Orange County Water District Debuts New Groundwater Replenishment System

In September, you assumed leadership of the Orange County Water District (OCWD). How is OCWD is integrating its supplies with state or federal water, especially in light of the recent reorganization of water rights on the Colorado River and the court decision that cut allotments from the State Water Project to protect the endangered delta smelt? What are the added challenges for Orange County?

The Orange County Water District manages a large groundwater basin in central and northern Orange County. Most of the water that we get or that we recharge into the ground comes from the Santa Ana River, so we have a constant source of water throughout the year, generated by upstream river flows. Agencies discharge their tertiary treated wastewater, it gathers in the river, comes down into Orange County, and then we capture it and percolate it into the ground.

In the past, we have also relied on purchasing imported water supplies from the Metropolitan Water District. They have what is referred to as replenishment water. When they have excess water, we will take that water and purchase it from them, and then percolate it into the groundwater basin. That allows us to pull more water out of the groundwater basin. With the cutbacks from the State Water Project, as well as the drought along the Colorado River, those replenishment waters are not available. In other words, the Metropolitan Water District doesn't have surplus supplies, and they, in turn, are unable to make them available to us to percolate into our groundwater basin. This means that we're unable to produce as much water out of our groundwater basin, causing a larger demand on the Met system.

Another part of our water supply that's going to come online within the next day or two is the Groundwater Replenishment System. The Groundwater Replenishment System will take water that is otherwise discharged to the ocean-highly treated sewer water-and run it through an advanced purification process utilizing micro-filtration reverse osmosis and UV light with hydrogen peroxide. We'll take about half of that water and put it into an existing seawater barrier that prevents seawater from coming inland and contaminating the groundwater basin. We'll pump the other half up to our recharge facilities in Anaheim, and it will become an additional source of water that we'll be able to put into our groundwater basin. So it's a new, locally controlled source of water that will help drought-proof central and northern Orange County. It will provide up to 72,000 acre-feet of water per year, enough for 500,000 people.

What technologies and processes does the new OCWD plant employ?

There are three major processes. The first process is micro-filtration. We're using a Siemens CMF-S submerged micro-filtration membrane system. Each one of these micro-filters consists of polypropylene fibers. The second step in the process, which really is the heart of the treatment process, is the reverse osmosis. The reverse osmosis removes any dissolved minerals, pharmaceuticals, or viruses in the water. We're using Hydranautics ESPA-2 membranes; they're a polyamide membrane. They operate at a pressure of about 150 psi, which is fairly low pressure. We have fairly low tds coming into the plant-about 1,000 parts per million. Unlike seawater, which has very high total dissolved solids, ours is relatively low, and therefore we're able to operate at a lower pressure.

The final major step of the process is the UV with hydrogen peroxide. We use low pressure, high output lamps, and through the UV process, certain trace organic compounds are destroyed through direct photolysis. There are some compounds that aren't affected by direct photolysis, so we add hydrogen peroxide into the water, and the hydrogen peroxide, through direct photolysis, transforms the peroxide into a hydroxyl radical. That hydroxyl radical will chemically combine with some trace organic compounds and render them neutral. So we really have two things going on with the UV: we have direct photolysis on one hand and advanced oxidation on the other. This is the best available technology and is fully endorsed by the regulators.

Our technology is state of the art. This is the most advanced treatment implemented today. We have a history of doing reverse osmosis here on site-we've been doing it for over 30 years. We had a predecessor facility to the Groundwater Replenishment System called Water Factory 21, which was really the first plant of its kind. It used reverse osmosis to treat sewer water, and it was so pure that the regulators allowed us to inject it into the ground. Candidly-the regulatory requirements that we have for injecting this water into the ground-drive the technology.

State health officials had to approve a discharge permit before the reclamation plant opened in January, which they did. What did this approval process involve?

We have to sample the constituents on our discharge permit, so we have to take all the various compounds on our permit, grab our water samples, test them, and show that we're in compliance with that discharge permit. Having done that, we submit that to the California Department of Public Health. They, in turn, review the information and write us a letter saying that it's okay to start injecting the water.

In a recent interview in the Metro Investment Report, MWD manager Jeff Kightlinger opined that, in the future, local projects would provide an important source of water supply in metropolitan Los Angeles. Besides the reclamation plant that we've been talking about, what other Orange County projects that deal with local supply are you contemplating or engaged with?

The only project we're looking forward to in the future is expanding the Groundwater Replenishment System. The problem we're having with that right now is that we're taking almost 100 percent of the flow from the sanitation district next door, and we're recycling about 100 percent of what they're producing. Our challenge is going to be finding additional sources of water to recycle, but we do foresee expanding this project in the future.

Jeff Kightlinger also mentioned that water storage is becoming quite partisan at the state level, with Democrats favoring below-ground storage and Republicans favoring above-ground storage. What's your vision of how the water storage portfolio ought to come together at the state level in terms of guidance and signals to local government?

There has to be a mix of the two. Certainly, the statewide challenges are immense, and there is no real silver bullet. When you talk to most water experts, they'll tell you that it really needs to start with conservation, and then we have to look at ways to develop the local projects that Jeff mentioned. That's why the groundwater replenishment really is a shining example of a local project. We came up with this project to help solve some of our water problems in central and northern Orange County. We were very fortunate-we were able to get some money from the Metropolitan Water District's Local Resources Program, and we're actually applying for the remaining amount of water through that program, as well.

The Bay Delta is in a state of ecological crisis, the Legislature has had trouble finding a solution, and Senator Perata is talking about bringing back another water measure. What should the state be doing to help water districts like Orange County deal with their challenges?

From a Southern California perspective, we have to make sure that some means of alternative conveyance is a part of whatever is agreed upon with the Delta fix, understanding that the environmental issues have to be balanced with the alternate conveyance. But certainly Southern California is dependent on that water source, and any decrease of that water source will have severe impacts on Southern California.

Jeff Kightlinger was quite candid in his interview with us about the degree of challenge facing the state and Southern California. Can you add your thoughts on what's ahead as California's population continues to grow and the droughts we face continue to challenge the water supply?

It's a very daunting challenge-with global warming, the environmental problems in the Delta, and the eight-year drought along the Colorado River. The water supply is going to diminish as our population increases. So it is a very, very important issue. Obviously, we're reliant upon water to survive. People forget that we live in the desert. We live in a semi-arid environment, and our choices are limited. We need conservation, water recycling, and at some point in time, ocean desalination could become economically viable as an additional source.

If we were to interview you a year from now, what would be on the agenda of our conversation?

From our point of view, I think that we would be continuing to look at the challenges of managing our groundwater basin. We're looking at challenges in trying to increase our percolation rates into the groundwater basin, looking for additional sources of water that we can utilize in that basin, and looking at opportunities to clean up some problem areas where we have contamination, to recover part of the water in the basin.

From a state level, we'd be talking about the Delta. I think that the Delta is really a key source of water. It's a little over half the water that Met supplies to Southern California, so we absolutely, positively have to come up with a realistic fix. We have to come up with a plan, and so far, there hasn't been a plan. We have to figure out what the fix is and then commit the dollars to fix it.

Will a water bond still be on the agenda? Is a political agreement possible?

I think eventually a water bond has to be on the agenda. I would hope that we could come to some sort of agreement on what needs to be a part of that water bond, what needs to be fixed, and then commit the dollars to those fixes.

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