PERCHLORATEPERCHLORATEKevin Mayer - U.S. EPA, Region 9

75 Hawthorne, San Fran. CA 94105 mayer.kevin@epa.gov

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

Cl

0

00

0

PERCHLORATE ClO4

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

Perchlorate Mode of Action

Pituitary

THYROIDGLAND

T4 and T3

TSH

Perchlorate

Iodide

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 MANUFACTURERS and USERS

MARCH, 2003

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

PERCHLORATE RELEASES – March, 2003

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