Water containing wastes – aka wastewater – from residential,
commercial and industrial processes requires treatment to remove
pollutants prior to discharge. After treatment, the water is
suitable for nonconsumption (nonpotable) and even potable use.
In California, water recycling is a critical component of the
state’s efforts to use water supplies more efficiently. The state
presently recycling about 669,000 acre-feet of water per year and
has the potential to reuse an additional two million acre-feet
per year.
Non-potable uses include:
landscape and crop irrigation
stream and wetlands enhancement
industrial processes
recreational lakes, fountains and decorative ponds
toilet flushing and gray water applications
as a barrier to protect groundwater supplies
from seawater intrusion
wetland habitat creation, restoration, and maintenance
Wastewater plants emit about twice as much greenhouse gas as
previously believed, according to Princeton engineers who used
a mobile lab to check plants across the country. In an
article published Oct. 8 in the journal Nature Water, a
research team led by professors Mark Zondlo and Z. Jason Ren,
in collaboration with Prof. Francesca Hopkins of UC-Riverside,
reported that collectively sewer plants produced 1.9 times the
nitrous oxide gas estimated by the Environmental Protection
Agency and 2.4 times the methane. Based on the new
measurements, wastewater plants contribute 2.5 percent of U.S.
methane emissions and 8.1 percent of nitrous oxide.
For more than two decades, small-scale farmers and community
gardeners have grown fresh fruits and vegetables, native
plants, flowers and other produce at the Tijuana
River Valley Community Garden, a 20-acre complex of
publicly owned farmland adjacent to the Tijuana River.
… All of that came to a halt last week when
representatives from the Resource Conservation District of
Greater San Diego County, which manages the garden, issued mass
eviction notices to all 217 community gardeners and
farmers. One reason for the sudden eviction, the
district’s executive director said, was a series of pollution
warning signs erected six weeks ago at several locations
throughout the river valley, including at the garden itself.
San Diego County’s largest community garden, the Tijuana River
Valley Community Garden, is set to close after more than two
decades, displacing hundreds of local gardeners and small
farmers. The Resource Conservation District of Greater San
Diego County has decided to end its lease to operate the
garden, citing ongoing concerns with sewage
issues and potential flooding. This decision
will return the site to the county, leaving the future of the
garden uncertain.
… The city [Palo Alto] broke ground in September on Bay
Area’s first horizontal levee, a gently sloped expanse next to
the Regional Water Quality Control Plant that officials hope to
finish by next spring. Once completed, landscaped levee will
incline from the tide toward Embarcadero Road. The area will be
filled with marsh plants that will be treated with treated
wastewater from the wastewater plant through an underground
pipe. The levee will serve as yet another filtering system for
the effluent as it goes from the treatment plant to the Bay.
… The shutdown may result in regulatory delays that included
new or pending permits, guidance documents and approvals.
State-submitted programs like NPDES permits and TMDLS won’t be
acted on during shutdowns. … Routine EPA inspections for
drinking water systems, wastewater facilities or stormwater
compliance are paused until a funding bill is passed.
Enforcement only continues if it is tied to imminent threats to
human health or property. No new EPA grants for water
infrastructure upgrades, stormwater resilience or research
partnerships will be awarded during the shutdown.
Baja California has launched a landmark water regeneration
project designed to treat and reuse up to 720L/s of wastewater,
aiming to boost water security, reduce reliance on the Colorado
River, and strengthen binational cooperation with the United
States. … The initiative is part of the agreements under
the Minute 328 for the Sanitation of the Tijuana River.
… The plan includes the rehabilitation of the Ing.
Arturo Herrera and La Morita Wastewater Treatment Plants
(WWTPs), as well as the construction of a conveyance system to
channel treated water into a tributary leading to the Abelardo
L. Rodríguez Dam.
After more than five years of construction, San Mateo’s
upgraded Wastewater Treatment Plant was unveiled in a
ribbon-cutting ceremony. It is the largest infrastructure
project in San Mateo’s history, and developers say it’s one of
the most sustainable wastewater treatment facilities in the
country. … The plant is part of San Mateo’s $1 billion
Clean Water Program, an initiative that was launched in 2015 in
response to a cease and desist order the city received
mandating sewer system improvements to prevent overflow into
the San Francisco Bay.
The Town of Windsor has reached a major milestone: 100% of
the community’s wastewater is now recycled and reused. …
[B]ecause the storage is now jointly managed [with Sonoma
Water], Windsor avoids having to discharge wastewater into Mark
West Creek and the Russian River Basin. Instead, they now
provide fully treated recycled water for irrigation of parks,
public spaces and golf courses, as well as water for power
generation at the Geysers.
As the San Diego City Council prepares to make major water rate
hikes, city staff clearly want weary councilmembers to blame
the San Diego County Water Authority and not the wastewater
recycling project the city is building. … On Friday,
city Public Utilities staff released a new cost analysis that
showed how Pure Water, a multi-billion-dollar wastewater
recycling project, could produce cheaper water than what the
San Diego County Water Authority provides. The city’s new Pure
Water numbers are the latest jab at the Water Authority over
growing water prices.
South Platte Renew, which serves 300,000 customers in both
Littleton and Englewood, has transformed wastewater treatment
into a success story in renewable energy. … The team at
South Platte Renew considered how to capture the methane gas
and reuse it, eventually proposing a biogas pipeline injection
system in 2019. It was approved, and the $7.8 million price tag
was paid for through sewer funds from Englewood and Littleton.
It was the first of its kind system in the state of Colorado.
… South Platte Renew has now helped other water
treatment facilities in the state get their systems up and
running.
Located on the shore of Harbor Marsh in the Palo Alto Baylands,
the Palo Alto Horizontal Levee Pilot Project is the first
horizontal levee to be built in the San Francisco Bay that
beneficially reuses treated wastewater for irrigation.
Construction began in September 2025. … A horizontal levee is
a nature-based solution that provides many benefits over
traditional levees. Their unique designs have a wide gentle
slope which helps a marsh adapt as sea level rises. This one
will also use treated wastewater to restore a native habitat on
its slope. The process will further filter pollutants out of
the treated wastewater.
A new pilot project to clean the Tijuana River using ozone
nanobubbles has sparked concerns from a UC San Diego researcher
who believes the experimental technology could pose health
risks to South Bay residents. The International Boundary and
Water Commission launched the 60-day project on Monday, testing
whether tiny ozone bubbles can help clean the polluted
waterway. However, Dr. Kimberly Prather from UC San Diego is
raising red flags about the untested approach. … [S]he
warns that when they pop, the ozone gas gets released into the
air, potentially putting more South Bay residents at risk.
California voters approved Proposition 4 last year. It will
yield $10 billion to pay for environmental projects and
programs. Of that total, $50 million is earmarked to spend on
water quality projects in the polluted Tijuana River. … San
Diego Supervisor Paloma Aguirre flew to Sacramento to ask the
State Water Resources Control Board on Tuesday for the full $50
million. … But Calexico Mayor Diana Nuricumbo said that
her city is relying on its share of the $50 million to pay for
upgrades to its wastewater treatment plant, which
processes and cleans wastewater before discharging it into the
New River.
A historic East Bay company that generated the foul stench of
sewage odor, polluting a town’s air, has settled a lawsuit with
Contra Costa County prosecutors for approximately $500,000,
authorities said Tuesday. C&H Sugar, whose plant has been a
staple in the unincorporated city of Crockett since 1906,
committed the odor violations in 2022 at a
wastewater treatment plant it jointly owns on
Dowrelio Drive, according to a statement from the Contra Costa
County District Attorney’s Office. They added that the company
agreed to pay $400,000 in civil penalties and $100,000 in
costs.
On Wednesday, the Tahoe City Public Utility District celebrated
the Grand Opening of the West Lake Tahoe Regional Water
Treatment Plant. … The plant can currently deliver one
million gallons of water per day and may be further expanded to
reach more customers from Tahoma to Timberland. The utility
district stated that the approximately $30 million project was
made possible by grant funding as well as a loan from the CA
State Water Resources Control Board.
Recently elected San Diego County Supervisor Paloma Aguirre
took office in July promising to wield the full powers of her
new job against the sewage crisis in the Tijuana
River. … Aguirre plans to ask the county to begin work
immediately on two region-wide studies approved by the Board in
June. … She also will ask the Board to spend roughly $100,000
to hire a new lobbyist to educate federal lawmakers about the
extent of sewage pollution in South County and build support
for a comprehensive bi-national cleanup effort.
Over the holiday weekend, many people looking to cool off from
the summer heat were disappointed as some beaches were closed
or authorities advised against swimming because of unsafe
levels of bacteria. The advisories and closures popped up
across the East Coast, from Florida to Maine, along inland
streams and rivers, and throughout the California coast. The
culprit: fecal contamination detected in the water that
presents a risk of illness. … Experts told USA TODAY
that stormwater runoff and sewage overflows were among the most
likely causes, both of which are exacerbated by heavy rains,
flooding and warming temperatures.
The U.S. Environmental Protection Agency (EPA) and the U.S.
International Boundary and Water Commission (USIBWC) announced
the completion of a 10 million-gallon-per-day expansion at the
South Bay International Wastewater Treatment Plant (SBIWTP) in
San Diego. The project boosts the facility’s capacity from 25
to 35 mgd, a 40% increase aimed at reducing cross-border sewage
flows from Tijuana into the Tijuana River Valley. Originally
planned as a two-year project, the expansion was completed in
just 100 days.
On Aug. 30, Environmental Protection Agency (EPA) Administrator
Lee Zeldin signed a final action that withdrew proposed
revisions to the EPA’s Meat and Poultry Products Effluent
Limitations Guidelines (ELG) for wastewater discharged by meat
and poultry processing and rendering facilities. The
agency determined that existing federal wastewater regulations
under the Clean Water Act are effective compared to the
proposed changes. Zeldin stated in his remarks how withdrawing
the proposed revisions would advance the Trump Administration’s
effort to lower food costs for American families and farmers.
Cities across California and the Southwest are significantly
increasing and diversifying their use of recycled wastewater as
traditional water supplies grow tighter.
The 5th edition of our Layperson’s Guide to Water Recycling
covers the latest trends and statistics on water reuse as a
strategic defense against prolonged drought and climate change.
Momentum is building for a unique
interstate deal that aims to transform wastewater from Southern
California homes and business into relief for the stressed
Colorado River. The collaborative effort to add resiliency to a
river suffering from overuse, drought and climate change is being
shaped across state lines by some of the West’s largest water
agencies.
Martha Guzman recalls those awful
days working on water and other issues as a deputy legislative
secretary for then-Gov. Jerry Brown. California was mired in a
recession and the state’s finances were deep in the red. Parks
were cut, schools were cut, programs were cut to try to balance a
troubled state budget in what she remembers as “that terrible
time.”
She now finds herself in a strikingly different position: As
administrator of the U.S. Environmental Protection Agency’s
Region 9, she has a mandate to address water challenges across
California, Nevada, Arizona and Hawaii and $1 billion to help pay
for it. It is the kind of funding, she said, that is usually
spread out over a decade. Guzman called it the “absolutely
greatest opportunity.”
Innovative efforts to accelerate
restoration of headwater forests and to improve a river for the
benefit of both farmers and fish. Hard-earned lessons for water
agencies from a string of devastating California wildfires.
Efforts to drought-proof a chronically water-short region of
California. And a broad debate surrounding how best to address
persistent challenges facing the Colorado River.
These were among the issues Western Water explored in
2019, and are still worth taking a look at in case you missed
them.
The southern part of California’s Central Coast from San Luis Obispo County to Ventura County, home to about 1.5 million people, is blessed with a pleasing Mediterranean climate and a picturesque terrain. Yet while its unique geography abounds in beauty, the area perpetually struggles with drought.
Indeed, while the rest of California breathed a sigh of relief with the return of wet weather after the severe drought of 2012–2016, places such as Santa Barbara still grappled with dry conditions.
Blasted by sun and beaten by waves,
plastic bottles and bags shed fibers and tiny flecks of
microplastic debris that litter the San Francisco Bay where they
can choke the marine life that inadvertently consumes it.
Summer is a good time to take a
break, relax and enjoy some of the great beaches, waterways and
watersheds around California and the West. We hope you’re getting
a chance to do plenty of that this July.
But in the weekly sprint through work, it’s easy to miss
some interesting nuggets you might want to read. So while we’re
taking a publishing break to work on other water articles planned
for later this year, we want to help you catch up on
Western Water stories from the first half of this year
that you might have missed.
Each day, people living on the streets and camping along waterways across California face the same struggle – finding clean drinking water and a place to wash and go to the bathroom.
Some find friendly businesses willing to help, or public restrooms and drinking water fountains. Yet for many homeless people, accessing the water and sanitation that most people take for granted remains a daily struggle.
Californians have been doing an
exceptional job
reducing their indoor water use, helping the state survive
the most recent drought when water districts were required to
meet conservation targets. With more droughts inevitable,
Californians are likely to face even greater calls to save water
in the future.
For the bulk of her career, Jayne
Harkins has devoted her energy to issues associated with the
management of the Colorado River, both with the U.S. Bureau of
Reclamation and with the Colorado River Commission of Nevada.
Now her career is taking a different direction. Harkins, 58, was
appointed by President Trump last August to take the helm of the
United States section of the U.S.-Mexico agency that oversees
myriad water matters between the two countries as they seek to
sustainably manage the supply and water quality of the Colorado
River, including its once-thriving Delta in Mexico, and other
rivers the two countries share. She is the first woman to be
named the U.S. Commissioner of the International Boundary and
Water Commission for either the United States or Mexico in the
commission’s 129-year history.
Although Santa Monica may be the most aggressive Southern California water provider to wean itself from imported supplies, it is hardly the only one looking to remake its water portfolio.
In Los Angeles, a city of about 4 million people, efforts are underway to dramatically slash purchases of imported water while boosting the amount from recycling, stormwater capture, groundwater cleanup and conservation. Mayor Eric Garcetti in 2014 announced a plan to reduce the city’s purchase of imported water from Metropolitan Water District by one-half by 2025 and to provide one-half of the city’s supply from local sources by 2035. (The city considers its Eastern Sierra supplies as imported water.)
Imported water from the Sierra
Nevada and the Colorado River built Southern California. Yet as
drought, climate change and environmental concerns render those
supplies increasingly at risk, the Southland’s cities have ramped
up their efforts to rely more on local sources and less on
imported water.
Far and away the most ambitious goal has been set by the city of
Santa Monica, which in 2014 embarked on a course to be virtually
water independent through local sources by 2023. In the 1990s,
Santa Monica was completely dependent on imported water. Now, it
derives more than 70 percent of its water locally.
In rural areas with widely dispersed houses, reliance upon a
centralized
sewer system is not practical compared to individual
wastewater treatment methods. These on-site management facilities
– or septic systems – are more commonplace given their simpler
structure, efficiency and easy maintenance.
Microplastics – plastic debris
measuring less than 5 millimeters – are an
increasing water quality concern. They enter waterways and
oceans as industrial microbeads from various consumer
products or larger plastic litter that degrades into small bits.
Microbeads have been used in exfoliating agents, cosmetic washes
and large-scale cleaning processes. Microplastics are used
pharmaceutically for efficient drug delivery to affected sites in
patients’ bodies and by textile companies to create artificial
fibers.
Microplastics disperse easily and widely throughout surface waters and sediments. UV
light, microbes and erosion degrade the tiny fragments, making
them even smaller and more difficult for wastewater treatment
plants to remove.
The particles, usually made of polyethylene or polypropylene
plastic, take thousands of years to biodegrade
naturally. It takes prohibitively high temperatures to
break microplastics down fully. Consequently, most water treatment plants cannot remove
them.
The health effects of consumption are currently under
investigation.
Responses
Many advocacy groups have published lists of products containing
microbeads to curb their purchase and pollution.
The U.S. Environmental Protection Agency regulates microbeads in
industrial, but not domestic, wastewater.
Federal
law required microbeads to be phased out of rinse-off
cosmetics beginning in July 2017. Dozens of states also
regulate microbeads in products. California has the strictest
limitation, prohibiting even the use of biodegradable microbeads.
Microplastics in California Water
In 2019, the San Francisco Estuary Institute published a
study estimating that 7 trillion pieces of microplastic
enter San Francisco
Bay annually from stormwater runoff, about 300
times the amount in all wastewater treatment effluent entering
the bay.
California lawmakers in 2018 passed a package of bills to raise
awareness of the risks of microplastics and microfibers in the
marine environment and drinking water. As
directed by the legislation, the State Water Resources Control
Board in 2020 adopted an official
definition of microplastics in drinking water and in 2022
developed the world’s standardized methods for testing drinking
water for microplastics.
The water board was expected by late 2023 to begin testing
for microplastics in untreated drinking water sources tapped by
30 of the state’s largest water utilities. After two years, the
testing was expected to extend to treated tap water served
to consumers. A progress report and recommendations for
policy changes or additional research are required by the end of
2025.
Directly detecting harmful pathogens in water can be expensive,
unreliable and incredibly complicated. Fortunately, certain
organisms are known to consistently coexist with these harmful
microbes which are substantially easier to detect and culture:
coliform bacteria. These generally non-toxic organisms are
frequently used as “indicator
species,” or organisms whose presence demonstrates a
particular feature of its surrounding environment.
The biochemical oxygen demand (BOD) of water determines the
impact of decaying matter on species in a specific ecosystem.
Sampling for BOD tests how much oxygen is needed by bacteria to
break down the organic matter.
Point sources release pollutants from discrete conveyances, such
as a discharge pipe, and are regulated by federal and state
agencies. The main point source dischargers are factories and
sewage treatment plants, which release treated
wastewater.
This 30-minute documentary-style DVD on the history and current
state of the San Joaquin River Restoration Program includes an
overview of the geography and history of the river, historical
and current water delivery and uses, the genesis and timeline of
the 1988 lawsuit, how the settlement was reached and what was
agreed to.
This 25-minute documentary-style DVD, developed in partnership
with the California Department of Water Resources, provides an
excellent overview of climate change and how it is already
affecting California. The DVD also explains what scientists
anticipate in the future related to sea level rise and
precipitation/runoff changes and explores the efforts that are
underway to plan and adapt to climate.
Many Californians don’t realize that when they turn on the
faucet, the water that flows out could come from a source close
to home or one hundreds of miles away. Most people take their
water for granted; not thinking about the elaborate systems and
testing that go into delivering clean, plentiful water to
households throughout the state. Where drinking water comes from,
how it’s treated, and what people can do to protect its quality
are highlighted in this 2007 PBS documentary narrated by actress
Wendie Malick.
A 30-minute version of the 2007 PBS documentary Drinking Water:
Quenching the Public Thirst. This DVD is ideal for showing at
community forums and speaking engagements to help the public
understand the complex issues surrounding the elaborate systems
and testing that go into delivering clean, plentiful water to
households throughout the state.
The 28-page Layperson’s Guide to California
Wastewater is an in-depth, easy-to-understand publication
that provides background information on the history of wastewater
treatment and how wastewater is collected, conveyed, treated and
disposed of today. The guide also offers case studies of
different treatment plants and their treatment processes.
The 24-page Layperson’s Guide to the Delta explores the competing
uses and demands on California’s Sacramento-San Joaquin Delta.
Included in the guide are sections on the history of the Delta,
its role in the state’s water system, and its many complex issues
with sections on water quality, levees, salinity and agricultural
drainage, fish and wildlife, and water distribution.
Wastewater management in California centers on the collection,
conveyance,
treatment, reuse and disposal of wastewater. This process is
conducted largely by public agencies, though there are also
private systems in places where a publicly owned treatment plant
is not feasible.
In California, wastewater treatment takes place through 100,000
miles of sanitary sewer lines and at more than 900 wastewater
treatment plants that manage the roughly 4 billion gallons of
wastewater generated in the state each day.
