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California County Recycles All Its Wastewater, a World First

Orange County, sixth largest in the country by population, is home to the world’s largest wastewater recycling facility. Here's the water district’s path to a 100 percent recycling rate.

The Groundwater Replenishment System in Orange County, Calif., is the largest facility of its kind in the world. It recently announced that it is now recycling 100 percent of the reclaimable wastewater from the county's sanitation district. The resulting potable water is being used to recharge the county's groundwater basin.
In Brief:
  • In drought-prone regions, recycling is an integral part of water security.
  • Orange County, Calif., announced that 100 percent of the reclaimable water from its sanitation district is now being recycled and used to recharge its groundwater basin.
  • The director of the water district, program manager for this work since its inception in 2008, discusses the foundations of this milestone accomplishment.

  • On April 14, Orange County, Calif.’s Water District (OCWD) and Sanitation District (OC San) announced that together, they had accomplished something that has never been done anywhere else, ever. They are purifying and recycling 100 percent of the county’s reclaimable wastewater.

    The county’s Groundwater Replenishment System (GWRS), operational and expanding continuously since 2008, is the largest indirect potable water reuse facility in the world. It uses a three-step process — incorporating microfiltration, reverse osmosis and ultraviolet light. Purified water is pumped to recharge basins, where it percolates into a groundwater basin that provides drinking water to 2.5 million people.

    The GWRS now provides 130 million gallons of water a day, enough to meet the daily needs of a million residents. Mike Markus, the general manager of OCWD, has managed this work since its inception. He talked to Governing about the origins of the project and factors in its success. The interview has been edited for clarity and length.
    Reverse Osmosis (RO) pressure vessels.jpg
    Reverse osmosis pressure vessels. Reverse osmosis is one of the steps in a three-step process used to purify wastewater.

    Governing: How did this project get off the ground?

    Mike Markus: The project really started back in the mid-'90s with some of the pilot testing on the technology that was used. That took about two to three years.

    In 1997, the two agencies formed a joint committee to study the project and to decide whether to move forward on it. In 2002, I was appointed as the program manager and I took over management of the entire project.

    Governing: Was 100 percent recycling where you were heading all along?

    Mike Markus: We kind of stumbled upon it. In the early planning phases, we knew that we had to give the sanitation district at least 100 million gallons per day of relief for their outfall [that is, the wastewater leaving a treatment facility].

    We decided to incrementally add an additional 30 million gallons per day. We were coming out of one of our many droughts, and we picked that number thinking that we'd be able to get the necessary flows from the sanitation plant in Fountain Valley.

    Interestingly enough, those flows never developed. For our final expansion we actually had to take flow from the sanitation plant at the coast highway and pump that wastewater about four miles to our recycling facility, to give us flows necessary to be able to recycle 130 million gallons per day.

    Governing: Was the fact that you knew adequate water supply is not a given in California a driving force for this work?

    Mike Markus: That's a good way to put it. Water is not a given.

    I've lived here all my life. It is not uncommon for us to go multiple years in a row with below average rainfall, followed by a couple years of above average rainfall.

    This year we're close to 25 inches of rainfall, where normally we'd be receiving about 13 inches. We had a good year this year, but we live in a desert and it's not going to rain this much every year. We have to look back historically, knowing that we are prone to drought, and develop projects that can get us through those years.

    Governing: What were some of the key factors that made it possible to take a project this big to completion, over an extended period of years?

    Mike Markus: There were probably two issues that drove the project toward success. It starts with the partnership that we have with the Orange County Sanitation District. That partnership goes back to the late '70s, when we built a project in Fountain Valley called Water Factory 21. It was the first project in the world to use reverse osmosis on wastewater and inject that ultrapure water into a seawater barrier.

    We were looking to expand our seawater barrier at the same time sanitation was looking at having to build a second ocean outfall five miles off the coast of Huntington Beach. The two agencies got together and decided that if OCWD built recycled water projects that could safely treat and dispose of flows when sanitation had peak wet weather events, sanitation wouldn't have to build the second outfall. As a result, the sanitation district kicked in half the capital costs of that original project.

    You don't see too many agencies working together to try to solve problems like that. They don't charge us for the wastewater — that becomes an issue with some agencies. They’ve made changes to their treatment process to make it easier to treat the wastewater.
    GWRS sinks - purified water is available to taste.jpg
    Visitors to the Groundwater Replenishment System are invited to taste purified water. Though the water is not provided directly to homes, it exceeds state and federal drinking water standards.

    Governing: What was the second factor?

    Mike Markus: In the late '90s there were a few projects trying to do what we ended up doing — one down in San Diego, one in the San Gabriel Valley and one in the city of L.A. All were not developed at that time because of public outcry. That's where the term “toilet to tap” was first developed.

    When we were just starting our project, and to our board's credit, it decided that one of the first things we needed to do was public outreach. We started the outreach very, very early. We built up stakeholder support in the environmental community, the health and medical communities. We talked to all of the elected officials — local, state, federal — and got letters of support from everyone that was going to use the water.

    We were totally open and transparent, and as a result, we had no active opposition when we went online with the initial project in 2008.

    Governing: Speaking of “toilet to tap,” isn’t the water you’re using to recharge your aquifer cleaner than the water that’s already in it?

    Mike Markus: It actually is cleaner. The water we're putting in is cleaner than the water in the ground.

    Over time, we're going to get a mixing of those waters and that will actually provide a water quality benefit for all of the people who are pumping the water out and using it in their households.
    Mike Markus.jpg
    Mike Markus: "We have the technology. We've proven the technology. It’s just a matter of getting set up and executing your game plan."

    Governing: Is everyone in arid parts of the country going to need a system like this?

    Mike Markus: I believe that they will. Let's call it the “dry Southwest,” our neighbors in Arizona, New Mexico and Texas — and even Florida, though that's not the Southwest. We have to develop a water portfolio. We have to conserve the best we can, but then we have to recycle as much as we can.

    Governing: What advice would you offer to others who want to move in this direction? 

    Mike Markus: It goes back to those two keys of success. First and foremost, you’ve got to make sure that you have a partner that will be supportive of the efforts and that both boards are aligned and have the same vision.

    Then you have to communicate early and often. If you can work through those issues initially, that will act as a springboard for what's left to be accomplished.

    We have the technology. We've proven the technology. It’s just a matter of getting set up and executing your game plan.
    Carl Smith is a senior staff writer for Governing and covers a broad range of issues affecting states and localities. He can be reached at or on Twitter at @governingwriter.
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