HomeMy WebLinkAboutWater Quiality Report 2019 (PDF)
2019 Water Quality Report
Cohasset Water Department, 339 King Street, Cohasset, MA 02025 (781) 383-0057 http:/www.cohassetma.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
7,500 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, 2019. 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 2019 was about
786,000 gallons per day, and the maximum daily demand was about
1.5 million gallons.
The Water Department has one ground water source, the
Ellms Meadow Well-field (ID# 4065000-02G), which is located at
24 James Ln. and has been approved for up to 141,000 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 August
and September 2019. The process consisted of taking
samples from 24 different residential homes, all public
schools, and all licensed day care facilities with an
enrollment of 25 or more.
The sampling plan was approved by the DEP based
on when the homes were constructed and the type of
material used for the water 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 92% of the
samples collected were below the Action Level for Lead.
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 is available at the Water
Department offices.
Vulnerable Populations Warning
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/email Brenda Douglas at the Water
Dep artment (781) 383 -0057/bdouglas@woodard
curran.com 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.cohassetma.org.
Cohasset Board of Water Commissioners
Rolf N. Gjesteby - Chair
Leonora C. Jenkins - Vice Chair
John W. Steinmetz - Clerk
page 2
SOURCE WATER ASSESSMENT PROGRAM
(SWAP)
The Massachusetts Department of Environmental
Protection (MassDEP) prepared source water assessments
in 2004 for all public water systems as required by the Safe
Drinking Water Act amendments. A susceptibility ranking of
high was assigned to this system using information collected
by the DEP.
The Cohasset Water Department, SWAP can be found
online at http://www.mass.gov/dep/water/drinking/3065000.pdf
We encourage our customers to become familiar with this
report. The report identifies steps you can take to help protect
our sources of drinking water here in Cohasset. Note: As a
result of potential vehicle accidents or chemical spills the
Route 3A transportation corridor presents a moderate hazard
to our drinking water supply. To alleviate this hazard, an
oil/water separator has been installed in the Pond St area and
rain gardens have been installed throughout much of the
watershed.
HOW YOUR WATER IS TREATED
The treatment process consists of a series of steps. Raw
water is drawn from Lily Pond and passed through
course and fine screens at our intake building. The
water continues to a mixing tank at the treatment facility
where ferric chloride, sodium hydroxide, 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, making them heavy
enough to settle from the treatment process. After settling
the water is filtered through layers of fine coal and
silicate sand to reduce turbidity (turbidity is a common
measure of the clarity of water). Following filtration,
sodium hydroxide and phosphates are added for
corrosion control, chlorine for disinfection, and fluoride
to promote strong teeth. We carefully monitor the
amount of chlorine, adding the lowest amount
necessary to protect the safety of your water without
compromising taste. The water is then pumped to water
towers and into your home or business.
FLUORIDATION
Fluoride is added to your drinking water to prevent
tooth decay and cavities. Fluoride has been added since
1952. Fluoride is a naturally occurring element in
many water supplies in trace amounts. As of May
1, 2015 the fluoride level in our system was adjusted
downward from 1.0 parts per million to an optimal
level of 0.7 parts per million as prescribed by the
Massachusetts Department of Public Health to
improve oral health in children. At this level it is
safe, odorless, colorless, and tasteless. There are over
3.9 million people in 140 Massachusetts water systems
and 184 million people in the 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
potentially unhealthy connections to our water system. State
regulations currently control 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 any actual or potential physical
connection or arrangement between a pipe conveying
potable water from a public water system and any non-
potable water supply, piping arrangement or equipment
including, but not limited to, waste pipe, soil pipe, sewer,
drain, other unapproved sources. An example is the piping
between a public water system or consumer's potable water
system and an auxiliary water system (including wells),
cooling system, or irrigation system.
What is backflow?
Backflow is the flow of water or other liquids, mixtures, or
substances into the distributing pipes of a potable water
supply from any source other than the intended source or
sources other than its intended source.
Educational Statement Concerning 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
Hotline or at http://www.epa.gov/safewater/lead
page 3
What is backpressure?
Backpressure is backflow that occurs when the pressure in
an unprotected downstream piping system exceeds the
pressure in the supply piping.
What is back siphonage?
Back siphonage is backflow resulting from negative
pressures in the distributing pipes of a potable water supply.
What is a backflow preventer?
A backflow preventer is a method or mechanism to prevent
backflow. The basic method of preventing backflow is an
air gap, which is a physical separation of the public water
mains and the customers plumbing equal 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 mechanism for 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 Vacuum Breaker, Double
Check Valve 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 moving parts 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 Bib 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 back pressure, only back siphonage. They
should be installed above the level of the hose being used
and not put under continuous pressure for more than 12
hours at a time.
For more information contact the Cohasset Water
Department at (781) 383-0057.
Cohasset Water Department RGPCD Plan
All Public Water Supplies in Massachusetts that are issued a
Water Management Act Permit by the Massachusetts DEP
are required to meet a performance standard of 65 gallons or
less for residential gallons per capita day (RGPCD) or have
an on-going plan in place that insures “best practices” for
controlling residential water use. Cohasset’s RGPCD for
2018 was 66 gallons and a program to control residential
water use was instituted. Cohasset’s RGPCD for 2019 was
64 requiring no expansion of the plan. Some of the actions
taken to date to reduce per capita usage include, quarterly
billing, an increased block rate, conversion to radio read
meters, and a regulation that requires moisture sensors on
automatic irrigation systems.
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 ).
page 4
2019 Cohasset Water Quality Results
The water quality information presented in the tables below is from the most recent round of testing done in
accordance with the regulations. All results shown were from samples collected during the calendar year unless
otherwise noted in the tables. Only the detected contaminants are shown.
REGULATED CONTAMINANTS
Microbial
Contaminants
Date(s)
Sampled MCL MCLG
Highest
Level
Detecte
d
Range of
Detection
Viola
tion ?
(Y/N)
Possible Source(s) of
Contamination
Coliform Bacteria Monthly
2019
One positive
monthly sample for
systems that collect
less than 40 samples
0 0 0 N Naturally present in the environment
Health Effects: Total coliforms are bacteria that are naturally present in the environment and are used as a n indicator that other potentially
harmful bacteria may be present.
Inorganic
Contaminants
Date(s)
Sampled
MCL MCLG Highest Level
Detected
Range of
Detection
Viol
ation
(Y/N
)
Possible Source(s) of
Contamination
Fluoride (ppm) Monthly
2019 4 (1) 4 0.9 0.5 - 0.9 N Water additive which promotes
strong teeth.
Nitrate (ppm) 2019
10
.
0
2.42
0.16 – 2.42
N
Runoff from fertilizer use; Leaching
from septic tanks, sewage; Erosion
of natural deposits.
Barium (ppm) 2019 2 2 0.018 0.018 - 0.021 N
Discharge of drilling wastes;
discharge from metal refineries;
erosion of natural deposits.
Chromium (ppb) 2019 100 6 ND – 6 N Discharge from steel and pulp mills;
Erosion of natural deposits.
Perchlorate (ppb) 2019 2 N/A 0.21 ND - 0.21 N Rocket propellants, fireworks,
munitions, flares, blasting agents.
(1) Fluoride also has an optimal level of 0.7ppm and a secondary maximum contaminant level (SMCL) of 2ppm.
Disinfectant and
Disinfection By-
Products
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,
2019 75 18-120 80 No Byproduct of drinking water
chlorination
Haloacetic Acids
(HAA5’s) (ppb)
Quarterly,
2019 43 1.7-82 60 No Byproduct of drinking water
chlorination
Chlorine (ppm) (free)
8 times per
Month
2019
0.42 (2) 0.03 – 1.38 4 4 No Water additive used to control
microbes
2. Highest Monthly average
Radioactive
Contaminants
Date(s)
Collected
Highest Level
Detected
Range
Detected
MCL or
MRDL
MCLG or
MRDLG
Violation
?
(Y/N)
Possible Source(s) of
Contamination
Gross Alpha (pCi/l) 9/12/16 ND 15 0 N Erosion of natural deposits
Radium 226 & 228
(pCi/l) 9/12/16 0.76 ND – 0.76 5 0 N Decay of natural and manmade
deposits
page 5
Lead & Copper (3)
Date(s)
Collected
90th Percentile Action Level MCLG
# sites
above AL # sites
sampled Possible Sources of Contamination
Lead (ppb) Jul – Sep
2019
11
15 0
0
24
Corrosion of household plumbing
systems. Erosion of natural deposits.
Copper (ppm) Jul – Sep
2019
0.216 1.3 1.3
0 24 Corrosion of household plumbing
systems; leaching from wood
preservatives.
(3) Reduction in frequency for Lead & Copper sampling to every 3 years.
Turbidity
TT
Lowest Monthly % of
Samples Highest Monthly
Value
Violation? Possible Sources of
Contamination
Monthly 2019 Maximum (NTU) 1.0 NTU (1) ---- 0.50 No Soil Runoff
Monthly 2019 Compliance (NTU) 0.3 NTU (2) 97% ---- No
Turbidity is a measure of the cloudiness of the water. We monitor it continuously because it is a good indicator of the effectiveness of our filtration system.
1.
(1) Maximum turbidity limit that the system may not exceed at time during the month.
(2) Monthly turbidity compliance is related to a specific treatment technique (TT). Our system filters the water so that
at least 95% of our samples each month must be less than or equal to 0.3 NTU
UNREGULATED CONTAMINANTS
Unregulated Contaminants are those for which EPA has not established drinking water standard. The
purpose of unregulated contaminant monitoring is to assist EPA in determining their occurrence in
drinking water and whether future regulation is warranted.
Contaminants
(units)
Date(s)
Collected
Highest
level
Detected
Range of
Detection
Average
Detected
SMCL Health Advisory ORSG Possible Source(s) of
Contamination
Sodium (ppm) 2019 75 37 - 75 56 20 Natural sources; runoff from
use of salt on roadways; by-
product of treatment process.
Nickel (ppb) 2019
76
54 – 76 65
100 Discharge from domestic
wastewater, landfills, and
mining and smelting
operations
Cyanotoxins 2018 -19 ND All types of waterbodies.
Manganese (ppb) 2017
82
ND - 82
50 300
Erosion of natural deposits.
Health Effects Statements
Sodium: Sodium sensitive individuals, such as those experiencing hypertension kidney failure, or congestive heart failure
who drink water containing sodium should be aware of the sodium levels where exposures are being carefully controlled.
Manganese: “Manganese is a naturally occurring mineral found in rocks, soil, ground, 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 p arts per
billion. In addition, EPA and MassDEP have also established public health advisory levels. Drinking water may naturally
have manganese and, when concentrations are greater that 50ug/L, the water may be discolored and taste bad. Over a
lifetime, EPA recommends that people drink water with manganese levels less than 300ug/L and over the short term, EPA
recommends that people limit their consumption of water with levels over 1000ug/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
300ug/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
page 6
Important Information about Your Drinking Water
Availability of Monitoring Data for Unregulated Contaminants for
Cohasset Water Department
As required by US Environmental Protection Agency (EPA), our water system has sampled for a series
of unregulated contaminants. Unregulated contaminants are those that don’t yet have a drinking water
standard set by EPA. The purpose of monitoring for these contaminants is to help EPA decide whether
the contaminants should have a public health protection standard.
What should I do?
You do not have to do anything but as our customers you have a right to know that these data are
available.
You may share this information with other people who drink this water, especially those who may not
have received this notice directly (for example, people in apartments, nursing homes, schools, food
establishments, medical facilities and businesses).
For more information
For additional information on your water and the unregulated contaminants we sampled for, see your
water department’s Consumer Confidence Report (CCR), or called a water quality report, delivered by
your water department by July 1 of each year. If you have any questions about your CCR, see the contact
information below for your water department.
For information on the Unregulated Contaminant Monitoring Program, visit the MassDEP website
(http://www.mass.gov/eea/agencies/massdep/water/drinking/water-systems-ops.html) and navigate to
Unregulated Contaminant Monitoring Program.
If you want to speak with someone at the water department about the results, please contact Carl
Hillstrom at (781) 383-0057 or 339 King Street, Cohasset, MA.
This notice is being sent to you by: PWS ID#: Date distributed:
Cohasset Water Dept. 4065000 May 1, 2020
page 7
Water Quality Definitions
• 90th Percentile. Out of every 10 homes, 9 were at or
below this level. This number is compared to the action
level to determine lead and copper compliance.
• 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 (Action Level). The concentration of a contaminant that, if
exceeded, triggers treatment or other requirements which
must be followed.
• 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 contaminant in drinking water below which there is no
known or expected risk to health. MCLGs allow for margin
of safety.
• MRDL (Maximum Residual Disinfectant Level). The
highest level of a disinfectant allowed in drinking water.
There is convincing evidence that addition of a disinfectant
is necessary for the control of microbiological
contamination.
• MRDLG (Maximum Residual Disinfectant Level Goal).
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 contaminants.
• NTU (Nephelometric Turbidity Units) Measure of how
clear the water is
• ND Not detected. Refers to the detection limit of the
chemical analysis instrument or procedure.
• ORSG. Mass Office of Research and Standards
Guideline
Concentration of a chemical in drinking water, at or
below which adverse health are unlikel y to occur after
chronic lifetime) exposure.
• SMCL. Secondary Maximum Contaminant Level These
standards protect the aesthetic qualities of drinking water and
are not health based.
• TT (Treatment Technique) — A required process intended to
reduce the level of a contaminant in drinking water.
• Unregulated Contaminants. Unregulated Contaminants are
those for which EPA has not established drinking water standards.
The purpose of unregulated monitoring is to assist EPA in
determining their occurrence in drinking water and whether future
regulation is warranted.
• Variances & Exemptions — State or EPA permission not to
meet an MCL or a treatment technique under certain
conditions
“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.)”
Sources of Drinking Water and Drinking Water Contaminants
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.
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.
page 8
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.
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