A meeting on Desalination was held at UC Irvine School of Law on Oct. 15, 2015. The meeting was sponsored by the Center for Land, Environment, and Natural Resources (CLEANR), Water UCI, and Brown Rudnick.
I will report here on the Keynote Address, the talk by the Pacific Institute, and the panel on Southern California projects.
The Keynote Address was given by Frances Spivy-Weber, Vice Chair, State Water Resources Control Board.
She spoke about better water metering, monitoring, and our water footprint. The price of water is rising as will be charged by water districts. This is an important factor in considering water production. She recommended a portfolio approach to water production. Desalination may be used on groundwater basins where there is brackish ground water.
She divided water sources into Reliable and Intermittent. Reliable sources include recycled surface water, and desalinated water. Intermittent sources include capturing storm water or runoff. Imported water is not reliable, especially in this drought. Ground water is not being restored. She also classified sources as Centralized or Decentralized. Conservation and rain capture are decentralized sources, as can be desalinated water.
In evaluating desalination we must look at its benefits, costs, and who are winners and losers. It has been chosen by very few places. In time, its price will be less outrageous. We haven’t had a major test yet. The Santa Barbara plant is not yet on. (The Carlsbad plant will be discussed below.) Huntington Beach is a possible new plant.
The Setting and Current Issues talk was given by Heather Cooley, the Water Program Co-Director of the Pacific Institute.
She reported that 15 desalination plants have been proposed on the California coast, competing with other sources. Important factors are energy use and greenhouse gas emissions, as well as cost and financing. Also important is the marine impact.
(An acre-foot of water is about the amount used by two families of four for a year. An acre is about the size of the yardage part of a football field, and an acre-foot covers this with a foot of water.) The energy required for desalination of sea water is about 4,000 to 6,000 kWh per acre-foot. Two thirds of the energy is used for the desalination itself, and one third for pre- and post- water treatment, as well as water movement. The State Water Project uses about 3,000 to 4,700 kWh per acre-foot. Brackish water desalination takes between 1,000 to 2,700 kWh per acre-foot. Local groundwater uses less than 1,000 kWh per acre-foot.
The cost of water has an exposure to the price of energy. Energy prices go up in droughts, since there is less hydropower available. The cost of energy is expected to rise 2% to 6% a year over the next 20 to 30 years.
The cost of desalinated water in California runs from about $1,900 to $3,000 per acre-foot. The lower cost goes with the larger plants. Compared to this, recycled water costs $600 per acre-foot, while advanced recycled is $1300 per acre foot. However, we don’t directly drink recycled water, but use it for outside watering.
The costs of desalinated water are apportioned as energy, 36%, capital, 37%, chemicals, 12%, maintenance, 6%, and labor, 4%. The risk to the demand for desalinated water is alternate supplies.
She reviewed the fate of other desalinated plants. Tampa Bay is running at 25% of capacity, and seemed necessary since Florida does not have any mountains or snow packs, but uses groundwater. The Santa Barbara desalination plant initially cost $35 million, but was mothballed. It would cost $50 million to restart it with modern equipment.
There are two main marine impacts: killing sea life on the intake screen, and brine discharge, which is twice as salty as sea water, and therefore heavier, and falling to the sea floor. A solution may be to use a subsurface intake. In general, California has been moving away from coastal power plants, although the Carlsbad plant could use the same filtered sea water for desalination after it had passed through cooling the power plant.
Heather Cooley’s summary was to be cautious and thoughtful about a desalination plant, and to make use of other alternatives.
Existing and Operating Projects: Challenges, Benefits, and Results.
Paul Beard, Counsel of Alston and Bird LLP moderated the discussion.
Andrew Kingman, Executive Vice President, Poseidon Water LLC, described their new desalination plant in Carlsbad California.
The plant can deliver 58,000 acre-feet per year, which is 8% of San Diego’s water usage. The plant pre-filters organics and seaweed. It desalinates using reverse osmosis at 800 pounds per square inch pressure. The water molecules get pressed through the filters or membranes, but the salt molecules cannot go through and are filtered out. After that, lime is added to the water, and the acidity or pH is balanced to neutral. They use 800 membranes, at $400 per membrane. They can recover the energy on the half of the water that goes through the filter, and the rest with double the salt is returned. The water is then pumped up 1,000 feet to the aqueduct that supplies San Diego’s water. Greenhouse gases are made by the power plant that supplies power to the desalination plant. That power emits 20% more greenhouse gases than is emitted in transporting State Water Project water to San Diego.
Joe Geever, Environmental Consultant, Surfrider Foundation and Residents for Responsible Desalination spoke against desalination.
He was opposed to both the Carlsbad and Huntington Beach plants. He said that we suffer a 15% reduction in water about every 15 years. To overcome this we need to do more on conservation, as people are doing. We have to make the state water system more reliable by collecting more water. Other areas such as Los Angeles are now going to move into recycling wastewater, which will relieve the pressure on other communities. We do not need to fund continuous desalination plants when we only have deficits every 15 years.
Andrew Kingman commented that they had to fight 14 lawsuits to build their plant. He said that he had learned to try to work with environmental groups from the start. This was not yet working with Coastkeepers of San Diego.
(I did not stay for the remainder of the Symposium but went to the Great Park to see the student built houses in the Solar Decathlon of 2015. Although the Irvine City Council thought the turnout was low and they would not host the Decathlon again, when we were there the park was mobbed by Orange County students that had been bused in. It was a unique educational opportunity for them to learn about a sustainable future.)