Tooele Transcript Bulletin – News in Tooele, Utah

March 15, 2016
Bonneville Salt Flats are ‘not disappearing’

In your “Save the Salt” editorial (March 1, 2016), you discuss reasons why the U.S. Bureau of Land Management needs to “get busy” formulating a plan to restore the Bonneville Salt Flats (BSF) to safe land-speed racing conditions. These additional facts may be useful to you and your readers.

Regarding stewardship of BSF, the BLM has actually been quite busy. For the last 19 years, the BLM has engaged in a cooperative agreement with two potash mining companies (Intrepid Potash Wendover, LLC and its predecessor, Reilly Industries, Inc.) to conduct an experimental Salt Laydown Project to replenish salt to BSF. Since 1997 (initiation of the Laydown Project) to present, an estimated 11.3 million tons of sodium-chloride salt have been transferred from company private land to BSF north of Interstate 80.

The BLM’s monitoring and data collection from the laydown experiment, and its subsequent 2003 salt-crust thickness study, produced three peer-reviewed published papers that assessed the Salt Laydown Project’s efficacy (see BLM’s West Desert District “Salt Flats Research” website, www.blm.gov/ut/st/en/fo/salt_lake/recreation/bonneville_salt_flats.html).

Objectives of publishing these papers were threefold: 1) archive study results as a permanent readily-accessible public record and inform the public of amount and fate of salt transferred annually to BSF; 2) preserve and provide analyses of the large body of geochemical and hydrological data collected by BLM and U.S. Geological Survey since mid-1970s; and 3) provide the BLM with data-compelled conclusions regarding performance of the Salt Laydown Project and findings from the BLM’s 2003 salt-crust thickness studies, so BLM could make science-based decisions going forward with management of BSF.

Based on conclusions from the three papers and review of Intrepid’s 2006 mining and reclamation plan, BLM mandated Intrepid 1) continue Salt Laydown Project for life of lease; 2) quantify and report salt tonnage being withdrawn from federal-lease collection ditches; 3) balance annual tonnage extracted from federal-lease collection ditches north of I-80 with annual tonnage being replaced through the Salt Laydown Project; and 4) perform a salt-crust thickness study similar to BLM’s 2003 study by 2018.

However, the BLM must also honor provisions of the federal potash lease, a valid existing right issued in 1963. This was prior to the National Environmental Policy Act (1969), which required consideration of impacts to the environment.

Intrepid recently contracted with Dr. Brenda Bowen, Associate Professor, Geology & Geophysics, University of Utah, to conduct the 2018 salt-crust thickness study. Research elements contained in Dr. Bowen’s study are a significant expansion of tools not available to the BLM during its 2003 Salt-Crust Thickness Study. As part of her study, Dr. Bowen will collect complete drill-core sets of salt-crust from the same 70 borehole locations of the BLM’s 2003 study. Complete drill-core sets will provide baseline for comparison with 2003 and future salt-crust thickness measurements and volume calculations to confirm if and how BSF salt-crust mass and volume have changed over time. The BLM will use results of Dr. Bowen’s 2018 study to determine if additional mitigating measures will be necessary in management and protection of BSF.

Regarding cancellation of 2015 racing events, it is indisputable that surface salt-crust stratum conditions changed last year from previous drought-influenced years. Specifically, during the 1997 – 2015 period, May 2015 was wettest on record for Wendover, Utah and vicinity where it received 2.35 inches of rain; in July 2015 it received 0.75 inches (Western Regional Climate Center, www.wrcc.dri.edu). On 15 July 2015, BLM and University of Utah geologists examined salt-crust exposures at mile posts 3 and 5 of Speed Week’s 2015 proposed race course. Results of this examination showed that surface salt-crust stratum had thinned, become soft and slushy in some areas, and like scattered popcorn in others, exposing underlying thin gypsum stratum.

While this condition likely had the appearance of salt-crust thinning, disappearing, and exposing Lake Bonneville clays underlying the salt-crust mass, this was not the case. The thin gypsum stratum is actually a natural component of the existing salt-crust sequence comprising multiple strata of halite and gypsum.

BLM-augered boreholes adjacent to each mile post showed that an additional 2 to 3 feet of salt-crust thickness was present beneath the thin, 0.5 to 1-inch thick gypsum stratum. Although 2015 surface salt-crust stratum changed, overall mass and volume of the salt flats remains relatively unchanged. This is based on BLM salt crust thickness studies conducted in 1988, 2003, and field-checked in 2015. Consequently, the geologic feature which is BSF is not disappearing, only changing seasonally.

In conclusion, effects of weather such as those observed from May and July 2015 rain events are beyond the BLM’s control. Consequently, it is impossible for the BLM to guarantee yearly safe land-speed racing conditions, especially if seasonal weather is determined to be the dominant factor governing the natural cyclic constructive-deconstructive condition of the surface salt-crust stratum/racing surface. Where the BLM does have, and has exhibited control, is its mandate to continue the Salt Laydown Project, and to require assessment of its efficacy through salt-crust thickness studies such as Dr. Bowen’s 2018 study.

White is a registered professional geologist and was the BLM’s physical scientist responsible for monitoring and assessing progress of the Salt Laydown Project from 1997 through 2007. He lives in Heber City, Utah. His email is wwwhiteiii43@q.com.

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