arsenic rule

8/8/2019 Arsenic Rule

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Presentation prepared for Arsenic in Drinking Water: An International Conference atPresentation prepared for Arsenic in Drinking Water: An International Conference at

Columbia University, New York, November 26Columbia University, New York, November 26--27, 200127, 2001

U.S. Federal Regulation ofU.S. Federal Regulation ofArsenic in Drinking WaterArsenic in Drinking Water

Bruce A. Macler, Ph.D.

USEPA Region 9

(415) 972-3569

[email protected]


2/23

Arsenic RuleArsenic Rule Rule promulgated January 22, 2001

FR 66, #14, pp 6975-7066

Effective date February 22, 2002 MCL proposed at 5 ug/L, set at 10 ug/L

Based on cost-benefit balance

Used bladder and lung cancer risks

5-year implementation period

MCL compliance January 23, 2006

CCR reporting beginning February 22, 2002


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A Bit of Arsenic RegulatoryA Bit of Arsenic Regulatory

HistoryHistory Original Public Health Service standard was

50 ug/L

Based on non-cancer endpoints

PHS standard grandfathered as EPA

Maximum Contaminant Level in 1974

1986 Safe Drinking Water Act amendments

directed EPA to review, revise arsenic MCL

Concern for skin cancer


4/23

The Safe Drinking Water ActThe Safe Drinking Water Act

Directs EPA's RegulationsDirects EPA's Regulations Maximum Contaminant Level Goals

Not enforceable, but direct MCL

"Each MCLG...shall be set at the level at which no knownor anticipated adverse effects on the health of persons occurand which allow an adequate margin of safety"

National Primary Drinking Water Regulations Enforceable

Set as close as feasible to MCLGs Feasible analytical methods and treatment technologies

Administrator can adjust MCL for cost reasons

Other regulatory applications generally not considered


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EPA Public Health Goals forEPA Public Health Goals for

DW StandardsDW Standards Forcontaminants with no threshold for adverse

effects (i.e., initiator carcinogens)

MCLG = zero as default or positive data for initiation

MCL generally set between 1/10,000 and 1/million increased

lifetime risk for cancer, based on risk assessments

Forcontaminants showing a threshold for adverse

effects (promoter carcinogens, non-carcinogens) MCLG based on Reference Dose (RfD), set to be below any

known adverse health effects

MCL set as close as feasible to MCLG


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Arsenic is a PoisonArsenic is a Poison Arsenic health effects have been extensively studied

A variety of human cancers are associated witharsenic ingestion

Lung, bladder, prostate, skin, liver Arsenic inhibits chromosomal repair, enhances cancer

progression

Circulatory and neurological damage, diabetes also

can occur Arsenic inhibits mitochondrial respiration

High disease levels seen in populations drinkingwater with arsenic 5-20 times higher than current 50ug/L MCL


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New Arsenic Health WorriesNew Arsenic Health Worries We dont lack health data

100s of arsenic publications in last two years

Arsenic appears to act as endocrine disrupter to

block glucocorticoid action May affect diabetes, hypertension, cancer

Acts as low as 10 ug/L

Dimethylarsinic acid is toxic

Causes DNA strand breaks in lung tissue (completecarcinogen)

Promotes bladder, kidney, liver and thyroid cancers

Methylation NOT a detoxification mechanism


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Arsenic Regulatory IssuesArsenic Regulatory Issues Money

Affected drinking water purveyors

Other affected parties

Health effects/ regulatory benefits

Treatment


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Affected Drinking WaterAffected Drinking Water

Systems, ISystems, I ~59,000 community water systems in US

~10,000 use surface water, ~49,000 use ground

water About 2500 utilities serve >10,000 people

>90% of smallest systems use groundwater

Highest arsenic levels are in smallgroundwater systems

3300 GW systems, 90 SW systems >10 ug/L

3300 small (


10/23

Affected Drinking WaterAffected Drinking Water

Systems, IISystems, II

Most affected systems are very small, rural

Smaller systems not really utilities Few have a full-time operator

Little or no treatment infrastructure

Limited financial resources

Most affected systems have had fewregulations to follow up to now

Basically, implementation starts from scratch


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Other Affected Parties

Other Affected Parties

Drinking water MCLs used for Superfund and

other hazardous waste cleanups

While not directly applicable, these are considered

relevant and appropriate regulations

Groundwater cleanups may be set at MCL

Mine wastes, oil extraction brines, coal flyash

often high in arsenic Arsenic may be dominant risk in site assessments

Cleanup costs are less important

Costs could be greater than for all drinking water


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Health Effects Issues, IHealth Effects Issues, I

SafeSafe Drinking WaterDrinking Water Is arsenic a public health problem in the US?

SDWA goals versus risk perceptions

Safety is in the eye of the beholder SDWA has de minimuspublic health risk goal

MCLs have been set with estimated risks between

1/10,000 - 1/million excess lifetime

Not law, but precedent

There are no bodies in the streets in U.S. from

arsenic


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Health Effects Issues, IIHealth Effects Issues, II

Risk AssessmentRisk Assessment Epidemiology, medicine can at best resolve risks

>1/100 level

For arsenic, exposures not high enough forepidemiology to find disease in U.S.

Risk assessments can extrapolate data to lowerexposures and risk levels Regulatory risk assessments are conservative, generally

go to upper risk boundaries

Arsenic has always been here, so somebiochemical detoxification mechanism must exist Real risks could be lower


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Treatment Issues

Treatment Issues

For smaller GW systems, going from

nothing to something

For larger GW systems, wellhead treatment

at multiple wells

Waste disposal hassles and costs

Peripherals: land, permits, human

resources, NIMBYs, etc


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More Arsenic RegulatoryMore Arsenic Regulatory

HistoryHistory In early 1990s, new cancer concerns were growing

But strong opposition by oil, extractive and drinking

water industries 1996 SDWA amendments featured arsenic, cost-

benefit decision-making

EPA proposed 5 ug/L as arsenic MCL in June 2000

EPA promulgated MCL at 10 ug/L in January 2001 New Administration postponed effective date, set

up review


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What Was Reviewed?What Was Reviewed?

EPA Administrator Whitman said, It's only a

review. The MCL may stay the same or even go

down. National Academy of Sciences reviewed health

data and risk assessments from 3-20 ug/L

National Drinking Water Advisory Committee

reviewed cost and technologies materials

EPA Science Advisory Board reviewed benefits

analysis


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NAS Health

and Risk ReviewNAS Health

and Risk Review The Academys National Research Council

reviewed EPAs arsenic risk assessment

Reviewed use ofTaiwanese studies andTaiwanese populations

Evaluated data for 1% (ED01) cancer risk level

Considered EPAs analysis of mode of action

and dose-response uncertainties

Judged whether EPA risk estimates for 3, 5, 10

and 20 ug/L were consistent with current science


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NAS ConclusionsNAS Conclusions Data from Taiwan, Chile indicate high risks for

cancer Appropriate for risk assessment use

Utah study too problematic for use Use linear approach to extrapolate from 1% (ED01)

cancer risk to 1/10,000 regulatory risk level Sublinear extrapolation not justified

Substantial variation in human response needs to beincorporated

Consider using U.S. background cancer levels

Epidemiological studies unlikely to show effects inU.S.


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NAS: Cancer Risks fromNAS: Cancer Risks from

Arsenic IngestionArsenic IngestionNAS estimated arsenic-associated lung and

bladder cancers

Bladder cancer risk about 12-23/10,000 @ 10 ug/L

Lung cancer risk about 14-18/10,000 @ 10 ug/L

(EPA had estimated bladder + lung cancer at 0.6-

3/10,000 @ 10 ug/L)

Other cancers not quantified, but add risk

Overall 1% cancer risk level < 50 ug/L


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EPA SAB Benefits ReviewEPA SAB Benefits Review Science Advisory Board examined how EPA valued

benefits from Arsenic Rule Reviewed quantification of cancer costs, and benefits from

not getting cancer Also reviewed quantification of costs of other diseases

Recommended EPA quantify ischemic heart disease,diabetes mellitus and skin cancer

Suggested EPA consider quantifying prostate cancer,nephritis, nephrosis, hypertension, hypertensive heartdisease and non-malignant respiratory disease

Said EPA should consider latency adjustment

Net result could increase or decrease benefits of Rule


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NDWAC Treatment CostNDWAC Treatment Cost

ReviewReview Examined costing methodologies,

assumptions, information and national

estimate of system costs for the Arsenic Rule Concluded that EPAs estimate was credible

Offered a variety of improvements

New technologies will lower costsNecessary related activities add to costs

Net result unlikely to significantly change nationalcosts


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Arsenic Proposed Proposed What If Final Final

g/L Cost Benefits Benefits Cost Benefits

3 $645-756 $44-104 $42-448 $698-792 $214-491

5 $379-445 $32-90 $35-384 $415-472 $191-356

10 $165-195 $18-52 $20-224 $180-206 $140-198

20 $63-77 $8-30 $9-128 $67-76 $66-75

Costs and benefits in $M/yrAlso, unquantified health benefits for cancers of the skin, kidney, nasal

passages, liver, and prostate and noncancer effects on the cardiovascular,

immune, nervous, and glandular systems likely to be substantial

Cost and Benefits Comparison(from January 22, 2001 FR)


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Whats Next?Whats Next?

EPA let MCL stand at 10 ug/L without

comment on reviews

Implementation by small systems will be achallenge

Need simple, user-friendly treatment

Must be easy to design, off-the-shelf to cut costs

Need to find and train operators

Need money

Need to change some minds

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