San Fran salt harvest has long history

October 24, 1995

From Correspondent Don Knapp

NEWARK, California (CNN) -- The Gold Rush of 1849 helped create what may be the San Francisco Bay's oldest industry: 49ers heading for the foothills paid $50 a ton for salt. By 1849 standards, salt seemed just about worth its weight in gold, and quite a bit easier to find.

Its value encouraged early entrepreneurs to create vast systems of evaporation ponds on the edge of the bay, after learning the method from American Indians. Today's ponds produce a million tons of salt each year.

It's like farming, workers say. They nurture a crop of crystals for five years, shifting water from one concentrating pond to another until the salt drops out. Then they harvest the salt. Heavy machinery shaves it from the bottom of the drained ponds, and a tiny railroad carries it away.

"We use Mother Nature as much as possible," said John Pyles of Cargill Salt. "We use the tide to push the water into our system. And then we use the sun and wind to go to work and evaporate the water and concentrate it for us."

Also like farmers, saltmakers depend on the rain. For them, rain is the key to naturally rinsing Bay mud from a salt pile that will grow 90 feet high and nearly a thousand feet long by harvest's end. (134K/12 sec. AIFF or WAV sound)

The crazy-quilt pond patterns, colored by microorganisms, lay beneath the approach to San Francisco International Airport. Different salt concentrations in each of the ponds encourage different organisms, and different colors -- for example, the red pigment comes from beta carotene.

Biology students from San Jose State University are studying the microbes that manage to live in the super-concentrated salt water. "These are among the oldest microbes ever investigated," according to biology professor Pat Grilione, who says some date back to ancient times.

The ponds also host salt pond brine shrimp, which attract waterfowl. Cargill Corporation claims its ponds support 30 percent of the bay's waterfowl.

While some credit the ponds with keeping wetlands free of development, and providing habitat for wildlife, others want the levees opened and the shoreline to return to its natural wetlands state.

In fact, Cargill did agree to set aside property on the northern side of the bay as a permanent wildlife reserve, to be managed by the California Department of Fish and Game. The group of salt ponds, mudflats and tidal wetlands span three counties -- they were formerly used to make salt at the smallest of Cargill's three San Francisco Bay-area salt operations.

Its other operations are going nowhere for at least the next 10 years, since the company already has government approval to continue harvesting salt through 2006. And so the saltmakers will do, much as they have on San Francisco Bay for 120 years.

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