Solute Travel‐time Estimates for Tile‐drained Fields: III. Removal of a Geothermal Brine Spill from Soil by Leaching

Abstract

The time required to leach a slug of saline, sodic geothermal brine from the point of injection to the tile outlet of an artificially drained field is calculated. Sprinkler, complete, and partial ponding leaching methods are compared as a function of drain spacing and initial location of the spill. Calculated results are presented as dimensionless parameters which scale the drainage system dimensions and the soil water transport properties. Ponded leaching required more water, but less time to leach brine out of the system for all situations except where the brine spill occurs near the midpoint between tile lines.A simple calculation is proposed to estimate the leaching fluid volume required to remove excess Na+ from the exchange complex. Good agreement was attained between simulated and experimental results involving a laboratory soil column. For fine‐textured soils in the Imperial Valley of California it may require up to 30 pore volumes of leaching fluid to replace Na+ with Ca2+ if saturated gypsum solution is used in reclamation. Application time per pore volume was calculated to be in excess of 1 year for all cases except ponded leaching directly over a tile line.

Approaching Brine Spill Remediation from the Surface: A New In Situ Method

“…Since 2001, official brine spill reports filed at the North Dakota Department of Health and the North Dakota Industrial Commission exceed 13,000 cases with an average of 42 reports filed per week during 2014 (North Dakota Department of Health, 2015). These brines contain sodium and chloride at >10,000 and >100,000 mg L -1 , respectively, with electrical conductivities (EC) often above 200 dS m , values similar to those reported by others across North America (Tomlinson et al, 2015;Dresel and Rose, 2010;Jury and Weeks, 1978).…”

“…The infiltration of divalent cations (mainly Ca 2+ based) is to displace sodium from soil exchange sites, minimize soil dispersion, and increase effective pore diameters to leach salts from the root zone. Remediation timelines can range from 1 to >1000 yr while deploying this traditional method (Jury and Weeks, 1978). Given these time scales, it is surprising that no efforts attempting to bring salts to the soil surface for harvesting are reported in the literature.…”

Comparison of soil-to-water suspension ratios for determining electrical conductivity of oil-production-water-contaminated soils

“…Soil contamination from oil and geothermal production brines, with similar solution chemistries as those in North Dakota, have been reported in Kansas (Latta 1963), Ohio (Munn and Stewart 1989), Oklahoma (Atalay et al 1999;Sublette et al 2005Sublette et al , 2007, Pennsylvania (Dresel and Rose 2010), Texas (McFarland et al 1987), and California (Jury and Weeks 1978). Oil and geothermal production brine is a concentrated mixture of dissolved salts, the most abundant being sodium chloride (NaCl) (Aschenbach and Kindscher 2006).…”

Crystallization Inhibitors and Their Remediation Potential on Brine‐Contaminated Soils

“…Drilling wastewaters, a byproduct of oil and gas drilling and production operations, often referred to as brine, contain high quantities of soluble salts. These brines typically contain total dissolved solids (TDS) in excess of 100,000 mg L −1 , comprised mostly of Na + and Cl − ions, and exhibit electrical conductivities (ECs) >200 dS m −1 (Lauer et al, 2016;Dresel and Rose, 2010;Sublette et al, 2007;Jury and Weeks, 1978). Brines produced in North Dakota contain some of the highest levels of salinity (Horner et al, 2016).…”

“…Since 2001, official brine-spill reports in North Dakota have averaged 18 per week, with several pipeline leaks spilling >4 million L of brine each (Lauer et al, 2016;North Dakota Department of Health, 2015). Common in situ methods for remediating brine spills involve applying a chemical amendment and subsequent leaching of the salts below the plant root zone (Ashworth et al, 1999;Atalay et al, 1999;Halvorson and Lang, 1989;De Jong, 1982;Jury and Weeks, 1978). However, these chemical amendments are often effective to the depth they are incorporated into the soil Robbins, 1986) and large amounts of water and time (1 to >1000 yr) are required for treatments to be effective (Jury and Weeks, 1978).…”