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Grand Jury makes the case for implementing large desalination projects

As a follow-on to its earlier report on water sustainability in Orange County, the Orange County Grand Jury released Sustainable and Reliable Orange County Water Supply: Another Endangered Species?—but provides more detailed recommendations and conveys a sense of urgency not present in the earlier report.

The Orange County Grand Jury is tasked with criminal indictments, as we expect with a grand jury, and with civil investigations, including watchdog responsibilities.  This investigation falls under its civil investigations/watchdog responsibilities.

A key problem identified in the report is that Orange County’s water supply is vulnerable to drought, climate effects and catastrophic events.  About 50% of the county’s water supplies are imported—though it is not distributed evenly across the county.  With such a heavy reliance on imported water, a breakdown in the supply chain would substantially impact the county.

The county will also need to meet increased water demands.   Population growth from both infill and new development is projected to increase water demands 15% by 2035—a jump from a county-wide average of about 560,000 AF/year to 700,000 AF/year.

Also among the county’s water supply problems are a shortfall in 30-60 day emergency supplies in the southern part of the county and contamination of some wells by seawater or industrial chemicals.

The Grand Jury considers at multiple solutions to shoring up the county’s water supply:

  • The Bay-Delta Conservation Plan (BDCP), which is expensive, does not meet urgent needs, has unknowns regarding key impacts of climate change on water allocations and the vulnerability of the proposed tunnels, and is not actionable by any county entity at this point
  • Wastewater treatment to be used for landscape irrigation or groundwater replenishment, which is actionable—but so much work has already been done in this area that additional projects are likely to yield only marginal benefits
  • Locally-sourced desalinated water, which the Grand Jury sees as “a primary candidate to ensure water supplies against climate change, drought or a catastrophic event.” 

So with desalination projects squarely in its sight, the Grand Jury looks at the existing projects.  There are two projects in Orange County: the large Huntington Beach plant, which is in the final stages of permitting and financing, and the smaller South Coast Ocean Desalination Project in Doheny Beach, which has a small pilot project in place to evaluate a new intake system with low environmental impact.  There are also two projects in San Diego County: the much-proclaimed Carlsbad desalination project, which is under construction, and the Camp Pendleton, for which feasibility and conceptual design studies have been completed.

The desalination plants could meet 1/5 of Orange County’s water needs—replacing 40% of its imported water purchases.  Such substantial impact on water supplies makes these plants the solution, despite the cost, complexity and time needed for regulatory approvals.

But other arguments supporting and opposing desalination must be examined.  Supporting arguments noted by the Grand Jury include:

  1. Seawater is a nearly unlimited supply source that will only become more abundant under sea level rise
  2. The Huntington Beach plant is nearly shovel ready—and can constructed faster and with less risk than the BDCP infrastructure
  3. The reverse osmosis (RO) filtering technology is mature and widely used
  4. A desalination plant has little impact on marine life
    Citing an evaluation of the comparably-sized desalination plant in Perth, Australia, the Grand Jury argues that marine impacts are negligible 200 ft. from intake and discharge locations.  Furthermore, desalination plants like the Huntington Beach and Carlsbad Desalination Plants use existing power plant discharges, which, due to the dilution, reduce salinity.
  5. New technology, such as low pressure RO membranes and energy efficient designs, are in development to reduce power consumption and, thereby, reduce one of the largest operating costs. 

Opposing arguments were also noted and rebutted:

  1. Desalinated water is expensive
    The cost of desalinated water currently runs from $1,700/AF to $1,900/AF—compared to $1,000/AF for imported supplies.  But the Metropolitan Water District of Southern California (MWD) is currently offering a $250/AF incentive to develop local water supplies. And according to estimates by the San Diego County Water Authority (SDCWA), the Carlsbad Desalination Project will increase residential water bills by $5/month to $7/month.  The similarly configured Huntington Beach desalination plant is expected to have a similar impact.

    Ultimately, though, they argue that the cost argument becomes moot when the lower cost imported supplies are substantially reduced or lost.

  2. Marine ecology is damaged by the plant.
    According to the Grand Jury this is a very local effect that “can be substantially mitigated with good design practice…”
  3. Additional wastewater recycling and other more cost effective options are still available.
    As noted earlier, these are being pursued—but they are small scale projects that are not capable of replacing the potential loss of 40% of the county’s water supply
  4. Water demands fluctuate and, therefore, the based-loaded constant flow RO technology that is used is not suitable
    Water produced during low demand times can be banking the Santa Ana Aquifer or in the retail agencies’ reservoirs.

The Grand Jury says, “It’s time to complete the permitting and contract negotiations, and start construction of the Huntington Beach desalination plant!”

In addition to pushing forward on the Huntington Beach plant, the Grand Jury sees the potential for south Orange County to connect to the proposed Camp Pendleton desalination project.  They recommend that the MWDOC and the Orange County Water District form and fund a working group with SDCWA to explore the possibility of developing that plant.

Ultimately, the Grand Jury makes formal recommendations that include practical actions to improve the county’s water supply security.  They recommend that MWDOC and OCWD form an inter-agency advocacy group to push permitting and construction of the large-scale desalination projects, work with legislators, regulatory agencies and other involved parties to streamline the large infrastructure permitting process, develop and coordinate plans that investigate the impact of certain infrastructure outage scenarios—with the goal of integrating the local water infrastructure, and consider merging to create a single county-wide wholesale agency to improve management of the water resources and implementation of the other recommendations.  In addition, they recommend that MWDOC (who brings in the lion’s share of the county’s imported water) monitor and support the BDCP, but avoid expending resources until the uncertainties water supply allocations and vulnerability of the proposed tunnels is resolved.

Read the Grand Jury report

Written by Marta Weismann