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This presentation includes: Background, Offshore Discharge, Inland Surface Water Discharge, Irrigation, Surface Impoundment, and Underground Injection.
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Brine Disposal Alternatives
Options for Disposing of DesalinationConcentrate and Water Treatment Residuals
Anthony E. Bennett, R.S.Technical DirectorAECOM Water
Anthony E. Bennett, R.S.Technical Director
AECOM Water
Introduction
BackgroundOffshore DischargeInland Surface Water DischargeIrrigationSurface impoundmentUnderground Injection
Background
Desalination initiativeSeawater desalinationSeawater desalinationBrackish groundwaterBrackish groundwater
Recent Drinking Water StandardsArsenicArsenicRadionuclidesRadionuclidesStage 2 Surface Water TreatmentStage 2 Surface Water Treatment
Discharge to freshwater surface water(TPDES individual permit required)
Freshwater surface water usecan be adversely affected byincreases in salinityConcentrate TDS typically
much greater than waterquality standardsSalinity, Metals, toxic
substances, and naturallyoccurring radioactive materialsare concentrated bymembrane technologydesalination and can be apossible concern
Discharges to Publicly Owned Treatment Works (POTWs)(no TCEQ permit required)
Ability of the POTW to accept the wastewatervolume of the concentratevolume of the concentratesalinity of the concentratesalinity of the concentrate
Irrigation(TLAP individual permit required)
Any buildup of salt constituents can become toxic to thecrop and/or the soil biosphereWithout the crop and soil mechanisms, there is anincreased probability of impacting surface waters and/orimpacting groundwater
Surface Impoundment Evaporation(TLAP individual permit required)
No discharge to water in thestate is authorized by thisdisposal methodDisposal is entirely dependenton the evaporation rates in thelocation of the facilityImpoundments must be sizedproperly and lined toappropriately deal with overflowand prevent discharges(percolation) to groundwater
Solid Waste Disposal
Treatment residuals which can de driedTreatment residuals which can pass the TCLP can bedisposed of in municipal waste sitesTreatment residuals which cannot pass TCLP must behandled as hazardous waste
Discharge to marine surface waters(TPDES individual permit required)
No numerical water quality standards for TDS or ChlorideDischarges can adversely affect aquatic ecosystems ofestuaries and tidal riversMetals, toxic substances, and naturally occurringradioactive materials can be a concernDischarges further than 3 leagues offshore are underEPA jurisdiction
Underground Injection(UIC permit required)
Under Federal and Texas Statutes and regulations, apermit is required if disposal will occur below the base ofunderground source of drinking waterDisposal of a waste stream into a Useable Source ofDrinking Water (USDW) that is not hazardous and cannotdegrade an underground drinking water source isauthorized by rule (Class V)
Class I Injection Well
Injection of non Oil and Gas Waste below a UseableSource of Drinking Water (USDW)HB 2567 exempts Class I Desal disposal wells fromcontested case hearing
Class II Injection Well
Salt water co-produced with oil and gasFluids for enhanced recovery of oil and gasStorage of hydrocarbons that are liquid atstandard temperature and pressureWithout further federal rulemaking,desalination concentrate would have to beinjected into oil and gas producing zones forlegitimate enhanced recovery
UIC Revisions Under HB 2654
HB 2654 passed by 80th Texas LegislatureProvides for
State rules to allow desalination and other drinking waterState rules to allow desalination and other drinking watertreatment residuals into enhanced recovery wells permitted bytreatment residuals into enhanced recovery wells permitted byTXRRC without a Class I permit from TCEQTXRRC without a Class I permit from TCEQClass I permits by TCEQ for wells that are constructed to nonClass I permits by TCEQ for wells that are constructed to non--hazardous waste standards for disposal of desalination andhazardous waste standards for disposal of desalination anddrinking water treatment residualsdrinking water treatment residualsGeneral permits to authorize nonGeneral permits to authorize non--hazardous waste disposal ofhazardous waste disposal ofdesalination and drinking water treatment residualsdesalination and drinking water treatment residualsTCEQ rules addressing these provisions were adopted by TCEQTCEQ rules addressing these provisions were adopted by TCEQin June 2008, Effective July 10, 2008in June 2008, Effective July 10, 2008
TCEQ Non-Hazardous General Permit
Has not yet been adopted by TCEQWould apply only to disposal of desalination and drinkingwater treatment residualsIntended to apply also to dual permitting of Class IIdisposal wells
There are approximately 31,000 Class II wells inThere are approximately 31,000 Class II wells inTexasTexas
From UT Bureau of Economic Geology
From AECOM display of TXRRC data
Class V Injection Wells
Much faster and simpler approval processInjection must not cause pollution in the receivinggroundwater (30 TAC 331.5)
injectate is "as good or betterinjectate is "as good or better”” than receivingthan receivinggroundwatergroundwater
TCEQ has developed a list of other factors forconsideration in making the needed determinationsThis type of injection well authorization was utilized by ElPaso Water Utilities
Conclusion
Multiple options for Desalination Residual disposalOffshore DischargeOffshore DischargeInland Surface Water DischargeInland Surface Water DischargeIrrigationIrrigationSurface impoundmentSurface impoundmentDischarge to sanitary sewerDischarge to sanitary sewerUnderground InjectionUnderground Injection
Selection of an appropriate and affordable residuals managementoption is often the determining factor in project feasibility
Questions?