With the diversion of the Owens River into the Los Angeles Aqueduct beginning in 1913, Owens Lake, the river’s natural terminus, became bone dry by 1926. Shortly thereafter, severe alkali dust storms arising from the 108 square-mile dry lakebed began to plague the region regularly—as much as four million tons of Owens Lake dust per year has been reported to have traveled as far as San Bernardino and other southern locations.[1]
By the 1980s, national air pollution standards had been set by the EPA for windblown particulate matter ten microns in diameter or less. Normally associated with dust, smoke, and haze resulting from natural fires, motor vehicles, industry, or agriculture, the PM-10 emanating off of Owens Lake is considered to be the largest single source of this pollutant in the nation.[2]
With the passing of California Health and Safety Code 42316, a series of negotiations with the Great Basin Unified Air Pollution Control District (GBUAPCD) took place during the late 1990s. The City of Los Angeles and GBUAPCD entered into a Memorandum of Agreement (MOA) in July 1998, requiring the LADWP to implement dust control mitigation measures designed to meet state and federal air quality standards by the mid-2000s. It was agreed that LADWP would remediate forty square-miles of the dry Owens lakebed—initiating the largest dust control project of its kind ever attempted in North America.
Although the MOA did not require LADWP to fully rewater Owens Lake, it did stipulate that the department needed to begin trials of three approved dust control remediation strategies including shallow flooding, managed vegetation, and gravel cover with other approved “reasonable measures.”
Shallow flooding through a bubbler system was the first dust control method implemented when trials began in 2001. A positive by-product of the flooding was the creation of marsh and shallow lake habitat that was quickly utilized by migratory birds and other resident wildlife. Although flooding is an obvious choice for dust abatement, it is costly and requires a ton of water. LADWP claims that up to 95,000 acre-feet of water per year is currently used in Owens Lake remediation efforts—an amount nearly equal to the City of San Francisco’s annual water supply.[3]
Managed vegetation utilizing native grasses and other rhizomes to control dust is the second control method. This technique has been successful at some locations but only works where soil and drainage conditions are optimum. Compared with shallow flooding this method uses a third of the water required for flooding to be effective.
The third method involves covering large areas with gravel four inches deep over an industrial type fabric. This technique has been used on 1.4 square miles of the lakebed to date. This particular approach has been difficult to gain approval for, as it fails to provide any viable habitat for birds and other wildlife. Gravel is also terribly expensive—costing up to $30 million for a single square-mile of the material. Additionally, the gravel method presents other problems; expensive heavy machinery used to move gravel has sunk into the unstable lakebed on numerous occasions.[4] Another proposed, but failed strategy includes the “moat & row” tillage method.
VanWagoner stated in his interview that the LADWP has spent to date 1.2 billion dollars on the Owens Lake Dust Mitigation Project, which includes construction, operation, and maintenance of any implemented mitigation measure. Additionally, the City of Los Angeles must pay to replace the water purchased from more expensive outside sources to compensate for the water used to rewater Owens Lake.
An attorney for LADWP announced in February 2012 that it is “done” with furthering its dust mitigation efforts on Owens Lake.[5] The LADWP’s press release stated that it plans to fulfill and maintain its current remediation obligations but will fight any future mitigation measures brought to court by GBUAPCD or other entities. The release additionally stated that “less water-intensive control measures have proved unnecessarily difficult, if not impossible” creating a conundrum for the department whose ultimate mission is to deliver water from the Eastern Sierra to the City of Los Angeles, not vice-versa.
Track Credits
Music: Claire Diterzi, “White Sands” (used by permission).
FOOTNOTES (click to open/close)
[1] Molly Peterson, “Owens Lake dust kicks up questions about DWP’s eastern Sierra efforts,” 89.3 KPCC, December 12, 2010.
[2] Great Basin Unified Air Pollution Control District, accessed on September 17, 2012, http://www.gbuapcd.org/Information/OwensLakeParticulateMatterHealthEffects.htm.
[3] William VanWagoner, interview with Kim Stringfellow in Los Angeles, August 17, 2012.
[4] Molly Peterson, “LADWP says Owens Lake’s ‘Owengeti’ could suggest new modes for dust control,” 89.3 KPCC, June 15, 2012.
[5] Mike Gervais, “DWP tells state board it’s ‘done’ at Owens Lake,” The Inyo Register, June 25, 2012.