Solar Energy

Solar Energy Project


Regional San constructed a solar energy array at the Sacramento Regional Wastewater Treatment Plant. The solar array is one of the largest located at a wastewater treatment plant in the nation. The solar array offers a clean and sustainable energy source with several benefits.

Regional San entered into a power purchase agreement with Tesla (formerly SolarCity) who will finance, own, and operate the array. Under the agreement, Tesla will sell the power produced at the site to Regional San for a 25-year term at a fixed rate.  

This solar array increases and diversifies our green energy portfolio, provides a clean and sustainable energy source, and brings financial benefits by reducing energy costs. The estimated savings to Regional San over the 25-year period is about $10 million. The solar array also meets environmental requirements for greenhouse gas mitigation as part of the EchoWater Project, the massive ongoing upgrade of the treatment plant.

The newly developed 4.2 megawatt solar array has a footprint of approximately 21 acres of open space designated for future treatment processes. It will produce approximately eight percent of Regional San’s current energy needs which is enough to power approximately 750 homes annually.


In 2014, Regional San’s Board of Directors certified the EchoWater Project Final Environmental Impact Report, which included a mitigation measure to reduce project-generated greenhouse gas emissions. Subsequently, Regional San chose to install solar panels at the Plant to reduce the EchoWater Project’s overall consumption of non-renewable energy.

The project team completed the required environmental evaluations and analysis, which determined the solar array project would not result in any new or significant environmental impacts beyond those described in the certified EchoWater EIR.

Project Benefits

  • Diversifies Regional San’s alternative energy portfolio and demonstrates a commitment to renewable energy resources
  • Provides a substantial financial benefit to Regional San that can be applied to Bufferlands restoration, sustainability, and outreach efforts
  • Mitigates greenhouse gas emissions impacts related to EchoWater Project construction and future operational emissions

For More Information . . .

For more information about this project, please contact Steve Nebozuk, Senior Civil Engineer, at (916) 876-6118, or via email at


View Jan. 27, 2016, Board Item Second Amendment to Certified EIR

View Jan. 27, 2016, Board Item Approval of Preferred Alternative and Best Value Provider

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