Download - Arsenic Rule
-
8/8/2019 Arsenic Rule
1/23
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
-
8/8/2019 Arsenic Rule
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
-
8/8/2019 Arsenic Rule
3/23
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
-
8/8/2019 Arsenic Rule
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
-
8/8/2019 Arsenic Rule
5/23
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
-
8/8/2019 Arsenic Rule
6/23
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
-
8/8/2019 Arsenic Rule
7/23
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
-
8/8/2019 Arsenic Rule
8/23
Arsenic Regulatory IssuesArsenic Regulatory Issues Money
Affected drinking water purveyors
Other affected parties
Health effects/ regulatory benefits
Treatment
-
8/8/2019 Arsenic Rule
9/23
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 (
-
8/8/2019 Arsenic Rule
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
-
8/8/2019 Arsenic Rule
11/23
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
-
8/8/2019 Arsenic Rule
12/23
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
-
8/8/2019 Arsenic Rule
13/23
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
-
8/8/2019 Arsenic Rule
14/23
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
-
8/8/2019 Arsenic Rule
15/23
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
-
8/8/2019 Arsenic Rule
16/23
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
-
8/8/2019 Arsenic Rule
17/23
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
-
8/8/2019 Arsenic Rule
18/23
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.
-
8/8/2019 Arsenic Rule
19/23
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
-
8/8/2019 Arsenic Rule
20/23
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
-
8/8/2019 Arsenic Rule
21/23
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
-
8/8/2019 Arsenic Rule
22/23
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)
-
8/8/2019 Arsenic Rule
23/23
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