating water per-
colates down and fills the cracks between
rocks and particles of soil. When all the cracks
in a layer are full of water it is said to be satu-
rated. If we can drill a well down into this
saturated layer and pump useable amounts of
water out , we have an aquifer. All of Renton’s
drinking water comes from the groundwater
found in aquifers or springs.
Even though it may seem counterintuitive,
ground water is generally a very clean source
of water, requiring little or no filtration. This is
because the soil and rock that the rain water
passes through on its way to the aquifer filters
and cleans it. Debris and large particles are
filtered out by the small cracks that the water
must pass through. Chemicals and pollutants
adhere to soil particles or are broken down by
friendly microbes. This process is very reli-
able—unless, of course, it is overloaded.
Groundwater contamination can come
from a number of natural and human-made
sources. The City of Renton has, through
education, regulation, and monitoring, under-
taken the task of protecting our water
supply from industrial and commercial pol-
lution sources. There are also many ways
that citizens can help protect our water.
Excess fertilizers and pesticides applied to
your lawn and garden overload the natural
groundwater cleansing systems. Over-wa-
tering can quickly flush even moderate
amounts of chemicals deep into the ground.
Even washing your car on the lawn can lead
to an overload of the soil’s cleansing
system. Take your car to a commercial car
wash where the wash water is recycled or
sent to a sanitary sewer.
Drinking WaterQuality Report2002
Who Do I Call?Who Do I Call?Who Do I Call?Who Do I Call?Who Do I Call?
6 Questions about this report?
Call Water Utility Engineering at 425-430-7287
6 Questions about water discoloration, taste, or odor problems?
Call Water Quality at 425-430-7400 (7 a.m. to 3:30 p.m.)
or 425-430-7500 after hours.
6 To report water pressure problems, a broken water main,
water leaks in street hydrants or at a meter,
call Water Maintenance at 425-430-7400 (7 a.m. to 3:30 p.m.)
or 425-430-7500 after normal working hours or on weekends.
6 Moving? To arrange a change of water service
billing, or for general billing questions, call Utility Billing
at 425-430-6852.
6 Emergencies after 3:30 p.m. or on weekends, call 911.
WWWWWant Tant Tant Tant Tant To Geo Geo Geo Geo Ge t Involved?t Involved?t Involved?t Involved?t Involved?
The City of Renton welcomes your interest in its water
system. The Renton City Council is the City’s decision making
body. The Council meets on the first four Mondays of each
month at 7:30 p.m. in the Council Chambers on the seventh
floor of City Hall. Call the City Clerk’s office at 425-430-
6510 or visit the city’s website at www.ci.renton.wa.us for
meeting or agenda information. If you are interested in get-
ting involved with our Aquifer Protection Education or Ground-
water Guardian Team, you can call 425-430-7287.
About ThisAbout ThisAbout ThisAbout ThisAbout This
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The purpose of this report
is to let our customers know that
the City’s water met or ex-
ceeded state and federal stan-
dards for drinking water qual-
ity during the 2001 calendar
year. This report is written and
distributed in compliance with
the federal Safe Drinking Wa-
ter Act, which requires water
utilities to provide annual “con-
sumer confidence” reports
which describe where drink-
ing water comes from, what it
contains, how it compares to
stringent water quality stan-
dards and how water supplies
are protected.
We hope this Water Quality
Report will help our customers
to better understand our drinking
water and to heighten their
awareness of the need to pro-
tect our water resources. We
would also like to assure our cus-
tomers that providing high
quality, safe drinking water is
Renton’s highest priority.
cont. on page 3
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page 1
From June of 1999 through the end of
2001, the Maplewood Wells supplied water
to a portion of the Renton Highlands. The
Maplewood Well field was developed to
serve as an alternate source of drinking water
to the City of Renton in the event that the
Downtown Wells become contaminated.
Additionally, these wells and the associated
booster pump station provide an abundant
supply of water for fire fighting and drinking
water, as well as provide a supply to help
meet future peak summer demands. The
Maplewood Wells pump from a deep aqui-
fer that is less vulnerable to natural contami-
nation. However, the water from this aqui-
fer contains dissolved iron, manganese,
hydrogen sulfide, and ammonia. While the
water, as currently treated, is safe to drink,
its taste and odor is objectionable to some
people and it can stain dishes, laundry, and
plumbing fixtures.
Health Information
Most people give little thought to the
water that comes out of their tap. But
even in a crystal clear glass of water, there
are many other possible ingredients be-
sides H2O. Our drinking water comes
from wells and springs. As our water trav-
els through the ground to the wells, it can
dissolve naturally occurring minerals as
well as substances from human activity.
Drinking water, including bottled water,
may reasonably be expected to contain at
least small amounts of some contaminants.
The presence of contaminants does not
necessarily indicate that water poses a
health risk. More information about con-
taminants and potential health effects can
be obtained by calling the Environmental
Protection Agency’s Safe Drinking Wa-
ter Hotline at (1-800-426-4791).
Making Progress with MaplewoodMaking Progress with MaplewoodMaking Progress with MaplewoodMaking Progress with MaplewoodMaking Progress with Maplewood
WWWWWatatatatater Imprer Imprer Imprer Imprer Impr ooooo vementsvementsvementsvementsvements
During the summer of 2001, the City
conducted a pilot test of candidate treatment
methods to deal with the aesthetic problems
of the Maplewood Well water. The testing
included evaluation of the taste and flavor
of the treated water by a panel of Renton
citizens and City staff members. Based upon
the results of the pilot study, the City chose
a treatment scheme that includes using
specially coated sand filters, granulated
activated carbon filters, and chlorination. A
project to modify the existing treatment
facility and add additional treatment
facilities is currently being designed.
Construction of the project is scheduled to
begin in 2003 with completion in 2004. The
Maplewood Wellfield has been taken out of
active service and will remain in stand-by
mode until the completion of the construc-
tion project.
Based upon the results of the
pilot study the City chose a
treatment scheme that includes
using specially coated sand
filters, granulated activated car-
bon filters and chlorination.
Special Information Available
Some people may be more vulnerable
to contaminants in drinking water than the
general population. Immuno-compro-
mised persons such as persons with can-
cer 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. EPA/Center for
Disease Control guidelines on appropri-
ate means to lessen the risk of infection
by microbial contaminants are available
from the Safe Drinking Water Hotline
(1-800-426-4791).
page 2 page 7
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DETECTED
COMPOUND
Maximum Total
Trihalomethane
Potential
Fluoride
Nitrate
Sulfate
Sodium
Fluorotrichloromethane
MCL
No MCL established.
AL = 100 ppb
4 ppm (see note 2)
10 ppm
No primary MCL,
Secondary MCL = 250 ppm
No MCL established
(see note 3)
Not regulated
MCLG
No MCLG Established
4 ppm (see note 2)
10 ppm
No MCLG established
No MCLG established
(see note 3)
Not regulated
POSSIBLE SOURCES OF
DETECTED COMPOUNDS
By-product of drinking
water chlorination
Water additive which
promotes strong teeth
Runoff from fertilizer use;
Leaching from septic
tanks; Erosion of Natural
Deposits
Erosion of natural
deposits
Erosion of natural
deposits
Refrigerant, Degreasing
agent and propellant
HIGHEST AMOUNT
AND RANGE DETECTED
29.9 ppb (13.9 - 29.9
ppb, tested 3/29/2000)
1.3 ppm (0.8 - 1.3 ppm)
2.3 ppm
14 ppm
6.9 ppm
0.71 ppb (tested 12-6-2000)
What’s in our Drinking WWhat’s in our Drinking WWhat’s in our Drinking WWhat’s in our Drinking WWhat’s in our Drinking W atatatatat er?er?er?er?er?
Lead and Copper MonitoringLead and Copper MonitoringLead and Copper MonitoringLead and Copper MonitoringLead and Copper Monitoring
The EPA requires monitoring for the presence of lead and
copper to minimize human exposure to these substances in
drinking water. Neither lead nor
copper has been detected in
Renton’s water sources. How-
ever, our water is naturally cor-
rosive which could cause lead
and/or copper present in your
home plumbing to leach into your
drinking water.
To reduce its potential to cor-
rode household plumbing, we treat
our water with sodium hydroxide
to raise its pH. The City then tests
for lead and copper at household
taps to make sure that our Corro-
sion Control Treatment is work-
ing.
Results of Lead and Copper Sampling at Residential Water Taps
Includes areas served by the Downtown Wells, Springbrook Springs and Maplewood Wells
To ensure that the tap water delivered to your home
is safe to drink, the EPA adopts regulations setting the
water quality standards for public water systems. The
data in the following Water Quality Monitoring tables
show what is in our water. As you can see, the water
from the Downtown Wells, Springbrook Springs and the
Maplewood Wells all met or exceeded federal and state
primary drinking water quality standards. In 2001, none
of the 67 samples tested exceeded the action level for
lead and copper.
2002002002002001 W1 W1 W1 W1 Watatatatater Quality Dater Quality Dater Quality Dater Quality Dater Quality Dat a fa fa fa fa f or the 2002 Consumer Confor the 2002 Consumer Confor the 2002 Consumer Confor the 2002 Consumer Confor the 2002 Consumer Conf idence Ridence Ridence Ridence Ridence Reporeporeporeporepor ttttt
POSSIBLE SOURCES OF
DETECTED COMPOUNDS
By-product of drinking
water chlorination
Water additive which
promotes strong teeth
Erosion of natural
deposits
Erosion of natural
deposits
DETECTED
COMPOUND
Maximum Total
Trihalomethane
Potential
Fluoride
Sodium
Manganese
MCL
No MCL established.
AL = 100 ppb
4 ppm (see note 2)
No MCL established
(see note 3)
No primary MCL,
Secondary MCL = 50 ppb
MCLG
No MCLG Established
4 ppm (see note 2)
No MCLG established
(see note 3)
No MCLG established
HIGHEST AMOUNT
AND RANGE DETECTED
42.5 ppb
(tested 8-9-2000)
1.3 ppm (0.8 - 1.3 ppm)
14 ppm
89 ppb
Year 2001 Water Quality Data For Downtown Wells and Springbrook Springs
Regulated at the Ground Water Source Before Treatment
Regulated at the Ground Water Source After Treatment
Year 2001 Water Quality Data For Maplewood Wells
Notes:Notes:Notes:Notes:Notes:
2. The primary MCL and MCLG for fluoride is 4 ppm. The secondary MCL for fluoride is 2 ppm.
3. The EPA has established a recommended level of 20 ppm for sodium as a level of concern for those consumers that may be restricted for daily sodium intake in their diets.
City staff monitoring pH at the Corrosion Control Facility.
MCLG (Maximum Contaminant Level Goal): 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.
MCL (Maximum Contaminate Level): 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.
DefDefDefDefDefinitions finitions finitions finitions finitions for Ror Ror Ror Ror R eading Weading Weading Weading Weading Watatatatater Quality Ter Quality Ter Quality Ter Quality Ter Quality Tablesablesablesablesables
AL (Action Level): The concentration of a contaminant which, if exceeded, triggers
treatment or other requirements which a water system must follow.
ppb (parts per billion): One part per billion is equivalent to 1/2 of a dissolved
aspirin tablet in 1000 full bathtubs of water (approximately 50,000 gallons of water).
ppm (parts per million): One part per million is equivalent to 1/2 of a dissolved
aspirin tablet in a full bathtub of water (approx. 50 gallons).
Unregulated at the Groundwater Source after Treatment
Regulated at the Ground Water Source After Treatment
Regulated at the Ground Water Source Before Treatment
IDEAL GOAL
(MCLG)
0 ppb
1.3 ppm
90TH PERCENTILE VALUES
3 ppb * (see note 1)
1.03 ppm * (see note 1)
POSSIBLE SOURCES OF
DETECTED COMPOUNDS
Corrosion of household
plumbing systems.
Corrosion of household
plumbing systems.
ACTION LEVEL
15 ppb
1.3 ppm
PARAMETER
Lead
Copper
Notes:Notes:Notes:Notes:Notes:
1.1.1.1.1.90 percent of the samples tested had levels at or below this value (10 percent of the samples tested had levels90 percent of the samples tested had levels at or below this value (10 percent of the samples tested had levels90 percent of the samples tested had levels at or below this value (10 percent of the samples tested had levels90 percent of the samples tested had levels at or below this value (10 percent of the samples tested had levels90 percent of the samples tested had levels at or below this value (10 percent of the samples tested had levels
above this value).above this value).above this value).above this value).above this value).
The City has tested for the presence of arsenic and radon
and found that both compounds are either non-detect or
are below the current EPA’s maximum contaminant levels.
page 4 page 5
The City Water Quality and Water
Maintenance staff regularly monitors the
quality of our water supply. Field and labo-
ratory analyses include tests for bacteria,
as well as chemical, physical, and radio-
logical indicators. We test for over 120
compounds to make sure our drinking wa-
ter is safe.
In 2001, Renton drew its drinking water
from three sources: five downtown wells,
which draw water from the Cedar Valley
Aquifer; Springbrook Springs, a small springs
located at the extreme southern city limits;
and two wells, which draw from the
Maplewood Aquifer source.
The downtown wells are our major source
of water, producing over 64 percent of
Renton’s water, or an average of 4.6 million
gallons a day. Approximately 14 per-
cent, or one million gallons per day, of
Renton’s drinking water is supplied by
Springbrook Springs.
The water pumped from these sources is
very clean and needs minimal treatment. We
add chlorine for disinfection, which destroys
&Q A
Does the City add fluoride to the
water?
Yes. In 1985, the citizens of Renton
voted to have fluoride added to the City’s
drinking water. Fluoride is added at a rate
of one part per million to help prevent tooth
decay.
Is Renton’s water soft or hard?
A water’s hardness is dependent upon
the levels of two naturally occurring
soluble minerals - calcium and magnesium.
Renton’s water falls within the soft range
with about 3.0 grains per gallon of hard-
ness. This means that dishwashing and
clothes washing require relatively less
soap than in other areas where the water
is hard.
Why does my water sometimes
smell or taste like chlorine?
Renton’s water is very clean when it
comes from the ground. Chlorine is added
to stop bacteria from growing in the wa-
ter delivery pipelines. If you are sensitive
to the smell or taste of chlorine, you can
use one of the following techniques. Keep
a pitcher of water in the refrigerator, the
chlorine will dissipate within a few hours
and you will conserve water by not hav-
ing to run the tap to get a cool drink. You
can speed the chlorine dissipation process
up by pouring water back and forth be-
tween two pitchers. Many faucet filters
will also remove chlorine taste and smell
– make sure you maintain the filter, as an
improperly maintained filter can actually
make water less safe.
Is bottled water safer than tap
water and do I need a home water
treatment device?
Not necessarily. The safety of bottled
water depends on the source of water and
the treatment it receives. Bottled water
is regulated by the Food and Drug Ad-
ministration, which has less rigorous test-
ing and purity standards than the
US Environmental Protection Agency,
which regulates tap water.
The use of bottled water or a home
water treatment device is a personal
choice that may be based on taste prefer-
ences. If you use a treatment device, be
sure to select a unit approved by the Na-
tional Sanitation Foundation (NSF) and also
be sure to properly maintain the device to
avoid water quality problems.
666
Frequently Asked QuestionsFrequently Asked QuestionsFrequently Asked QuestionsFrequently Asked QuestionsFrequently Asked Questions
any bacteria and viruses. Because our wa-
ter is naturally soft, sodium hydroxide is added
to stop corrosion of plumbing. Fluoride is
also added to prevent tooth decay. In the
areas of Renton Hill, Talbot Hill, and West
Hill, ortho polyphosphates are added to re-
duce corrosion of iron water pipes.
Until recently, our second major source
of drinking water was from two wells that
tap into the deep Maplewood aquifer and pro-
duced 22 percent, or 1.5 million gallons of
water per day. This water was used to sup-
ply customers in a portion of the Renton High-
lands, and also served as a backup water
supply to the downtown wells.
The City disinfected Maplewood water
with chlorine, which reacts with naturally oc-
Where Does RWhere Does RWhere Does RWhere Does RWhere Does Rentententententon’s Drinking Won’s Drinking Won’s Drinking Won’s Drinking Won’s Drinking Watatatatater Come Fer Come Fer Come Fer Come Fer Come Frrrrr om?om?om?om?om?
curring ammonia to form chloramines.
Chloramines act as a secondary disinfec-
tant to destroy any harmful bacteria that may
enter the water distribution system. Sodium
fluoride was added to prevent tooth decay.
Sulfuric acid and sodium hydroxide were
used in a process to remove naturally
occurring hydrogen sulfide.
Although the Maplewood water supply
meets all health-related water quality stan-
dards, it contains low levels of manganese
that can stain plumbing fixtures, dishwash-
ers, and sometimes clothing. To reduce man-
ganese precipitation, ortho polyphosphates
were added to the water. Starting in
February 2002, the city stopped pumping
water from the Maplewood wells.
Water Goes Round & Round
KKKKKeeping Yeeping Yeeping Yeeping Yeeping Your Wour Wour Wour Wour Watatatatater Safer Safer Safer Safer Saf e and Moe and Moe and Moe and Moe and Movingvingvingvingving
In general, anything that is labeled with
the words “DANGER”, “WARNING” or
“CAUTION”, should be considered haz-
ardous and should not be poured out onto
the ground. Dispose of hazardous prod-
ucts such as oil-based paints, pesticides,
thinners, solvents, antifreeze, and gasoline
at the Wastemobile or take them to a fixed
collection site. Many auto parts stores and
auto repair businesses take used oils. La-
tex paint can be recycled at the
Wastemobile and other locations. Please
contact the Hazards Line at
(206) 296-4692 or visit the Local Hazard-
ous Waste Management Program Website
www.metrokc.gov/hazwaste for sched-
ules, maps, and more information.
If each of us does a little bit to help
protect our groundwater, we can keep our
supply of drinking water clean and safe
forever.
Water Goes Round & Round, cont. from page 1
The highest water demand day for 2001
occurred on August 10 when 12 million
gallons of water were consumed. The Water Distribution Maintenance team
routinely monitors and maintains 9 reservoirs,
18 pump stations, 2 water treatment facili-
ties, 278 miles of water mains, 3,000 fire
hydrants, and 14,300 water meters. This
team is ever ready to repair the more than
263 leaking services and 20 water main
breaks that occur each year.
What’s New?What’s New?What’s New?What’s New?What’s New?
Major Water Utility projects for the
2002 -2003 year:
6 Complete construction of the well house
and pump station in Downtown Well field
for emergency water source.
6 Construct large piping for additional dis-
infection contact time in Liberty Park.
6 Repair and construct seismic upgrade to
the Rolling Hills and Highlands elevated
water storage tanks.
6
In 2001, Renton Water Utility produced an average of
7.1 million gallons of drinking water per day.
see related article on page 7
page 6 page 3