Mayor Garcetti at Hyperion water reclamation plant announcing that Los Angeles will recycle 100% of city’s wastewater by 2035. (City of Los Angeles photo)

Operation NEXT – LA’s New Water Supply Program

By Sarah Mouakkad, Los Angeles Department of Water and Power
Resource Recovery, Technology and Innovation

Converting Waste to Resource

The Hyperion Water Reclamation Plant (HWRP), located in Playa Del Rey, CA, is one of the largest reclamation plants in the nation, treating an average of 260 million gallons per day (MGD) to full secondary standards. HWRP currently treats 82 percent of Los Angeles’ wastewater and discharges most of its effluent into the ocean.

With climate change, growing population, and imported water becoming increasingly unreliable and costly, the need for a local sustainable water supply has never been greater.

The Operation NEXT Water Supply Program (Program) is a transformational initiative to recycle 100 percent of available treated wastewater for beneficial reuse from the HWRP by 2035. The Program supports Los Angeles’ Green New Deal, published in April 2019, which stipulated ambitious goals to reduce purchases of imported water by 50 percent, recycle 100 percent of all wastewater for beneficial reuse by 2035, and source 70 percent of our water locally by 2035.

The Los Angeles Department of Water and Power (LADWP) is partnering with Los Angeles Sanitation and Environment (LASAN) to accomplish these goals by retrofitting the HWRP with advanced water treatment facilities to produce up to 170 MGD (190,000 AFY) of purified recycled water.

The largest undertaking since the construction of the Los Angeles Aqueduct, this new drought-proof water supply will offset purchased imported water by building water storage within local groundwater aquifers, augment surface water supplies, and potentially meet up to one-third of the City’s water demand.

“Looking to the future, LADWP and the City of Los Angeles are focused on becoming Water Strong – building resilient, sustainable local water supplies through stormwater capture, groundwater remediation and replenishment, conservation, and recycling 100% of our wastewater.

Operation NEXT will be the biggest transformation of LA’s water system since Mulholland built the Los Angeles Aqueduct. It’s the NEXT big thing, it will literally be the NEXT aqueduct right here in Los Angeles. Our vision to keep LA’s water supply sustainable such that the words “Drought” and “Los Angeles” will never be used in the same sentence again.” – Richard Harasick, Senior Assistant General Manager, Water System, LADWP

This bold and visionary Program is already underway. LASAN and LADWP are partnering on two pilot projects to study the feasibility of converting HWRP into a full advanced water purification facility (AWPF).

The Nitrification-Denitrification Membrane Bioreactor (NdN MBR) Pilot Study is currently in construction and set for commissioning in September 2021. The purpose of the study is to test various MBR units, obtain data to develop the design and operating criteria of MBR treatment and to receive Division of Drinking Water regulatory approval on pathogen log removal credits by this treatment method to be used in the future conversion at HWRP.

Furthermore, LADWP and LASAN are collaborating on the Hyperion Advanced Water Purification Facility, a 1.5 MGD pilot that will provide advanced treated recycled water to nearby Los Angeles International Airport for heating, cooling, and toilet flushing.  Results from these projects will inform the transformation of HWRP.

It is expected that advanced treatment processes will include membrane bioreactor, reverse osmosis, ultraviolet, and advanced oxidation process.

Groundwater Nexus

In addition to fully converting HWRP to an AWPF, Operation NEXT comprises four main concepts to make use of the new supply and leverage groundwater storage.

(1) LADWP and the Water Replenishment District of Southern California (WRD), Watermaster of the West Coast and Central Groundwater Basins, are collaborating on a Joint Basin Master Plan which will determine optimal locations to convey HWRP water into underlying aquifers.

(2) LADWP will extract and treat the groundwater for distribution into the potable water system.

(3) LADWP will convey HWRP water to replenish the San Fernando Groundwater Basin, and provide raw water augmentation at the Los Angeles Aqueduct Filtration Plant (LAAFP), the main water treatment plant at the northern end of the City.

(4) Additionally, LADWP will potentially convey HWRP water to the Jensen Water Filtration Plant and MWD’s Regional Recycled Water Program Backbone System, the other major Direct Potable Reuse (DPR) project in Southern California.

The City has historically underutilized its water rights in local groundwater basins due to reliance on imported water, aging infrastructure, and distribution system limitations.

The Program concepts allow for an operational strategy that permits extraction above adjudicated rights and establishes sustainable source water for augmentation. LADWP estimates that there is currently about 1,000,000 acre-feet of available storage in the three major groundwater basins that underlie the City.

By comparison, the City’s annual demand is approximately 500,000 acre-ft. Recycled water used in conjunction with groundwater management provides operational flexibility to supplement supplies in dry years and store supplies during wet years.

The real strength of this Program is its ability to provide resilience and a true hedge against earthquake, climate change, and prolonged drought.

Developing Regulations

The Program is being planned as regulations are still in development. The results of the NdN MBR Pilot Study will assist in seeking regulatory approval for the use of MBR in lieu of microfiltration for advanced treated water.

With the passage of California Assembly Bill 574, the California State Water Resources Water Board (SWRCB) will adopt uniform regulations for Raw Water Augmentation by the end of 2023. If approved, DPR will play a major role in the Program.

The large pipeline from HWRP heading north will facilitate raw water augmentation at the LAAFP to supplement surface supplies.

Furthermore, LADWP is currently planning a DPR Demonstration Facility to help establish LADWP’s overall DPR program. This DPR Facility will pilot test various advanced treatment technologies, and this information will be shared with regulators as they develop Statewide regulations for DPR.

Environmental Permitting

A program of this size requires a programmatic approach to CEQA. Completion of the Programmatic Environmental Impact Report (EIR), which is anticipated by 2022, will allow for further planning and design of the components as individual EIRs will result for each project.

Based on preliminary environmental review, potential environmental actions include:  Waste Discharge Requirements from the State Water Resources Control Board for all components that include direct potable reuse, groundwater augmentation, injection, and percolation via spreading grounds.


The Operation NEXT Water is one of the largest potable reuse projects in the Country, and this Program will drastically change LA’s water system.

A robust communications and outreach plan will be necessary to engage the public and stakeholders on the Program goals and benefits.  A communications matrix will help identify stakeholders and their information needs.

This will provide an opportunity to incorporate public education and showcase the Program’s benefit to the region through outreach consistent with the CEQA process.

Institutional Implementation

The preliminary cost estimate is about $3 billion to convert HWRP to an AWPF and $5.4 billion for the four other main Program concepts. Potential funding mechanisms being evaluated include State Revolving funds, MWD LRP, Title XVI, and federal programs.

Internal planning includes forecasting resource needs and building a management structure that support program implementation.

Operation NEXT demonstrates integrated regional water resources planning and management in that collaboration, multiple planning efforts, and other inter-agency agreements are laying the framework to advance the Program.

Next Steps

Next steps include completing the joint master plan with WRD, conveyance route studies in preparation for Programmatic EIR, developing the stakeholder communication and outreach plan, and evaluating potential funding mechanisms.

Operation NEXT will change the paradigm of water supply in the region and set the precedent for DPR in the state.