perchlorate kevin mayer - u.s. epa, region 9 75 hawthorne, san fran. ca 94105 [email protected]...
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PERCHLORATEPERCHLORATEKevin Mayer - U.S. EPA, Region 9
75 Hawthorne, San Fran. CA 94105 [email protected]
What is Perchlorate - Chemistry & Uses What is Perchlorate - Chemistry & Uses
ToxicityToxicity
Brief History of Environmental ConcernBrief History of Environmental Concern
Regulatory StatusRegulatory Status
OccurrenceOccurrence
Perchlorate Perchlorate CHEMISTRYCHEMISTRY
Highly Oxidized Chlorine, ClO4-Highly Oxidized Chlorine, ClO4-
Dissociated Salt, Anion, in WaterDissociated Salt, Anion, in Water
Highly Soluble, Mobile, StableHighly Soluble, Mobile, Stable
Difficult to Detect, Difficult to TreatDifficult to Detect, Difficult to Treat
Standard Ion Chromatography MethodStandard Ion Chromatography Method
- Detection > 400 ppb - Detection > 400 ppb - - CA method to CA method to 4 ppb4 ppb by March 1997 by March 1997
USES of PERCHLORATE USES of PERCHLORATE
90% used as Solid Rocket Fuel Oxidizer90% used as Solid Rocket Fuel Oxidizer
ExplosivesExplosives
Fireworks and PyrotechnicsFireworks and Pyrotechnics
Reported in Nitrate Fertilizer from ChileReported in Nitrate Fertilizer from Chile
Before 1997 Before 1997 PERCHLORATE HISTORYPERCHLORATE HISTORY
1980s - Aware of Perchlorate in CA and NV1980s - Aware of Perchlorate in CA and NV
1985-86 - San Gabriel Valley Superfund Site1985-86 - San Gabriel Valley Superfund Site
1990s - Rancho Cordova (Aerojet) ppm1990s - Rancho Cordova (Aerojet) ppm
1992 and 1995 - Provisional Reference Dose1992 and 1995 - Provisional Reference Dose
1997 - Analytical Breakthrough to 4 ppb1997 - Analytical Breakthrough to 4 ppb
Agency for Toxic Substances and Disease Agency for Toxic Substances and Disease Registry - ATSDR Registry - ATSDR (January 21, (January 21, 19861986):):
“… the data do not prove that perchlorate ion has actually been found.”“… the data do not prove that perchlorate ion has actually been found.”
. .
“The scientific database is insufficient to generate either an acute or longer-term health advisory for drinking water. ”
“The scientific database is insufficient to generate either an acute or longer-term health advisory for drinking water. ”
Perchlorate Perchlorate TOXICOLOGY
Before 1997TOXICOLOGY
Before 1997
ThyroidThyroid Disruption (Iodide Mimic) Disruption (Iodide Mimic)
Human Drug Tests in 1950'sHuman Drug Tests in 1950's
EPA Provisional Reference Dose 1992 / 95EPA Provisional Reference Dose 1992 / 95Range of 4 to 18 ppb in Drinking WaterRange of 4 to 18 ppb in Drinking Water
Children's Health and Chronic Effects Not AddressedChildren's Health and Chronic Effects Not Addressed
High UncertaintiesHigh Uncertainties
ToxicologyToxicologyEPA InterpretationsFrom January 2002 DraftEPA InterpretationsFrom January 2002 Draft
Draft Reference Dose of 0.00003 Draft Reference Dose of 0.00003 mg/kg-daymg/kg-day
AdultAdult DW Exposure DW Exposure = 1 ppb= 1 ppb
Effects in rat pups after dosing mothersEffects in rat pups after dosing mothers
Ecological Risks not ClearEcological Risks not Clear
Other Routes of Exposure? Food?Other Routes of Exposure? Food?
Thyroid hormones
Brain morphometry
Thyroid histopathology
EPA 2002 Draft
Effects on Lab Animals0.01 mg/kg-day, lowest dose
EPA 2002 Draft
Effects on Lab Animals0.01 mg/kg-day, lowest dose
Science Based Only, Not a RegulationScience Based Only, Not a Regulation
RfD =RfD =
What is a REFERENCE DOSE (RfD)?
What is a REFERENCE DOSE (RfD)?
DOSE is mg chemical per kg body wt. / dayDOSE is mg chemical per kg body wt. / day
Uncertainty FactorsUncertainty FactorsExperimental MinimumExperimental Minimum
ToxicologyToxicology
EPA InterpretationsFrom January 2002 DraftEPA InterpretationsFrom January 2002 Draft
Uncertainty Factors total 300-fold (Order of Magnitude=10 or ½ O.M. = 3)Uncertainty Factors total 300-fold (Order of Magnitude=10 or ½ O.M. = 3)
Lowest Observed Adverse Effect Level 10XLowest Observed Adverse Effect Level 10X
Sensitive Subpopulations (Intraspecies) 3XSensitive Subpopulations (Intraspecies) 3XDuration (Lifetime exposures?) 3XDuration (Lifetime exposures?) 3X
Data Deficiencies (Immunotox.?) 3XData Deficiencies (Immunotox.?) 3X
This is NOT a very large Uncertainty FactorThis is NOT a very large Uncertainty Factor
Interspecies (Animal-Human) 1XInterspecies (Animal-Human) 1X
January – June 2002 External Peer ReviewJanuary – June 2002 External Peer Review
Spring 2003 Final Draft Internal ReviewSpring 2003 Final Draft Internal Review
2003 ? National Academy of Science Review2003 ? National Academy of Science Review
2004 ? Revised Reference Dose on IRIS2004 ? Revised Reference Dose on IRIS
Integrated Risk Information SystemIntegrated Risk Information System
EPA 2002 Draft
TOXICITY SCHEDULE EPA 2002 Draft
TOXICITY SCHEDULE
PERCHLORATE PERCHLORATE SHIPMENTS SHIPMENTS
Primarily Manufacturer's InformationPrimarily Manufacturer's Information
Over 220 facilities Over 220 facilities
40+ States40+ States
Most Information in Last 20 YearsMost Information in Last 20 Years
PERCHLORATE in the PERCHLORATE in the ENVIRONMENT ENVIRONMENT
Alabama, Arizona, Arkansas, Colorado, Iowa, Kansas, Maryland, Missouri, Massachusetts, Minnesota, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Pennsylvania, Texas, Utah, Virginia, Washington, West Virginia
Alabama, Arizona, Arkansas, Colorado, Iowa, Kansas, Maryland, Missouri, Massachusetts, Minnesota, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Pennsylvania, Texas, Utah, Virginia, Washington, West Virginia
CALIFORNIACALIFORNIA
Over 5000 Water Supply Wells TestedOver 5000 Water Supply Wells TestedDetected in 292 sources, 49 Wells over 18 ppbDetected in 292 sources, 49 Wells over 18 ppb
RELEASES REPORTED IN 25 STATESRELEASES REPORTED IN 25 STATES
January, 2003
EPAREGION 9
PERCHLORATE RELEASES
Drinking Water Contamination
Monitoring Wells Only
Colorado River Contamination
GlendalePasadena
Santa Clarita
SanFrancisco
Sacramento
San Jose
Los Angeles
Lake Tahoe
M E X I C O
C A L I F O R N I A
Carson City
Reno
Las Vegas
N E V A D A
A R I Z O N A
Hollister
Edwards AFB
Rialto
Redlands
Santa Susanna
Baldwin Park
El Toro MCAS
Lincoln
Tracy
Phoenix
Tucson
San Nicholas Island Stringfellow
Benson
Gila River
Davis Monthan
Goodyear
White Tanks
Rancho Cordova
27 Sites11 Superfund
Morgan Hill
Casmalia
Aerojet
BMI Kerr-McGee
PEPCON
Regulatory AuthorityRegulatory Authority
(SDWA, RCRA, CERCLA)(SDWA, RCRA, CERCLA)
Hazardous Material CharacteristicsHazardous Material Characteristics
Contaminant Candidate List (UCMR data)Contaminant Candidate List (UCMR data)
Possible EPA Health Advisory (OGWDW)Possible EPA Health Advisory (OGWDW)
State Action Levels May Lead to Drinking Water Standards
State Action Levels May Lead to Drinking Water Standards States and Tribes May Set StandardsStates and Tribes May Set Standards
Not a Federally “Listed” ChemicalNot a Federally “Listed” Chemical
Federal Drinking Water Standard
Federal Drinking Water Standard
Safe Drinking Water Act – Office of WaterSafe Drinking Water Act – Office of Water
Drinking Water Data Collected through 2003Drinking Water Data Collected through 2003
Decision to Regulate, Or Not – 2004 possiblyDecision to Regulate, Or Not – 2004 possibly
Final MCL – 18 to 24 Months later (2008?) A Public Policy Process – Public Comment Final MCL – 18 to 24 Months later (2008?) A Public Policy Process – Public Comment
Possible EPA Health Advisory (OGWDW )Possible EPA Health Advisory (OGWDW )
Proposed MCL (MCLG) - 24 MonthsProposed MCL (MCLG) - 24 Months
State “Advisories”State “Advisories”California… 4 ppb
New York… 5 ppb and 18 ppb
Texas… 4 ppb, 7 ppb or 10 ppb
Arizona… 14 ppb
Massachusetts… 1 ppb
Maryland… 1 ppb
New Mexico… 1 ppb
Nevada… 18 ppb
California… 4 ppb
New York… 5 ppb and 18 ppb
Texas… 4 ppb, 7 ppb or 10 ppb
Arizona… 14 ppb
Massachusetts… 1 ppb
Maryland… 1 ppb
New Mexico… 1 ppb
Nevada… 18 ppb
Comparative Risk Derivations
• “What if” calculation based on human data 0.007 mg/kg-day Uncertainty factor of 100 parceled as:
• Intrahuman variability: 3• LOAEL to NOAEL: 3• Subchronic to chronic duration: 3• Database insufficiency: 3
Result is 0.00007 mg/kg-day
• If a larger UF was applied for intrahumanvariability then resultant estimate would be essentially equivalent to that proposed
Ecological RisksEcological Risks
Direct Effects on Fish/Animals at Direct Effects on Fish/Animals at High ConcentrationsHigh Concentrations
Unknown Developmental EffectsUnknown Developmental Effects
Concern for Arid Region WetlandsConcern for Arid Region Wetlands
Agriculture Uses Colorado R. and GWAgriculture Uses Colorado R. and GWLettuce near Yuma / Crops along Colorado R.Lettuce near Yuma / Crops along Colorado R.Imperial Valley/Coachella ValleyImperial Valley/Coachella ValleyCitrus in RiversideCitrus in Riverside
Ecological RisksEcological Risks
Texas Tech Fish - Accumulated in Heads Texas Tech Fish - Accumulated in Heads
Texas Frogs - Developmental EffectsTexas Frogs - Developmental Effects
Accumulation in Las Vegas Wash RodentsAccumulation in Las Vegas Wash Rodents
Plant Uptake Research – Not DefinitivePlant Uptake Research – Not DefinitiveSome Translocation and Concentrationin Lettuce, Tobacco, Salt CedarSome Translocation and Concentrationin Lettuce, Tobacco, Salt Cedar
Perchlorate TreatmentPerchlorate Treatment
Treatment Systems are Operating Treatment Systems are Operating
Full Scale, Commercially AvailableFull Scale, Commercially Available
Ion ExchangeIon Exchange
Various Types of Biological SystemsVarious Types of Biological Systems
Perchlorate Treatment
ION EXCHANGEPerchlorate Treatment
ION EXCHANGE
Effective, Familiar TechnologyEffective, Familiar Technology
Accepted by State Regulators for Potable WaterAccepted by State Regulators for Potable Water
Resins Have Different Sorption/ DesorptionResins Have Different Sorption/ Desorption
Carbon – GAC – Not EffectiveCarbon – GAC – Not Effective
Waste Brine, or Waste ResinWaste Brine, or Waste Resin
Perchlorate Treatment
BIOLOGICALPerchlorate Treatment
BIOLOGICAL
Similar or Identical to Nitrate TreatmentSimilar or Identical to Nitrate Treatment
Anoxic EnvironmentAnoxic Environment
Destroys Perchlorate to Cl and ODestroys Perchlorate to Cl and O
Must Add a Bacteria Growth Substrate, BODMust Add a Bacteria Growth Substrate, BOD
Perchlorate Treatment
INFORMATIONPerchlorate Treatment
INFORMATIONU.S EPA Technology Innovation Officewww.clu-in.org/perchlorateU.S EPA Technology Innovation Officewww.clu-in.org/perchlorate
American Water Works Assn Research www.awwarf.com/research/spperch.aspAmerican Water Works Assn Research www.awwarf.com/research/spperch.asp
VendorsVendors
May 2000 GWRTAC Technology Summary www.frtr.gov/perchlorateMay 2000 GWRTAC Technology Summary www.frtr.gov/perchlorate