HomeMy WebLinkAboutWater Quality Report 2005 (PDF)THE COHASSET WATER
DEPARTMENT
(DEP ID# 3065000),
under the direction of the elected
Board of Water Commissioners,
provides public drinking water to
2,411 connections for about
7,100 Cohasset residents and
provides and maintains a water
system for fire fighting.
We provide drinking water for
almost 90% of the population of
Cohasset, excluding North
Cohasset which get its water
from the Aquarion Water
Company of Massachusetts.
This Water Quality Report
describes the sources of our
drinking water and the quality of
that water for the period from
January 1–Dec. 31, 2004.
In 2004 we exceeded the stan-
dard for Total Trihalomethanes
(TTHMs) in drinking water, but
were able to come into compli-
ance in the 2nd quarter of 2005.
In 2004 we were in compliance
with all other applicable drinking
water standards.
RainGarden recently installed to clean stormwater draining from the parking lot at the Lily Pond Water Treatment Plant before it drains into Lily Pond.
The Water Commission plans to install more RainGardens in the Lily Pond and Aaron River Reservoir over the next 3 years to reduce the amount
of pollutants draining into the water supply. Visit the Lily Pond Water Treatment Plant on King Street to see the entire garden
and the RainGarden technology display in the Treatment Plant lobby.
Cohasset Water Department_339 King Street Cohasset MA 02025_781-383-0057 www.cohassetwater.org July 1, 2005
2004 WATER SYSTEM
IMPROVEMENTS
In 2004 the Water
Commission:
•Acquired 53.5 acres of
land in the Lily Pond
watershed to protect
drinking water quality
•Replaced 7,500 feet,
about 1.42 miles, of
undersized water
mains (North
Main Street, Jerusalem
Road Drive, Haystack
Lane, Redgate Lane)
•Looped water mains
between Elm Court and
Newtonville Lane to
eliminate two dead ends
•Replaced 10 fire
hydrants, installed 10
new hydrants, painted
90% of the hydrants,
replaced 1 gate valve
and installed 10 new
gate valves
•Completed first Taste &
Odor Study
•Improved water quality
by implementing
enhanced coagulation
and optimizing the
treatment process
•Improved the structural
integrity of the Aaron
River Dam by clearing
brush & repairing rip rap
•A dam inspection con-
cluded that the dam is in
“excellent” condition.
WHERE YOUR WATER
COMES FROM
Your drinking water comes
from two surface water sup-
plies, Lily Pond (DEP ID#
065-01S), and the Aaron
River Reservoir (DEP ID#
065-02S).
Lily Pond has a maximum
capacity of about 100 mil-
lion 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 (see
enclosed map) 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 is
about 710,000 gallons per
day, and the maximum daily
demand, in the summer, is
2.2 million gpd.
Projections show that our
existing water supply will be
capable of meeting projected
water system demands for
the next 20 years or more.
The Water Department has
two wellfields - the Ellms
Meadow Wellfield (ID#
065-02G), which has been
approved for up to 170,000
gallons per day. The wellfield
will be reactivated in 2005
when the pumphouse is
rebuilt.
The Sohier Street Wells (ID#
065-01G & 03G) are
currently out of service but
are planned to be reactivated
when the wellhead is relocat-
ed with mitigation funds
from the MBTA.
– Printed on 100% Recycled Paper –
2004 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 Date(s) Highest Range Highest MCL or MCLG or Violation? Possible Source(s)
CONTAMINANTS Collected Detect Detected Average MRDL MRDL (Y/N) of Contamination
INORGANIC
Fluoride (ppm) Daily, 2004 1.34 .80-1.34 ––– 4 4 No Additive to water to promote strong teeth
Barium (ppm) 6/23/04 0.007 ––– ––– 2 2 No Discharge of drilling wastes; discharge
from metal refineries; erosion of natural
deposits
VOLATILE ORGANIC
Chlorine (ppm) Daily,2004 1.91 .80-1.91 ––– 4 4 No Water additive used to protect
public health by controlling microbes
Total Trihalomethanes 129 62-129 100 80 ––– Yes Byproduct of drinking water chlorination
(TTHMs) (ppb)
Haloacetic Acids 119 ND-119 22 60 ––– No Byproduct of drinking water chlorination
(HAC’s) (ppb)
RADIOACTIVE
Gross Alpha (pCi/l) 2/17/04 -1.3+/-1.0 ––– ––– 15 0 No Erosion of natural deposits
Gross Beta (pCi/L) 2/17/04 2.9+/-2.2 ––– ––– 50 0 No Decay of natural and man-made deposits
Radium 226 2/17/04 0.3+/-0.2 ––– ––– 0.1 0 No Erosion of natural deposits
Radium 228 2/17/04 1.0+/-0.8 ––– ––– 0.5 0 No Erosion of natural deposits
SYNTHETIC ORGANIC
Hexachlorocyclo-pentadiene 6/3/03 0.1 ––– ––– 50 50 No Discharge from chemical factories
(ppb)
LEAD & COPPER Date(s) 90th Action MCLG # Sites above AL Violation? Possible Sources
(20 sites sampled each) Collected Percentile Level of Contamination
Lead (ppb) 9/15/04 9 15 0 2 of 20 No Corrosion of household plumbing systems
Copper (ppm) 9/15/04 .80 1.3 1.3 0 of 20 No Corrosion of household plumbing
systems; leaching from wood preservatives
Lowest
TURBIDITY TT Monthly % Highest Detected Daily Value Violation? Possible Sources
of Samples of Contamination
Daily Compliance (NTU) 5 ––– 0.47 No
Soil runoff
Monthly Compliance at least 95% 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 Date(s) Results Average SMCL ORSG Violation? Possible Sources
CONTAMINANTS (1)Collected Detected of Contamination
INORGANIC
Sodium (ppm) 6/23/04 23/2 ––– ––– 20 No Runoff from use of salt on roadways to protect
public safety
Sulfate (ppm) 6/23/04 38.9 ––– 250 ––– No Natural sources
(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 deter-
mining their occurrence in drinking water and whether further regulation is warranted. Exceeding a SMCL or ORSG for an unregulated contaminant is not a violation.
– 2 –
SWAP Report on Cohasset
The Department of Environmental Protection (DEP) has
prepared a Source Water Assessment Program (SWAP)
Report for the water supply sources serving the Cohasset
Water Department.
The SWAP Report notes that the key issues for water
supply protection are: protection of the Zone A (see map
inside), protecting the watershed outside Cohasset, pub-
lic education, and control of residential uses that might
contaminate the watershed.
The report commends the water system for mapping
storm drains, conducting a study on the health of Lily
Pond, and taking preliminary steps to develop a lawn
care program.
The Water Commission plans to address the protection
recommendations by implementing all the SWAP recom-
mendations and by implementing our Surface Water
Supply Protection Plan that was completed and approved
by DEP in 2002.
The complete SWAP report is available at the Water
Department. For more information, call the Water
Department at 781-383-0057.
Contaminants in
Drinking Water
Drinking water, including
bottled water, may reasonably
be expected to contain at least
small amounts of some con-
taminants. 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).
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-occur-
ring 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, which may come
from sewage treatment
plants, septic systems,
agricultural livestock
operations, and wildlife
•Inorganic contaminants,
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 such as
agriculture, urban
stormwater runoff, and
residential uses
•Organic chemical contami-
nants, including synthetic
and volatile organic chemi-
cals, which are by-products
of industrial processes and
petroleum production, and
can also come from gas
stations, urban stormwater
runoff, and septic systems
•Radioactive contaminants,
which can be naturally-
occurring or be the result
of oil and gas production
and mining activities
To ensure that tap water is
safe to drink, the DEP and
EPA prescribe regulations
which limit the amount of
certain contaminants in water
provided by public water sys-
tems. The Food and Drug
Administration (FDA) and
the Mass. Department of
Public Health (DPH) regula-
tions establish limits for con-
taminants in bottled water
which must provide the same
protection for public health.
Vulnerable Populations
Warning
Some people may be more
vulnerable to contaminants in
drinking water than the gen-
eral population.
Immuno-compromised per-
sons such as persons with can-
cer undergoing chemotherapy,
persons who have undergone
organ transplants, people with
HIV/AIDS or other immune
system disorders, some elder-
ly, and infants can be particu-
larly 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).
Definitions
90th Percentile:9/10 were at
or below this level
pCi/L:Picocuries per liter
(radioactivity)
ppb:parts per billion, micro-
grams per liter (ug/l)
ppm: parts per million, milligrams
per liter (mg/l)
AL (Action Level):The con-
centration of a contaminant that,
if exceeded, triggers treatment or
other requirements which must be
followed
MCL:(Maximum Contaminant
Level): Highest level of contami-
nant 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 con-
taminant 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. Disinfection is
necessary to control microbiologi-
cal contamination
MRDLG:(Maximum Residual
Disinfectant Level Goal). Level of
a drinking water disinfectant
which there is no known or
expected risk to health; do not
reflect the benefits of the use of
disinfectants to control microbio-
logical contaminants
NTU:(Nephelometric Turbidity
Units) Measure of how clear the
water is
ORSG:Mass Office of Research
and Standards Guideline
SMCL:Secondary Maximum
Contaminant Level These stan-
dards protect the aesthetic quali-
ties of drinking water and are not
health based
TT (Treatment Technique):
95% of all monthly samples taken
must be less than/equal to 0.50
NTU
Variances & Exemption:
State or EPA permission not to
meet an MCL or a treatment
technique under certain condi-
tions
Health Effects
Information
Total Trihalomethanes
(TTHMs) Some people
who drink water contain-
ing trihalomethanes in
excess of the MCL over
many years experience
problems with their liver,
kidneys, or central nerv-
ous system. They may
have an increased risk of
getting cancer.
– 3 –
PRESORTED
STANDARD
US POSTAGE
PAID
PERMIT NO. 47
COHASSET, MA
339 King Street _ Cohasset MA 02025
POSTAL PATRON
COHASSET, MA 02025
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The Water Commission has
taken action to come into
compliance with the TTHM
regulation as of the 2nd
Quarter 2005 with the
following improvements:
•changing to a more
effective coagulant which
removes 10% more total
organic content (TOC)
from the water
•replacing the filter media
which results in even
higher TOC removal
•moving the pre-chlorina-
tion point in the plant and
installing baffles in the
clearwell which has allowed
a reduction in the amount
of chlorine that needs to
be added
•operating the treatment
plant 24 hours a day
which dramatically
reduces the amount of
time that water is stored
in the distribution
system
In 2005 the Water
Commission plans to make
the following improvements
to further lower TTHM levels
and improve drinking water
quality:
•reactivate the Ellms
Meadow Wellfield, which
will provide good quality
water to mix with the
existing supply and provide
an emergency supply
•install mixers in the two
water storage tanks, which
will improve consistency of
water quality and improve
taste & odor
•conduct a tracer study in
the distribution system to
allow us to lower water age
to improve water quality
Water Commissioners John McNabb (L) and
Glenn Pratt (R) thanking TTHM expert David Reckhow
for his assistance in the TTHM issue at his January 14
visit to the Water Treatment Plant.
HOW WE SOLVED THE TTHM PROBLEM COMMUNITY
INVOLVEMENT
We encourage public
interest and participation
in Cohasset’s decisions
affecting drinking water.
The Water Commission
usually meets every other
Thursday at 7:30 pm at
the Lily Pond Water
Treatment Plant,
339 King Street.
Meeting notices are post-
ed at Town Hall. Feel free
to attend and to partici-
pate in our meetings.
Please call the Water
Department at 383-0057
(fax 383-2906) with any
questions or concerns.
This report is available at
the Water Department,
Town Hall, and the Paul
Pratt Memorial Library,
and on our website,
www.cohassetwater.org.
Cohasset Board
of Water
Commissioners
Glenn A. Pratt
Chairman
John K. McNabb
Vice-Chairman
Nathaniel Palmer
Clerk
– 4 –
Where Your Drinking Water Comes From
This area of Cohasset is served by the
Aquarion Water Company
of Massachusetts.
For a copy of their Water Quality Report,
Contact them at 800-832-2373 or go to
http://aquarion.com/MAwaterquality.html
Cohasset Water Commission Storm Water
BMP Implementation Project
Proposed Locations for RainGardens
NOTE: Locations are approximate
Consumer Confidence Report Map – 2005
Produced by: Norfolk Ram Group
July 1, 2005
COHASSET BOARD OF
WATER COMMISSIONERS
Glenn A. Pratt, Chairman
John K. McNabb, Jr.,Vice Chairman
Nathaniel Palmer, Clerk
CONTACT INFORMATION
Cohasset Water Department
339 King Street
Cohasset MA 02025
781-383-0057 phone
781-383-2960 FAX
www.cohassetwater.org
What the Water Department is Doing
to Protect Our Water Supply
Serving the Community Since 1950
The Sources of the Cohasset Water Department’s
Public Drinking Water Supply