HomeMy WebLinkAboutWater Quality Report 2010 (PDF)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/l)
• 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. Disinfection
is necessary to control microbiological 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 microbiological
contaminants.
• NTU (Nephelometric Turbidity Units) Measure of how clear
the water is
• ORSG. Mass Office of Research and Standards Guideline
Concentration of a chemical in drinking water, at or below
which, adverse health effects are unlikely 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.
• Variances & Exemptions – State or EPA permission not to
meet an MCL or a treatment technique under certain
conditions.
Consumer Confidence Rule Violation
In 2009, The Cohasset Water Department violated the
Drinking Water, Consumer Confidence Reporting (CCR)
regulations. The CCR requires all customers be provided a copy
of the water quality report annually by July 1st of each year. All
customers received the CCR as required. The rule also requires
the utility to submit its annual CCR to the State DEP offices by
July 1st. The utility did not submit copy of the CCR to MA DEP
until July 2, 2010 and failed to submit the required certification to
MA DEP until July 12, 2010. We have modified our operating
procedures to ensure future compliance with this regulation.
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, lime, sodium permanganate, and
polyaluminum chloride are added. The addition of these chemicals
converts the dissolved organic mater 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, lime and polyphosphate is added for
corrosion control, and chlorine is added for disinfection, and fluoride is
added 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. In our
system the fluoride level is adjusted to an optimal level averaging one
part per million 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.
New Water Quality Initiatives
The Cohasset Water Department implemented a phosphate
corrosion control program in November 2010. This program was
mandated by MA DEP. It is an additional measure to maintain the
excellent lead and copper results and also to minimize discolored water
events in the distribution system. This program has been highly
successful since its introduction in November 2010.
The Cohasset Water Department is also enhancing is water
quality instrumentation by adding an online continuous UV Analyzer
and Raw water pH probe. The UV Analyzer measures Lily Pond raw
water and finished water UV absorbance and continuously displays the
real time efficiency of the coagulation process. The Raw water pH
probe will assist in maintaining optimized coagulation conditions,
therefore more efficient organic removal.
2010 Water Quality Report Cohasset Water Department, 339 King Street, Cohasset, MA 02025 (781) 383-0057 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 2,400 connections for about 6,500 Cohasset
residents and provides and maintains a water system for fire fighting.
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, 2010. 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 is about 800,000
gallons per day, and the maximum daily demand, in the summer, is 2.2
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 Now Below Action Levels
The Cohasset Water Department performed its required sampling
for Lead and Copper during the second and fourth quarter of 2010. This
process consisted of taking samples from 40 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 lead residuals are now 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, consult our Lead Education Brochures which are
available at the Water Department offices, town library, and on our
website www.cohassetwater.org .
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)
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.eap.gov/safewater/lead
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 Superintendent Norman Lavigne at
the Water Department at 781-383-0057 (fax 781-
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
Peter DeCaprio- Chair
Chris Seebeck, -Vice Chair
Leonora Jenkins - Clerk
Postal Patron
Cohasset, MA 02025
Cohasset Water Department
2010 Water Quality Report