South Bay Salt Works

The South Bay Salt Works is a salt factory in southern San Diego, near Chula Vista, in the South Bay region of San Diego County, California.

South Bay Salt Works
South Bay Salt Works montague.jpg
Coordinates32°36′5″N 117°5′34″W / 32.60139°N 117.09278°W / 32.60139; -117.09278Coordinates: 32°36′5″N 117°5′34″W / 32.60139°N 117.09278°W / 32.60139; -117.09278
ProductsMagnesium chloride

Initially operating under the name La Punta Salt Works operations dating back to at least 1871, for a period of time it was the sole supplier of salt for Southern California. In 1902 it was purchased and renamed Western Salt Company, and later had narrow-gauge rail installed. During the rest of the 20th century, it was the second largest salt producer in California. The land was purchased by the San Diego County Regional Airport Authority in 1999 and transferred to the United States Fish and Wildlife Service. In 2000, it assumed its current name, and has continued salt harvesting operations.

Water evaporated at the salt works comes from the Pacific Ocean since its inception, more than a million tons of salt has been harvested. The salt ponds are a stopping point for migratory birds, some of them threatened or endangered. In 2011, two of the works' salt ponds were restored to marshlands.


Salt evaporation ponds and mounds of crystallized salt awaiting the harvest

Initially the operation began as the La Punta Salt Company.[3] Records date its origin as being before 1872.[1] This is supported by a 1965 report by the State of California, and a 2015 notice by the City of Imperial Beach state that the area has been used as a salt works as early as the 1860s.[4][5] In 1883, the salt works were the only salt producer in the county, supplying the salt needs of all of Southern California.[1][2] Around the turn of the 20th century, the salt works were the only industrial employment in the Chula Vista area, other than produce packing plants.[6]

In 1902, La Punta Salt Works was purchased, and renamed to Western Salt Company.[1] In the 1910s, about forty thousand tons of salt were harvested annually from the salt works.[7] In 1915, a narrow-gauge railway was installed, and crossed over standard-gauge railway of the San Diego and Arizona Railway; the narrow-gauge railway was dismantled in the 1970s, except for where it crossed over standard-gauge rail, preserving the only instance of such an occurrence in the United States.[1] In 1916, operations were disrupted due to flooding;[8] the flood destroyed the salt ponds and the salt works built up to that point.[9] In 1918, reconstruction began due to damage caused during the 1916 flooding, reaching completion in the 1950s.[10] After the 1910s, other salt producers in San Diego County closed, leaving the salt works the sole salt producer in the county.[4]

In the 1920s another company, California Chemical Corporation, extracted bromine from the waters from the salt ponds.[4][6] In addition the company also produced magnesium chloride, beginning as early as the 1910s.[4] Production of bromine ended after World War II.[4]

During the majority of the 20th century, the amount of salt harvested at the salt works remained relatively constant.[1] In 1958, Western Salt Company was the second largest salt producer in California, which also had salt production operations in Newport Beach, at the time.[1] As late as 1978, the salt works supplied the salt needs of San Diego's tuna fleet.[11] In 1999, the salt ponds were sold to the San Diego County Regional Airport Authority, transferring the salt ponds to the United States Fish and Wildlife Service; both have leased it out for continued salt harvesting.[3] The leasers are a company formed by former employers of Western Salt Company, who changed the name to its present name, maintaining the buildings as private property of the salt works itself.[1] In 2005, right of way of the former Coronado Belt Line in the salt pools, were designated historic by the city of San Diego[12] and later converted into a bike path as part of the "Bayshore Bikeway".[13] In 2009, the city of San Diego claimed land use authority over the property.[9] In 2011, two of the works' salt ponds were restored to marshlands.[14] Additional work is a requirement of the permit for the Carlsbad desalination plant.[15]


Satellite view of the salt ponds.

The operation is the second-longest running business in San Diego, behind the San Diego Union Tribune.[16][17] In Chula Vista, it is the city's longest running business.[3] Although in the Chula Vista area, it is not within the Chula Vista city limits;[6] the property is actually in the Nestor neighborhood.[9] The buildings of the salt works are eligible to be placed on the U.S. National Register of Historic Places;[1] the buildings are already on the California Register of Historical Places.[9][18]

On the West Coast of the United States, only San Francisco Bay and San Diego Bay have the natural conditions that allow for salt extraction from sea salt to be feasible.[19] Water evaporated at the salt works come from the Pacific Ocean, not San Diego Bay.[20] The salt works produces about 75,000 tons of salt every year from salt ponds that cover over a thousand acres of land.[21][22] Since operations began at the salt works, more than a million and a half tons of salt have been harvested.[4] Gypsum can also be sourced from the salt works, as was done in a 2008 study of the mineral.[23] Magnesium chloride is also produced during the solar salt operation and is sold for industrial use.[8] In 2005, the salt works employed twenty-two people.[21] In 2017, the salt works continued to produce about 80,000 pounds of salt per harvest.[24]

Since 1999, the parcel which the salt works is on has been owned by the San Diego Regional Airport Authority, leased to the South Bay Salt Works company.[25] In 2015, the Airport Authority planned to sell the land which the salt works are on to the San Diego Foundation, to mitigate the building of a substation by San Diego Gas & Electric.[26] It is planned that when the lease on the land ends, the buildings will be re-purposed similar to those on Cannery Row.[26] One proposed use is to convert the salt works into an interpretive center for the United States Fish and Wildlife Service.[25][27]


Elegant terns at the salt works in 2009

The salt ponds of the salt works fall within the San Diego Bay National Wildlife Refuge.[8][28] The salinity of the salt ponds creates an environment which breeds brine flies (Ephydridae) and brine shrimp (Artemia), a food source for the birds.[16] During the winter months, there are monthly tours out into the salt ponds to observe migratory birds.[29]

Ninety-four different species of birds reside in the area of the salt ponds, including migratory species; seven of the species are threatened or endangered.[16] In 2010, over twenty thousand birds were counted at the salt ponds, including the endangered species California least tern (Sternula antillarum browni) and gull-billed tern (Gelochelidon nilotica vanrossemi).[30]

In 2011, a nearly $8 million project restored two of the westernmost ponds to marshland.[14] In 2013, a study of the hypersaline waters of the salt works showed that its microbial makeup differs substantially from those of a similar salt pond in Santa Pola, Spain.[31] Due to the presence of these threatened and endangered species at the salt ponds, they were included in Port of San Diego's natural resources management plan, which was completed in September 2013.[32]

See alsoEdit


  1. ^ a b c d e f g h i Angie Gustafson; Carrie Gregory; Karen J. Weitze (2001). "Western Salt Company Works" (PDF). Historic American Landscapes Survey. Library of Congress. Retrieved April 29, 2015.
  2. ^ a b Lynne Newell Christenson; Ellen L. Sweet (2008). Ranchos of San Diego County. Arcadia Publishing. p. 121. ISBN 978-0-7385-5965-0.
  3. ^ a b c Frank Roseman (April 16, 2008). Chula Vista. Arcadia Publishing. p. 71. ISBN 978-1-4396-2011-3.
  4. ^ a b c d e f F. Harold Weber Jr.; Ray M. Kepner Jr.; George B. Cleveland; R.M. Stewart (1963). "Geology and Mineral Resources of San Diego County, California, County Report 3" (PDF). California Division of Mines and Geology. State of California. Archived from the original (PDF) on June 26, 2016. Alt URL
  5. ^ "Notice of Intent and Availability for Public Review and Comment Period of Draft Mitigated Negative Declaration" (PDF). Community Development Department. City of Imperial Beach, California. September 25, 2015. Archived from the original (PDF) on September 2, 2015. Retrieved April 29, 2015. P-37-026582 is the historic Western Salt Company Salt Works, which has been in operation since the 1860s.
  6. ^ a b c Shannon Davis; Sarah Stinger-Bowsher; Jennifer Krintz; Sinead Ni Ghabhlain (November 2012). "Historical Resource Survey, Chula Vista, California". City of Chula Vista. Retrieved May 1, 2015.
  7. ^ Southern California: Comprising the Counties of Imperial, Los Angeles, Orange, Riverside, San Bernardino, San Diego, Ventura. Southern California Panama Expositions Commission. 1914. p. 237.
  8. ^ a b c "Comprehensive Conservation Plan and Environmental Impact Statement, Volume II" (PDF). San Diego Bay National Wildlife Refuge. United States Fish and Wildlife Service. August 2006. Retrieved April 30, 2015.
  9. ^ a b c d Kelly Saunders (September 18, 2009). "Item 6 – Western Salt Company Salt Works" (PDF). Historic Resources Board. City of San Diego. Retrieved May 2, 2015.
  10. ^ Tierra Environmental Services (January 2, 2001). "The Biological Resources of South San Diego Bay and the Effect of Thermal Effluent from the South Bay Power Plant" (PDF). State Water Sources Control Board. State of California. Retrieved May 1, 2015.
  11. ^ "The San Diego Tuna Industry and Its Employment Impact on the Local Economy" (PDF). National Marine Fisheries Service. National Oceanic and Atmospheric Administration. July 1978. Retrieved May 2, 2015.
  12. ^ "San Diego council upholds historic designation of an unused 1.5-mile stretch of the Coronado Belt Line railway". San Diego Union Tribune. North County Times wire services. September 14, 2005. Retrieved May 2, 2015.
  13. ^ "Final Environmental Assessment" (PDF). San Diego National Wildlife Refuge Complex. United states Fish and Wildlife Service. October 20, 2009. Retrieved May 2, 2015.
    Mike Westlake; Patricia Grabski (August 30, 2007). "Bayshore Bikeway – Project No. 1901. Process 5" (PDF). Planning Commission. City of San Diego. Retrieved May 2, 2015.
    Ed Kravitz (December 19, 2014). "I'm going to bury your little railroad". San Diego Reader. Retrieved May 2, 2015.
  14. ^ a b Davis, Rob (September 23, 2011). "The Environmental Resurrection of South San Diego Bay". Voice of San Diego. Retrieved May 1, 2015.
    Joyce, Ed; McVicker, Nicholas (November 2, 2011). "Estuary Reborn In South San Diego Bay". KPBS. San Diego. Retrieved May 1, 2015.
    "South San Diego Bay Restoration". Project Board. Southern California Wetlands Recovery Project. 2015. Retrieved May 1, 2015.
  15. ^ Diehl, Phil (August 8, 2022). "Poseidon failed to start wetlands restoration on time, says Coastal Commission". San Diego Union-Tribune. Retrieved August 8, 2022.
  16. ^ a b c Lea Yu (June 16, 2008). "The Hidden Salt Ponds of Chula Vista". Voice of San Diego. Retrieved April 29, 2015.
  17. ^ Jenkins, Logan (March 24, 2015). "Salt works: Symbol of change?". San Diego Union-Tribune. Retrieved September 3, 2018.
    Chen, Ruby (June 24, 2018). "Explore San Diego: The Salt Mines of Chula Vista". KSWB. San Diego. Retrieved September 3, 2018.
  18. ^ John Blocker. "San Diego's Lost Landscape: La Punta" (PDF). History of Otay Valley. Otay Valley Regional Park. Archived from the original (PDF) on September 24, 2015. Retrieved April 30, 2015.
  19. ^ Lou Ann Speulda-Drews; Nicholas Valentine (March 9, 2009). "Appendix E: Identification and Evaluation of the South San Francisco Solar Salt Industry Landscape" (PDF). South Bay Salt Pond Restoration Project. United States Fish and Wildlife Service. Retrieved May 2, 2015. On the West Coast, only San Francisco Bay and San Diego Bay possess the exact conditions to allow the industry to thrive. In order for the solar salt industry to flourish several natural features need to occur: a protected bay; large expanses of flat, shallow water shoreline; abundant salt water; months of dry, sunny weather; and periods of rain.
  20. ^ "Best of 2001: Best Place To Buy Your Locally Grown Salt". San Diego Reader. December 27, 2001. Retrieved May 2, 2015.
  21. ^ a b Earnie Grafton (October 22, 2005). "Focal Point: South Bay Salt Works" (PDF). Sign On San Diego. San Diego Union-Tribune. Archived from the original on October 22, 2005. Retrieved April 30, 2015.
  22. ^ CurtCo/SDM LLC (October 2011). San Diego Magazine. CurtCo/SDM LLC. p. 46. ISSN 0036-4045.
  23. ^ Andrew D. Aubrey (2008). Amino Acid Biosignatures – Implications for the Detection of Extinct Or Extant Microbial Communities on Mars. pp. 34–35. ISBN 978-0-549-49065-4.
  24. ^ Bailey, Torrey (May 3, 2017). "Neighborhood Watch: Chula Vista". San Diego City Beat. Retrieved February 15, 2019.
  25. ^ a b Pentiss Williams (November 9, 2006). "Western Salt Works Site Assessment and South San Diego Bay Trail Linkages" (PDF). Coastal Conservancy. State of California. Retrieved May 1, 2015.
  26. ^ a b Jenkins, Logan (March 24, 2015). "Salt works: Symbol of change?". San Diego Union Tribune. Retrieved May 1, 2015.
  27. ^ Romero, Fernando (May 10, 2008). "Historic salt plant may get new role along waterfront". San Diego Union-Tribune. Retrieved September 3, 2018.
    Blocker, John. "San Diego's Lost Landscape: La Punta" (PDF). Otay Valley Regional Park. Multi-jurisdictional effort by the City of Chula Vista, County of San Diego and the City of San Diego. Archived from the original (PDF) on September 24, 2015. Retrieved September 3, 2018.
    "Exhibit 6: Letters of Support" (PDF). Coastal Conservancy. State of California. 2006. Retrieved May 1, 2015.
  28. ^ "Map". San Diego Bay National Wildlife Refuge. United States Fish and Wildlife Service. 2015. Retrieved April 30, 2015.
  29. ^ "Visitor Activities". San Diego Bay National Wildlife Refuge. United States Fish and Wildlife Service. 2015. Retrieved April 30, 2015.
  30. ^ Barbara Moreno (May 27, 2010). "Bird Population Thriving in South San Diego Bay". Environment. Unified Port of San Diego. Retrieved April 30, 2015.
  31. ^ Zhaxybayeva, Olga; Stepanauskas, Ramunas; Mohan, Nikhil Ram; Papke, R. Thane (January 29, 2013). "Cell sorting analysis of geographically separated hypersaline environments". Extremophiles. 17 (2): 265–275. doi:10.1007/s00792-013-0514-z. PMID 23358730. S2CID 5933801.
  32. ^ "Natural Resources & Wildlife". Environment. Unified Port of San Diego. 2015. Retrieved April 30, 2015.

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