PROGRAMS

Water Energy

Shasta Lake, the largest manmade reservoir in California.
Shasta Lake, the largest manmade reservoir in California.

The nation’s water and energy resources are inextricably entwined. Significant energy is used by water infrastructure to pump, treat, transport, heat, cool, and recycle water. At the same time, a significant amount of water is also required to produce electricity.

Growing population is increasing the demand for water and the energy needed to deliver and treat it. Meanwhile, climate change threatens to adversely affect existing water resources, demanding new methods of mitigation and adaptation. Without advances in technology, water-related energy use is likely to grow significantly. This growth will be caused by increasing water conveyance and treatment requirements.

With the assistance of its Water-Energy Advisory Committee, the Alliance is exploring opportunities for optimizing the state’s vital water and energy resources on a fully integrated basis and is documenting strategies for water agencies to reduce their own energy use and supply more sustainable water. As part this effort the Alliance issued its study of “The Role of Recycled Water in Energy Efficiency and Greenhouse Gas Reduction” in May 2008. That study concluded that substantial water, energy and environmental benefits were achievable by accelerating development and use of recycled water in Southern California.

To ensure a truly sustainable future for California, we must better understand the water-energy nexus and implement mutually beneficial strategies to improve the sustainable development and use of water and energy resources.

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On-site water recycling holds potential water savings for commercial and municipal buildings.
On-Site Water Recycling Policy Brief

California continues to face various challenges in reliably meeting its demand for water. As population increases and the aging water infrastructure becomes less efficient, drought and water scarcity remain long-term concerns. Water recycling is thereby emphasized in California policies and mandates as one way to alleviate some of the uncertainties in the future water supply. A 2012 Alliance Huntington Beach study found that on-site recycled water systems can supply water at lower energy intensity than imported water and desalination in Southern California. Such on-site technologies can be a good fit for developers interested in reducing the water consumption of new commercial and municipal buildings. In addition, the customization options of the systems are appealing, and the cost is incremental as compared to larger municipal water recycling and desalination efforts.

Nevertheless, on-site water recycling is a relatively new concept and doesn’t fit neatly into existing jurisdictions overseeing water-recycling and water- and waste-water treatment. Figuring out who has jurisdiction can be tricky for project developers as well as for those charged with preserving public health and safety. Still, the demand for non-potable water for uses like flushing toilets and irrigating landscapes could be met by recycled water, and frameworks have been developed to enable on-site water recycling to meet those needs.

In December 2013, the Alliance completed a study entitled California On-Site Water Recycling: Policy Brief that documents the barriers to implementing on-site water recycling systems and also presents potential solutions. The policy brief focuses on these barriers:

  • Lack of clear information about how to apply for permits
  • Expensive daily coliform laboratory sampling and analysis
  • Stringent certification requirements for system operators

Key study conclusions include:

·      On-site recycled water systems are an emerging technology with the potential to play a role in helping manage California’s increasing water scarcity. 

·      Immediate actions should be taken to perform additional work on understanding potential regulatory models, estimating benefits, and initiating pilot activity.

·      An information portal should be designed so that potential developers of on-site water recycling systems and staff at key agencies have access to detailed information. 

·      One stretch goal to work towards is an exception to the Title 22 requirement for daily coliform sampling for on-site water recycling systems with a track-record of high water quality.

The study also highlights a number of case studies as examples of on-site water recycling. Download  the full report for more details.

 

On-Site Water Generation

California water supplies are stressed as a result of decreasing supply and increasing demand.  While conservation and efficiency are the most cost effective solutions, they may not completely solve the problem. Water recycling is an additional solution that is applicable across the entire state and can produce a relatively consistent resource regardless of the season or weather.  Wherever there is a wastewater treatment plant there is an opportunity to generate a local, sustainable supply of recycled water.  Indeed, generating recycled water is not a challenge, distributing it is.  A major barrier to implementing a successful regional recycled water system is the cost of distribution pipelines.

Recycled water can be implemented on a smaller scale; generating water in the same location as its demand eliminates the need for expensive distribution systems. Similarly, rainwater harvesting can also provide a local, low-cost supply of water. On-site water generation (both recycling and rainwater harvesting) has the potential to not only conserve water but save energy used by supply and distribution infrastructure.

In December 2012, the Alliance completed a study entitled On-Site Water Generation: An Analysis of Options and Case Study  that documents the characteristics of the on-site water generation systems and also conducts a detailed cost benefit analysis for a representative case study on the City of Huntington Beach. The study sought to understand:

  • Types of technologies available to provide on-site water generation.
  • Costs and benefit analysis of the on-site water generation options.
  • Primary market barriers to technology adoption.

Key study conclusions include:

  • On-site recycled water systems can supply water at lower energy intensity than imported water and desalination in Southern California. 
  • On-site recycled water systems are most cost-effective in larger capacities. 
  • On-site water recycling can provide more water than rainwater harvesting. 
  • Rainwater harvesting systems are more cost effective in areas with a good balance of supply (rain) and demand throughout the year.

The study also discusses a number of recommendations for California policy-makers to stimulate the production and use of on-site water generation. Download the full report for more details.

Wastewater treatment plants have multiple options to reduce energy use
Wastewater treatment plants have multiple options to reduce energy use
Best Practices Study

In 2010 the California Public Utilities Commission completed a series of studies and pilot projects documenting significant opportunities for reducing the energy requirements of the water sector (including production, treatment, distribution and water conservation.) To build upon this, the Alliance developed the Eastern Municipal Water District: A Case Study of Best-In-Class Water-Energy Programs and Practices report documenting for retail water and waste-water agencies:

  • The range of potential energy efficiency and generation opportunities that could be implemented;
  • The types of programs and technologies available to help water agencies achieve energy benefits; and
  • The primary barriers that need to be overcome to increase adoption of “best” energy programs, practices and technologies. 

The Eastern Municipal Water District (EMWD) serves as a case study to illustrate the types of strategies and measures California water agencies can implement to improve energy efficiency.  In the case study, the Alliance documented EMWD’s progressive implementation of multiple best practice strategies and interviewed operations staff to document barriers and lessons learned.

Key findings from this study include:

  • A close relationship between water agencies and energy utilities is instrumental to achieving energy savings in the water sector; 
  • Smart meters and SCADA can provide large amounts of data to baseline the energy use of water agency; however, availability of detailed data is not required to identify promising energy saving opportunities.  A simple bill analysis could still lead to savings.
  • Technology risk and the need for investment prioritization may prevent water agencies from installing certain efficiency measures.
  • Newly adopted South Coast Air Quality Management District emissions limits may prevent water agencies from continuing to beneficially use biogas; complying with new limits may prove cost prohibitive for some water agencies.

Download the full report for more details.

Showcase Water Agencies

In the last two years, the Alliance recognized two water agencies as leaders in sustainability: Inland Empire Utilities Agency and Sonoma County Water Authority. The Alliance celebrates their success and the excellent work they are doing to improve sustainability and provides important information to other organizations about the strategies that these water agencies have used to achieve their goals.

Inland Empire Utilities Agency is a leader in best-in-class projects and initiatives that range from green buildings and energy efficient systems and operations, to innovative environmental and resource management strategies. The Agency has become the leader in recycled water production in California as it accelerated development of its infrastructure so that all recycled water produced through its wastewater treatment activities can be beneficially used.

IEUA Headquarters
Inland Empire Utilities Agency's LEED headquarters.

Sonoma County Water Agency pledged to eliminate its carbon footprint by 2015 through its Carbon Free Water effort. The Agency has taken several steps towards its goal including: improving energy efficiency, using hybrid vehicles into its fleet, installing three solar projects, conducting ongoing studies of alternative energy generation options, and co-founding a county-wide financing mechanism to spur investment in efficiency and renewable energy for existing homes and buildings.

SCWA Solar
Sonoma County Water Agency’s solar panels.
Water Energy Video

Water-Energy Nexus

Water related energy use accounts for nearly 20% of all electricity consumed in California. Below, Cynthia Truelove, Senior Water Policy Analyst, California Public Utilities Commission, discusses the water-energy nexus and how water can be conserved and used more efficiently to decrease energy usage. As part of California's Climate Action Team focused on water and energy, Cynthia discusses six measures identified as principle targets to reduce GHGs in addition to those required under AB32.

Water Treatment Plant Operator holding a sample of recycled water
Water Treatment Plant Operator holding a sample of recycled water
Recycled Water Study

In the U.S., many non-potable uses are served by potable water that has been treated to safe drinking water standards established by the federal Environmental Protection Agency and state and local agencies charged with protecting public health and safety.  Recycled water can be used to safely displace use of potable water for these types of non-potable uses such as toilet flushing, landscape irrigation, commercial car washing, and fire protection. 

Recycled water is produced by treating municipal wastewater.  California treated about 5 million acre-feet of municipal wastewater in 2002.  About half of that amount was recoverable as recycled water.  However, as much as 70% is discharged without beneficial use to natural waterways and to the ocean every year, representing a viable, untapped resource – a lost opportunity.

Recycled water could be used to enhance potable supplies after undergoing highly advanced treatment. Several water agencies in Southern California are taking advantage of advanced technologies to produce recycled water that exceeds California drinking water standards.  These agencies are using this recycled water to protect and replenish groundwater aquifers that serve as a major potable supply to the region. 

In May 2008, the Alliance released a study titled The Role of Recycled Water in Energy Efficiency and Greenhouse Gas Reduction that estimated the potential energy and carbon benefits of accelerating and increasing the development and use of recycled water in Southern California.

Results of the study show up to 580,000 acre-feet of existing recycled water supply in Southern California is currently being released to streams and the ocean without benefit.  This supply could meet all of Southern California’s projected increase in water use through 20301 . According to the study, every gallon of recycled water that is not used to offset potable water use is a missed opportunity for California to increase water and energy supplies and to reduce carbon emissions.

Download the full report for more information.  See the appendices for profiles of each of the participating water agencies.

1As projected by the Department of Water Resources under a Business As Usual scenario

Appendices include: