Posts Tagged: water
Report: Wastewater recycling essential to resilient water future for LA region
Wastewater recycling in Los Angeles is the focus of a new report released by the UCLA Luskin Center for Innovation and the UC Agriculture and Natural Resources. The report, Making the Most of Landmark Recycled Water Investments in Los Angeles: Technical Advisory Recommendations for the Region, was commissioned by Los Angeles Waterkeeper. The goal of the report is to support ongoing efforts to improve local water security and rely less on expensive, energy-intensive and increasingly unreliable water imports from faraway places, like the Sacramento-San Joaquin Delta and the Colorado River.
Experts involved in developing the report agree that expanding the use of recycled wastewater has emerged as a key, scalable water supply strategy that can offer certainty and reliability in the region in light of our new climate reality.
“Both the Metropolitan Water District of Southern California and the City of LA's Department of Water and Power have made significant investments in wastewater recycling, and they plan to do more,” said Bruce Reznik, executive director of LA Waterkeeper. “But there are a lot of moving parts and some critical decisions to be made in the short term if we're going to make significant progress toward reliable local water supplies.”
“The purpose of this report is to help decisionmakers see the full picture so they can prioritize and develop informed strategies for expanding and integrating the disparate wastewater recycling projects into a more cohesive wastewater system – all while taking community voices and environmental impacts into account,” he added.
Local leaders recognize the region must further invest in equitable, climate-smart, affordable local water strategies. LA County's Water Plan, released in late 2023, calls for 80% of water to come from local sources by 2045 (compared with approximately 40% currently). Four major centralized wastewater recycling projects, including two that are landmark in size and scope, have either broken ground or are in the active planning stages throughout Los Angeles County. Collectively, this regional effort may represent the most important water supply investment in the American West in the last half century.
“In many ways, our region has taken great strides toward embracing wastewater recycling,” said report co-author Edith B. de Guzman, UC Cooperative Extension water equity and adaptation policy specialist. “But we need a clearer pathway for how these projects can be built and possibly integrated into a more cohesive system. This report provides a blueprint for water agencies on the project design, community engagement and governance steps that must be made to ensure progress toward rapidly increasing our local water independence.”
Upwards of $20 billion in investment in wastewater recycling projects is planned for the coming years. But as local water and wastewater agencies make these investments, it's essential that they design systems to both maximize benefits and minimize impacts that could be damaging to people and the environment, all while ensuring water remains affordable. Just as importantly, the report flagged the need to effectively engage the public in key decisions to foster public trust in these emerging water technologies and facilitate coordination between agencies to create a resilient regional water supply system.
Specific action items identified in the report are organized under eight principal recommendations:
- Take actionable steps on current key decision points pertaining to major recycling facilities. The report encourages agencies to make several decisions that will impact the design of the overall wastewater recycling systems imminently. These include resolving differences between the City of LA's Hyperion 2035 and Operation NEXT efforts, deciding whether to upgrade existing wastewater recycling infrastructure like the Edward C. Little Water Recycling Facility, and making key pipeline and routing decisions.
- Conduct a more nuanced regional analysis of system facilities, with an emphasis on evaluating distributed alternatives. While some assessment of a more distributed system has been undertaken, additional analysis is still needed on the issues of energy demand, the cost of distributing water under different alternatives, and impacts on aquatic and marine ecosystems.
- Identify and establish a structure for collaborative governance that enables agencies to work together to realize a regional advanced wastewater recycling network.
- Adopt a coordinated monitoring plan to ensure water quality is safeguarded for public and ecological health.
- Balance the adoption of Indirect Potable Reuse (IPR) and Direct Potable Reuse (DPR) with a near-term focus on IPR to the extent feasible and using DPR to fill in service gaps.
- Perform robust regional forecast and impact analyses to improve future-proofing of facility and network designs, maximize benefits, minimize harm, and avoid stranded assets.
- Design and execute a collaborative communication and community engagement strategy that offers a clear narrative, emphasizes the benefits of a secure water supply, meets the needs of water customers, and is delivered by trusted messengers.
- Coordinate across agencies on strategies to attract project financing while taking household affordability into account.
“This report is by no means the final word,” said co-author Gregory Pierce, research and co-executive director at UCLA Luskin Center for Innovation. “The point of this study is to provide guidance and spur discussion, and we hope and expect to see ongoing research and coordination on all of these issues.”
The report was informed by input from a Technical Advisory Committee of 20 people from fields including academia and think tanks, conservation advocacy, labor, the private sector, and current and former water district leaders not affiliated with the projects that are the focus of the report. This effort also benefited from the feedback and insight of more than 20 public agency representatives, including many from the City of Los Angeles (including Los Angeles Department of Water and Power and LA Sanitation and Environment), Metropolitan Water District of Southern California, Los Angeles County Sanitation Districts, Las Virgenes Municipal Water District, and West Basin Municipal Water District.
The full report is available at https://innovation.luskin.ucla.edu/wp-content/uploads/2024/06/Making-the-Most-of-Landmark-Recycled-Water-Investments-in-LA.pdf.
The Water Girls
If you're struggling with triple-digit temperatures, think about the honey bees. They need to...
A honey bee, its proboscis extended, collects water from the edges of a birdbath. (Photo by Kathy Keatley Garvey)
For worker bees: Two's company, three's a crowd, and four is a work party. Bees collecting water from a birdbath. (Photo by Kathy Keatley Garvey)
'The Water Girls'--six of them--collecting water at a Vacaville birdbath. Note the absence of birds. (Photo by Kathy Keatley Garvey)
A honey bee heading back to her colony after collecting water to cool down the hive. (Photo by Kathy Keatley Garvey)
Patterns and drivers of water-wise landscaping for urban water conservation
Front yard with water-wise landscaping. Photo Credit: Cadenasso Lab, UC Davis
California's urban water agencies have long relied on conservation measures to promote reliability and manage costs. Since landscapes are a large portion of water demand in California cities, many water agencies encourage water conservation by incentivizing the replacement of water-intensive turf lawns with water-efficient or “water-wise” landscaping.
In California's Mediterranean climate, traditional turfgrass lawns require irrigation to maintain their appearance through the hot summer months. Inefficient, poorly managed spray irrigation systems can also result in considerable water loss from runoff and evaporation. Replacing turf and overhead sprinklers with low-water-use plants, alternative ground covers like mulch and kurapia, and more efficient drip irrigation systems can potentially save hundreds of gallons of water per square meter every year.
Although the water savings from turf replacement can be substantial, generating widespread buy-in is a challenge. Landscape renovation can be expensive and intimidating, requiring residents to learn new landscape management practices or pay for professional assistance. In addition, many people appreciate their lawns as spaces for children, pets, or entertainment. Some prefer the look of turfgrass, especially where neighborhood norms promote a unified lawn aesthetic.
To help overcome cost barriers and encourage water-wise landscaping, government agencies and water suppliers commonly offer “cash for grass” programs, in which residents are offered a rebate for landscaping expenses based on the amount of turf they replace. These programs also aim to promote neighborhood adoption of water-wise landscaping by providing attractive examples. Turf replacement incentive programs are likely to expand under proposed new water use efficiency regulations, Making Conservation a California Way of Life (AB1668 - SB606).
While large-scale, regional turf replacement programs in Southern California have been evaluated in peer-reviewed studies, questions remain about the extent and impact of these programs in other parts of the state. How widely are turf replacement programs utilized, and by whom? Are these programs responsible for a substantial amount of water-wise landscaping?
Water-wise landscaping in Sacramento
With these questions in mind, we wanted to understand how both rebate recipients and houses with independently installed water-wise landscaping were distributed across an entire city in inland Northern California. The study was recently published in the Journal of Urban Ecology.
We visually surveyed the front yards of all single-family homes in 100 census tracts across the city of Sacramento—109,062 homes in total—and compared the prevalence of water-wise landscaping with the city's turf replacement rebate data. We especially wanted to understand how this landscape water conservation measure was being adopted by communities of varying socioeconomic and demographic characteristics, and which communities were benefitting from the rebate program.
Front yard with traditional turf. Photo Credit: Cadenasso Lab, UC Davis
In Sacramento, the City's Department of Utilities has offered a rebate of (typically) $1.50 per square foot of turf removed since the summer of 2014. To qualify for the rebate, replacement landscapes must meet several criteria, including efficient irrigation systems and approved plants that cover more than half of the area at maturity. The planting requirement addresses an important concern with turf replacement—the potential for an increase in urban heat. Lawns have a cooling effect through evapotranspiration, and if they are replaced primarily with non-living groundcovers, temperatures could increase. However, such program requirements can make some residents reluctant to participate.
When we conducted our visual survey of front yards in 2018, we found that approximately 10% of Sacramento's single-family-homes had water-wise yards, while 88% had conventional lawns. Only around 3% of water-wise yards were rebate recipients, though, meaning that the vast majority—97%—of water-wise yards were landscaped independently from the city's rebate program. We also found support for neighborhood adoption effects, with clustering of water-wise yards at the city block scale.
The prevalence of independent water-wise yards should be good news for water conservation, since it would not be feasible for the city to fund many thousands of turf replacement projects. However, independent turf replacement projects don't need to comply with the city's requirements for plant coverage or irrigation system efficiency, meaning that they could be contributing to increased urban temperatures or failing to save water.
Our study also showed that water-wise landscaping was more common in census tracts with less diverse, more highly educated, and more affluent populations, as well as fewer households with children. Rebate recipients followed the same trends, suggesting that rebates weren't overcoming barriers to adoption. The uneven distribution of resources necessary for turf replacement—money, time, and information—is likely an important driver of this pattern, along with cultural or functional preferences for lawns. Lawns may play a particularly important role for families as spaces for children to play.
Photo Credit: Cadenasso Lab, UC Davis
A Tool in the Toolbox
Turf replacement is one important tool in the water conservation toolbox, and our research suggests that many residents voluntarily install water-wise landscapes even without a rebate. However, adoption is not equal across communities. The roots of this disparity likely reflect uneven distributions of resources and preferences.
With thoughtful program design and outreach, incentive programs could help overcome some of these barriers, although funding and staffing limitations in water agencies pose a challenge for implementation. For instance, carefully crafted direct installation programs could reach lower-income residents who find it difficult to pay up-front costs associated with rebates. Tailoring efforts to the needs of lower-income and marginalized communities will be important to ensure that they do not end up with unirrigated, high-heat landscapes instead of attractive, water-wise yards.
In the Sacramento region, focus groups conducted for the Regional Water Authority revealed that some residents have a very strong preference for lawns. In these cases, water suppliers may have greater impact by promoting efficient irrigation practices, turfgrass varieties that use less water, and climate-appropriate shade trees. Partial lawn conversions are also a viable water-saving strategy, and one that Sacramento's rebate program supports.
As California's cities grapple with climate change, water reliability, cost effectiveness, and meeting new water use efficiency standards, reducing high-water-use turf lawns will continue to be an important adaptation strategy. Figuring out how to support effective and equitable landscape water conservation programs must be a focus of future research and evaluation studies to promote a California where everyone benefits from climate adaptation measures.
Joanna Solins is an Environmental Horticulture Advisor with UC Cooperative Extension, serving Sacramento, Solano, and Yolo Counties, and is an Affiliate Researcher with the California Institute for Water Resources and the UC Davis Department of Plant Sciences.
Acknowledgments: Many thanks to Erik Porse, Amy Talbot, Jasmin Green, and Mary Cadenasso for their input and assistance with this post.
Additional Reading
Green, J. C., Solins, J. P., Brissette, L. E. G., Benning, T. L., Gould, K., Bell, E. M., & Cadenasso, M. L. (2024). Patterns of water-wise residential landscaping in a drought-prone city. Journal of Urban Ecology, 10(1), juae003. https://doi.org/10.1093/jue/juae003
Alliance for Water Efficiency. (2019). Landscape transformation: Assessment of water utility programs and market readiness evaluation. https://www.allianceforwaterefficiency.org/impact/our-work/landscape-transformation-assessment-water-utility-programs-and-market-readiness
Matlock, M., Whipple, R., & Shaw, R. (2019). Just for the turf of it: Turf replacement as a water conservation tool. Journal of Soil and Water Conservation, 74(5), 449–455. https://doi.org/10.2489/jswc.74.5.449
Pincetl, S., Gillespie, T. W., Pataki, D. E., Porse, E., Jia, S., Kidera, E., Nobles, N., Rodriguez, J., & Choi, D. (2019). Evaluating the effects of turf-replacement programs in Los Angeles. Landscape and Urban Planning, 185, 210–221. https://doi.org/10.1016/j.landurbplan.2019.01.011
Simpson, S.-A., Altschuld, C., Ortiz, A., & Aravena, M. (2023). Green to gold mile: An environmental justice analysis of drought and mitigation policy impacts on home landscapes in Sacramento California. Landscape and Urban Planning, 234, 104729. https://doi.org/10.1016/j.landurbplan.2023.104729
Young orchard water and nutrient management workshops offered in Modesto, Merced, Fresno, Bakersfield
Growers invited to discuss young almonds, pistachios, walnuts, olives and citrus orchards starting May 9
To help growers manage irrigation and nutrients for young and immature orchards, UC Cooperative Extension is offering workshops in Modesto, Merced, Fresno and Bakersfield.
The workshops will feature presentations by various experts and researchers focusing on best irrigation and nutrient management practices tailored specifically for young orchards in the San Joaquin Valley. They will cover almonds, pistachios, walnuts, olives and citrus.
“Attendees will gain insights into the irrigation and nutrient needs of young orchards, which are different from those applicable to mature orchards, and learn strategies for adjusting these practices as orchards mature,” said Moneim Mohamed, UC Cooperative Extension irrigation and soils advisor for Stanislaus, San Joaquin and Merced counties. “This knowledge aims to ensure healthier tree development, better resource use and more resilient orchards in the face of climate change.”
Growers, certified crop advisers and other agricultural professionals are encouraged to attend. Workshop attendees may request one-on-one assistance from a UCCE farm advisor.
Speakers include UCCE advisors Mohamed, Mae Culumber, Tobias Oker, and Cameron Zuber, UCCE specialist Giulia Marino, Andre Daccache of UC Davis, Charles Hillyer and Shawn Ashkan of Fresno State.
The Young Orchard Irrigation and Nutrient Management workshops will be held in four locations:
May 9 (8 a.m.–12:30 p.m.)
UC Cooperative Extension, Room HI, 3800 Cornucopia Way
Register at https://ucanr.edu/orchardsmodesto
Merced
May 14 (8 a.m.–12:30 p.m.)
UC Cooperative Extension, 2145 Wardrobe Avenue
Register at https://ucanr.edu/orcharsmerced
Fresno
May 22 (8 a.m.–12:30 p.m.)
Fresno State, 5370 N. Chestnut M/S OF 18
Register at https://ucanr.edu/orchardsfresno
Bakersfield
June 5 (8 a.m.–12:30 p.m.)
UC Cooperative Extension, 1031 South Mount Vernon Avenue
Register at https://ucanr.edu/orchardsbakersfield
Workshops are free and include coffee breaks, lunch, workshop materials along with the presentations. Registration is required.
These workshops are supported by a grant from California Department of Food and Agriculture and sponsored by Almond Board of California, California Pistachio Research Board, WiseConn Engineering and Irrometer Company, Inc.
Sewage to Sustenance
Senior Public Information Officer
- UC Riverside,Plant materials that would otherwise become trash may be the key to solving two big problems: diminishing freshwater supplies for farms and diminishing effectiveness of antibiotics.
On average, agriculture accounts for 70% of global freshwater use. In California, which produces nearly half of all U.S.-grown fruits, nuts, and vegetables, that number rises to 80%.
The United Nations estimates food production will need to double by 2050. However, water supplies will not increase accordingly. Instead, due to climate change and drought, water resources are quickly shrinking.
One solution to the increasing need for farm water is to use treated municipal wastewater. There are roughly 16,000 wastewater treatment plants in the U.S., each of them capable of processing up to 10 million gallons every day.
“It's a huge amount of processed water that's mostly clean and can be used again, but there's a problem,” said Ananda Bhattacharjee, assistant project scientist at the U.S. Department of Agriculture's Salinity Laboratory, based at UC Riverside.
“This water can contain chemicals of emerging concern, like antibiotics, that are difficult to detect and treat without advanced and expensive instrumentation,” he said. “These instruments also require trained laboratory personnel to operate and maintain.”
Once exposed to the antibiotics in the water supply, soil bacteria immediately start developing resistance to the drugs because they want to survive. “Bacteria are amazing biological sensors,” he said. As the bacteria develop resistance, antibiotics stop working.
Once crops are irrigated with contaminated reclaimed water, plants that get harvested and come to our dinner tables may contain residual antibiotics, resistance genes, and resistant bacteria.
To correct this issue, Bhattacharjee is leading a new, $1 million project testing a low-cost technology to make the reclaimed water safer for agricultural re-use. Funded by the USDA's Agriculture and Food Research Initiative, the project will test how effectively biochar made from various types of discarded plant materials can “polish” the water.
Biochar is a charcoal-like substance made by burning organic material. Burning any organic matter, even wood chips, in limited-oxygen environments retains the mass of the burned substance. The remaining, charred substance is highly absorbent.
“It's like activated charcoal used in HEPA filters and HVAC systems. Biochar works on the same principal; it adsorbs chemicals present in reclaimed water and allows only clean water to pass through,” Bhattacharjee said.
Based on this principle, Daniel Ashworth, a soil scientist at the Salinity Laboratory, first built a bench-scale filtration system with biochar for the removal of antibiotics in synthetic wastewater. The results were very promising, with antibiotics removal efficiency of up to 98%.
“Encouraged by Dr. Ashworth's experiments, we will be designing the larger-scale biochar-based polishing systems for removing residual antibiotics in reclaimed water,” Bhattacharjee said.
Using biochar polishers could potentially remove the need to detect the antibiotics in reclaimed water, assisting treatment plants that do not have advanced detection or treatment technologies, and cannot afford them.
Affordability is one of the best features of the biochar system. “As engineers, we try to keep it simple. If we can build something for a dime, we don't want to have to spend a dollar,” Bhattacharjee said.
For this project, scientists from UC Riverside, the U.S. Department of Agriculture, US Salinity Laboratory, and the University of California's Agriculture and Natural Resources are teaming up to test biochar made from multiple kinds of plant materials left over from agricultural field production.
To start, they'll collect treated sewage sludge and plant materials such as pistachio shells and date palm leaves which would otherwise be thrown away. These materials will be turned into biochar for designing filtration systems that reclaimed water can pass through.
Ultimately, the team would like to develop a database of different, inexpensive biochar materials that can all be used for removing harmful compounds from reclaimed water for agricultural reuse, especially crop irrigation.
If the costs remain low and effectiveness remains high, the research team hopes growers will install biochar-based reclaimed water polishing systems on their farms. “That is the major goal of the project, taking this from bench scale to full field scale,” Bhattacharjee said.
Right now, the whole ecology of fields is changing due to residual antibiotics in irrigation systems. The reclaimed water gets into the soil, earthworms feed on organic matter in the soil, and they develop antibiotic resistance in their guts. Then they may release this resistance through their feces, making additional changes to soil microflora, which keeps the cycle of resistance going.
“We are slowly spiking our own agricultural fields with this resistance,” Bhattacharjee said. “Demonstrating this issue was our first project, Bacteria Wars: episode one. Now we have a technique to remove the antibiotics and resistant bacteria, reducing the antimicrobial resistance spread in agriculture. This is our episode two: Researchers Strike Back.”
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