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The IEUA joined the RAND Corp. with funding from the National Science Foundation to conduct a study of the potential impacts of climate change on the water supplies of the IEUA service area. The modeling analysis identified the potential vulnerabilities and risks to the Colorado River and northern California water supplies as a result of climate change, such as reduced snowpack, longer and more extreme droughts, and increased peak storm runoff requiring additional storage. Photos: Inland Empire Utilities Agency
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Solar panels at the IEUA's wastewater treatment facilities generate 3.5 MW of power annually.

In the past five years the utility and seven of its municipal customers have invested more than $350 million in new water infrastructure, including a new 75-mile recycled water pipeline distribution system that delivers recycled water from four existing waste-water recycling plants to industries, parks, schools, golf courses, and other irrigation customers. The recycled water treatment process ranges from primary to tertiary treatment, including filtration and disinfection. The new distribution system consists of pump stations, pipelines, and reservoirs that deliver recycled water from the treatment facilities to the customers' sites.

Additionally, 20 new wells were added to the Chino Basin, which is now home to more than 100 municipal wells and 150 agricultural and industrial wells. The basin is a mixture of sand, gravel, silt, and clay soils, so most new wells are easy to drill.

Groundwater recharge facilities — a combination of 19 existing flood control retention basins and new recharge basins — have been improved at a cost of $50 million to enhance stormwater capture and to increase capacity to more than 110,000 acre-feet annually. Basin maintenance, including silt removal to maintain recharge capacity, averages $500,000 annually.

With federal and state funding, the cost of developing the new local supplies is cost-effective compared to purchasing imported water from MWD. Although each city council sets its rates and charges differently, the increased use of recycled water will offset the need for more imported water — ultimately reducing costs to customers by 10% to 20% as the population increases.

The recycled water distribution system from the utility's wastewater plants throughout its service area is a key part of the program. Through a $200 million capital improvement budget — funded by low-interest loans from the State Revolving Fund, revenue bonds, both state and federal grants, as well as local property taxes, connection fees, and user charges — the utility plans to increase its annual daily amount of reuse to more than 50 mgd from 15 mgd in the next three years, increasing the amount of produced recycled water reused to more than 85% from just 25%. The energy savings of using recycled water over importing water will be equivalent to about 7,500 kWh per 1 million gallons of water.

To further increase self-sufficiency, the IEUA began a comprehensive energy efficiency program in 2002 that includes:

  • Energy of audits of all facilities, including the sewer collection and wastewater treatment facilities
  • A LEED Plantinum Administrative Building complex that uses 15% of the energy needs of a comparable building (with heating and cooling recovery, solar on the roof, and efficient lighting)
  • A 3-MW dairy cow power project with grant funding from the California Energy Commission, a $5 million USDA Natural Resources and Conservation Service grant, and a $2.3 million renewable energy grant from the U.S. Department of Energy for projects using new technology using biogas
  • The installation of internal combustion engines and optimized self generation of biogas supplemented with natural gas
  • The use of hybrid and electric vehicles.

As a result, the IEUA has adopted a goal to be off the electric grid by 2020 through maximum use of renewable energy, optimizing energy usage, and implementation of new generation technologies. Current total electrical usage is about 13 MW annually and will increase to 18 MW as a result of the increased pumping of recycled water to customers.

Finally, the utility has implemented a program to maximize its local reuse of biosolids recovery through composting.

Through a joint project with the Sanitation Districts of Los Angeles County, it's composting all 75,000 tons of biosolids its service area produces every year and selling it to city parks, golf courses, and landscapers from an enclosed converted warehouse building used by the IEUA. The distance from the IEUA sewage treatment plants to the local composting plant is a few miles, compared to the 150- to 320-mile trip to haul biosolids away from the metropolitan Los Angeles area. Those reduced trips have reduced fuel consumption, air pollution, and CO2 emissions by the utility's fleet of 50 vehicles by more than half.

Today the IEUA operates four tertiary wastewater plants with a combined capacity of approximately 85 mgd. It produces and distributes about 20 mgd of recycled water, operates a 25-mgd groundwater desalination plant to produce drinking water, a dairy manure/food waste anaerobic digester facility, and an indoor biosolids composting facility. IEUA produces recycled water, renewable energy at its waste-water treatment plants, and biosolids and cow manure compost products.

— Atwater is the CEO/general manager of the Inland Empire Utilities Agency in Chino, Calif.