HomeMy WebLinkAbout2020-04-21; Municipal Water District; ; Carlsbad Municipal Water District 2019 Triennial Report on Water Quality Relative to Public Health Goals.Meeting Date:
To:
From:
Staff Contact:
Subject
April 21, 2020
President and Board Members
Scott Chadwick, Executive Manager
Mark Biskup, Municipal Projects Manager
mark.biskup@carlsbadca.gov, 760-603-7352
CA Review CJL W
Carlsbad Municipal Water District 2019 Triennial Report on Water Quality
Relative to Public Health Goals.
Recommended Action
1) Adopt a Resolution of the Board of Directors of the Carlsbad Municipal Water District
(Board) approving the Carlsbad Municipal Water District (CMWD) 2019 Triennial Report
on Water Quality Relative to Public Health Goals.
2) Hold a public hearing to receive public comments on the CMWD 2019 Triennial Report
on Water Quality Relative to Public Health Goals.
Executive Summary
CMWD publishes Annual Water Quality Reports, also referred to as Consumer Confidence
Reports (CCR). These reports are published on the City of Carlsbad's website, and hard copies
are provided to customers upon request. The annual reports provide extensive water quality
information including data on:
• Maximum Contaminant Levels (MCLs) -state and federal mandatory and enforceable limits
set by the California State Water Resources Control Board Division of Drinking Water (DDW)
and U.S. Environmental Protection Agency (USEPA) to ensure a safe supply of public
drinking water
• Maximum Contaminant Level Goals (MCLGs) -the federal non-regulatory and non-
enforceable goal that is the level of a chemical contaminant in drinking water that does not
pose a significant risk to health and is set by USEPA
• Public Health Goals (PHG) -the state non-regulatory and non-enforceable level of a
chemical contaminant in drinking water that does not pose a significant risk to health set by
the California Office of Environmental Health Hazard Assessment (OEHHA). The submittal of
the required report is enforced by DDW. The state-established PHGs are equivalent to or
more stringent than the MCLGs established by USEPA.
In addition to the Annual Water Quality Reports, California Health and Safety Code Sections
116470(b) and 116470(c) specify that water utilities with more than 10,000 service
connections, once every three years, shall prepare a brief written report in plain language by
July ist and hold a public hearing presenting the report, if their water quality measurements
have exceeded any PH Gs (or MCLGs if there is no PHG for the contaminant).
April 21, 2020 Item #6 Page 1 of 36
The purpose of the required public hearing is to give consumers access and ability to comment
on information on levels of contaminants, including those that are below the enforceable MCL
limits. DDW requests that utilities report in writing as to how they have complied with the
fundamental requirements of California Health and Safety Code Sections 116470(b) and
116470(c) including requirements to prepare a brief written report, hold a public hearing and
notify DDW that the meeting was held and the report is available.
CMWD's water system complies with all federal and state MCL health-based drinking water
regulatory and enforceable standards. However, testing from sampling between 2013 and 2018
identified five constituents that exceeded the PHG and MCLG limits (non-enforceable goals).
The levels for these constituents were well below the MCLs (enforceable regulatory standards),
and therefore they did not violate any enforceable drinking water regulations. The 2019
Triennial Report was made available to the public on the City of Carlsbad's website on July 1,
2019. A public hearing is being held tonight to provide the public with an opportunity to
provide comments on the report.
Discussion
CMWD is a retail water district that purchases and receives 100% of its drinking water from the
San Diego County Water Authority (SDCWA), a wholesale water agency. All of CMWD's drinking
water is supplied from the Metropolitan Water District's {MWD) Skinner Treatment Plant,
SDCWA's Twin Oaks Valley Treatment Plant, and SDCWA's Desalination Plant via the SDCWA
aqueduct system. MWD and SDCWA conducted all of the sampling required for CMWD's 2019
Triennial report, and the data shows the results from MWD's and SDCWA's water quality
testing. Both agencies are required to report this data annually to the retail water agencies, like
CMWD, showing the results of their water quality testing.
The last CMWD PHG Report was published in 2013 for years 2010, 2011 and 2012. A report was
due in 2016 for the years 2013, 2014 and 2015, but it was inadvertently missed. Hence, this
current report for 2019 covers six years (2013 through 2018).
Testing from the sampling between 2013 and 2018 identified five constituents that exceeded
the PHG and MCLG limits including arsenic, uranium, bromate, chromium VI and N-
Nitrosodimethylamine (NOMA). The levels for these constituents were well below the MCLs
(enforceable regulatory standards), and therefore did not violate any enforceable drinking
water regulations. The information is provided for advisory purposes only.
These results are consistent with other water agencies in the region who receive their water
from MWD and SDCWA. Table 1 below shows a summary of the range levels detected that
exceeded PHGs during this period. More detailed tables are provided in the attached 2019 PHG
Report.
April 21, 2020 Item #6 Page 2 of 36
April 21, 2020 Item #6 Page 3 of 36
April 21, 2020 Item #6 Page 4 of 36
RESOLUTION NO. 1638
A RESOLUTION OF THE BOARD OF DIRECTORS OF THE CARLSBAD
MUNICIPAL WATER DISTRICT (BOARD) APPROVING THE CARLSBAD
MUNICIPAL WATER DISTRICT (CMWD) 2019 TRIENNIAL REPORT ON WATER
QUALITY RELATIVE TO PUBLIC HEALTH GOALS
EXHIBIT I
WHEREAS, CMWD is required to prepare a report comparing CMWD's drinking water quality
and source water quality with Public Health Goals (PHGs) adopted by California EPA's Office of
Environmental Health Hazard Assessment and with maximum contaminant level goals (MCLGs)
adopted by the United States Environmental Protection Agency (USEPA); and
WHEREAS, PHGs and MCLGs are not enforceable standards and no action to meet them is
mandated; and
WHEREAS, CMWD's drinking water is supplied from the Metropolitan Water District's (MWD)
Skinner Treatment Plant, the San Diego County Water Authority's (SDCWA) Twin Oaks Valley Treatment
Plant and the Claude "Bud" Lewis Carlsbad Desalination Plant via the SDCWA aqueduct system; and
WHEREAS, California Health and Safety Code Sections 116470(b) and 116470(c) require that,
every three years, a public water system provider with more than 10,000 service connections prepare
a Public Health Goal Report and conduct a public hearing to accept and respond to public comment on
the report; and
WHEREAS, the last CMWD PHG Report was published in 2013 for years 2010, 2011, and 2012.
A report due for 2016 for the years 2013, 2014, and 2015 was inadvertently missed, therefore this
current report for 2019 includes six years (2013 through 2018); and
WHEREAS, on July 1, 2019 the CMWD 2019 Triennial Report on Water Quality Relative to Public
Health Goals was published on the City of Carlsbad's website; and
WHEREAS, a Public Hearing was held on April 21, 2020 to accept and respond to public comment
regarding the report; and
NOW, THEREFORE, BE IT RESOLVED by the Carlsbad Municipal Water District Board of the City
of Carlsbad, California, as follows:
1. That the above recitations are true and correct.
2. That the Board approves the CMWD 2019 Triennial Report on Water Quality Relative to
Public Health Goals, attached as Attachment A.
April 21, 2020 Item #6 Page 5 of 36
EXHIBIT I
3. That the Board authorizes the General Manager to submit the report to the State Water
Resources Control Board.
PASSED, APPROVED AND ADOPTED at a Special Meeting of the Board of Directors of the
Carlsbad Municipal Water District of the City of Carlsbad, California on the 21st day of April, 2020, by
the following vote, to wit:
AYES:
NAYS:
ABSENT:
Blackburn, Bhat-Patel, Schumacher.
None.
Hall.
MATT HALL, PRESIDENT
. u~Jbrbrt~
r"'L-BARBARA ENGLESON, SECRETARY
(SEAL)
April 21, 2020 Item #6 Page 6 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 1 of 8
Introduction
Carlsbad Municipal Water District (CMWD) publishes Annual Water Quality Reports every year. These
are published on the City of Carlsbad/ CMWD’s website1 and provided to customers upon request. Once
every three years, the California Health and Safety Code2 specifies that water utilities with more than
10,000 service connections prepare a special report by July 1st if their water quality measurements have
exceeded any Public Health Goals (PHGs) in the previous three years.
The last CMWD PHG Report was published in 2013 for years 2010, 2011, and 2012. A report was due for
2016 for the years 2013, 2014, and 2015. This was inadvertently missed. Hence, this current report for
2019 covers six years (2013 through 2018).
The drinking water quality of the CMWD meets all State of California, Department of Public Health
and USEPA drinking water health-based maximum contaminant level (MCL)3 regulatory standards set
to protect public health.
Guidelines Followed:
The Association of California Water Agencies (ACWA)4 formed a workgroup which prepared guidelines
for water utilities to use in preparing these required reports. The ACWA guidelines were used in the
preparation of our report. No guidance was available from state regulatory agencies.
Best Available Treatment Technology and Cost Estimates:
Both the United States Environmental Protection Agency (USEPA5) and California Department of Public
Health (CDPH)6 adopt what are known as Best Available Technologies (BATs), 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 maximum contaminant level goals (MCLGs) are set much lower than
the MCL, it is not always possible, nor feasible to determine what treatment is needed to further reduce
1 https://www.carlsbadca.gov/services/depts/pw/utils/water/quality.asp
2 https://leginfo.legislature.ca.gov/faces/codesTOCSelected.xhtml?tocCode=HSC
3 MCLs are adopted as regulations. They are health protective drinking water standards to be met by public water
systems. MCLs take into account not only chemicals' health risks but also factors such as their detectability and
treatability, as well as costs of treatment. For more information, please refer to this site:
https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/MCLsandPHGs.html
4 https://www.acwa.com/
5 https://www.epa.gov/
6 https://www.cdph.ca.gov/
CARLSBAD MUNICIPAL WATER DISTRICT
2019 TRIENNIAL REPORT ON WATER QUALITY RELATIVE TO PUBLIC
HEALTH GOALS
April 21, 2020 Item #6 Page 7 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 2 of 8
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.
What are PHGs?
PHGs are non-enforceable goals established by the Cal-EPA's Office of Environmental Health Hazard
Assessment (OEHHA)7. A PHG is the level of a chemical contaminant in drinking water that does not pose
a significant risk to health. PHGs are not regulatory standards. However, state law requires State Water
Resources Control Board (SWRCB) to set drinking water standards for chemical contaminants as close to
the corresponding PHG as is economically and technologically feasible. In some cases, it may not be
feasible for the SWRCB to set the drinking water standard for a contaminant at the same level as the
PHG. The technology to treat the chemicals may not be available, or the cost of treatment may be very
high. There are currently 91 chemicals on the PHG list.
The process for establishing a PHG for a chemical contaminant in drinking water is very rigorous. OEHHA
scientists first compile all relevant scientific information available, which includes studies of the
chemical's effects on laboratory animals and studies of humans who have been exposed to the chemical.
The scientists use data from these studies to perform a health risk assessment, in which they determine
the levels of the contaminant in drinking water that could be associated with various adverse health
effects. When calculating a PHG, OEHHA uses all the information it has compiled to identify the level of
the chemical in drinking water that would not cause significant adverse health effects in people who
drink that water every day for 70 years. OEHHA must also consider any evidence of immediate and
severe health effects when setting the PHG.
For cancer-causing chemicals, OEHHA typically establishes the PHG at the “one-in-one million” risk level.
At that level, not more than one person in a population of one million people drinking the water daily
for 70 years would be expected to develop cancer as a result of exposure to that chemical. 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 goals (MCLGs).
The MCLG is the maximum level of a contaminant in drinking water at which no known or anticipated
adverse effect on the health of persons would occur, allowing an adequate margin of safety. MCLGs are
non-enforceable public health goals. MCLGs consider only public health and not the limits of detection
and treatment technology effectiveness. Therefore, they sometimes are set at levels which water
systems cannot meet because of technological limitations.
7 https://oehha.ca.gov/water/public-health-goals-phgs
April 21, 2020 Item #6 Page 8 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 3 of 8
There are a few constituents that are routinely detected in water systems at levels usually well below
the drinking water standards for which no PHG nor has MCLG yet been adopted by OEHHA or USEPA.
The PHGs and MCLGs are not enforceable and are not required to be met by any public water system.
CMWD Water Quality Data
All the water quality data collected between 2013 and 2018 for purposes of determining compliance
with drinking water standards was considered for this report. This data is usually available and
summarized in the Annual Water Quality Reports published on the City of Carlsbad/ CMWD’s website8. If
a constituent was detected in the District's water supply between 2013 and 2018 at a level exceeding an
applicable PHG or MCLG, this report provides the information required to understand the risks. Included
is the numerical public health risk associated with the MCL and the PHG or MCLG9, the category or type
of health risk, the best treatment technology available that could be used to reduce the constituent
leve110, and an estimate of the cost to install that treatment, if it is appropriate and feasible.
CMWD imports ALL of its drinking water from three sources:
· The Metropolitan Water District (MWD) Lake Skinner water treatment plant in Southern
Riverside County,
· The San Diego County Water Authority (SDCWA) Twin Oaks Valley water treatment plant in San
Marcos,
· The Claude ”Bud” Lewis Carlsbad Desalination Plant, privately owned and operated, and sourced
by SDCWA,
Water from these treatment plants are received by CMWD via SDCWA’s complex system of aqueducts
and pipelines where the water from all these sources are thoroughly blended before reaching CMWD’s
system connections. At any moment of time, it is very difficult for CMWD to know the exact proportion
of the blend. Where applicable, data from all three treatment plants are included in this report.
Constituents Detected That Exceed a PHG or a MCLG:
The following is a discussion of constituents that were detected at a level above the associated PHG, or
if there is no PHG, above the MCLG. The levels for theses constituents were well below their respective
MCLs (regulatory standards), so this does not constitute a violation of drinking water regulations and is
for advisory purposes only. These results are typical of all the water agencies in the region who receive
their water from the same MWD and SDCWA water treatment plants.
8 https://www.carlsbadca.gov/services/depts/pw/utils/water/quality.asp
9 Health Risk Information for Public Health Goal Exceedance Reports (OEHHA) https://oehha.ca.gov/water/public-
health-goal-report/health-risk-information-public-health-goal-exceedance-reports-2019
10 Cost Estimates for Treatment Technologies (ACWA)
April 21, 2020 Item #6 Page 9 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 4 of 8
Arsenic
The contamination of a drinking water source by arsenic can result from either natural or human
activities. Arsenic is an element that occurs naturally in rocks and soil, water, air, plants, and animals.
Volcanic activity, the erosion of rocks and minerals, and forest fires are natural sources that can release
arsenic into the environment. About 90 percent of the arsenic used by industry in the United States is
currently used for wood preservative purposes; arsenic is also used in paints, drugs, dyes, soaps, metals
and semiconductors. Agricultural applications, mining, and smelting also contribute to arsenic releases.
The CADPH and USEPA have determined that arsenic is a health concern at certain levels of exposure.
The category of health risk associated with arsenic, and the reason that a drinking water standard was
adopted for it, is that some people who drink water containing arsenic above the MCL over many years
may experience skin damage and circulatory system problems and are at a higher risk of getting cancer.
The numerical health risk for the PHG of 4 ng/L is one excess cancer case per million people. The
numerical health risk for the MCL of 10 µg/L is 2.5 excess cancer cases per thousand people.
The level of arsenic detected in CMWD's source water supplied by MWD and SDCWA for 2013 and 2018
are listed below.
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Source: SDCWA Twin Oaks Plant
Arsenic ppb 10 0.004 Average 2 3.4 3.0 2.4 2 3
Source: SDCWA Carlsbad Desal Plant
Arsenic ppb 10 0.004 Average NA NA ND 0.42 0.42 ND
ppb = parts per billion. ND = Non Detect. NA = Not Available
Uranium
Radiological constituents come from decay and erosion of natural deposits of certain minerals that are
radioactive and may emit a form of radiation known as alpha radiation, photons and beta radiation.
Uranium is a naturally occurring radioactive element that is ubiquitous in the earth's crust. Uranium is
found in ground and surface waters due to its natural occurrence in geological formations. The uranium
intake from water is about equal to the total from other dietary components. An additional source of
radiological contamination is from mine tailings in Moab Utah.
The State of California has a uranium MCL of 20 pCi/L based on earlier studies of toxicity to the kidney in
rabbits. Cancer risk is stated in terms of excess cancer cases per million (or fewer) population exposed
for a lifetime (theoretically 70 years). The numerical health risk at the MCL is 5x10-5. This means five
cancer cases per 100,000 population. The numerical health risk at the PHG is 1x10-6. This means one
cancer case per 1,000,000 population. The health risk category for uranium is carcinogenicity: chronic
toxicity. Carcinogenic risk means capable of producing cancer. Chronic toxicity risk means there may be
April 21, 2020 Item #6 Page 10 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 5 of 8
adverse effects that usually develop gradually from low levels of chemical exposure and that persist for
a long time. The primary non-carcinogenic toxic effect is on kidneys.
The level of radionuclide constituents detected in CMWD's source water supplied by MWD and SDCWA
for 2013 and 2018 are listed below.
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Source: MWD’s Skinner Plant
Uranium pCi/L 20 0.43 Average 1 2 2 2 ND ND
Source: SDCWA Twin Oaks Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Uranium pCi/L 20 0.43 Average 2.0 2.0 2.0 2.9 2.9 2.2
pCi/L = picoCuries per Liter of water (approximately parts per billion). ND= Non Detect
Bromate
Bromate is a byproduct of water disinfection and occurs when bromide in the water reacts with the
ozone disinfectant. Bromate consumed in drinking water in excess of the MCL over many years may
cause an increased risk of cancer. Bromate is categorized as a haloacetic acid.
The State of California has a bromate MCL of 0.010 mg/L and a PHG of 0.0001 mg/L. Bromate values
ranged from 0.0001 to 0.0005 mg/L. The levels detected were below the MCLs at all times. Bromate can
be found in drinking water as a byproduct of the ozonation disinfection process. The Office of
Environmental Health Hazard Assessment (OEHHA) has developed a Public Health Goal for bromate in
drinking water, based on its carcinogenicity. The numerical health risk at the MCL is 1x10-4. This means
one cancer cases per 10,000 population. The numerical health risk at the PHG is 1x10-6. This means one
cancer case per 1,000,000 population.
The level of bromate detected in CMWD's source water supplied by MWD and SDCWA for 2013 and
2018 are listed below.
Source: MWD Skinner Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Bromate ppb 10 0.1 Highest RAA 5.9 3.6 4.3 4.2 4.1 3.7
Source: SDCWA Twin Oaks Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Bromate ppb 10 0.1 Highest RAA 2.6 3.1 4.2 5.9 6.0 5.0
RAA = Running Annual Average. Highest RAA is the highest of all Running Annual Averages calculated as the
average of all samples collected within a 12-month period. ppb = parts per billion.
April 21, 2020 Item #6 Page 11 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 6 of 8
Chromium VI
Hexavalent Chromium (chromium VI) occurs in natural waters in the environment and is present in
water from the erosion of chromium deposits found in rocks and soils. It is also produced by industrial
processes and manufacturing activities including discharges from steel and pulp mills, among others. It
can also be released to the environment via improper storage and disposal practices.
Hexavalent chromium consumed in drinking water in excess of the MCL over many years may cause
allergic dermatitis. This chemical has been shown to cause cancer in laboratory animals, such as rats and
mice, and humans when they are exposed at high levels over their lifetimes. The numerical health risk
for the PHG of 0.02µg/L is one excess case of cancer per million people. The numerical health risk for the
MCL of 10 µg/L is one excess of cancer per fifty thousand people.
The level of hexavalent chromium detected in CMWD's source water supplied by MWD and SDCWA for
2013 and 2018 are listed below.
Source: SDCWA Twin Oaks Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
Chromium VI ppb 10 0.02 Average ND ND 0.04 0.06 ND 0.09
ppb = parts per billion. ND = Non Detect.
NDMA
NDMA is a chemical formed in both industrial and natural processes. It is a byproduct of chlorination at
wastewater treatment plants that use chloramines for disinfection. NDMA was also formerly used in the
production of rocket fuel, antioxidants, and softeners for copolymers.
Although NDMA is listed as a priority toxic pollutant, no federal MCL has been established for drinking
water. It is classified as a probable human carcinogen. The Notification Level (NL) for NDMA is a health-
based advisory level established by the Division of Drinking Water (DDW) for chemicals in drinking water
that do not have MCLs. In 2013, sample results included a value of 11 ppt, which exceeded the NL of 10
ppt.
The level of hexavalent N-Nitrosodimethylamine (NDMA) detected in CMWD's source water supplied by
MWD and SDCWA for 2013 and 2018 are listed below.
Source: MWD Skinner Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
NDMA ppt NL=10 3 Range ND ND-
2.3
ND-
3.1
ND-
3.2
NDMA ppt NL=10 3 D. Wide ND-ND-ND ND-
April 21, 2020 Item #6 Page 12 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 7 of 8
Source: MWD Skinner Plant
Constituent Units MCL PHG
(MCLG)
2013 2014 2015 2016 2017 2018
6.0 5.1 3.2
NDMA ppt NL=10 3 Single 6.5 2.0-
2.9
ppt = parts per trillion. NL = Notification Level. D. Wide = District Wide. ND = Non Detect
Cost Estimate for Treatment
The best available technology (BAT) to lower the level of these compounds below the PHG is reverse
osmosis. Since the levels are already below the MCL, reverse osmosis would be required to attempt to
lower the levels to below the PHG. Please note that accurate cost estimates are difficult, if not
impossible, and are highly speculative and theoretical. All costs including annualized capital,
construction, engineering, planning, environmental, contingency, and O&M are included, but only very
general assumptions can be made for most of these items. Costs estimating guides from the Association
of California Water Agencies guidance report were used in determining the estimated cost to implement
the BAT. The cost of implementing RO treatment would start at approximately $1.85 - $4.33 per 1,000
gallons treated. CMWD’s annual water usage is approximately 15,000 to 18,000 acre feet and therefore
will cost approximately $23 million per year to treat, and does not include the capital costs of
installation of such facilities and maintenance thereafter. There would be additional costs for corrosion
control because water treated by reverse osmosis is corrosive and could cause the water to exceed the
lead and copper regulations. Additionally, CMWD does not have a treatment plant of its own where
such a treatment plant is not feasible. Hence, it is logistically not possible for CMWD to implement such
a BAT. As previously stated, it is unclear whether treatment to lower a constituent below the PHG or
MCLG would be feasible, as BATs are designated for treatment to achieve compliance with the
corresponding MCL only, and not the PHG or MCLG.
Recommendations:
The drinking water quality of the Carlsbad Municipal Water District meets all State of California,
Department of Public Health and USEPA 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, 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.
NDMA ppt NL=10 3 Sample ND-6.7 ND-
5.0
April 21, 2020 Item #6 Page 13 of 36
For more information contact Carlsbad Municipal Water District, 5950 El Camino Real, Carlsbad 92008;
phone: 760-438-2722; email: water@carlsbadca.gov
Page 8 of 8
The health protection benefits of these further hypothetical reductions are not at all clear and may not
be quantifiable. Therefore, no action is proposed.
CMWD’s drinking water is provided by the MWD and SDCWA water treatment plants and these source
plants treat water prior to being received by CMWD. CMWD continues to work with MWD and SDCWA
to ensure that the drinking water is safe and affordable.
April 21, 2020 Item #6 Page 14 of 36
(;£\ __
I\~ STATE Of CALIFORNIA
~" AUTHENTICATED I ~~i'~t~S ELECTRONIC LEGAL MATERIAL
State of California
HEALTH AND SAFETY CODE
Section 116470
Exhibit~
116470. (a) As a condition of its operating permit, every public water system shall
annually prepare a consumer confidence report and mail or deliver a copy of that
report to each customer, other than an occupant, as defined in Section 799.28 of the
Civil Code, of a recreational vehicle park. A public water system in a recreational
vehicle park with occupants as defined in Section 799 .28 of the Civil Code shall
prominently display on a bulletin board at the entrance to or in the office of the park,
and make available upon request, a copy of the report. The report shall include all of
the following information:
(1) The source of the water purveyed by the public water system.
(2) A brief and plainly worded definition of the terms "maximum contaminant
level," "primary drinking water standard," and "public health goal."
(3) If any regulated contaminant is detected in public drinking water supplied by
the system during the past year, the report shall include all of the following
information:
(A) The level of the contaminant found in the drinking water, and the corresponding
public health goal and primary drinking water standard for that contaminant.
(B) Any violations of the primary drinking water standard that have occurred as
a result of the presence of the contaminant in the drinking water and a brief and plainly
worded statement of health concerns that resulted in the regulation of that contaminant.
(C) The public water system's address and phone number to enable customers to
obtain further information concerning contaminants and potential health effects.
(4) Information on the levels of umegulated contaminants, if any, for which
monitoring is required pursuant to state or federal law or regulation.
(5) Disclosure of any variances or exemptions from primary drinking water
standards granted to the system and the basis therefor.
(b) On or before July 1, 1998, and every three years thereafter, public water
systems serving more than 10,000 service connections that detect one or more
contaminants in drinking water that exceed the applicable public health goal, shall
prepare a brief written report in plain language that does all of the following:
(1) Identifies each contaminant detected in drinking water that exceeds the
applicable public health goal.
(2) Discloses the numerical public health risk, determined by the office, associated
with the maximum contaminant level for each contaminant identified in paragraph
(1) and the numerical public health risk determined by the office associated with the
public health goal for that contaminant.
April 21, 2020 Item #6 Page 15 of 36
(3) Identifies the category of risk to public health, including, but not limited to,
carcinogenic, mutagenic, teratogenic, and acute toxicity, associated with exposure to
the contaminant in drinking water, and includes a brief plainly worded description of
these terms.
( 4) Describes the best available technology, if any is then available on a commercial
basis, to remove the contaminant or reduce the concentration of the contaminant. The
public water system may, solely at its own discretion, briefly describe actions that
have been taken on its own, or by other entities, to prevent the introduction of the
contaminant into drinking water supplies.
(5) Estimates the aggregate cost and the cost per customer of utilizing the
technology described in paragraph (4), if any, to reduce the concentration of that
contaminant in drinking water to a level at or below the public health goal.
( 6) Briefly describes what action, if any, the local water purveyor intends to take
to reduce the concentration of the contaminant in public drinking water supplies and
the basis for that decision.
( c) Public water systems required to prepare a report pursuant to subdivision (b)
shall hold a public hearing for the purpose of accepting and responding to public
comment on the report. Public water systems may hold_ the public hearing as part of
any regularly scheduled meeting.
( d) The department shall not require a public water system to take any action to
reduce or eliminate any exceedance of a public health goal.
( e) Enforcement of this section does not require the department to amend a public
water system's operating permit.
(f) Pending adoption of a public health goal by the Office of Environmental Health
Hazard Assessment pursuant to subdivision ( c) of Section 116365, and in lieu thereof,
public water systems shall use the national maximum contaminant level goal adopted
by the United States Environmental Protection Agency for the corresponding
contaminant for purposes of complying with the notice and hearing requirements of
this section.
(g) This section is intended to provide an alternative form for the federally required
consumer confidence report as authorized by 42 U.S.C. Section 300g-3(c).
(Repealed and added by Stats. 1996, Ch. 755, Sec. 12. Effective January 1, 1997.)
April 21, 2020 Item #6 Page 16 of 36
Health Risk Information for
Public Health Goal Exceedance Reports
Prepared by
Office of Environmental Health Hazard Assessment
California Environmental Protection Agency
February 2019
EXHIBIT 3
Under the Calderon-Sher Safe Drinking Water Act of 1996 (the Act), public water
systems with more than 10,000 service connections are required to prepare a report
every three years for contaminants that exceed their respective Public Health Goals
(PHGs).1 This document contains health risk information on regulated drinking water
contaminants to assist public water systems in preparing these reports. A PHG is the
concentration of a contaminant in drinking water that poses no significant health risk if
consumed for a lifetime. PHGs are developed and published by the Office of
Environmental Health Hazard Assessment (OEHHA) using current risk assessment
principles, practices and methods. 2
The water system's report is required to identify the health risk category (e.g.,
carcinogenicity or neurotoxicity) associated ~ith exposure to each regulated
contaminant in drinking water and to include a brief, plainly worded description of these
risks. The report is also required to disclose the numerical public health risk, if
available, associated with the California Maximum Contaminant Level (MCL) and with
the PHG for each contaminant. This health risk information document is prepared by
OEHHA every three years to assist the water systems in providing the required
information in their reports.
Numerical health risks: Table 1 presents health risk categories and cancer risk values
for chemical contaminants in drinking water that have PH Gs.
The Act requires that OEHHA publish PHGs based on health risk assessments using
the most current scientific methods. As defined in statute, PHGs for non-carcinogenic
1 Health and Safety Code Section 1164 70(b)
2 Health and Safety Code Section 116365
Office of Environmental Health. Hazard Assessment
Water Toxicology Section
February 2019
Ll.(1
1
Item 2.1 April 21, 2020 Item #6 Page 17 of 36
(Continued)
chemicals in drinking water are set at a concentration "at which no known or anticipated
adverse health effects will occur, with an adequate margin of safety." For carcinogens,
PHGs are set at a concentration that "does not pose any significant risk to health."
PHGs provide one basis for revising MCLs, along with cost and technological feasibility.
OEHHA has been publishing PHGs since 1997 and the entire list published to date is
shown in Table 1.
Table 2 presents health risk information for contaminants that do not have PHGs but
have state or federal regulatory standards. The Act requires that, for chemical
contaminants with California MCLs that do not yet have PH Gs, water utilities use the
federal Maximum Contaminant Level Goal (MCLG) for the purpose of complying with
the requirement of public notification. MCLGs, like PHGs, are strictly health based and
include a margin of safety. One difference, however, is that the MCLGs for carcinogens
are set at zero because the US Environmental Protection Agency (US EPA) assumes
there is no absolutely safe level of exposure to such chemicals. PHGs, on the other
hand, are set at a level considered to pose no significant risk of cancer; this is usually
no more than a one-in-one-million excess cancer risk (1 x1 Q·6) level for a lifetime of
exposure. In Table 2, the_ cancer risks shown are based on the US EPA's evaluations.
For more information on health risks: The adverse health effects for each chemical
with a PHG are summarized in a PHG technical support document. These documents
are available on the OEHHA website (http://www.oehha.ca.gov). Also, technical fact
sheets on most of the chemicals having federal MCLs can be found at
http://www.epa.gov/your-drinking-water/table-regulated-drinking-water-contaminants.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
41
2
Item 2.1 April 21, 2020 Item #6 Page 18 of 36
(Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California Cancer California Cancer
Chemical Health Risk Category1 PHG Risk3 MCL4 Risk at the
(mg/L)2 at the (mg/L) California
PHG MCL
Alachlor carcinogenicity 0.004 NAs,s 0.002 NA
( causes cancer)
Aluminum neurotoxicity and 0.6 NA 1 NA
immunotoxicity
(harms the nervous and
immune systems)
Antimon~ digestive system toxicity 0.02 NA 0.006 NA
(causes vomiting)
Arsenic carcinogenicity 0.000004 1 x1 o-6 0.01 2.5x10-3
' ( causes cancer) (4x10-6) (one per (2.5 per
million) thousand)
Asbestos carcinogenicity 7 MFL7 1 x1 o-6 7 MFL 1 x1 o-6
( causes cancer) (fibers (fibers (one per
>10 >10 million)
microns in microns in
length) length)
Atrazine carcinogenicity 0.00015 1 x10-6 0.001 7x10-6
( causes cancer) (seven per
million)
1 Based on the OEHHA PHG technical support document unless otherwise specified. The categories are
the hazard traits defined by OEHHA for California's Toxics Information Clearinghouse (online at:
http://oehha.ca.gov/multimedia/green/pdf/GC Reqtextb11912.pdf).
2 mg/L = milligrams per liter of water or parts per million (ppm)
3 Cancer Risk = Upper bound estimate of excess cancer risk from lifetime exposure. Actual cancer risk may
be lower or zero. 1x10-5 means one excess cancer case per million people exposed. '
4 MCL = maximum contaminant level.
5 NA = not applicable. Cancer risk cannot be calculated.
6 The PHG for alachlor is based on a threshold model of carcinogenesis and is set at a level that is believed
to be without any significant cancer risk to individuals exposed to the chem.ical over a lifetime.
7 MFL = million fibers per liter of water.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019 3
ltP.m 2_1 April 21, 2020 Item #6 Page 19 of 36
(Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California Cancer
Chemical Health Risk Category1 PHG Risk3
(mg/L)2 at the
PHG
Barium cardiovascular toxicity 2 NA
(causes high blood
pressure)
Bentazon hepatotoxicity and 0.2 NA
digestive system toxicity
(harms the liver,
intestine, and causes
body weight effects8)
Benzene carcinogenicity 0.00015 1 x1 o·6
(causes leukemia)
Benzo[a]g~rene carcinogenicity 0.000007 1 x1 o-6
( causes cancer) (7x10·6)
BeD'.llium digestive system toxicity 0.001 NA
(harms the stomach or
intestine)
Bromate carcinogenicity 0.0001 1x10·6
(causes cancer)
Cadmium nephrotoxicity 0.00004 NA
(harms the kidney)
Carbofuran reproductive toxicity 0.0007 NA
(harms the testis)
8 Body weight effects are an indicator of general toxicity in animal studies.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
California Cancer
MCL4 Risk at the :
(mg/L) California
MCL
1 NA
0.018 NA
0.001 7x10·6
(seven per
million)
0.0002 3x10·5
· (three per
hundred
thousand)
0.004 NA
0.01 1x104
(one per
ten
. thousand)
0.005 NA
0.018 NA
4
Item 2.1 April 21, 2020 Item #6 Page 20 of 36
. ( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California Cancer California Cancer
Chemical Health Risk Category1 PHG Risk3 MCL4 Risk at the
(mg/L)2 at the (mg/L) California
PHG MCL
Carbon carcinogenicity 0.0001 1 x10-6 0.0005 5x10-6
tetrachloride ( causes cancer) (five per
million)
Chlordane carcinogenicity 0.00003 1 x10-6 0.0001 3x1 o-6
( causes cancer) (three per
million)
Chlorite hematotoxicity 0.05 NA 1 NA
(causes anemia)
nei.Jrotoxidty
(causes neurobehavioral
effects)
Chromium, carcinogenicity 0.00002 1 x1 o-6 none NA
hexavalent (causes cancer)
Copper digestive system toxicity 0.3 NA 1.3 (AL9) NA
( causes nausea,
vomiting, diarrhea)
Cyanide neurotoxicity 0.15 NA 0.15 NA
( damages nerves)
endocrine toxicity
(affects the thyroid)
Dalapon nephrotoxicity 0.79 NA 0.2 NA
(harms the kidney)
Di(2-ethylhexyl} developmental toxicity 0.2 NA 0.4 NA
adipate (DEHA) (disrupts development)
Diethylhexyl-carcinogenicity 0.012 1 x1 o-6 0.004 3x10-7
phthalate ( causes cancer) (three per
(DEHP} ten million)
9 AL = action level. The action levels for copper and lead refer to a concentration measured at the tap. Much
of the copper and lead in drinking water is derived from household plumbing (The Lead and Copper Rule,
Title 22, California Code of Regulations [CCR] section 64672.3).
Office of Envj ronmental Health Hazard Assessment
Water Toxicology Section
February 2019
44
5
Item 2.1 April 21, 2020 Item #6 Page 21 of 36
( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
• Chemical Health Risk Category1 PHG
(mg/L)2
1,2-Dibromo-3-carcinogenicity 0.0000017
·chloror2ro12ane (causes cancer) (1.7x10-6)
(DBCP)
1 ,2-Dichloro-hepatotoxicity 0.6
benzene (harms the liver)
(o-DCB)
1 A-Dichiaro-carcinogenicity 0.006
benzene ( causes cancer)
(l;!-DCB)
111-Dichloro-carcinogenicity 0.003
ethane ( causes cancer)
(1, 1-DCA)
112-Dichloro-carcinogenicity 0.0004
ethane (causes cancer)
(1 12-DCA)
1, 1-Dichloro-hepatotoxicity 0.01
ethylene (harms the liver)
(1, 1-DCE)
112-Dichloro-nephrotoxicity 0.013
ethylene, cis (harms the kidney)
1,2-Dichloro-immunotoxicity 0.05
ethylene, trans (harms the immune
system)
Dichloromethane carcinogenicity 0.004
(methylene ( causes cancer)
chloride)
Office of Environmental Health Hazard Assessment ·
Water Toxicology Section
February 2019
· 45
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
1 x1 o-6 0.0002 1x10-4
(one per
ten
thousand)
NA 0.6 NA
1x10-6 . 0.005 8x10-7
(eight per
ten million)
1 x1 o-6 0.005 2x10-6
(two per
million)
1 x1 o-6 0.0005 1 x1 o-6
(one per
million)
NA 0.006 NA
NA 0.006 NA
NA 0.01 NA
1 x1 o-6 0.005 1 x1 o-6
(one per
million)
6
Item 2.1
April 21, 2020 Item #6 Page 22 of 36
( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
.
California
Chemical Health Risk Category1 PHG
{mg/L)2
2_4-Dichloro-hepatotoxicity and 0.02
12heno~acetic nephrotoxicity
acid (214-D} (harms the liver and
kidney)
1 12-Dichloro-carcinogenicity 0.0005
propane ( causes cancer)
(propylene
dichloride}
113-Dichloro-carcinogenicity 0.0002
propene (causes cancer)
(Telone II®}
Dinoseb reproductive toxicity 0.014
(harms the uterus and
testis)
Diquat ocular toxicity 0.006
(harms the eye)
developmental toxicity
(causes malformation)
Endothall digestive system toxicity 0.094
(harms the stomach or
intestine)
Endrin neurotoxicity 0.0003
(causes convulsions)
hepatotoxicity
(harms the liver)
Ethylbenzene hepatotoxicity 0.3
(Qhenylethane} (harms the liver)
Ethylene carcinogenicity 0.00001
dibromide (1 12-( causes cancer)
Dibromoethane}
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
46
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
NA 0.07 NA
1 x10-6 0.005 1 x10-5
(one per
hundred
thousand)
1x10-6 0.0005 2x1 o-6
(two per
million)
NA 0.007 NA
NA 0.02 NA
NA 0.1 NA
NA .0.002 NA
NA 0.3 NA
1 x1 o-6 0.00005 5x10-6
(five per
million)
7
Item 2.1
April 21, 2020 Item #6 Page 23 of 36
(Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
Chemical Health Risk Category1 PHG
(mg/L)2
Fluoride musculoskeletal toxicity 1
(causes tooth mottling)
Gl~Qhosate nephrotoxicity 0.9
(harms the kidney)
HeQtachlor carcinogenicity 0.000008
( causes cancer) (8x10·6)
HeQtachlor carcinogenicity 0.000006
eQoxide (causes cancer) (6x1 o-6)
Hexachloroben-carcinogenicity 0.00003
zene ( causes cancer)
Hexachloro-digestive system toxicity 0.002
c~cloQentadiene ( causes stomach
(HCCPD) lesions)
Lead developmental 0.0002
neurotoxicity
( causes neurobehavioral
effects in children)
cardiovascular toxicity
(causes high blood
pressure)
carcinogenicity
(causes· cancer)
Lindane carcinogenicity 0.000032
(y-BHC) ( causes cancer)
Mercury neph rotoxicity 0.0012
(inorganic) (harms the kidney)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
47
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
NA 2 NA
NA 0.7 NA
1 x1 o-6 0.00001 1 x1 o-6
(one per
million)
1 x1 o-6 0.00001 2x10·6
(two per
million)
1 x1 o-6 0.001 3x10·5
(three per
hundred
thousand)
NA 0.05 NA
<1 x10·6 0.015 2x10-6
(PHG is (AL8) (two per
not based million)
on this
effect)
1 x1 o-6 0.0002 6x10-6
(six per
million)
NA 0.002 NA
8
Item 2.1
April 21, 2020 Item #6 Page 24 of 36
( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California Cancer California Cancer
Chemical Health Risk Category1 PHG Risk3 MCL4 Risk at the
(mg/L)2 at the .(mg/L) California
PHG MCL
Methoxychlor endocrine toxicity 0.00009 NA 0.03 NA
( causes hormone
effects)
Methyl tertiaiv-carcinogenicity 0.013 1 x1 o-6 0.013 1 x1 o-6
butvl ether (causes cancer) (one per
(MTBE} million).
Molinate carcinogenicity 0.001 1 x1 o-6 0.02 2x10-5
(causes cancer) (two per
hundred
thousand)
Monochloro-nephrotoxicity 0.07 NA 0.07 NA
benzene (harms the kidney)
( chlorobenzene}
Nickel developmental toxicity 0.012 NA 0.1 NA
( causes increased
neonatal deaths) '
Nitrate hematotoxicity 45 as NA 10 as NA
(causes nitrate nitrogen
methemoglobinemia) (=45 as
nitrate)
Nitrite hematotoxicity 3 as NA 1 as NA
(causes nitrite nitrogen
methemoglobinemia) (=3 as
nitrite)
Nitrate and hematotoxicity 10 as NA 10 as .. NA
Nitrite (causes nitrogen10 nitrogen
methemoglobinemia)
10 The joint nitrate/nitrite PHG of 10 mg/L (10 ppm, expressed as nitrogen) does not replace the individual
values, and the maximum contribution from nitrite should not exceed 1 mg/L nitrite-nitrogen.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
48
9
Item 2.1
April 21, 2020 Item #6 Page 25 of 36
(Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
Chemical Health Risk Category1 PHG
(mg/L)2
N-nitroso-carcinogenicity b.000003
dimethyl-amine ( causes cancer) (3x1 o-6)
(NOMA}
Oxamyl general toxicity 0.026
( causes body weight
effects)
Pentachloro-carcinogenicity 0.0003
ghenol (PCP} ( causes cancer)
Perchlorate endocrine toxicity 0.001
(affects the thyroid)
developmental toxicity
( causes neurodevelop-
mental deficits)
Picloram hepatotoxicity 0.166
(harms the liver)
Polychlorinated carcinogenicity 0.00009
bighenyls ( causes cancer)
(PCBs}
Radium-226 carcinogenicity 0.05 pCi/L
( causes cancer)
Radium-228 c;:arcinogenicity 0.019 pCi/L
( causes cancer)
Selenium integumentary toxicity .0.03
(causes hair loss and
nail damage)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
49
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
1 x1 o-6 none NA
NA 0.05 NA
1 x1 o-6 0.001 3x10·6
(three per
million)
NA 0.006 NA
NA 0.5 NA
1 x1 o-6 0.0005 6x10·6
(six per
million)
1x10-5 5 pCi/L 1x1Q-4
(combined (one per
Ra22a+22a) ten
thousand)
1 x1 o-6 5 pCi/L 3x10-4
(combined (three per
Ra22a+22a) ten
thousand)
NA 0.05 NA
10
Item 2.1
April 21, 2020 Item #6 Page 26 of 36
(Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
Chemical Health Risk Category1 PHG
(mg/L)2
Silvex (2,4,5-TP) hepatotoxicity 0.003
(harms the liver)
Simazine general toxicity 0.004
( causes body weight
effects)
Strontium-90 carcinogenicity 0.35 pCi/L
( causes cancer)
Styrene carcinogenicity 0.0005
(vinylbenzene) ( causes cancer)
1, 1,2,2-carcinogenicity 0.0001
Tetractiloro-( causes cancer)
ethane
2,3,7,8-Tetra-carcinogeniGity 5x10·11
chlorodibenzo-Q-( causes cancer)
dioxin (TCDD, or
dioxin)
Tetrachloro-carcinogenicity 0.00006
ethylene ·(causes cancer)
(gerchloro-
ethylene, or .
PCE)
Thallium integumentary toxicity 0.0001
( causes hair loss)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
50
Cancer Californi~ Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
NA 0.05 NA
NA 0.004 NA
1 x1 Q-6 8 pCi/L 2x10·5
(two per
hundred
thousand)
1 x1 o-6 0.1 2x104
(two per
ten
thousand)
1 x1 o-6 0.001 1 x1 o-5
(one per
hundred
thousand)
1 x10·6 3x10·8 6x104
(six per ten
thousand)
1 x10·6 0.005 8x10·5
(eight per
hundred
thousand)
NA 0.002 NA
11
Item 2.1
April 21, 2020 Item #6 Page 27 of 36
( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
Chemical Health Risk Category1 PHG
(mg/L)2
Thiobencarb general toxicity 0.042 ( causes body weight
effects)
hematotoxicity
( affects red blood cells)
Toluene hepatotoxicity 0.15
(meth~lbenzene} (harms the liver)
endocrine toxicity
(harms the thymus)
Toxa12hene carcinogenicity 0.00003
( causes cancer)
112A-Trichloro-endocrine toxicity 0.005
benzene (harms adrenal glands)
11111-Trichloro-neurotoxicity 1
ethane (harms the nervous
system),
reproductive toxicity
(causes fewer offspring)
hepatotoxicity
(harms the liver)
hematotoxicity
( causes blood effects)
11112-Trichloro-carcinogenicity 0.0003
ethane (causes cancer)
Trichloro-carcinogenicity 0.0017
eth~lene (TCE} ( causes cancer)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
51
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
NA 0.07 NA
NA 0.15 NA
1 x1 o·6 0.003 1x104
(one per
ten
thousand)
NA 0.005 NA
NA 0.2 NA
1 x1 o·6 0.005 2x10·5
(two per
hundred
thousand)
1 x10·6 0.005 3x1 o·6
(three per
million)
12
Item 2.1
April 21, 2020 Item #6 Page 28 of 36
( Continued)
Table 1: Health Risk Categories and Cancer Risk Values for Chemicals
with California Public Health Goals (PHGs)
California
Chemical Health Risk Category1 PHG
(mg/L)2
Trichlorofluoro-accelerated mortality 1.3
methane (increase in early death)
(Freon 11}
11213-Trichloro-carcinogenicity 0.0000007
propane ( causes cancer) (7><1 o·7)
(1,2,3-TCP)
1, 1,2-Trichloro-hepatotoxicity 4
112,2-trifluoro-(harms the liver)
ethane
(Freon 113)
Tritium carcinogenicity 400 pCi/L
( causes cancer)
Uranium carcinogenicity 0.43 pCi/L
(causes cancer)
Vinyl chloride carcinogenicity 0.00005
( causes cancer)
Xylene neurotoxicity 1.8 (single
(affects the senses, isomer or
mood, and motor sum of
control) isomers)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
52
Cancer California Cancer
Risk3 MCL4 Risk at the
at the (mg/L) California
PHG MCL
NA 0.15 NA
1x1 o·6 0.000005 7x'.I0·6
(5x10·6) (seven per
million).
NA 1.2 NA
1x10·6 20,000 5x10-5
pCi/L (five per
hundred
thousand)
1 x1 o-6 20 pCi/L 5x10·5
(five per
hundred
thousand)
1 x1 o-6 0.0005 1x10·5
(one per
hundred
thousand)
NA 1.75 (single NA
isomer or .
sum of
isomers)
13
Item 2.1
April 21, 2020 Item #6 Page 29 of 36
( Continued)
Table 2: Health Risk Categories and Cancer Risk Values for Chemicals
without California Public Health Goals
US EPA Cancer California Cancer
Chemical Health Risk Category1 MCLG2 Risk3 @ MCL4
(mg/L) MCLG (mg/L)
Disinfection byproducts (DBPs)
Chloramines acute toxicity 4s.s NA7 none
( causes irritation)
digestive system toxicity
(harms the stomach)
hematotoxicity
(causes anemia)
Chlorine acute toxicity 4s.s NA none
(causes irritation)
digestive system toxicity
(harms the stomach)
Chlorine dioxide hematotoxicity o.ss,6 NA none
(causes anemia)
neurotoxicity
(harms the nervous
system)
Disinfection byproducts: haloacetic acids (HAAS)
Monochloroacetic general toxicity 0.07 NA none
acid (MCA) ( causes body and organ
weight changes8)
Dichloroacetic carcinogenicity (causes 0 0 none
acid (DCA) cancer)
1 Health risk category based on the US EPA MCLG document or California MCL document
unless otherwise specified.
2 MCLG = maximum contaminant level goal established by US EPA.
Risk@
California
MCL
NA
NA
NA
NA
NA
3 Cancer Risk ::: Upper estimate of excess cancer risk from lifetime exposure. Actual cancer risk
may be lower or zero. 1 x1 o-s means one excess cancer case per million people exposed. ·
4 California MCL ::: maximum contaminant level established by California.
5 Maximum Residual Disinfectant Level Goal, or MRDLG.
6 The federal Maximum Residual Disinfectant Level (MRDL), or highest level of disinfectant
allowed in drinking water, is the same value for this chemical.
7 NA ::: not available.
8 Body weight effects are i;m indicator of general toxicity in animal studies.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
53
14
Item 2.1
April 21, 2020 Item #6 Page 30 of 36
(Continued)
Table 2: Health Risk Categories and Cancer Risk Values for Chemicals
without California Public Health Goals
US EPA
Chemical Health Risk Category1 MCLG2
(mg/L)
Trichloroacetic hepatotoxicity 0.02
acid (TCA) (harms the liver)
Monobromoacetic NA none
acid (MBA)
Dibromoacetic NA none
acid (OBA)
Total haloacetic general toxicity, none
acids (sum of hepatotoxicity and
MCA, OCA, TCA, carcinogenicity (causes
MBA, and OBA) body and organ weight
changes, harms the liver
and causes cancer)
Disinfection byproducts: trihalo.methanes (THMs)
Bromodichloro-carcinogenicity (causes 0
methane (BOCM) cancer)
Bromoform carcinogenicity (causes 0
cancer)
Chloroform hepatotoxicity and 0.07
neph rotoxicity
(harms the liver and
kidney)
Dibromo-hepatotoxicity, 0.06
chloromethane nephrotoxicity, and
(OBCM) neurotoxicity
(harms the liver,.kidney,
and nervous system)
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019 · ·
54
Cancer
Risk3 @
MCLG
NA
NA
NA
NA
0
0
NA
NA
California Cancer
MCL4
(mg/L)
none
none
none
0.06
none
none
none
none
Risk@
California
MCL
NA
NA
NA
NA
NA
NA
NA
NA
15
Item 2.1
April 21, 2020 Item #6 Page 31 of 36
. ( Continued)
Table 2: Health Risk Categories and Cancer Risk Values for Chemicals
without California Public Health Goals
US EPA Cancer California Cancer
Chemical Health Risk Category1 MCLG2 Risk3 @ MCL4 Risk@
(mg/L) MCLG (mg/L) California
MCL
.Total carcinogenicity none NA 0.08 NA
trihalomethanes ( causes cancer),
(sum of BDCM, hepatotoxicity,
bromoform, nephrotoxicity, and
chloroform and neurotoxicity
DBCM) (harms the liver, kidney,
and nervous system)
Radionuclides
Gross alpha carcinogenicity O (210po 0 15 pCi/L 10 up to 1x1O-3
particles9 ( causes cancer) included) (includes (for 210Po,
226Ra but the most
not radon potent
and alpha
uranium) emitter
Beta particles and carcinogenicity 0 (21opb 0 50 pGi/L up to 2x1O-3
photon emitters9 ( causes cancer) included) Gudged (for 21opb,
equiv. to 4 the most
mrem/yr) potent
beta-
emitter)
9 MCLs for gross alpha and beta particles are screening standards for a group ofradionuclides.
Corresponding PHGs were not developed for gross alpha and beta particles. See the OEHHA
memoranda discussing the cancer risks at these MCLs at
http://www.oehha.ca.gov/water/reports/grossab.html.
10 pCi/L = picocuries per liter of water.
Office of Environmental Health Hazard Assessment
Water Toxicology Section
February 2019
55
16
Item 2.1
April 21, 2020 Item #6 Page 32 of 36
WATER QUALITY
Report 2018
r EXHIBIT4
(_earls bad
Este informe contiene informacion muy importante sobre su agua potable. Traduzcalo o hable con
alguien que lo entienda bien.
Water provided by the Carlsbad Municipal Water District meets all 2018 State and
Federal drinking water standards. This report provides detailed water quality test
results and explains where Ca rl sbad's water comes from.
Where our water comes from
Municipal Water District
A subsidiary district of the
City of Carlsbad
The Carlsbad Municipal Water District currently imports all of its drinking water. The water supply
begins hundreds of miles away as snow melt or rainfall that flows into rivers. The two main water
sources are the Colorado River, where the water is transported through the Colorado Rive~
Sources
Aqueduct, and Northern California, that brings the water through the California Aqueduct (also known as the State
Water from these sources is treated by the Metropolitan Water District of Southern California at its Lake
Skinner Treatment Plant in Riverside County and by the San Diego County Water Authority. After rigorous
treatment, the water travels through San Diego County Water Authority owned pipelines and is purchased
and distributed by the Carlsbad Municipal Water District to its customers. The Claude"Bud" Lewis Carlsbad
Desalination Plant delivers water to the San Diego County Water Authority, which blends the water with
the region's imported water supply and delivers it to water agencies throughout San Diego County.
We encourage residents and businesses to continue making water conservation a way of
life. For more information on water use rules and recommended conservation measures,
please visit www.carlsbadca.gov/water.
Sources of drinking water (both tap water and bottled water) include oceans, 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.
Drinking water, including bottled water, may reasonably be expected to contain at
least small amounts of some contaminants. The presence of contaminants does not
necessarily indicate that water poses a health risk. More information about contaminants California Aqueduct
and potential health effects can be obtained by calling the U.S. Environmental Protection Agency's Safe Drinking Water Hotline at
800-426-4791.
Contaminants that might be present in source water include:
• Microbial contaminants, such as viruses and bacteria that can come from sewage treatment plants, septic systems, agricultural
livestock operations and wildlife.
• Inorganic contaminants, such as salts and metals, that can be naturally occurring or result from urban storm water runoff,
industrial or domestic wastewater discharges, oil and gas production, mining or farming.
April 21, 2020 Item #6 Page 33 of 36
2018 CARLSBAD WATER QUALITY ANALYSIS
State or PHG
Units Federal (MCLG) Skinner Twin Oaks CMWD Carlsbad
Parameter MCL [MRDL] State Range Average Plant Plant System Desai Plant Major Sources In Drinking Water
[MRDL] DLR Effulent Samples
Ranoe 0-84 NA NA NA
Percent State Project Water % NA NA NA Averaae 34 NA NA NA --.-I •-1 ,. ., ,.
CLARITY
Combined Filter NTU TT;1 I Hiohest I 0.08 I 0.01-0.02 I NA I 0,15 I
Effluent Turbiditv/at % TT lat NA NA % s 0.3 I 100% 100% I NA I 98.0% I Soil runoff
MICROBIOLOGICAL
I Ranoe I NA I ND I NA I ND I
Total Coliform Bacteria (b) % 5.0 MCLG;0 NA Average NA ND NA ND Naturally present in the environment
E.coli (c) NA TT MCLG;0 NA Positive sample NA I 0 0 0 Human and animal fecal waste
INORGANIC CHEMICALS
Range ND NA NA ND Natural deposits erosion, glass and
Arsenic ppb 10 0.004 2 Averaae ND 3 NA ND electronics, production wastes
No.>AL NA 0 0 0 Internal corrosion of household pipes natural
2018 Copper Samples ppm AL; 1.3 0.3 0.05 90%ile NA ND 0.13 ND deposits erosion
Control Range NA 0.6-1.2 NA NA
Fluoride (f) Ootimal Fluoride Level NA 0.7 NA NA
Range 0.6-0.9 0.6-0.9 NA 0.60-0.83 Erosion of natural deposits
Treatment-related Fluoride ppm 2.0 1 0.1 water additive that promotes strong teeth
Average 0.7 0.7 NA 0.72
No.>AL 0 0 0 0
2018 Lead Samples ppb 15 ppb 0.2 5 House pipes internal corrosion; erosion of
90%ile ND ND 0.0013 ND natural deposits
Runoff and leaching from fertilizer use,
Nitrate ppm 10 10 0.4 Ranae ND ND-0.6 NA ND septic tank and sewage; natural deposits
Averaae ND 0.4 NA ND erosion
RADIOLOGICALS
Range ND-3 NA NA ND
Uranium pCi/L 20 0.43 1 I Averaae I ND I 2.2 I NA I ND I Erosion of natural deposits
DISINFECTION BY-PRODUCTS, DISINFECTANT RESIDUALS, AND DISINFECTION BY-PRODUCT PRECURSORS {o)
Total Trihalomethanes (g) (TTHM) ppb 80 NA 1.0 Ranae 15-35 22-35 12-19 ND By-product of drinking water chlorination
Hiohest LRAA 24 30 16 ND
Haloacetic Acids (HAAS) ppb 60 NA 1,0 Ranae 1.2-18 ND-7 2.4-5 ND By-product of <::,rinking water chlorination
Highest LRAA 8.6 4.0 3.8 ND
Total Chlorine Residual ppm [4.01 [4.0] NA Ranae NA 1.3-3.4 2.6-3.0 1.8-3.4 Drinking water disinfectant added for
Hiqhest RAA NA 3.1 2.8 3.10 treatment
Ranae ND-5.9 1-15 NA NA
Bromate (d) ppb 10 0.1 1.0 Hiohest RAA 3.7 5.0 NA NA By-product of drinking water ozonation •i.•••·· • •· ... •· •r:i••
Range 90-93 NA NA 55.2-118 Runoff leaching from natural deposits
Chloride ppm 500 NA NA Average 92 90 NA 73.7 seawater influence
Range ND-1 ND NA ND
Color Units 15 NA NA Average ND ND NA ND Naturally-occurring organic materials
Odor Threshold TON 3 NA 1 Range 3 ND NA ND-1
Averaae 3 ND NA ND Naturally-occurring organic materials
Range 841-851 NA NA 304-599.8 Substances that form ions in water seawater
Specific Conductance µSiem 1600 NA NA influence Average 846 810 NA 418.40
Sulfate ppm 500 NA 0.5 Ranae 168-175 NA NA 8.5-17.2 Runoff leaching from natural deposits
Averaae 172 160 NA 12.2 Industrial wastes
Total Dissolved Solids (TDS) ppm 1000 NA NA Ranoe 510-526 NA NA 119.333 Runoff leaching from natural deposits
Averaoe 51 8 510 NA 21 7,0 seawater influence .......... ' ... "=-
CHEMICAL
Ranae 104-109 NA NA 42-80
Alkalinity ppm NA NA NA Samele 106 110 NA 63.4
Boron ppb NL;1.000 NA 100 Range 120 NA NA 0.37-0.92 Runoff leaching from natural deposits,
Averaae 120 130 NA 0.61 Industrial wastes
Ranae 54-58 NA NA 17.4-35
Calcium ppm NA NA NA Sample 56 55 NA 22.8
Range 43 160-290 NA NA By-product of drinking water chlorination
Chlorate ppb NL;800 NA 20 Averaae 43 219 NA NA Industrial processes
Ranoe ND 0.04-0.17 NA NA Runoff leaching from natural deposits;
Chromium VI (h) ppb 10 0.02 1 Average ND 0.09 NA NA discharge from industrial waste factories
Corrosivity (i) Al NA NA NA Ranae 12.3-12.4 NA NA 11.6-12.3 Elemental balance in water; affected by
(as Aggressiveness Index) Averaae 12.4 12 NA 12.1 temperature, other factors
Corrosivity 0) (as Saturation Index) Range 0.54-0.59 NA NA 0.05-0.53 Elemental balance in water affected by
SI NA NA NA Averaoe 0.56 0.64 NA 0.29 temperature & other factors
Hardness ppm NA NA NA Range 218-238 NA NA 42.2-70.9
Samele 228 220 NA 54
No.>AL NA NA 0 NA
lead Sampling in schools(k) ppm AL;0.015 0.2 5 90%lle NA NA ND NA Internal erosion of natural deposits
Ranae 21-22 NA NA 0.46-1.1
Magnesium ppm NA NA NA Samele 22 20 NA 0.69
Range 8.1-8.2 7.1-8.5 NA 8.01-8.66
pH pH NA NA NA Averaae 8.2 8.2 NA 8.54
Ranae 4-4.5 NA NA 1-3.7
Potassium ppm NA NA NA Sample 4.2 4.0 NA 2.4
Range 85-92 NA NA 16.2-78.4
Sodium ppm NA NA NA Samele 88 82 NA 54.2
Various natural and man-made sources
TOC ppm TT NA 0.30 RanQe 2-2.7 2.1-2.6 NA NA
N-Nitrosodimethylamine (NOMA) Range 4.1 NA NA NA By-product of drinking water ppt NL ; 3 2
10 D.Wide ND-3.2 2 NA NA
April 21, 2020 Item #6 Page 34 of 36
How to read this report
As you read the water quality tables in this report, compare the level of
contaminants found in Carlsbad Municipal Water District's water in the "Skinner
Plant" and "Twin Oaks Valley Plant" columns with the standards set for them in
the MCL and PHG columns. The Carlsbad Municipal Water District met all drinking
water standards in 2018.
The following are key terms to help you understand the standards used to
measure drinking water safety.
Maximum Contaminant Level (MCL) The highest level of a contaminant that is
allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as
is economically and technologically feasible. Secondary MCLs are set to protect
the odor, taste and appearance of drinking water.
Maximum Contaminant Level Goal (MCLG) The level of a contaminant in drinking
water below which there is no known or expected risk to health. MCLGs are set by
the U.S. Environmental Protection Agency.
Public Health Goal (PHG) The level of a contaminant in drinking water below
which there is no known or expected risk to health. PH Gs are set by the California
Environmental Protection Agency.
Maximum Residual Disinfectant Level (MRDL) The highest level of a disinfectant
allowed in drinking water. There is convincing evidence that addition of a
disinfectant is necessary for control of microbial contaminants.
Abbreviations
Al
AL
CDPH
CFE
CFU
DBP
DLR
MCL
MCLG
MFL
MRDL
MRDLG
N
NA
ND
NL
NTU
pCi/L
PHG
ppb
ppm
ppq
ppt
RAA
SI
TOC
TON
TT
µSi em
Aggressiveness Index
Action Level
California Department of Public Health
Combined Filter Effuent
Colony-Forming Units
Disinfection By-Products
Detection Limits for purposes of Reporting
Maximum Contaminant Level
Maximum Contaminant Level Goal
Million Fibers per Liter
Maximum Residual Disinfectant Level
Maximum Residual Disinfectant Level Goal
Nitrogen
Not Applicable
Not Detected
Notification Level
Nephelometric Turbidity Units
picoCuries per Liter
Public Health Goal
parts per billion or micrograms per liter (µg/L)
parts per million or milligrams per liter (mg/L)
parts per quadrillion or picograms per liter (pg/L)
parts per trillion or nanograms per liter (ng/L)
Running Annual Average; highest RAA is the highest of all Running
Annual Averages calculated as average of all the samples collected
within a 12-month period
Saturation Index (Langelier)
Total Organic Carbon
Threshold Odor Number
Treatment Technique is a required process intended to reduce the level
of a contaminant in drinking water
microSiemen per centimeter; or micromho per centimeter (µmho/cm)
Required information for 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.
Carlsbad Municipal Water District is responsible for providing high quality drinking
water, but cannot control the variety of materials used in plumbing components.
When your water has been sitting for several hours, you can minimize the potential
-for lead exposure by flushing your tap for 30 seconds to 2 minutes before using
water for drinking or 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 www.epa.gov/safewater/lead. Carlsbad Municipal
Water District has complied and meets Lead and Copper standards.
Maximum Residual Disinfectant Level
Goal (MRDLG) The 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.
Primary Drinking Water Standard (PDWS)
MCLs and MRDLs for contaminants that
affect health along with their monitoring
and reporting requirements, and water
treatment requirements.
Treatment Technique A required process intended to reduce the level of
a contaminant in drinking water.
Regulatory Action Level The concentration of a contaminant which,if
exceeded, triggers treatment or other requirements that a water system
must follow.
This report can be downloaded from www.carlsbadca.gov/
water-quality-report
Footnotes
(a) (Skinner) As a Primary Standard, the turbidity levels of the filtered
water were s 0.3 NTU in 95% of the online measurements taken
each month and did not exceed 1 NTU for more than one hour.
The turbidity levels for grab samples at these locations were in
compliance with the Secondary Standard. (Twin Oaks) The turbidity
level from the CFE of the membranes shall bes 0.1 NTU in 95% of
the measurements taken each month and shall not exceed 1.0 NTU
at any time. Turbidity, a measure of the cloudiness of water, is an
indicator of treatment performance.
(b) Total coliform MCLs: No more than 5.0% of the monthly samples
may be total coliform positive. Compliance is based on the
combined distribution system sampling. In 2017, 1,560 samples were
analyzed with no positive samples. The MCL was not violated.
(c) E.coli MCL: The occurrence of two consecutive total coliform-
positive samples, one of which contains E.coli, constitutes an acute
MCL violation. The MCL was not violated.
(d) Twin Oaks running annual average was calculated from quarterly
results of monthly and daily samples. Bromate reporting level is
4.2 ppb.
(e) Lead and copper are regulated by Action Levels under the Lead and
Copper Rule, which requires water samples to be collected at the
consumers' tap. If action levels are exceeded in more than
10% of the samples, water systems must take steps to reduce these
contaminants.
(f) Skinner and Twin Oaks were in compliance with all provisions of the
State's Fluoridation System Requirements.
(g) Twin Oaks/Skinner met all provisions of the Stage 1 Disinfectants/
Disinfection By-Products (D/DBP) Rule. Compliance was based on
Locational RAA. Average and range for the treatment plant effuent
were taken from daily and monthly samples for TTHM and HAAS.
(h) Chromium VI reporting level is 0.04 ppb, which is below the state
DLR of 1 ppb.
(i) Al <10.0 = Highly aggressive and very corrosive water. Al ;:,:12.0 =
Non-aggressive water. Al (0.14 -13.0) = Moderately aggressive
water.
(j) Positive 51 index= non-corrosive; tendency to precipitate and/or
deposit scale on pipes. Negative 51 index= corrosive; tendency to
dissolve calcium carbonate.
(k) A total of 8 schools submitted requests to be sampled for lead.
Five samples were collected at each school. Additional information
on this subject can be found at http://www.waterboards.ca.gov/
drinking_water/certlic/drinkingwater/leadsamplinginschools.shtml
April 21, 2020 Item #6 Page 35 of 36
Sources continued
• Pesticides and herbicides, that
can come from a variety of
sources such as agriculture,
urban stormwater runoff and
residential uses.
• Organic chemical contaminants,
including synthetic and
volatile organic chemicals, that
are byproducts of industrial
Colorado River
processes and petroleum production, and can also come from gas stations,
urban stormwater runoff, agricultural application and septic systems.
• Radioactive contaminants, that can be naturally occurring or be the result of oil
and gas production and mining activities.
Drinking water regulations
To ensure tap water is safe to drink, the U.S. Environmental Protection Agency
and the State Water Resou rces Control Board set regulations that limit the
amount of certain contaminants in water provided by public water systems. State
Water Resources Control Board regulations also establish limits for contaminants
in bottled water that must provide the same protection for public health.
Special note:
Some people might be more vulnerable to contaminants in drinking water
than the general population. lmmuno-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
persons, and infants can be particularly at
risk from infections. These people should
seek advice about drinking water from their
health care providers. U.S. Environmental
Protection Agency/Centers for Disease
Some people might
be more vulnerable to
contaminants in drinking
w ater than the general
population.
Control guidelines on appropriate means to lessen the risk of infection by
cryptosporidium and other microbial contaminants are available from the Safe
Drinking Water Hotline at 800-426-4791.
Source water assessment and protection
The Metropolitan Water District of Southern California completed the one
time source water assessment required by the USEPA in December 2002.*
Colorado River supplies are
considered to be most vulnerable
to contamination from recreation,
urban/stormwater runoff, increasing
urbanization in the watershed and
wastewater. State Water Project
supplies are considered to be
most vulnerable to contamination
from urban/stormwater runoff,
wildlife, agriculture, recreation and
wastewater. A summary of the assessment can be obtained by calling the
Metropolitan Water District at 213-217-6850.
Metropolitan's most recent watershed sanitary surveys were completed in March (Colorado River)
and June 2012 (State Water Project). These reports are required by the SWRCB every five years.
How to contact us
This report covers testing for contaminants in
2018. For questions or concerns regarding the
quality of Carlsbad's drinking water, contact
the Carlsbad Municipal Water District at
760-438-2722 or email water@carlsbadca.gov.
To participate in decisions that
affect drinking water in the
Carlsbad Municipal Water District
service area, please watch the
Carlsbad Municipal Water District
Board of Directors meeting agenda
for drinking water items. Carlsbad
Municipal Water District
Board meetings are
held in conjunction
with the Carlsbad City Council on an as
needed basis on Tuesday evenings. Agendas
may be obtained at www.carlsbadca.gov
or Carlsbad City Hall, 1200 Carlsbad Village
Drive. Comments regarding drinking water are
always welcome.
This report can be downloaded from
www.carl sbadca.gov/water-quality-report.
Carlsbad Municipal Water District
5950 El Camino Real, Carlsbad, CA 92008
Hours: Monday through Friday, 8 a.m. to 5 p.m.
760-438-2722 • water@carlsbadca.gov
Additional sources for water quality
information:
San Diego County Water Authority
858-522-6600 • www.sdcwa.org
Metropolitan Water District of Southern
California
800-CALL-MWD (225-5693)
www.mwdh2o.com
State Water Resources Control Board
Division of Drinking Water & Environmental
Management
619-525-4159 • www.waterboardsca.gov
U.S. Environmental Protection Agency
Office of Ground Water & Drinking Water
Safe Drinking Water Hotline 800-426-4791
www.epa.gov/safewater/hfacts.html
Ccarlsbad
Municipal Water District
A subsidiary district of the
City of Carlsbad
April 21, 2020 Item #6 Page 36 of 36
Mark Biskup, Municipal Project Manger
April 21, 2020
Carlsbad Municipal Water District
2019 Triennial Report on Water Quality
Relative to Public Health Goals (PHGs)
Recommended Action
1)Adopt a Resolution of the Board of Directors of the Carlsbad Municipal Water District approving the Carlsbad Municipal Water District 2019 Triennial Report on Water Quality Relative to Public Health Goals.
2)Hold a public hearing to receive public comments on the
CMWD 2019 Triennial Report on Water Quality Relative
to Public Health Goals.
CMWD Purchases Treated Water
from San Diego County Water Authority
•The Metropolitan Water District (MWD)
–Lake Skinner water treatment plant in Southern Riverside County
•The San Diego County Water Authority (SDCWA)
–Twin Oaks Valley water treatment plant in San Marcos
•The Claude ”Bud” Lewis Carlsbad Desalination Plant
–privately owned and operated, and sourced by SDCWA
Intent of Triennial Public Health Goal Report on Water Quality
•Provide information to the public
Relative to Goals not Regulations
California H & S Code Section 116470(b)
Public Water Systems
>10,000 service connections are required to prepare a
report every three years for contaminants that exceed
•Public Health Goals “PHGs” (State)
•Maximum Contaminant Level Goals (Federal)
Triennial PHG Report Includes:
•Identifies each contaminant that exceed the Public Health Goals.
•Identifies the category of risk
•Numerical risk
•Cost estimate and BAT reduce contaminant levels
•Recommended Action
Constituents that exceeded a “Goal”
Constituent Units MCL PHG
(MCLG)
Range
Arsenic ppb 10 0.004 ND - 2.4
Uranium pC/L 20 0.43 ND - 2.9
Bromate ppb 10 0.1 2.6 - 6.0
Chromium VI Ppb 10 0.02 ND - 0.09
NDMA ppt *NL=10 3 ND – 6.5
•Best Available Technology (BAT) is Revers Osmosis (RO)
•Accurate costs not available
–$23 million/ year for treatment ONLY
–Additional costs to maintain system
–Additional costs to build a treatment plant and associated facilities
•CMWD has no existing treatment plant,
Treatment Options and Costs
Drinking Water provided by CMWD
meets all Federal & State Regulations
and Mandates
No action is recommended
Recommended Action
1)Adopt a Resolution of the Board of Directors of the
Carlsbad Municipal Water District approving the
Carlsbad Municipal Water District 2019 Triennial Report
on Water Quality Relative to Public Health Goals.
2)Hold a public hearing to receive public comments on the CMWD 2019 Triennial Report on Water Quality Relative to Public Health Goals.
Questions and Comments
Arsenic
•Result of natural or human causes
•Risk per OEHHA (state) and USEPA
–PHG is 0.004 ppb for 1 cancer case/ 1M people
–MCL is 10 ppb for 2.5 cancer case/ 1,000 people
•CMWD Water is Non Detect to 3.4 ppb
Uranium
•Radiological constituents come from decay and erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation, photons and beta radiation. Natural Causes.
•Risk per OEHHA and USEPA
–PHG is 0.43 pCi/L for 1 cancer case/ 1M people
–MCL is 20 pCi/L for five cancer cases/ 100,000 people
•CMWD Water is Non Detect to 2.9 pCi/L
Bromate
•Bromate is a byproduct of water disinfection and occurs when bromide in the water reacts with the ozone disinfectant
•Risk per OEHHA and USEPA
–PHG is 0.1 ppb for one cancer case/ 1M people
–MCL is 10 ppb for one cancer case /10,000 people
•CMWD Water is 2.6 to 6 ppb
Chromium VI
•Hexavalent Chromium (chromium VI) occurs in natural waters in the environment from the erosion of chromium deposits found in rocks and soils. Also produced by industrial processes and manufacturing activities including discharges from steel and pulp mills, among others. It can also be released to the environment via improper storage and disposal practices.
•Risk per OEHHA and USEPA
–PHG is 0.02 ppb for one cancer case/ 1M people
–MCL is 10 ppb for one cancer case /50,000 people
•CMWD Water is Non-detect to 0.09 ppb
NDMA (N-Nitrosodimethylamine)
•NDMA is a chemical formed in both industrial and natural processes. It is a byproduct of chlorination at wastewater treatment plants that use chloramines for disinfection. NDMA was also formerly used in the production of rocket fuel, antioxidants, and softeners for copolymers
•Risk per CADPH and USEPA
–PHG is 3 ppt for one cancer case/ 1M people
–No MCL, just a Notification Level is 10 ppt for one cancer case /100,000 people
•CMWD Water is Non-detect to 6.7 ppt
Regulations:
•Federal and State Mandates
•Maximum Contaminant Level (MCLs)
•Regulatory definition of what is “safe”
Enforceable Regulation
Water Quality Reports (Annual vs Triennial)
•Every Year in July, Annual Water Quality Reports are published
•California Health and Safety Code also requires a PHGs Report every three years
•2010 –2012 was published in 2013. This year, 2019 PHGs Report combines 2013 through 2018
https://www.carlsbadca.gov/services/depts/pw/utils/water/quality.asp
U111111esHome
Water
Recycling& Trash
Seawater
Desalination
WaterConserval10fl
Voeo,
Contact Us
••. •1 II
Water Quality
Home , • Utllittes , Water • Quaflty
We current~ import all of our drinking water supply. Imported water origmates hundreds of
miles away from the Colorado River through the Colorado River Aqueduct, and from Northern
California through the California Aqueduct (also known as the State Water Pro1ect). Water from
these sources is imported and treated by the Metropolitan Water Distnct of Southern Cahfornia
at 1ts lake Skinner Treatment Plant in RlverSlde County and the San Diego County Water
Authonty at its lwm Oaks Valley Water Treatment Plant m San Marcos.
After ngorous treatment and meetmg all regulatory requirements, the water travels through
San Diego County Waler Aulhonty owned ~pelmes and II purchased and d111nbuted by the
0 Carlsbad Municipal Water D1stnct to its customers. Each year, the water d1strKt delivers
dnnkmg waler 10 near~ 86,000 people through 447 miles of ~pelmes.
Trash Schedule ' ~
• Tnenmal Report on Water Duality Relatrye to PublK Health Goals
Environmental Management • Waterd1$tnctsseMn~
• FluorKlallOn • the crty receives fluoridated water from the Metropohtan Water District.
Fluoride concentration ranges from Ol to 0.4 parts per million .
• fm!ill!on.R[Q9rams for children
Ccarlsbad
Municipal Water District
Annual Water Quality Report / Annual Water Quality Report
WATER QUALITY
Report 2018
Water provided by the Carlsbad Municipal Water District meets all 2018 State and
Federal drinking water standards. This report provides detailed water quality test
results and explains where Carlsbad's water comes from.
Where our water comes from
~ EXHBIT4
(Carlsbad
Municipal Water District
Asubsldlarydlstrictofthe Ci1yof(arl~ad
. .
.
The Carlsbad Munkipal Water District currently imporu all of its drinking water. The water supply
begins hundreds of miles away as snow melt or rainfall that flows into rivers. The two main water
sources are the Colorado River, where the water is transported through the Colorado River I".-.;
.
Aqueduct, and Northern California, that brings the water through the California Aqueduct (also known as the State
Water from these sources is treated by the Metropolitan Water District of Southern California at its Lake
Skinner Treatment Plant in Riverside County and by the San Diego County Water Authority. After rigorous
treatment, the water travels through San Diego County Water Authority owned pipelines and is purchased
and distributed by the Carlsbad Municipal Water District to its customers. The Claude"Bud"Lewls Carlsbad
Desalination Plant delivers water to the San Diego County Water Authority, which blends the water with
the region's imported water supply and delivers it to water agencies throughout San Diego County.
Sources
We encourage residents and businesses to continue making water conservation a way of
life. For more information on water use rules and recommended conservation measures,
please visit www.carlsbadca.gov/water
Sources of drinking water (both tap water and bottled water) include oceans, 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.
Drinking water, including bottled water, may reasonably be expected to contain at
least small amounts of some contaminants. The presence of contaminants does not
necessarily Indicate that water poses a health risk. More Information about contaminants California Aqueduct
and potential health effects can be obtained by calling the U.S. Environmental Protection Agency's Safe Drinking Water Hotline at
800-426-4791.
Contaminants that might be present in source water include:
• Microbial contaminants, such as viruses and bacteria that can come from sewage treatment plants, septic systems, agricultural
livestock operations and wildlife.
• Inorganic contaminants, such as salts and metals, that can be naturally occurring or result from urban storm water runoff,
industrial or domestic wastewater discharges, oil and gas production, mining or farming.
2018 CARLSBAD WATER QUALITY ANALYSIS
Chn>ntumVl(n)
C•roolOltrll) (uA•roooi,,.n,■ool••l
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.....H llill'"•lnt•-1-;,,,,;•••""'"' •••r•l••-110
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pe,L 20 0.43 1 AV<1ra o NO 2.2 NA NO E'°"ionofnaturaldcposito
OISNFECTION BY-PROOUCTS,OISINFECTANT RESIDUALS ANO DISINFECTION BY-PRODUCT PRECURSORS o
Notu,on, rringorganicmo""1ol•
WO Watu,ally--,..;,,g .... nicr'll■loOOl■I•
NA -~II.I auN1■ that!••·•· -•--1• >---c---+~--+-=-+-~1--==---
A .. ,... 110 0 .•
P't, .. o 0.M ... 11 NA
■1.....,iuotof•·•k ... w1tor0hloO!lln,■toa 1 ...... , •• _,_
ll••--•-n1f-a•-••-·t■ ··-■ ... , ........... .,.1_ ...... .
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Ccarlsbad
Municipal Water District
True for both PHGs and MCLGs
•They are non-enforceable
•Most times significantly lower than the MCLs
•The recommended BAT to reach such low
levels are designed to reduce contaminants
below MCLs and not proven to reliably reach
the lower PHG levels.
Public Hearing
•Summarize the 2019 Triennial Report on Water
Quality Relative to Public Health Goals
•Respond to public comment
What are PHGs and MCLGs?Goals –Not Enforceable Mandates
•Public Health Goal (PHG)
•Concentration of contaminants that pose no significant
health risk if consumed for a lifetime (OEHHA)
•Maximum Contaminant Level Goal (MCLG)
•The level of a contaminant where there is no known or
expected risk to health. (USEPA)