Home California Progress Report Desal and “Carbon”ated Water: Coastal Commission Should Make the Carlsbad Project Offset All of Its Carbon Impacts

Desal and “Carbon”ated Water: Coastal Commission Should Make the Carlsbad Project Offset All of Its Carbon Impacts


Carbon emissions and water supply are two sides of the same coin. In California nearly 20 percent of our electrical energy is used to move water around the State, treat it for use and then treat it again for disposal. 

All of that energy generation emits huge amounts of carbon to our atmosphere.  So when Poseidon Corporation claims that its proposed desalination plant in Carlsbad will have a “zero carbon footprint” it may sound too good to be true. Well, that’s because it is.

In February the Coastal Commission will be reviewing the accuracy of information submitted by Poseidon for its permit to build the largest desalination facility in the Western Hemisphere in Carlsbad, California. The issue is Poseidon’s claimed CO2 offsets. 

Ocean desalination is the most energy/carbon intensive way to provide water – even more than pumping water more than 400 miles all the way from Northern California, up over the Tehachapi Mountains and on to San Diego.  Poseidon’s proposed ocean desalination plant would require 30 megawatts of generation. Producing this much energy would emit an additional 120,000 to 154,000 tons of carbon dioxide per year into our atmosphere.

Poseidon’s claim of carbon neutrality is a critical piece of their project for the Coastal Commission, which is charged with ensuring protection of California’s precious coast and marine environment from the multiple threats of climate change.

Now, the Coastal Commission staff and several public interest groups have uncovered evidence that the company’s carbon-neutral claim contradicts Poseidon’s agreement with the Metropolitan Water District of Southern California. Poseidon’s promise of a carbon neutral project, it turns out, is based on misrepresentations and Wall Street style math that just doesn’t add up. 

In its permit application, Poseidon claimed that the desalted water they produce will “replace” water that would otherwise be delivered to the region from Northern California. By promising that its project would replace water pumped from the north, Poseidon was able to claim a large reduction in the plant’s “net” carbon footprint. 

What the company withheld was that their financing contract with the Metropolitan Water District of Southern California specifically disallows this replacement. Poseidon, it turns out, is claiming it can trade something it doesn’t have.

Metropolitan alone decides how much water it will pump from the north and it is protective of this right – so protective that it specified that the contract is void if Poseidon interferes with Metropolitan’s water rights or water deliveries from the north.  
Metropolitan has stated publicly that it will pump as much water from Northern California as state and federal regulations allow. It is not going to reduce the amount of water that it is bringing down from Northern California based on what Poseidon produces or how much energy it uses. So Poseidon is using phony accounting to claim they will reduce their project’s greenhouse gas impact by “replacing” water that would otherwise be imported to the region.

That assumed carbon offset is key to the company’s claim of carbon neutrality, though the company also makes dubious claims of high-energy efficiency, green buildings, and new wind turbines. Thirty megawatts would be a large new energy demand, which will come from an in-state gas or out-of-state coal plant. 

The Coastal Commission, which is responsible for protecting our natural resources from the threats of global warming, should revoke the Coastal Development Permit and compel Poseidon to properly calculate the real greenhouse gas emissions caused by this energy-intensive plan – with a real plan to offset those emissions.

More importantly, water agencies including the state Department of Water Resources, Metropolitan Water District and local water districts need to focus on supply portfolios and management reforms that reduce “embedded energy” in our water supply management – not new sources that create more carbon emissions.

This State’s natural resources and economy are already being impacted by climate change, and water management reform is the low-hanging fruit for meeting California’s legislative mandate to reduce carbon emissions. The Coastal Commission needs to get this formula right by closely scrutinizing Poseidon’s self-serving semantics and arithmetic.

Jonas Minton is the Water Policy Advisor for the Planning and Conservation League. Mr. Minton previously served California as a Deputy Director at the Department of Water Resources and chaired the State Desalination Task Force.


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