Smart City Water Managers Are Recycling Waste Into Drinking Water

Addressing VerdeXchange 2017 in January, you chronicled wastewater reuse strategies in Los Angeles. Update our readers on LA Sanitation’s progress on wastewater and water management in the city.

Traci Minamide: It is very important to LA Sanitation to look at the water that we treat in our wastewater system as a resource—not as waste. We’ve been striving to move toward recycled water.

We just cut the ribbon on an expansion at the Terminal Island Water Reclamation Plant, taking production there to 12 million gallons per day of full advanced treated water, which we use primarily for injecting into the Dominguez Gap Seawater Intrusion Barrier. We’re very excited about that project; as far as we know, Terminal Island is the only facility in the country that takes in raw wastewater and produces, by the end, full advanced treated water suitable for drinking. It also diverts the discharge of treated water from the Los Angeles Harbor. That’s a big milestone for us.

We are also looking at recycled water projects in our upstream plants. Over the past year, we’ve been doing pilot work at the Tillman Water Reclamation Plant on new ways of advanced treating water that are less energy-intensive than the traditional microfiltration and reverse osmosis processes. We’ve got some great concepts going there—ideas that will reduce our energy footprint, save on capital costs, and produce good-quality advanced treated water that we can take to the Hansen Spreading Grounds.

Our flagship facility, Hyperion, is our big challenge. Right now, we treat that water to secondary standards and send it to the Santa Monica Bay. But we know that there’s a lot of opportunity to treat that water for reuse. We’re partnering with West Basin and the Department of Water and Power on a pilot of membrane bioreactor treatment to produce higher quality water, which can then go through reverse osmosis to produce advanced treated water. This project is on the fast track: We’re planning to launch the pilot within a year or so, and eventually, to scale it to our full 70 million gallons a day.

Another project we’re doing at Hyperion is a full advanced treatment facility for 1.5 million gallons a day, expandable to 5 million, that will produce water for us to send to the Los Angeles Airport. LAX is in the midst of a big expansion, building new terminals, and the plan is to provide highly treated water that can be used at those facilities as well as in their cooling water system.

There are many opportunities that we’re working on. It is a challenge, though. These projects are large-scale; particularly Hyperion, and we need to consider funding availability and partnering in creative ways.

Since the drought became a dominant California news story, and Mayor Garcetti issued his executive directive to cut imported water into the LA Basin by 50 percent, increased attention has been paid to your challenging work. Do you have the necessary political will, and the resources, to actually make progress?

The drought helped bring focus to the fact that water is a very rare commodity, and it’s really at its low point. With that has come the realization that we need to develop a sustainable local resource that will get us through the highs and lows. This approach has come through in the mayor’s executive directives, which talk not only about water conservation, but also about developing our local resources.

This is a long-term effort. It doesn’t happen overnight. We recognize that we can’t respond to a drought by building projects over a two-year period. That’s not enough time for us to plan and execute something that will be effective over the long term.

As I see it, the biggest change is that people are beginning to understand that we’re not just worried about a drought—as if once it rains we don’t have to worry about it anymore—but that we need to sustain our efforts, and make these projects happen regardless of whether we’re in a drought or not. That will ensure that, in the long run, we will have a more sustainable water supply and a secure water future.

You were a member of a California State Water Resources Control Board’s advisory group that looked at the feasibility of developing uniform water recycling criteria for direct potable reuse. Elaborate on the report’s findings, and their practical significance. 

Working as part of that State Water Resources Board advisory panel was a good opportunity for a lot of us different stakeholders to come to the table and gain an understanding of our different perspectives. The question that was put to us was: What is the feasibility of developing regulations that will allow direct potable reuse? The outcome was that it is feasible.

This has also raised awareness in our Legislature. There is a lot of legislation being put forth now that will drive recycled water.

All of that has done a lot to make people comfortable that investment in these projects can actually be successful in producing a valuable water resource. 

Over the last four decades, the oft-quoted political label “toilet to tap” has stymied progress on recycled water. What has changed since then to make possible renewed investment and public acceptance? Has it been technological innovations, or the threat of climate change?

So many technologies have evolved since the birth of that phrase. Back when that phrase took off, we were talking about doing groundwater spreading and replenishment in the San Fernando Valley with the tertiary water that we currently produce at the Tillman Water Reclamation Plant.

Today—after all of the research and regulation of different qualities of water—that water is still officially satisfactory, and meets the State Water Resource Control Board’s regulations for groundwater spreading. But technology has also advanced beyond that.

All over the world, from Orange County to Singapore, we’re using new technologies like reverse osmosis, microfiltration, and advanced oxidation, as well as piloting even newer technologies that are not as energy intensive, such as biological activated carbon and using ozone, as we have done at Tillman. We also understand better how the natural process in the groundwater aquifer treats the water. There have been quite a few advances in technology.

You mentioned Singapore. Where does your agency look for expertise and successful models to help LASAN accomplish its goals?

Singapore has always been out there in the front. They have a very well established, long-running program. Even here in California, there’s a lot that’s being done; our neighbors in Orange County are a big shining example.

In Europe as well, particularly in the Netherlands, facilities are using new technologies like granular active sludge, which helps with conditioning water so that it can move on to advanced treatment.

Are other jurisdictions and industry beginning to look to the new technologies and practices Los Angeles is adopting?

I think so! Some of our research and the new technologies that we’ve developed have become the industry standard.

Our plant manager, Dr. Roshanak Aflaki, did some work at Terminal Island Water Reclamation Plant on advanced oxidation, which is a component of advanced treatment, and came up with a new approach using UV and chlorine. It’s simpler and less expensive, from both a chemical and capital perspective, than some of the other advanced oxidation processes that have been standard. Now, it has become an industry standard.

Aflaki’s pilot work at Tillman Water Reclamation Plant has also really put us out there as an agency that’s looking at new ways of doing things.

In this issue of TPR, we also speak with Marty Adams from LADWP, your LASAN colleague Adel Hagekhalil, and Adam Krantz from NACWA about the One Water LA plan. After 25 years at LASAN, reflect on what One Water LA promises in terms of water sustainability. 

Looking at water as “one water” has helped us bridge our work. In the past, people on one end of the system looked at creating potable water supply, and people at the other end looked at treating the wastewater. This new piece in the middle—recycled water—has helped to pull everything together.

Working in a framework of water comprehensively as wastewater, recycled water, and stormwater has helped us to see the bigger picture in terms of how to meet our water needs. It’s absolutely essential for us to continue to sustain ourselves as our population grows. 

This issue also features LA County’s new Public Works Director, Mark Pestrella, who commented on County Supervisor Sheila Kuehl’s work to fund stormwater capture infrastructure. How does stormwater management fits into LASAN’s initiatives?

It is a big component of recycled water. At the Hansen Spreading Grounds in the San Fernando Valley, for example, stormwater and recycled water will be used in a blended fashion to recharge the aquifers. That’s also the case in other places throughout the region, not only in the city of LA.

This is something that needs to be considered from a regulatory perspective, as well. We need to work from both ends of the process to maximize the amount of water we can get into our aquifers.

Regarding the LA River revitalization, speak to LA Sanitation’s work on utilizing the recycled water that flows through the river while also providing wildlife habitat.

That’s very important to us; we see the value and the need to meet both of those benefits. On one hand, we need a flow of recycled water available for us to use. But at the same time, we see the benefit of the river revitalization as essential for the Los Angeles community.

We’re working on ways to manage the water in the river in order to retain the flows needed to sustain beneficial use and support the habitat. For example, could we dam up the water? Or could we manage the diurnal fluctuations? Perhaps we could make sure the flow is there during the day hours, when kayaking and other activities are happening, and maybe we can manage the flows differently during off-hours in the middle of the night.

It’s a challenge, but we certainly are up for it.

What do public officials and voters need to understand to better appreciate LA Sanitation’s water conservation and management challenges?

The problem is not necessarily that people don’t understand, but the fact is that the types of projects we do cannot happen overnight. To get the best projects, we need time to research the available technologies and determine which are going to be the best fit for us.

We sometimes find ourselves in a position where we’re faced with two options. One particular technology is established, proven, and safe. We know it will work. But there’s also an up-and-coming technology that looks very promising: It would have a much smaller energy footprint, and the quality of water could potentially be even better. But it’s not established, so it would be a risk to take it on. And it’s going to take time to look at it closely and do enough piloting to determine whether it will be something that we feel is going to work in the end.

What happens is that sometimes there’s pressure to do something now, or to meet a deadline. That could potentially force us into decisions where, if we had had more time, we might have been able to work out a better solution.

Lastly, the city and the county of LA are impacted by the priorities of the federal government and its infrastructure investment decisions. Despite our size and resources, LA is not an island. What do you hope or expect to see from the federal government in terms of support for wastewater management in metropolitan Los Angeles? 

There was a time when, under the Clean Water Act, federal funding was provided in the billions for wastewater treatment. That made a huge difference across the country. In LA, that federal funding was utilized to upgrade the Hyperion Treatment Plant.

In our current climate, we’re certainly not seeing that. We’re actually going in the other direction. Recognizing the benefits of what we do, and looking at it as creating a resource, would certainly help. Wouldn’t that be wonderful?