HomeMy WebLinkAboutWater Quality Report 2012 (PDF)2012 Water Quality Report
Cohasset Water Department, 339 King Street, Cohasset, MA 02025 (781) 383-0057 http:/www.cohassetwater.org
WATER QUALITY REPORT
The Cohasset Water Department (DEP ID# 4065000), under
the direction of the elected Board of Water Commissioners,
provides public drinking water to about 2,600 connections for about
7,000 Cohasset residents and provides and maintains a water system
for firefighting. We provide drinking water for almost 90% of the
population of Cohasset.
This Water Quality Report describes the sources of your
drinking water and the quality of that water for the period from
January 1 - Dec. 31, 2012. We are pleased to report that during the
past year, the water quality delivered to your home or business
complied with all state and federal drinking water requirements.
WHERE THE WATER COMES FROM
The Cohasset Water Department drinking water comes from
two surface water supplies, Lily Pond (DEP ID# 4065000-02S), and
the Aaron River Reservoir (DEP ID#4065000-01S).Lily Pond has a
maximum capacity of about 100 million gallons of water and is 52
acres in size. The 136 acre Aaron River Reservoir, which can hold a
maximum of 550 million gallons of water, is used to supplement Lily
Pond in times of high water demand.
The watershed for Lily Pond and the Reservoir covers an area
of 5,892 acres, 9.21 square miles. Only 2,339 acres (or 40%) is in
Cohasset. The safe yield of our surface water supplies is 5.2 million
gallons per day (gpd). Our average daily demand in 2012 was about
700,000 gallons per day, and the maximum daily demand was about
1.5 million gpd.
The Water Department has one ground water source- the
Ellms Meadow Well field (ID# 4065000-02G), located at 16 James
Ln., which has been approved for up to 170,000 gallons per day.
The distribution system of Cohasset is connected to both the
Hingham water system and the Scituate water system. In the event
of a water emergency, these interconnections could be opened to
transfer water from one system to another.
Great News!! Lead Residuals Below Action
Levels Again
The Cohasset Water Department performed its
required sampling for Lead and Copper between July and
August 2012. This process consisted of taking samples
from 20 different residential homes and two different
schools located in Cohasset.
The sampling plan was approved by the DEP based
on when the home was constructed and the type of
material used in the service line to the home. The
sampling plan is intended to capture locations with the
highest potential for lead exposure in drinking water.
The results of these tests show that 100%of the
samples collected were below the Action Level. This is
great news and reinforces our ongoing commitment to
providing high quality water.
We are proud of our success, but encourage all
customers to continue using measures to reduce the
potential for lead exposure:
- Always flush the cold water line for 20-30 seconds
before drawing water for drinking and cooking purposes.
CONSERVATION NOTE: Use this flushed water to
water your plants or for cleaning!
For more information, consult our Lead
Education Brochures which are available at the
Water Department offices, town library, and on our
website-www.cohassetwater.org
VulnerablePopulationsWarning
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.
EPA/CDC guidelines on appropriate means to lessen the risk
of infection by Cryptosporidium and other microbial
contaminants are available from the Safe Drinking Water
Hotline (1-800-426-4791)
Community Involvement
We encourage public interest and participation in
Cohasset's decisions affecting drinking water.
The Water Commission meets regularly at the Lily
Pond Water Treatment Plant, 339 King Street.
Please attend and participate in our meetings.
Meeting notices are posted at Town Hall and on our
website.
Please call Brenda Douglas at the Water
Department at 781-383-0057 (fax 781-383-2906)with any
questions or concerns.
The Water Department generates an annual Water Quality
Report.This report is available at the Water Department,
Town Hall, the Paul Pratt Memorial Library, and on our
website,www.cohassetwater.org.
Cohasset Board of Water Commissioners
Peter DeCaprio-Chair
Chris Seebeck, -Vice Chair
LeonoraJenkins-Clerk
page 2
SOURCEWATERASSESSMENTPROGRAM
(SWAP)
TheMassachusettsDepartmentofEnvironmental
Protection(MassDEP) prepared source water assessments
in 2004 for all publicwatersystemsasrequiredbytheSafe
DrinkingWaterAct amendments.
The Cohasset Water Department, SWAPcanbefound
onlineat http://www.mass.gov/dep/water/drinking/3065000.pdf
. We encourageourcustomerstobecomefamiliarwiththis
report.Thisreportidentifiesstepsyoucantaketohelpprotect
our sourcesofdrinkingwaterhere in Cohasset. Note: The
Route3Atransportation corridor presentsa moderate hazard
to our drinkingwatersupply,asa result ofpotential vehicle
accidents or chemical spills. Toalleviatethis hazard,an
oil/water separator hasbeen installed in the Pond St area and
rain gardenshave beeninstalledthroughout much ofthe
watershed.
HOWYOURWATERISTREATED
The treatmentprocessconsistsofaseriesofsteps.Raw
waterisdrawnfrom Lily Pond and passed through
course and fine screens at our intake building.The
watercontinues to amixingtank at thetreatment facility
where ferric chloride, lime, sodium permanganate, and
polyaluminum chloride are added. The addition of
these chemicals converts the dissolved organic matter
naturally occurring in Lily Pond to small solid
particles. Gentle mixing, along with the addition of a
slight dosage of polymer helps these particles adhere to
one another, makingthem heavyenoughtosettlefrom
thetreatmentprocess.Aftersettling the water is filtered
through layers of fine coal and silicate sand to reduce
turbidity(turbidityis a common measure of the clarity
of water). Following filtration, lime and
polyphosphate is added for corrosioncontrol,and
chlorineis addedfordisinfection,andfluorideis added to
promote strongteeth. We carefullymonitor the amount
of chlorine, adding the lowest amount necessaryto
protect the safetyof your water without compromising
taste. The water is then pumped to water towers and
into your home or business.
FLUORIDATION
Fluorideisaddedto yourdrinkingwatertoprevent
toothdecayandcavities. Fluoridehas beenaddedsince
1952.Fluorideis a naturallyoccurring element in
manywater supplies in trace amounts. In our system
the fluoride level is adjusted to an optimal level
averagingone part per million to improve oral health
in children. The Massachusetts DPH acceptable
range is 0.8 – 1.2 ppm. At this level it is safe,
odorless, colorless, and tasteless. There are over 3.9
million peoplein140Massachusetts watersystems
and184millionpeopleinthe United States who
receive the health and economic benefits of
fluoridation.
CROSS CONNECTIONS
The Cohasset Water Department has developed a State-
Mandated Cross Connection Control Program to control
potentiallyunhealthyconnections to our water system. State
regulations currentlycontrol all non-residential facilities.
The following information is a brief overview of what a
cross connection is and how to prevent the unhealthy effects
of them.
What is a cross-connection?
A cross-connection is anytemporaryor permanent
connection between a public water system or consumer's
potable (i.e., drinking) water system and anysource or
system containing non-potable water or other substances.
An example is the pipingbetween a public water system or
consumer's potable water system and an auxiliarywater
system (including wells), coolingsystem, or irrigation
system.
What is backflow?
Backflow is the undesirable reversal of flow of non-potable
water or other substances through a cross-connection and
into the pipingof a public water system or consumer's
potable water system. There are two types of backflow:
backpressure backflow and backsiphonage. Backpressure
backflow is backflow caused bya downstream pressure that
is greater than the upstream or supplypressure in a public
water system or consumer's potable water system.
Backsiphonage is backflow caused bya negative pressure in
the water mains, causing water to flow from a customer’s
water system backinto the public water mains.
Educational Statement Concerni ng Lead
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. Cohasset Water is responsible for providing high
quality drinking water, but cannot control the variety of
materials used in plumbing components. You can minimize
the potential for lead exposure by flushing your tap for 30
seconds to 2 minutes before using water for drinking and
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
Hotlineorat http://www.epa.gov/safewater/lead
page 3
What is a backflow preventer?
A backflow preventer is a method or mechanism to prevent
backflow. The basic method of preventingbackflow is an
air gap, which is a physical separation of the public water
mains and the customers plumbingequal to two diameters of
the two pipes (this gap must be at least 1 inch) and eliminates
a cross-connection by provides a physical barrier to
backflow. The basic mechanismfor preventing backflow is
a mechanical backflow preventer, which provides a physical
barrier to backflow.
What types of backflow assemblies, devices and methods
are permitted?
The following are types of permitted assemblies, devices and
methods: Air Gap, Atmospheric VacuumBreaker, Double
CheckValve Assembly, Pressure Vacuum Breaker
Assembly, and Reduced Pressure Principle Backflow
Prevention Assembly. The choice of device or method
depends on the type of cross connection hazard that is
present.
Why do backflow preventers have to be tested
periodically?
Mechanical backflow preventers have internal seals, springs,
and movingparts that are subject to fouling, wear, or fatigue.
Also, mechanical backflow preventers and air gaps can be
bypassed. Therefore, all backflow preventers have to be
tested annually to ensure that they are functioning properly.
Specific Information about a Hose Bibb Atmospheric
Vacuum Breaker
A hose bib vacuum breaker should be attached to all
threaded hose bibs to which a hose can be connected (unless
it has a built-in vacuum breaker). Cross-connections with
hoses are probably the most prevalent cause of backflow and
the contamination of the water system. These devices do not
protect against backpressure, onlysiphonage. Theyshould
be installed above the level of the hose being used on it and
not put under continuous pressure (more than 12 hours at a
time)
For more information contact the Cohasset Water
Department at 781-383-0057.
WATER CONSERVATION TIPS
Install water-saving devices: You can save water by
installing low-flow showerheads, high-efficiency toilets,
and kitchen/bathroom faucet aerators.
Take shorter showers: Reduce your shower by 1 – 2
minutes and save 5 gallons!
Turn water off while brushing your teeth: Save 3 gallons!
Fix leaky faucets: Save up to 20 gallons a day!
Wash a full load of laundry: Save 15 – 50 gallons per
load!
Broom instead of Hose: You can save as much as 100
gallons of water by cleaning your driveway by sweeping
instead of using the hose.
Water before 8 a.m.: You can save about 25 gallons each
time you water, by watering before 8 a.m. – watering
early reduces evaporation and puts that water to work
helping your plants grow .
From Lawn to Xeriscape (low water use landscaping):
Switch your garden from turf to drought tolerant plants,
and reduce your household water use by more than
30% (http://www.allianceforwaterefficiency.org/Xeriscap
e_Water_Savings.aspx ).
Major Repeat Violation for the month of December 2012 –Failure to conduct follow up monitoring after a total coliform –
Positive Sample
The Department of Environmental Protection was not notified of the E. Coli positive sample result (By 12/14/2012).
What Happened? - Voicemail notification was provided by the analytical laboratory however, voicemail was not checked within
the 24 hour reporting time period, resulting in a violation.
CorrectiveAction: - The Department of Environmental Protection was immediately notified of the voicemail. Repeat samples were
taken and analyzed and all the results were absent of Total Coliform and E. coli bacteria. Additional samples were taken
throughout the Lily Pond Treatment Process to confirm the process was performing in accordance with regulations. All Finished
Water sample results were absent of Total Coliform bacteria. Additionally, a protocol was established for checking incoming
messages and emails to prevent this oversight in the future.
HealthEffects:-Totalcoliformsarebacteriathatarenaturallypresentintheenvironmentandareusedasanindicatorthatotherpotentially
Harmful bacteria may be present.
Fecal Coliforms and E. coli are bacteria whose presence indicates that the water may be contaminated with human waste or
Animal wastes. Microbes in these wastes can cause short term effects, such as diarrhea, cramps, nausea, headaches, or other
symptoms. They may pose a special health risk for young children, and people with severely compromised immune systems.
page 4
2012 Cohasset Water Quality Results
The Cohasset Water Department tests for over 80 contaminants on a regular basis, in accordance with State and
Federal requirements. The following contaminants were the only ones detected in the most recent testing required.
Regulated Contaminants
Regulated Contaminant Date(s)
Collected Highest Detect Range
Detected
Highest
Average
MCL
or
MRDL
MCLG or
MRDLG
Violation ?
(Y/N)
Possible Source(s) of
Contamination
Fluoride (ppm) Daily, 2012 1.3 0.0-1.3 ----4 4 No Water additive which promotes
strong teeth
Nitrate (ppm) 4/10/12 .02 ----
----
----
----
10
10
10
10
No
No
Runoff from fertilizer use;
Leaching from septic tanks,
sewage; Erosion of natural
deposits.
Barium (ppm) 4/3/12 0.009 ---- ---- 2 2 No
Discharge of drilling wastes;
discharge from metal refineries;
erosion of natural deposits.
Disinfection By-Products
Regulated Contaminant Date(s)
Collected
Highest
Running
Average
Range Detected
MCL
or
MRDL
MCLG or
MRDLG
Violation ?
(Y/N)
Possible Source(s) of
Contamination
Total Trihalomethanes
(TTHMs) (ppb)
Quarterly,
2012 63.1 58.3-70.3 80 ----- No Byproduct of drinking water
chlorination
Halo acetic Acids
(HAA5’s) (ppb)
Quarterly,
2012 24.3 21.4-27.7 60 ----- No Byproduct of drinking water
chlorination
Chlorine (ppm) (free)
Distribution system
Monthly,
2012 .42 .04-.42 4 4 No Water additive used to control
microbes
Lead & Copper (2)
(40 sites every 6 Months)
Date(s)
Collected 90th
Percentile
Action
Level MCLG
# sites
above AL # sites
sampled
Possible Sources of
Contamination
Lead (ppb)July-
September 0.002 0.015mg/l 0 0 20 Corrosion of household
plumbing systems. Erosion of
natural deposits.
Copper (ppm)July-
September
0.244 1.3mg/l 0 0 20 Corrosion of household
plumbing systems; leaching from
wood preservatives.
Turbidity TT
Lowest
Monthly % of
Samples
Highest Detected Daily Value Violation?Possible Sources of
Contamination
Daily Compliance 0.3 ----.120 No Soil Runoff
Monthly Compliance At least 100%----No
Turbidity is a measure of the cloudiness of the water. We monitor it because it is a good indicator of water quality.
*Monthly turbidity compliance is related to a specific treatment technique (TT). Our system filters the water so at least 95% of our samples each month must be
below the turbidity limits specified in the regulations.
Unregulated Contaminants (1)
Inorganic
Contaminants
Date(s)
Collected Results
Average
Detected SMCL ORSG Violation?Possible Sources of Contamination
Sodium (ppm) 4/3/12 25 ---- ---- 20 No Runoff from use of salt on roadways to protect
public safety.
(1) Unregulated contaminants are those for which EPA has not established drinking water standards. The purpose of
unregulated contaminant monitoring is to assist EPA in determining their occurrence in drinking water and whether further
regulation is warranted. Exceeding a SMCL or ORSG for an unregulated contaminant is not a violation.
Unregulated Contaminants (1)
Inorganic
Contaminants
Date
Collected
Results of Range
Detected
Average
Detected
SMCL
(ppb)
EPA Health
Advisory Violation?Possible Sources of
Contamination
Manganese (ppb) 6/1/2012 0.0-246 30 50 300 No Erosion of natural deposits.
“Manganese is a naturally occurring mineral found in rocks, soil and groundwater, and surface water.
Manganese is necessary for proper nutrition and is part of a healthy diet, but can have undesirable
effects on certain sensitive populations at elevated concentrations. The United States Environmental
Protection Agency (EPA) and MassDEP have set an aesthetics-based Secondary Maximum Contaminant
Level (SMCL) for manganese of 50 ug/L (micrograms per liter), or 50 parts per billion, and health
page 5
advisory levels. In addition, EPA and MassDEP have also established public health advisory levels.
Drinking water may naturally have manganese and, when concentrations are greater than 50 µg/L,
the water may be discolored and taste bad. Over a lifetime, EPA recommends that people drink water
with manganese levels less than 300 µg/L and over the short term, EPA recommends that people limit
their consumption of water with levels over 1000 ug/L, primarily due to concerns about
possible neurological effects. Children up to 1 year of age should not be given water with manganese
concentrations over 300 ug/L, nor should formula for infants be made with that water for longer than
10 days.See:
http://www.epa.gov/safewater/ccl/pdfs/reg_determine1/support_cc1_magnese_dwreport.pdf.”
Water Quality Definitions
90th Percentile. Out of every 10 homes, 9 were at or
below this level.
pCi/L. Picocuries per liter (radioactivity).
ppb -parts per billion, micrograms per liter (ug/I)
ppm -parts per million, milligrams per liter (mg/l)
AL (ActionLevel).Theconcentrationofacontaminantthat,if
exceeded, triggers treatment or other requirements which
mustbefollowed.
MCL (Maximum Contaminant Level):Highest level
of contaminant allowed in drinking water. MCLs are set as
close to the MCLGs as feasible using the best available
treatment technology.
MCLG (Maximum Contaminant Level Goal):The level
of a contaminantindrinkingwaterbelow whichthereis no
knownor expected risk to health. MCLGs allow for margin
of safety.
MRDL (Maximum Residual Disinfectant Level).The
highest levelofadisinfectantallowedindrinkingwater.
Disinfectionis necessary to control
MRDLG (Maximum Residual Disinfectant Level
Goal).Level of a drinking water disinfectant which
there is no knownorexpectedrisktohealth;donotreflect
thebenefitsofthe use of disinfectants to control
microbiological contaminants.NTU (Nephelometric
Turbidity Units) Measure of how clearthe water is
ORSG.MassOfficeofResearchandStandards
Guideline
Concentration of a chemical in drinking water, at or
below which,adversehealth are unlikel y to occur after
chronic lifetime) exposure.
SMCL. Secondary Maximum Contaminant Level These
standards protect the aesthetic qualities of drinking water
and arenothealthbased.
TT (TreatmentTechnique)—Arequiredprocessintendedto
reduce the level of a contaminant in drinking water.
Variances&Exemptions—StateorEPApermissionnot
tomeet an MCL or a treatment technique under
certain conditions
Ground Water Rule Situation -Location: Ellms Meadow Well
Routine coliform monitoring from the Ellms Meadow Well indicated the presence of E.Coli in the untreated water on May
8, 2012. The treated water entering the distribution system was absent of Total Coliform. Note: The Well was taken offline
May 8, 2012. A Tier 1 public notice was issued within 24 hours and 5 repeat samples were collected. The required five
repeat samples were absent for total coliform and the Tier 1 situation was lifted on May 15, 2012. Under the GWR, absence
of total coliform from those samples would be sufficient to allow the source to be put back in service. However, additional
voluntary testing was conducted by the Cohasset Water Department in an effort to better characterize the nature of the fecal
contamination.
Total coliform was detected in several of these samples and the well was taken offline.
“Drinking water, including bottled water, may reasonably be expected to contain at least small
amounts of some contamination. The presence of contaminants does not necessarily indicate that water
poses a health risk. More information about contaminants and potential health effects can be obtained
by calling the EPA’s Safe Drinking Water Hotline (1-800-426-4791.)”
Highest #
Positive
in a month
MCL MCLG Violation
(Y/N)
Possible Source of Contamination
Total
Coliform 1 1 0 n Naturally present in the environment
Fecal
Coliform
or E. Coli
1 0 0 n Human and animal fecal waste
page 6
NOTICE
If you would like to have a hard copy of this report, please contact the
Cohasset Water Department at the telephone number in the report title and
one will be sent to you.
Sources of Drinking Water and Drinking Water Contaminants
Community Water Systems must include information on sources of drinking water, contaminants that
may be present in drinking water and reasons for EPA and FDA regulations. The following language
can be used, or you may develop your own comparable language. However, some form of the
following language is required in the report:
“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.
Contaminants that may be present in source water include:
Microbial contaminants, such as viruses and bacteria, may come from sewage treatment plants, septic
systems, agricultural livestock operations, and wildlife.
Inorganic contaminants,such as salts and metals, can be naturally-occurring or result from urban
storm water runoff, industrial, or domestic wastewater discharges, oil and gas production, mining, and
farming.
Pesticides and herbicides may come from a variety of sources such as agriculture, urban storm water
runoff, and residential uses.
Organic chemical contaminants include synthetic and volatile organic chemicals that are by-products
of industrial processes and petroleum production, and can also come from gas stations, urban storm
water runoff, and septic systems.
Radioactive contaminants can be naturally occurring or be the result of oil and gas production, and
mining activities.
In order to ensure that tap water is safe to drink, the Department and EPA prescribe regulations that
limit the amount of certain contaminants in water provided by public water systems. FDA and the
Massachusetts Department of Public Health regulations establish limits for contaminants in bottled
water that must provide the same protection for public health