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Groundwater / AquiferGroundwater / AquiferRemediationRemediation

State Water Plan Update State Water Plan Update

77th Advisory Committee 77th Advisory Committee MeetingMeeting

30 January 200430 January 2004

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Groundwater RemediationGroundwater Remediation Generally pertains to “pump and Generally pertains to “pump and

treat” systems treat” systems Groundwater is pumped to the Groundwater is pumped to the

surface and processed by some surface and processed by some technique that removes the technique that removes the contaminantcontaminant

Recharge and movement of water Recharge and movement of water thru the aquifer will also remediate thru the aquifer will also remediate the aquifer over timethe aquifer over time

Treated water can then be re-used or Treated water can then be re-used or disposed ofdisposed of

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Pump and TreatPump and Treat

Activated aluminaActivated alumina BiologicalBiological BlendingBlending Coagulation/Coagulation/

filtrationfiltration Granular activated Granular activated

carbon; GACcarbon; GAC

Ion exchange; IXIon exchange; IX Lime softeningLime softening Packed tower Packed tower

aeration; air aeration; air strippingstripping

Reverse osmosis; Reverse osmosis; RORO

Ultra-violet Ultra-violet photoionizationphotoionization

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Aquifer RemediationAquifer Remediation

Generally pertains to “in situ” Generally pertains to “in situ” treatment systemstreatment systems

Treatment is by physical, chemical, Treatment is by physical, chemical, biological, or electrokinetic methodsbiological, or electrokinetic methods

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In-situIn-situ

Air spargingAir sparging Bio-spargingBio-sparging Bio-ventingBio-venting CosolventsCosolvents ElectrokineticsElectrokinetics Electron acceptors; Electron acceptors;

NONO33, SO, SO44,Fe,Fe+3+3

Electron donors; Electron donors; chlorinated chlorinated hydrocarbonshydrocarbons

Fluid cyclingFluid cycling Hydro or pneumatic Hydro or pneumatic

fracturingfracturing Soil vapor extraction; Soil vapor extraction;

SVESVE Surfactant Surfactant

enhancementsenhancements Thermal Thermal

enhancementsenhancements Treatment wallsTreatment walls Vitrification Vitrification

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DesalinationDesalination

The removal of salt, especially from The removal of salt, especially from seawater, but also from brackish seawater, but also from brackish water starting at about 900 ppm water starting at about 900 ppm total dissolved solidstotal dissolved solids

May include removal of May include removal of trihalomethanes, nitrate, and trihalomethanes, nitrate, and hardnesshardness

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What is a salt?What is a salt? Sodium chloride, NaCl, or table salt, is an Sodium chloride, NaCl, or table salt, is an

example of a salt.  A salt is any compound example of a salt.  A salt is any compound that readily dissolves in water.  Salts are that readily dissolves in water.  Salts are formed by the combination of any negative formed by the combination of any negative ion, except hydroxide, with any positive ion, ion, except hydroxide, with any positive ion, except hydrogen or hydronium.  They can except hydrogen or hydronium.  They can also be the water soluble precipitate also be the water soluble precipitate produced as the result of neutralization of an produced as the result of neutralization of an acid with a base. Common salts in acid with a base. Common salts in California groundwater include sodium California groundwater include sodium chloride, sodium sulfate, potassium chloride, chloride, sodium sulfate, potassium chloride, calcium sulfate, magnesium sulfate, calcium sulfate, magnesium sulfate, magnesium chloride, calcium chloride, and magnesium chloride, calcium chloride, and sodium and calcium carbonate and sodium and calcium carbonate and bicarbonate. bicarbonate.

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Desalination vs. remediationDesalination vs. remediation

Desalination and remediation in their Desalination and remediation in their ‘purest’ forms are separate issues‘purest’ forms are separate issues

Today there is overlap depending on Today there is overlap depending on the constituent of interest & the the constituent of interest & the method used to remove that method used to remove that constituentconstituent

Membranes and nanofiltration Membranes and nanofiltration previously used in desal are more previously used in desal are more frequently being used in remediationfrequently being used in remediation

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Remediation sitesRemediation sites

Some type of treatment has taken place, Some type of treatment has taken place, or is taking place at about 18,500 sites in or is taking place at about 18,500 sites in CaliforniaCalifornia

Treatment is also taking place at Treatment is also taking place at thousands of drinking water sourcesthousands of drinking water sources

Records of these projects are on file in Records of these projects are on file in offices of the Regional Water Quality offices of the Regional Water Quality Control Boards, Department of Health Control Boards, Department of Health Services Districts, Department of Toxic Services Districts, Department of Toxic Substances Control, & local agenciesSubstances Control, & local agencies

The records have not been compiled in a The records have not been compiled in a statewide summarystatewide summary

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Contaminants--1Contaminants--1

1,2-Dibromo-3-chloropropane, DBCP1,2-Dibromo-3-chloropropane, DBCP 1,2-Dichloroethane1,2-Dichloroethane 1,2,3-Trichloropropane, 1,2,3-TCP1,2,3-Trichloropropane, 1,2,3-TCP Arsenic, AsArsenic, As Carbon tetrachloride, CTCCarbon tetrachloride, CTC Ethylene dibromide, EDBEthylene dibromide, EDB Methyl tertiary butyl ether, MTBEMethyl tertiary butyl ether, MTBE N-Nitrosodimethylamine, NDMAN-Nitrosodimethylamine, NDMA

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Contaminants--2Contaminants--2

Nitrate as NONitrate as NO33--

Nitrate + Nitrite (NONitrate + Nitrite (NO22) as N) as N Perchlorate, ClOPerchlorate, ClO44

Tetrachloroethylene, PCETetrachloroethylene, PCE Total petroleum hydrocarbons, TPHTotal petroleum hydrocarbons, TPH Trichloroethylene, TCETrichloroethylene, TCE Uranium, UUranium, U

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Total petroleum Total petroleum hydrocarbonshydrocarbons

Describes a large family of several Describes a large family of several hundred chemical compounds derived hundred chemical compounds derived from crude oilfrom crude oil

Examples are hexane, jet fuels, mineral Examples are hexane, jet fuels, mineral oils, benzene, toluene, xylenes, oils, benzene, toluene, xylenes, naphthalene, fluorene, petroleum naphthalene, fluorene, petroleum products, gasolineproducts, gasoline

Not practical to measure for each chemicalNot practical to measure for each chemical Thus, TPH is measuredThus, TPH is measured

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Potential costs with Potential costs with remediationremediation

Characterizing the aquifer or Characterizing the aquifer or groundwater in terms of all the groundwater in terms of all the contaminants presentcontaminants present

Capital cost of the remediation system Capital cost of the remediation system Operation & maintenance costs during Operation & maintenance costs during

the life of the projectthe life of the project Operation of the system may be Operation of the system may be

required for many yearsrequired for many years

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Potential costs without Potential costs without remediationremediation

Securing an alternative water supplySecuring an alternative water supply Long-term foregone profits and taxesLong-term foregone profits and taxes Foregone housing development Foregone housing development

because there is inadequate waterbecause there is inadequate water Continued spreading of the Continued spreading of the

contaminant, making eventual contaminant, making eventual remediation more costlyremediation more costly

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Major issues—water qualityMajor issues—water quality

Contaminant source must be eliminatedContaminant source must be eliminated Constituent and concentration varyConstituent and concentration vary Some constituents may be unregulatedSome constituents may be unregulated Contamination may be poorly Contamination may be poorly

characterizedcharacterized Locating plume dimension is costlyLocating plume dimension is costly Program design requires these dataProgram design requires these data Additional contaminants may be foundAdditional contaminants may be found

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Major issues—water Major issues—water quantityquantity

Aquifer geometry and characteristics Aquifer geometry and characteristics must be knownmust be known

Water budget should be developedWater budget should be developed

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Major issues—local Major issues—local government & land usegovernment & land use

Local government and local agencies Local government and local agencies should:should: Limit potentially contaminating activities Limit potentially contaminating activities

in recharge areasin recharge areas Work together to develop and maintain Work together to develop and maintain

a good quality long-term water supply a good quality long-term water supply for beneficial usesfor beneficial uses

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Major issues—costs of Major issues—costs of treatmenttreatment

Who are the responsible parties?Who are the responsible parties? How quickly can they be identified?How quickly can they be identified? Who will pay?Who will pay? What is the appropriate share for What is the appropriate share for

each responsible party?each responsible party?

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Major issues—potential Major issues—potential impactsimpacts

Remediation may increase the Remediation may increase the available water supplyavailable water supply

Aquifer remediation may increase Aquifer remediation may increase the amount of storage capacity that the amount of storage capacity that is available for use without is available for use without treatment, thereby lowering coststreatment, thereby lowering costs

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Recommendations--1Recommendations--1

Provide funding to local agencies for Provide funding to local agencies for remediation projectsremediation projects Identification of responsible partiesIdentification of responsible parties Capital costsCapital costs

Identify responsible parties more Identify responsible parties more quickly so funding is available soonerquickly so funding is available sooner

Provide technical assistanceProvide technical assistance

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Recommendations--2Recommendations--2 Compile information on current projectsCompile information on current projects

Contaminants involvedContaminants involved Amount of contaminantAmount of contaminant Type of treatmentType of treatment Projected life of the projectProjected life of the project Capital costCapital cost O & M cost, including waste disposalO & M cost, including waste disposal Amount of groundwater treatedAmount of groundwater treated Seasonal changes in amount treatedSeasonal changes in amount treated Extraction wellsExtraction wells Number of connections servedNumber of connections served

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Recommendations--3Recommendations--3

The 3 P rule for protecting The 3 P rule for protecting groundwater is: groundwater is: PREVENT, PREVENT, PREVENT, PREVENTPREVENT, PREVENT groundwater groundwater contaminationcontamination

Local agencies should implement Local agencies should implement source water protection programs source water protection programs based on the assessments completed based on the assessments completed in 2003in 2003

A lot more education is needed!!!A lot more education is needed!!!