Agencies ready to propose preferred salt-reduction method


May 22, 2001|By KELLY GRANT, Staff Writer

SALTON SEA — The decades-long debate on how to reduce the Salton Sea's salinity appears to be nearing completion as the lead agencies in the project prepare to propose a preferred method from narrowed-down options.

The Salton Sea Authority and the U.S. Department of the Interior's Bureau of Reclamation are looking at solar evaporation ponds and so-called enhanced evaporation system methods to reduce salt levels in the sea.

"These are the most practical and pragmatic (methods)," said Tom Kirk, executive director of the Salton Sea Authority.

Kirk estimates anywhere from dozens to hundreds of suggestions of how to desalinize the sea have been made in the past 30-plus years. The methods under consideration deal with the problem locally and are cost-effective, Kirk said.

The solar pond options include on-land or in-sea ponds.

According to a restoration plan status report presented to the Salton Sea Authority board of directors last week, each solar pond module will process 17,000 acre-feet of water and remove 1 million tons of salt per year.


Ponds built on flat land are the most cost-effective solar evaporation ponds at just 67 cents per ton of salt, according to the report.

Ponds built on steeper land will cost 98 cents per ton while in-sea ponds, separated from the rest of the sea by a dike, would cost $3.33 per ton.

It's estimated at least five to eight solar pond modules will be needed. Each module would cover 4.4 square miles.

Of the enhanced evaporation systems, the line-shower method sprays a fine mist of sea water from towers. Spraying the water like that speeds evaporation, Kirk said. The remaining salt is collected in basins below the towers.

The line-shower unit requires 32 towers and will use .8 square miles per unit.

The ground-based EES utilizes 316 turbo-enhanced evaporator units. The units take up .3 square miles.

Both EES process 17,000 acre-feet of water and 1 million tons of salt per year, similar to the solar pond modules.

While the EES would take up less space than the on-land solar ponds, they're more expensive.

The line-shower will cost $1.24 per ton of salt while the ground-based units will cost $1.68 per ton, according to the report.

In proposing a preferred method, selection of sites is important. Factors such as slope of land, elevation and distance from the sea must be considered.

The tons of salt left over will most likely be disposed of in a landfill as other alternatives aren't cost-effective, Kirk said.

"Unfortunately, there doesn't appear to be a good market for the salt we'd generate," Kirk said.

Its low value and high weight make it expensive to transport to market, Kirk said.

The Salton Sea Authority and the Department of the Interior will propose a preferred project within the next 30 to 60 days. After that an environmental report will be drawn up and made available for public viewing, Kirk said.

After that, it's up to the lawmakers to provide funding for the project.

"Ultimately, it's up to Congress and the state to make the financial commitment," Kirk said.

Staff Writer Kelly Grant can be reached at 337-3441.

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