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Who is the Metropolitan Water District of SoCal...and why should you care?
Metropolitan Water District of Southern California
http://www.mwdh2o.com/
NOTES taken from the November 200r Regional Urban Water Management Plan published by the MWDof SC
Coverage Area: Counties of Los Angeles, Orange, Riverside, San Bernardino, San Diego and Venturea
Population: 20,971,000 in the area: in MWD service area: (87%)
18,143,000
Population Growth: Population growth slowed
during the early 1990s to just over 50,000 in
1995, before again rising to more than
300,000 per year in the period 1999 through
2002. Growth has continued at just under
300,000 since that time.
Trends in Southern California
Population
Population is a key indicator of regional
growth. In the mid-1990s, population
growth in Metropolitan’s service area
slowed during the recession, which
disproportionately affected Southern
California. An estimated 400,000 jobs were
lost between 1990 and 1995, reducing
Metropolitan’s average population growth
to less than 150,000 people per year. During
the economic recovery from 1995 to 2000,
average population growth rebounded to
230,000 people annually. Since 2000,
population within Metropolitan’s service
area has grown to over 275,000 per year on
average, approaching the boom levels of
the 1980s. According to recent growth
forecasts, population growth in
Metropolitan’s service area will average just
over 150,000 people per year, increasing
from an estimated 18.2 million in 2005 to
22.0 million in 2030.
Within Metropolitan’s service area,
employment growth will not occur at the
same rate across the six counties. Over the
25-year period between 2005 and 2030, the
greatest employment increases are
expected to occur in Los Angeles County,
with over one million additional jobs
expected. Relative to existing employment,
Riverside and San Bernardino counties are
expected to have the highest percent
increases at 96 and 55 percent respectively,
followed by Ventura County at 44 percent.
Residential Water Use
Although single family homes account for
about 55 percent of the total occupied
housing stock, they account for about
70 percent of total residential water
demands. This variation occurs because
single-family households tend to use more
water than households living in multifamily
structures (such as duplexes, triplexes,
apartment buildings) on a per housing-unit
basis. Single family households tend to
have more persons living in the household;
they are likely to have more water-using
appliances and fixtures; and they tend to
have more landscaping per home.
Commercial, Industrial and Institutional
Water Use
CII water use represents about 25 percent
of the total M&I demands in Metropolitan's
service area. The CII (nonresidential) sector
represents water that is used by businesses,
services, government, institutions (such as
hospitals and schools), and industrial (or
manufacturing) establishments. Within the
commercial/institutional category, the top
water users include schools, hospitals,
hotels, amusement parks, colleges,
laundries, and restaurants. In Southern
California, the major industrial users include
electronics, aircraft, petroleum refining,
beverages, food processing, and other
industries that use water as a major
component of the manufacturing process.
These new population projections are lower
than prior estimates. The 1996 IRP
projection reached nearly 22 million by
2020, and the IRP Update projection
reaches about 21.4 million by that time.
More conservative projections of
employment growth and lowered estimates
of future birth rates are partly responsible for
the lower growth projections. Another
factor is the 2000 Census, which provided
population counts 0.48 million lower than
the best estimates from the DOF for the six
counties containing Metropolitan’s service
area.
The most populated cities within
Metropolitan's service area are Los Angeles
(largest city in the state), San Diego
(second largest in the state), Long Beach,
Anaheim, Santa Ana and Riverside.
Local Water Supplies
Local sources of water available to the
region include surface water, groundwater,
and recycled water. Some of the major river
systems in Southern California have been
developed into systems of dams, flood
control channels, and percolation ponds for
supplying local water and recharging
groundwater basins.
Groundwater sources account for about
90 percent of the natural local water
supplies, which are found in many basins
throughout the Southern California region.
Local surface water resources consist of
runoff captured in storage reservoirs and
diversions from streams. Reservoirs hold the
runoff for later direct use, and diversions
from streams are delivered directly to local
water systems.
Water recycling projects involve treating
wastewater to a level that is acceptable
and safe for many nonpotable
applications. This resource is providing an
increasing level of local water.
Drought
The fluctuation in
water supplies that occurred during this
1975-2004 period is the result of a number of
factors. California experienced an
extended drought during this period, which
was particularly severe in 1991 and 1992.
The long duration of this drought, which
began in 1987, resulted in a decline in local
supplies over the period due primarily to a
reduction in groundwater availability. In
addition, shortages in SWP supplies in 1991
and 1992 resulted in significant efforts to
increase water conservation activities and,
for part of that time, the imposition of water
rationing.
Major Challenges: In its role as supplemental supplier to the
Southern California water community,
Metropolitan faces ongoing challenges in
meeting the region’s needs for water supply
reliability and quality. Increased
environmental regulations and competition
for water from outside the region have
resulted in changes in delivery patterns and
timing of availability of imported water
supplies. At the same time, the Colorado
River basin has experienced a five-year
drought that is unprecedented in recorded
history, while total water demand continues
to rise within the region because of
population and economic growth.
Guiding Principles: WSDM Plan Principles and Goals
The guiding principle of the WSDM plan is to
manage Metropolitan’s water resources and
management programs to maximize
management of wet year supplies and
minimize adverse impacts of water shortages
to retail customers. From this guiding principle
came the following supporting principles:
• Encourage efficient water use and
economical local resource programs.
• Coordinate operations with member
agencies to make as much surplus water
as possible available for use in dry years.
• Pursue innovative transfer and banking
programs to secure more imported water
for use in dry years.
Increase public awareness about water
supply issues.
The WSDM plan also declared that if
mandatory import water allocations be
necessary, they would be calculated on the
basis of need, as opposed to any type of
historical purchases.
Public Participation: Because of the diverse needs, interests, and
institutional entities within the region,
goals will only be achieved through an open
and participatory process that involves the
major stakeholders. Public process reached
out to water managers, policy decisionmakers,
interest groups, and individuals. They
provided valuable input and guidance
regarding the preferred water resource
strategy and carefully reviewed the technical
analyses supporting the decision-making
process. The 1996 IRP and the IRP Update
contain details of the public participation.
Participants represented
organizations ranging from the Sierra Club,
the Mono Lake Committee and The Nature
Conservancy, to the Building Industry
Association and the Southern California
Water Committee, to agencies such as the
Los Angeles Department of Water and Power,
the San Diego County Water Authority, Mojave Water Agency, and
theSouthern California
Water Dialogue.
The Metropolitan Water District of
Southern California
Formation and Purpose
The Metropolitan Water District of Southern
California (Metropolitan) is a public agency
organized in 1928 by a vote of the
electorates of 13 Southern California cities.
The agency was enabled by the adoption
of the original Metropolitan Water District
Act (Metropolitan Act) by the California
Legislature "for the purpose of developing,
storing, and distributing water" to the
residents of Southern California. The
Metropolitan Act also allows Metropolitan
to sell additional water, if available, for
other beneficial uses. In 1992, the
Metropolitan Board of Directors adopted
the following mission statement: "to provide
its service area with adequate and reliable
supplies of high-quality water to meet
present and future needs in an
environmentally and economically
responsible way."
The first function of Metropolitan was
building the Colorado River Aqueduct to
convey water from the Colorado River.
Deliveries through the aqueduct began in
the early 1940s and supplemented the local
water supplies of the original Southern
California member cities. In 1960, to meet
growing water demands in its service area,
Metropolitan contracted for additional
water supplies from the State Water Project
(SWP) via the California Aqueduct, which is
owned and operated by the DWR. SWP
deliveries began in 1972. Metropolitan
currently receives imported water from both
of these sources: (1) the Colorado River
water via the Colorado River Aqueduct and
(2) the SWP.
Where does our water come from in Southern California?
Groundwater
The groundwater basins that underlie the
region provide approximately 90 percent of
the local water supply in Southern
California. The major groundwater basins in
the region provide an annual average
supply of approximately 1.41 million acrefeet.
Most of this water recharges naturally,
but approximately 200 taf is replenished
through imported supplies. By 2025,
estimates show that groundwater
production will increase to 1.44 million acrefeet.
Because the groundwater basins contain a
large volume of stored water, it is possible to
produce more than the natural recharge of
1.16 million acre feet and the replenishment
amount for short periods of time. During a
dry year, replenishment deliveries can be
postponed, but doing so requires that the
shortfall be restored in wet years. Similarly,
in dry years the level of the groundwater
basins can be drawn down, as long as the
balance is restored to the natural recharge
level by increasing replenishment in wet
years. Thus, the groundwater basins can
act as a water bank, allowing deposits in
wet years and withdrawals in dry years.
Surface Water
In addition to the groundwater basins, local
agencies maintain surface reservoir
capacity to capture local runoff. The
annual average yield captured from local
watersheds is estimated to average
approximately 100 taf per year. The
majority of this supply comes from reservoirs
within the service area of San Diego County
Water Authority.
Los Angeles Aqueduct
Although the LAA imports water from
outside the region, Metropolitan classifies
water provided by the LAA as a local
resource because it is developed and
imported by a local agency (the Los
Angeles Department of Water and Power).
This resource is estimated to provide
approximately 250 taf per year on average,
which may be reduced to approximately
96 taf during a historical dry period.
Surface Storage: Source Of Supply
Surface storage is a critical element of
Southern California’s water resources
strategy. Because California experiences
dramatic swings in weather and hydrology,
surface storage is important to regulate
those swings and mitigate possible supply
shortages. Surface storage provides a
means of storing water during normal and
wet years for later use during dry years,
when imported supplies are limited. Since
the early twentieth century the Department
of Water Resources and Metropolitan have
constructed surface water reservoirs to
meet emergency, drought/seasonal and
regulatory water needs for Southern
California. These reservoirs include Pyramid
Lake, Castaic Lake, Elderberry Forebay,
Silverwood Lake, Lake Perris, Lake Skinner,
Lake Mathews, Live Oak Reservoir, Garvey
Reservoir, Palos Verdes Reservoir, Orange
County Reservoir and Metropolitan’s
recently completed Diamond Valley Lake.
PROGRAMS
Conservation Credits Program
Metropolitan’s Conservation Credits Program
(CCP) provides the basis for financial
incentives and funding for urban BMP and
other demand management related
activities. Established in 1988, this funding
mechanism supports Metropolitan’s
commitment to conservation as a long-term
water management strategy.
The basis of Metropolitan financial support to
member agency conservation efforts is
estimated as the lesser of $154 per acre-foot
of water saved or one-half of the program
cost. In general, CCP funded water
conservation project proposals must:
• Have demonstrable water savings;
• Reduce water demands on
Metropolitan’s system; and
• Be technically sound and require
Metropolitan’s participation to make the
project financially and economically
feasible.
The Regional Supply Unit
Metropolitan staff is responsible for
developing and administering Metropolitan’s
water conservation policies and programs.
Approximately 10 people focus their efforts
on water conservation issues. Staff members
serve as the primary liaisons to Metropolitan’s
member agencies and other pertinent
agencies and organizations.
Metropolitan’s conservation programs focus
on three main areas: residential indoor
programs, landscape programs, and
commercial, industrial and institutional
programs.
Residential Programs
The residential conservation programs consist
of ultra-low-flush toilets (ULFT), high efficiency
clothes washers (HECW), and water-use
efficiency surveys (Surveys). Metropolitan
extended funding to include installing
conserving devices that exceed standards in
new development.
Ultra-Low-Flush Toilet (ULFT) Program
This program addresses BMP 14: conserving
water by replacing older, high water using
toilets (3.5 gallons-per-flush and greater) with
1.6 gallons per flush ULFTs. Metropolitan
began co-funding member agencymanaged
ULFT programs in 1988, and to
date, 25 of Metropolitan’s 26 member
agencies have conducted ULFT programs.
This activity is the largest of Metropolitan’s
conservation programs. Metropolitan funds
ULFT retrofit programs at $60 per ULFT installed.
In August 2002, Metropolitan began funding
dual-flush toilets at $80 per unit installed.
These toilets exceed the current standard of
1.6 gallons per flush and, thus, have higher
water savings than ULFTs.
ULFT programs are implemented through
rebates or distributions. Rebate programs
allow customers to purchase their choice of
ULFT. Distribution programs provide ULFTs to
customers at little or no charge. Rebates and
vouchers typically range in value from $60 to
$75, depending on the managing water
agency’s policy. In both the rebate and
voucher programs, the customer is
responsible for disposing of the old toilet.
Table III-4 shows the total cumulative savings
from ULFT toilets, including all previous
installations. In FY 2003-04, the estimated
savings were 81 taf per year, translating into a
lifetime savings exceeding 1.6 million af.
High Efficiency Clothes Washer Rebate
Program
The installation of high-efficiency clothes
washers (HECWs) is a growing segment in
water conservation. In September 1997, the
California Urban Water Conservation Council
adopted BMP 6 for HECWs, and it approved
revisions in March 2004. The revisions contain
two options for how to credit agencies. The
first option is based on the washer’s “water
factor” (WF), which is a measure of the
amount of water used to wash a standard
load of laundry. Washers with lower water
factors save more water. The first option
awards 1 point for HECWs with water factors
9.5 through 8.6; 2 points for WF 8.5 through
6.1; and 3 points for WF 6 and less. It does not
award points for HECWs with water factors
greater than 9.5. The second method grants
1 point for all washers regardless of the water
factor.
New Development Program
Metropolitan recently adopted incentives for
new developments to install highly efficient
fixtures that exceed current water use
efficiency standards. Other opportunities to
promote the installation of water-efficient
devices in new developments will be
explored with manufacturers, the building
industry, and stakeholders.
Residential outdoor audit program
Metropolitan funds a residential landscape
efficiency program through outdoor audits
and weather-based irrigation controller
rebates. Landscape audits provide customers
with a recommended irrigation schedule and
suggested improvements for irrigation
systems. Installation of weather-based
irrigation controllers (WBICs) is supported
through the coordinated rebate program
described below.
Residential Weather-Based Irrigation
Controller (WBIC) Rebate
Weather-based irrigation controllers are a
rapidly evolving conservation technology. It
entails devices that adjust irrigation schedules
based on rain, temperature, sunlight, soil
moisture, or some combination of indicators.
Metropolitan began funding WBIC incentives
in homes after conducting a pilot study that
evaluated potential savings and ease of use.
The incentive is $65 per WBIC, plus $5.50 per
station over 12 stations for residential sites.
Non-Residential Landscape Water Use
Efficiency Program
Metropolitan has funded large landscape
audits since 1993, retrofit of landscapes with
centralized irrigation controllers since 1998,
and rebates for weather-based irrigation
controllers (WBIC) since 2002.
Measured Water Savings:
Metropolitan
provides incentives to upgrade landscape
irrigation equipment that can provide verified
water savings. In addition, participants may
receive landscape water management
training. A dedicated landscape meter is
required to participate in this pay-forperformance
program component.
Incentives are $115 per acre-foot of verified
saving if Metropolitan provides the training,
and $154 per acre-foot if the agency
provides the training. The incentives continue
to be paid for up to five years or one-half of
the project cost.
Southern California Heritage Landscape
Program
In 2002, Metropolitan launched a public
outreach campaign targeting outdoor water
use. The campaign, coordinated with
participating member agencies, included
funding for the promotion of efficient
residential watering through irrigation
controllers, a watering index to assist in
estimating efficient watering times, and a
native and California-friendly plant program.
Metropolitan expanded these programs in
2003 and 2004 with an extensive media and
outreach campaign and launched a
consumer-oriented outdoor conservation
savings web site.
The landscape program is expected to
reduce summer and fall outdoor water use.
The actual savings rate will be measured, but
will not be included in the IRP Update’s
resource goals. Quantifying the potential
savings is complicated because of possible
overlaps with other programs – some of the
outdoor savings, when measured, may be
confounded with price-induced savings
unless the effort is preceded by a controlled
evaluation study.
Grant funding sources
Calfed
Prop 13 grants
Proposition 13 (The Safe Drinking, Clean
Water, Watershed Protection, and Flood
Protection Act) provided funding for water
conservation.
CPUC (w/CUWCC)
California Public Utilities Commission (CPUC)
Grants
• In 2003, Metropolitan partnered with the
California Urban Water Conservation
Council to use CPUC grant funding to
install 12,000 pre-rinse spray valves in
restaurants
USBR
U.S. Bureau of Reclamation Grants
The following projects received funding from
USBR during 2003:
• California Friendly Landscape pilot for
new homes
• Evaluation of data loggers, devices that
attach to a water meter to provide
precise, unobtrusive water use information
• Metropolitan facilitated grantees with
funding. Funds were granted directly to
applicants for four additional Innovative
Conservation Programs.
Water for the West
Protector del Agua. Development of webbased
classes
Prop 50
Proposition 50 Grant Funds
• Residential High Efficiency Clothes
Washers. Provided funds to increase the
rebate amount– $1.6 million.
• California Friendly Landscape Pilot for new
homes by $423,000
• High Efficiency Toilets – $1 million.
• Protector del Agua. Development of online
classes
Conservation-Related Activities
Speaker’s Bureau
Provides speakers for organizations, service clubs, churches,
business and other community groups and associations. An
estimated 15,000 – 20,000 people attend these presentations
annually.
Community Relations
Organizes and conducts an average of 80 Board of Directorsponsored
inspection trips of Metropolitan’s distribution system
per year for elected officials, community leaders and members
of the public. Approximately 3,000 people learn about
Metropolitan’s conservation and water management policies
and practices each year through these trips.
Additionally, Metropolitan’s education curriculum and program
activities engage an average of 150,000 students per year.
Media and
Publications
Conducts editorial briefings and media field trips; assembles
press packets; prepares and disseminates news releases,
speeches, videos, fact sheets, brochures, articles and editorials
describing Metropolitan’s water management objectives and
programs.
Government
Relations
Provides elected officials, public agencies, businesses and
organizations with information about Metropolitan’s water
management objectives and programs.
School Education Programs
Curriculum modules
Recycling
Local water recycling projects involve
collecting wastewater that is currently
discharged within the service area, treating
that water to a suitable standard for specific
uses, and using that recycled water for nonpotable
uses. This section provides a
description of the water sources that
potentially could be used for recycled water.
Groundwater Recharge
Metropolitan’s service area overlies numerous
groundwater basins, many of which are
overdrafted, and some of which are
threatened by seawater intrusion. Water
agencies along the Los Angeles and Orange
county coastline inject water into the
underlying groundwater basins to create a
barrier against this seawater. A limited
amount of the injected water originates as
captured storm water, but the major part is
recycled, imported, or extracted from deep
wells. Increasing the proportion of recycled
water can free imported water for direct
consumption. Currently, approximately 60 taf
per year of recycled water is “permitted” for
recharge and seawater barrier injection into
the Orange County, Central and West Coast
groundwater basins.
About 30 percent of the recycled water in
Metropolitan’s service area is used for
groundwater replenishment and seawater
barriers.
On average, these and other seawater
barriers recharge approximately 50 taf per
year with imported water or water from
extraction wells.
Irrigation
Currently, about 86 taf per year of recycled
water is used to irrigate golf courses, parks,
schoolyards, cemeteries and greenbelts
throughout Southern California. Using
recycled water for irrigation reduces the
need for imported water during the critical
summer months and in drought situations
when water supplies are most scarce.
Industrial
Industrial users represent a large potential
market for recycled water, particularly in
heavily industrialized areas, such as the cities
of Vernon, Commerce, Industry and the
Wilmington area of Los Angeles. Additionally,
refineries in El Segundo in West Basin MWD’s
service area and in the City of Torrance use
approximately 8 taf per year of recycled
water. Typical industrial uses include cooling
tower makeup water, boiler feed water,
paper manufacturing, carpet dying, and
process water. Industrial users are highdemand,
continuous-flow customers, which
allows greater operational flexibility by
allowing plants to base load operations rather
than contend with seasonal and diurnal flow
variations. Because of these operational
benefits, industrial users reduce the need for
storage and other peak demand facilities
and management.
Live Stream Discharge
A number of
inland plants pump treated effluent into
local streams and rivers. That water is
then used downstream for beneficial uses,
or it flows into the ocean. Some of the
affected rivers (or ephemeral streams)
include:
• Los Angeles River
• Santa Ana River
• Calleguas Creek
• Rio Hondo & San Gabriel Rivers
• Santa Margarita River
Groundwater Recharge
Metropolitan’s service area overlies numerous
groundwater basins, many of which are
overdrafted, and some of which are
threatened by seawater intrusion. Water
agencies along the Los Angeles and Orange
county coastline inject water into the
underlying groundwater basins to create a
barrier against this seawater. A limited
amount of the injected water originates as
captured storm water, but the major part is
recycled, imported, or extracted from deep
wells. Increasing the proportion of recycled
water can free imported water for direct
consumption. Currently, approximately 60 taf
per year of recycled water is “permitted” for
recharge and seawater barrier injection into
the Orange County, Central and West Coast
groundwater basins.
About 30 percent of the recycled water in
Metropolitan’s service area is used for
groundwater replenishment and seawater
barriers.
Seasonal Storage
Production of wastewater at a water
reclamation plant is relatively uniform year
round since indoor residential use does not
vary much from winter to summer. Flows may
be somewhat higher in the winter at the
wastewater reclamation plant from
stormwater inflow into the sewers, but more
than 60 percent of irrigation demand on
recycled water (parks, golf courses, etc.) is in
summer (May through September).
Seawater Desalination
Until recently, seawater desalination has
been considered uneconomical to be
included in the region’s water supply mix.
However, recent breakthroughs in membrane
technology and plant siting strategies have
helped reduce desalination costs, warranting
consideration among alternative resource
options outlined in Metropolitan’s IRP Update.
The IRP Update includes a target of 750 taf
per year of local water production by 2025
that could include up to 150 taf per year of
seawater desalination.
As a first step to implementing this plan,
Metropolitan issued a competitive request for
proposals targeting 50 taf per year of
desalinated seawater. Metropolitan would
provide financial assistance of up to $250 per
acre-foot of desalinated seawater
developed and used within Metropolitan’s
service area for up to 25 years. Five member
agencies submitted proposals for about
142 taf per year of desalinated seawater,
including San Diego County Water Authority,
Long Beach Water Department, Los Angeles
Department of Water and Power, West Basin
Municipal Water District, and the Municipal
Water District of Orange County, which are
expected to come on line by 2010.
Health Issues
Perchlorate:
Ammonium perchlorate is used as a main
component in solid rocket propellant, and it
can also be found in some types of
munitions and fireworks. Ammonium
perchlorate and other perchlorate salts are
readily soluble in water, dissociating into the
perchlorate ion (ClO4-), which is highly
mobile in the groundwater. The perchlorate
ion does not readily interact with the soil
matrix or degrade in the environment.
The primary human health concern related
to perchlorate is its effects on the thyroid.
Perchlorate interferes with the thyroid
gland's ability to produce hormones
required for normal growth and
development. Currently, the California
Department of Health Services (CDHS) has
adopted a notification level of 6 µg/L for
perchlorate and is in the process of
developing a drinking water regulation.
Total Organic Carbon and Bromide
When source water containing high levels
of total organic carbon (TOC) and bromide
is treated with disinfectants such as chlorine
or ozone, disinfection byproducts (DBPs)
form. Studies have shown a link between
certain cancers and DBP exposure. In
addition, some studies have shown an
association between reproductive and
developmental effects and chlorinated
water.
Existing levels of total organic carbon (TOC)
and bromide in Delta water supplies present
challenges for Metropolitan’s ability to
maintain safe drinking water supplies.
Levels of these constituents in SWP water
increase several fold due to agricultural
drainage and seawater intrusion as water
moves through the Delta.
Four other chemicals have been identified
as being of concern in Metropolitan’s water
supplies. These are MTBE, arsenic, radon
and uranium. The following sections detail
the reasons for Metropolitan’s concerns and
the plans for addressing them. Other
emerging contaminants, such as NDMA
and hexavalent chromium, could impact
the region’s water supplies; they have been
identified, but the full extent of problems
associated with them remains uncertain.
MTBE presents a significant problem to local
groundwater basins. Leaking underground
storage tanks and poor fuel-handling
practices at local gas stations may provide
a large source of MTBE. Only one gallon of
gasoline (11% MTBE by volume) is enough to
contaminate about 16.5 million gallons of
water at 5 µg/L. Within Metropolitan's
service area, local groundwater producers
have been forced to close some of their
wells due to MTBE contamination. For
example, the city of Santa Monica lost
about fifty percent of its production wells as
a result of MTBE.
Improved underground storage tank
requirements and monitoring, and the
phase-out of MTBE as a fuel additive, will
probably decrease the likelihood of MTBE
groundwater problems in the future.
However, it is difficult to estimate the
magnitude of the problem when a small
amount of MTBE can contaminate such a
large volume of water.
Radon
U.S. EPA has proposed a radon MCL of
300 picoCuries per liter (pCi/L), with an
alternative standard of 4,000 pCi/L if the
state has an approved Multimedia
Mitigation program to reduce the indoor
radon risk from soil and rocks underneath
homes and buildings. Radon levels in
Metropolitan’s water supplies have been
well below the proposed MCL of
300 pCi/L.11 Where radon is a problem, airstripping
through aeration is the costeffective
treatment option.
Arsenic
The new federal MCL for arsenic in
domestic water supplies is 10 µg/L, with an
effective date of 2006. The standard will
impact both groundwater and surface
water supplies. Metropolitan’s water
supplies have low levels of this contaminant
and will not require treatment changes or
capital investment to comply with this new
standard. However, some investment will
be needed to manage arsenic in the solids
resulting from treatment.
Uranium
A ten-and-a-half-million-ton pile of uranium
mine tailings at Moab, Utah lies 600 feet
from the Colorado River. Rainwater has
been seeping through the pile and
contaminating the local groundwater,
causing a flow of contaminants into the
river. It also has the potential to wash
millions of tons of material containing
uranium into the Colorado River as a result
of a flood or other natural disaster. Public
perception of drinking water safety is a
particular concern with uranium.
The Department of Energy has
agreed to move the tailings, but
remediating the site will require
Congressional appropriations, and
maintaining congressional support for a
cleanup will require close coordination and
cooperation with other Colorado River
users.
Other Emerging Contaminants
A number of other emerging contaminants,
most notably N-nitrosodimethylamine,
chromium VI, and pharmaceutical
products, may also impact groundwater
supplies.
Chromium VI is a possible contaminant in
groundwater and surface water.
Chromium is an inorganic chemical used in
electroplating, leather tanning, wood
treatment, pigments manufacture, and
cooling tower treatment for corrosion
control. Chromium can enter drinking
water sources through discharges from
industries, leaching from hazardous waste
sites, and erosion of natural deposits.
Pharmaceuticals and personal care
products in source water and recycled
water have led to growing expressions of
concern. The extent that these
contaminants are found to require
mitigation may increase the cost of
recycled water and wastewater treatment,
and they may require broad controls on
runoff into source water.
Water Conservation
Water conservation
distinguishes between:
• Code-Based Conservation – Water
saved as a result of changes in water
efficiency requirements for plumbing
fixtures in plumbing codes. Thus, this
form of conservation would occur
without any water agency action.
• Active Conservation – Water saved
directly as a result of conservation
programs by water agencies (includes
implementation of Best Management
Practices.) This form of conservation is
unlikely to occur without agency action.
Price-effect Conservation – Water saved
by retail customers attributable to the
effect of changes in the real (inflationadjusted)
price of water.
Single Family Residential and Multi Family Residential
Explanatory variables:
Climate
Household Size
Income
Price and Conservation
Housing Density
Service Area Location
Commercial, Industrial,
Institutional
Explanatory variables:
Climate
Price and Conservation
Industrial / Service
employment Share
Public Information Program Activities
Paid advertising
Public service announcements
Bill inserts
Newsletters
Brochures
Bill showing water usage in comparison to previous year's usage
Demonstration gardens
Special events
Speakers Bureau
Technical support
ULFT replacement
Residential retrofits
Commercial, industrial and institutional surveys
Residential and large turf irrigation
Conservation-related rates and pricing
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