HomeMy WebLinkAbout18 - 2010 Drinking Water Quality ReportCITY OF NEWPORT BEACH
CITY COUNCIL STAFF REPORT
Agenda Item No. 18
June 22 "d, 2010
TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL
FROM: Utilities Department
George Murdoch, Utilities Director
949 - 644 -3011 or gmurdoch(o)_newportbeachca.gov
SUBJECT: 2010 DRINKING WATER QUALITY REPORT ON PUBLIC HEALTH
GOALS
RECOMMENDATION:
Receive and file report.
DISCUSSION:
Background:
Provisions of the California Health and Safety Code Section 116470 (b) specify that
public water systems serving more than 10,000 service connections must prepare a
special report by July 1, 2010 if their water quality measurements have exceeded any
Public Health Goal (PHG). PHGs are non- enforceable goals established by the
California Environmental Protection Agency (CAL /EPA) Office of Environmental Health
Hazard Assessment ( OEHHA). The law also requires that where. OEHHA has not
adopted a PHG for a constituent, the water suppliers are to use the Maximum
Contaminant Level Goal (MCLG) adopted by U.S. Environmental Protection Agency
(U.S. EPA). Only constituents which have a California primary drinking water standard
and for which either a PHG or MCLG has been set need to be addressed.
If a constituent was detected in the City's water supply between 2007 and 2009 at a
level exceeding an applicable PHG or MCLG, this report provides the information
required by the law. Included is the numerical public health risk associated with the
Maximum Contaminant Level (MCL) and the PHG or MCLG, the report includes:
• A category or type of risk to health that could be associated with each constituent;
• The best treatment technology available that could be used to reduce the constituent
level; and
• An estimate of the cost to install that treatment if it is appropriate and feasible.
2010 Drinking Water Quality Report — Public Health Goals
June 22nd, 2010
What are PHGs?
PHGs are set by the OEHHA, and are based solely on public health risk considerations.
None of the practical risk - management factors that are considered by the U.S. EPA or
the California Department of Public Health (CDPH) in setting drinking water standards
(MCLs) are considered in setting the PHGs. These factors include analytical detection
capability, treatment technology available, benefits and costs. The PHGs are not
enforceable and are not required to be met by any public water system. MCLGs are the
federal equivalent to PHGs.
Water Qualitv Data Considered
All of the water quality data collected by the City between 2007 and 2009 for purposes
of determining compliance with drinking water standards was considered. This data
was summarized in our 2007, 2008, and 2009 Annual Consumer Confidence Reports,
which are mailed to all City customers annually by July 1.
Guidelines Followed:
The Association of California Water Agencies (ACWA) formed a workgroup that
prepared guidelines for water utilities to use in preparing these newly required reports.
The ACWA guidelines were used in the preparation for our report. No guidance was
available from state regulatory agencies.
Best Available Treatment Technology and Cost Estimates:
Both the U.S. EPA and CDPH adopt what are known as Best Available Technologies,
which are the best known methods of reducing contaminant levels to the MCL. Costs
can be estimated for such technologies. However, since many PHGs and all MCLGs
are set much lower than the MCL, it is not always possible or feasible to determine what
treatment might reduce a constituent downward to or near the PHG or MCLG, many of
which are set at zero. Estimating the costs to reduce a constituent to zero is difficult, if
not impossible, because it is not possible to verify by analytical means that the level has
been lowered to zero. In some cases, installing treatment to try and further reduce very
low levels of one constituent may have adverse effects on other aspects of water
quality.
Constituents Detected That Exceed a PHG or a MCLG:
The following is a discussion of constituents that were detected in one or more of our
drinking water sources at levels above the PHG, or if no PHG, above the MCLG.
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2010 Drinking Water Quality Report — Public Health Goals
June 22nd, 2010
Coliform Bacteria:
During 2007, 2008, and 2009, City staff collected over 4,713 samples for coliform
bacteriological analysis. In March of 2009, one sample was found to be positive for
coliform but absent for fecal. Three re -check samples were negative and follow -up
actions were taken. The MCL for coliform positive detection is less than 5% of all
samples per month and the MCLG is 0 %. The reason for the coliform drinking water
standard is to minimize the possibility of the water containing pathogens, which are
organisms that cause waterborne disease. Since coliform is only a surrogate indicator
of the potential presence of pathogens, it is not possible to state a specific numerical
health risk. While U.S. EPA normally sets MCLGs "at a level where no known or
anticipated adverse effects on persons would occur ", they indicate that they cannot do
so with coliforms.
Coliform bacteria are indicator organisms that are ubiquitous in nature and are not
generally considered harmful. They are used because of the ease in monitoring and
analysis. If a positive sample is found, it indicates a potential problem that needs to be
investigated and follow up sampling done. It is not at all unusual for a system to have
an occasional positive sample. It is difficult, if not impossible; to assure that a system
will never get a positive sample. The follow -up samples were negative, which indicate
no potential problem and no need for further investigation.
The City adds disinfectant in the form of Monochloramine to assure that the water
served is microbiologically safe. The Monochloramine residual levels are carefully
controlled to provide the best health protection without causing the water to have
undesirable taste and odor or increasing the disinfection byproduct level. This careful
balance of treatment processes is essential to continue supplying customers with safe
drinking water.
Other equally important measures that we have implemented include: an effective
cross - connection control program, maintenance of a disinfectant residual throughout the
City's system, an effective monitoring and surveillance program and maintaining
positive pressures in our distribution system. They City's system has already taken all
of the steps described by CDPH as "best available technology" for coliform bacteria in
Section 64447, Title 22, CCR.
Arsenic:
Arsenic is an element that naturally occurs in the earth's crust. Accordingly, there are
natural sources of exposure. Exposure to arsenic at high levels can pose serious health
effects, as it is known to cause skin cancer and other cancers of the internal organs. In
addition, it has been reported to affect the vascular system and has been associated
with the development of diabetes. The PHG set by OEHHA for Arsenic is 0.004 Parts
per billion (ppb). The U.S. EPA established a MCL for arsenic of 50 ppb in 1975. In
January 2002, U.S. EPA adopted a new standard for arsenic in drinking water that
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2010 Drinking Water Quality Report — Public Health Goals
June 22nd, 2010
requires water suppliers to reduce arsenic to 10 ppb by January 2006. Groundwater and
imported water in Orange County generally range between non - detectable levels and 5
ppb.
The Best Available Technologies treatment for Arsenic to lower the level below the MCL
is adsorptive media systems. Since the level of Arsenic in each of the City wells is
already below the MCL, the adsorptive media systems treatment method would likely be
used to attempt to lower the Arsenic level below the 0.004 ppb PHG. The U.S. EPA has
estimated that a centralized treatment plant of this type would cost approximately $8.4
million per year, including initial construction costs and additional operations and
maintenance costs. This would result in an assumed increased cost for each water
customer of about $343 per customer annually.
Uranium
The PHG set by OEHHA for Uranium is 0.43 picocuries per liter (pCi /L), and the CDPH
has set the MCL for Uranium at 20 pCi /L. Uranium is naturally occurring in groundwater.
The City has detected Uranium in its wells at levels between 1.8 to 15.8 pCi /L. The
levels detected were below the MCLs at all times. The category of health risk
associated with Uranium and the reason that a drinking water standard was adopted
was that people who drink water containing Uranium above the MCL throughout their
lifetime could experience an increased risk of cancer. CDPH says that "Drinking water
which meets this standard (the MCL) is associated with little to none of this risk and
should be considered safe with respect to Uranium."
The Best Available Technologies treatment for Uranium to lower the level below the
MCL is Ion Exchange/Water Softening treatment. Since the level of Uranium in each of
the City wells is already below the MCL, the Ion Exchanged/Water Softening treatment
method would likely be used to attempt to lower the Uranium level below the 0.5 pCi /L
PHG. The U.S. EPA has estimated that a centralized treatment plant of this type would
cost approximately $10.5 Million per year, including initial construction costs and
additional operations and maintenance costs. This would result in an assumed
increased cost for each water customer of about $531 per customer annually.
Lead:
There is no MCL for Lead. Instead the 90th percentile value of all samples from
household taps in the distribution system cannot exceed and Action Level of 0.015 mg /L
for lead. The PHG for Lead is 0.002 mg /L.
The Category of health risk for lead is damage to the kidneys or nervous system of
humans. Numerical health risk data on lead have not been provided by OEHHA.
Based on extensive sampling of our distribution system in 2009, the City's 90th
percentile value for Lead was 0.005 mg /L.
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2010 Drinking Water Quality Report — Public Health Goals
June 22nd, 2010
The City is in full compliance with the Federal and State Lead and Copper Rule. Based
on sampling it was determined by the State regulatory requirements that the City meets
the Action Levels for Lead. Therefore the City will be deemed by CDPH to have an
"optimized corrosion control" condition.
In general, optimizing corrosion control is considered to be the best available
technology to deal with corrosion issues and with any lead findings. The City continues
to monitor our water quality parameters that relate to corrosivity, such as pH, hardness,
alkalinity, total dissolved solids, and will take action if necessary to maintain our system
in an "optimized corrosion control' condition.
Since we the City will be meeting the "optimized corrosion control' requirements, it is
not prudent to initiate additional corrosion control treatment as it involves the addition of
other chemicals and there could be additional water quality issues raised. Therefore no
estimate of cost has been included.
Summary Table:
Constituent
PHG /MCLG
Action Limit
Actual
Coliform
0
N/A
1 in 4,713
*pCi/I
Arsenic
0.004 ppb
N/A
ND -2.9 ppb
Uranium
0.43 pCi /I
N/A
1.8 to15.8 pCi /I
Lead
0.002 mg / L
0.015 mg /L
N/A
(90%)0.005
mg /L
Recommendations for further action:
The drinking water quality of the City of Newport Beach meets all State of California,
Department of Public Health and U.S. EPA drinking water standards set to protect
public health. To further reduce the levels of the constituents identified in this report
that are already significantly below the health -based MCLs established to provide "safe
drinking water ", additional costly treatment processes would be required. The
effectiveness of the treatment processes to provide any significant reductions in
constituent levels at these already low values is uncertain. The health protection
benefits of these further hypothetical reductions are not at all clear and may not be
quantifiable. Therefore, no action is proposed.
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2010 Drinking Water Quality Report — Public Health Goals
June 22nd, 2010
Environmental Review:
Staff recommends the City Council finds that receiving this report is not subject to the
California Environmental Quality Act ( "CEQA ") pursuant to Sections 15060(c)(2) (the
activity will not result in a direct or reasonably foreseeable indirect physical change in
the environment) and 15060(c)(3) (the activity is not a project as defined in Section
15378) of the CEQA Guidelines, California Code of Regulations, Title 14, Chapter 3,
because it has no potential for resulting in physical change to the environment, directly
or indirectly.
Funding Availability:
No funding is required for this report.
Prepared by:
Gary Tegel
Water Quality Coordinator
Page 6 of 6
Submitted by:
'Z d�
Geo e M rdoch
Utilities Director