From The Editor | July 6, 2017

How IPR Can Keep California Out Of Drought

Peter Chawaga - editor

By Peter Chawaga

Despite the fact that California has declared an end to its years-long emergency drought, utilities throughout the state are still leading the charge in water reuse, recharge, and efficiency.

“This drought emergency is over, but the next drought could be around the corner,” Governor Jerry Brown said at the time. “Conservation must remain a way of life.”

The prolonged drought has left California as a leader in water resiliency, with a litany of desalination and reuse projects already in existence and more planned for the future. In an indicator of the lasting effects that the drought has had there, a state water system was recently recognized for its indirect potable reuse (IPR) project.

The City of Oceanside, CA, took home the Water Reliability Coalition’s “agency of the year” award for its aquifer augmentation project, an effort to bolster its groundwater extraction wells in the Mission Groundwater Basin and buttress against future drought issues.

“The recent extraordinary drought starting in 2010 and lasting through 2016 put tremendous stress on the basin, to where the city was able to extract only a fraction of the groundwater to which it has rights,” said Greg Keppler, a senior civil engineer for the City of Oceanside’s Water Utilities Department, which serves about 176,000 residents through 43,000 meter connections over 42 square miles. “In order to replenish the basin, the city will be making investments in water conveyance and treatment infrastructure to restore the basin back to historic norms.”

Right now, the city’s treated secondary wastewater is disinfected and discharged into the ocean, a “waste of a resource,” according to Keppler. The augmentation project will instead recycle nearly all of the water received at local San Luis Rey Water Reclamation Facility (SLR), which will employ various advanced treatment technologies.

“Modifications at SLR are required in order to nitrify and denitrify the secondary effluent,” Keppler said. “The water will then be processed through microfiltration, reverse osmosis, and ultraviolet/advanced oxidation. The highly-treated water will be conveyed through a dedicated distribution system and pumped into the groundwater basin… After spending approximately six months in the basin, permeating through the soil, the water will be extracted downstream and treated at the Mission Basin Groundwater Purification Facility for potable reuse.”

Oceanside is still studying the project, evaluating its feasibility, the treatment processes, and pathogen removal last year. It is currently in a second phase of the study, determining the best locations for groundwater injection wells within the basin. Following that, the design and construction are expected to wrap up in 2022 and provide 6 MGD of water reuse.

The $50 million effort is part of a larger plan in Oceanside, which imports much of its water. The city seeks to produce 50 percent of its supply locally by 2030 and will also employ a recycled water and conveyance program to offset water use in irrigation.

While the state is full of those actively seeking to avoid another emergency drought, this project is unlike many others.

“We are not the only ones researching and developing new water supplies through water reuse,” said Keppler. “However, our approach and methodology used to study the project is unique for our area and I believe that is why the project has garnered a lot of interest and recognition… For the City of Oceanside, our project has motivated us to research our basin in a way that has never been done before.”

That being said, there’s no reason that more communities could not follow the model that Oceanside has established. For those that do, Keppler offered some words of wisdom that could just as easily be applied to any ambitious water efficiency project.

“Meet with regulators early on in the process so they are familiar with the goals of the project and are supportive of the idea before forging ahead,” he said. “And be prepared to be flexible and patient, as there are many things that are beyond your control.”