Salt, An Important Ingredient to Life

Salt
A World History
By Mark Kurlansky
484 pp. New York
Walker and Company

The missing chapter—Salt and Water
By Richard Atwater

Salt has been an important ingredient for food and sustenance since civilization began. Humans and most animals need salt to survive. It is also an effective preservative, and for thousands of years salted fish and meats and brine treated vegetables have been staples of the human diet. Salt in your diet is a required element but, like many things, too much of it may have adverse health impacts, including hypertension and high blood pressure.

The history of salt, its usage and customs, is fully explored in Mark Kurlansky's latest book: Salt A World History. Kurlansky does not discuss water and its relationship to salt, although it is becoming a very important part of water infrastructure. California has had to deal with salt in water since the gold mining days.

Water was, in essence, mined for its salt. For example, the Chinese began harvesting salt from evaporating lakes more than 8,000 years ago and, as a result, built some of the earliest plumbing infrastructure known to man. Salt mining from brine wells was a significant part of the Sechuan economy. Thousands of years before Europeans began using plumbing, bamboo pipes carried brine to the surface and separate pipes channeled natural gas to cook stoves that helped evaporate water from the brine.

Salt even may have determined the outcome of the Civil War. During the war, the South had a shortage of salt and without an ample supply for medicine, preservation of food and other uses the South's war effort was restricted. The North, realizing this resource problem, attacked the South's saltworks, causing the rationing of salt and severe shortages.

Several other cultures depended on salt throughout the ages and Kurlansky makes interesting observations that relate indirectly to water. For example, Egyptians used salt to make mummies. Ancient Hebrews viewed salt as the eternal nature of God. On Friday nights Jews dip the Sabbath bread in salt to symbolize the preservation of the agreement between God and his people. In Christianity, salt is associated with truth and wisdom. The Catholic Church dispenses not only holy water but holy salt, the Sal Sapientia, the Salt of Wisdom.

Even in medieval Europe, salt was a critical resource. French kings began taxing the substance in the 13th Century. By the time of King Louis XIV (1660), the salt tax, or gabelle, was a major source of tax revenue for the Crown. The hated gabelle was a way to ensure that everybody, rich or poor, paid tax. It was repealed during the French Revolution in 1789.

Until the 20th century, salt was a commodity that countries valued so highly that they fought over it. That reliance ended once a Frenchman invented the "tin can" and we began preserving food through heating and sealing in an air-tight container. In the 1900s refrigeration made salt obsolete for preserving food. Today it may seem strange that salt was such a valued substance.

A noteworthy California supply of table salt is the salt evaporation ponds in the southern portion of San Francisco Bay. The ponds divided off portions of the rich marine habitat, beginning in the 1860s, to allow the sun to evaporate the seawater and leave salt crystals to be scooped up for markets. Initially, the biggest market for the bay salt was the Comstock Lode in Nevada for silver mining. Unfortunately, these salt evaporation ponds had a high environmental cost, destroying thousands of acres of marine habitat and reducing the bird and fish populations in San Francisco Bay. Slowly these ponds are being restored to their natural condition.

In the San Joaquin Valley, salt and irrigation management have been part of a controversial federal water project for more than 50 years. The federal Central Valley Project began bringing Delta water for irrigation to the Westside of the San Joaquin Valley (primarily Fresno County) in the early 1960s and it was recognized then that because of the clay soils, a sewer drain to the ocean was needed to export the salt accumulating in the soil from irrigation. The federal government stopped construction of the drain during the Vietnam War because of budget cutbacks and it has never been finished because of environmental controversy. Today, farming land in the Westlands Water District is being bought and taken out of production because of the high concentration of salt in the soil.

Water and salt, or what water managers call salinity has an incredible impact on the Southern California economy. Too much salt in our water supplies corrodes pipes, water heaters and other mechanical equipment. Too much salinity in water supplies also reduces plant production or at some levels will kill plants that are salt sensitive. About half of our water supplies in Southern California are imported from the Colorado River, northern California through the State Water Project, and the eastern Sierra through LADWP's Owens Valley project.

The Colorado River supply is the most salty and is legendary for its salt content affecting farmers and now the urban areas that use its water (Phoenix, Tucson, Las Vegas, and Southern California). For more than five decades the seven states that divert and use Colorado River and the federal government have debated how to reduce the salinity of the Colorado River. A 1972 treaty between the United States and Mexico adopted salinity standards for the Colorado River water at the border. Additionally, the United States committed to a salinity control plan to ensure that Mexico received water less salty than the border water quality standard.

State Water Project supplies are less salty but also affect our economy. Because of tidal influences in the Delta, State Water Project supplies can vary in salinity from 100 mg/L to over 400 mg/L during droughts. The higher salinity affects crop production in Ventura County and causes violations of state wastewater discharge rules for water released into the Santa Clara and Los Angeles River watersheds.

LADWP's supply is generally low salinity (about 100 mg/L) Sierra mountain water and therefore, has no adverse salinity affects.

To deal with varying salinity and recognizing the importance of water quality has on our economy, Metropolitan's Board of Directors adopted a Salinity Management Plan in 1998 that blends its imported water to maintain targeted levels of salts in the water supplies. This blending policy and an action plan to manage salinity sources in our imported and local water supplies is important part of the overall Southern California water management strategy.

Salt today is a ubiquitous mineral that we buy in the supermarket in the blue round container at a very inexpensive price. Water, in the same way, is relatively very inexpensive. But both are intertwined in chemistry and ecology and future management of our water supplies will require the careful management and disposal of salt.

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