epa drinking water regulatory update (from a wastewater perspective) october 2011 bruce macler usepa...
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EPA Drinking Water Regulatory Update (from a Wastewater Perspective)October 2011
Bruce Macler
USEPA Region 9
(415) 972-3569
Topics (not necessarily in order) Direct impacts
Pathogenic microorganisms Nitrate/nitrite NDMA and other nitrosamines Other disinfection byproducts Pesticides, pharmaceuticals, etc
Indirect impacts Nutrients Blue-green algae
Perhaps of personal interest Hexavalent chromium Perchlorate Arsenic
EPA DW Regulatory StatusProposed (and closed)
Total Coliform Rule revisions 6-Year Review candidates for revision Unregulated Contaminant Monitoring Rule 3
In development Contaminant Candidate List 3 regulatory
determinations Perchlorate Carcinogenic VOCs Lead and Copper Rule revisions
6-Year Review Status Candidates for revision announced on
March 29, 2010 FR 75, #59, pp 15499-15572
Acrylamide and epichlorohydrin Treatment technique approach
Trichloroethylene and tetrachloroethylene Lower PQLs allow lower MCLs
Fluoride may be considered independently Arsenic, nitrate/nitrite, chromium not
reconsidered this time
Acrylamide, EpichlorohydrinBoth occur as left-over monomer in
treatment polymersTreatment technique regulation
Comply by certification from supplier6-year Review revision decision
Levels are lower now, so can Probably will comply as before
Workgroup not yet established
Fluoride News EPA released a new health and exposure
document Jan 7, 2011 New RfD at 0.08 mg/kg/d for severe dental
fluorosis (~0.8 mg/L for children <6yrs) Began reviewing fluoride MCL (4 ug/L) with
respect to this (off cycle from 6-year Review)
CDC revised its recommended exposure level to 0.7 mg/L Continues to support fluoridation for all Can be a bit above or below 0.7 mg/L No harm seen < 2 mg/L
Chromium Trivalent chromium (Cr+3) is a nutrient Hexavalent chromium (Cr+6) is toxic CA OEHHA has a revised PHG at 0.02
ug/L for hexavalent chromium Considers hexavalent chromium carcinogenic
EPA has its risk assessment out for review Number is about the same as OEHHA’s But EPA considering new data on Mode of
Action of carcinogenicity
Cr+6 Mode of Action??? Mode of Action (MOA) describes how
something could be toxic For carcinogens, some can damage DNA,
chromosomes directly (genotoxicity) Some carcinogens kill cells; healing
process can trigger cancer (cytotoxicity) CA OEHHA considers Cr+6 primarily
genotoxic Other data indicate that Cr+6 cytotoxicity
dominates at lower exposures
Regulatory Changes for Chromium? Federal MCL is 100 ug/L, CA is 50 ug/L
Based on general toxicity, not cancer Essentially a hexavalent chromium MCL Trivalent chromium is a necessary nutrient
CA DPH required to do hexavalent chromium-specific MCL
Cancer assessment points to a downward revision But 5x less risk than for arsenic
Could get occurrence info from UCMR3 Treatment and costs are a big deal
City of Glendale treatment project is significant
ArsenicArsenic MCL currently at 10 ug/LNAS (and OEHHA) risk assessment
says it’s 15 x more toxic than thought ~1% cancer risk at 50 ug/L
Relatively expensive to treat High O&M costs
Political push back
Nitrate/ Nitrite Pacific Institute issued report on nitrate
problems in San Joaquin Valley Nitrate (nitrite, really) can lead to
methemoglobinemia in infants Very rare, though (ave 3 cases/year in US) Often not DW related Usually related to diarrhea
Not an issue for adults at DW levels Cancer data equivocal
Nitrosamines > nitrite > nitrate
Contaminant Candidate List 3 Final list published in Federal Register on
October 8, 2009 FR 74, #194 pp 51850-51862
116 CCL 3 members 12 microbial pathogens 104 chemicals or chemical groups
N-nitroso compounds are prominent Nine hormones Blue-green algal toxins Rest mostly “usual suspect” VOCs, metals,
pesticides
CCL3 Regulatory Determinations
EPA workgroup determining which may be suitable (or not) for regulation
UCMR 1 & 2 and other data being used for occurrence and exposure estimates
All available health information being collected for risk assessments
List first cut down to 32 Based on availability of data
Final determinations expected 2012
Current CCL3 Data AvailabilityMost listed chemical contaminants (69)
lack adequate occurrence information Some don’t even have suitable methods
Most (75) lack adequate health effect information
A few (32) may have both These being reviewed for 1st cut
No listed microorganism has adequate risk or occurrence data
Possibilities for Decisions Some may go forward for regulations
Nitrosamines, individually or grouped 1,2,3-trichloropropane, chlorate, strontium
Some may be dropped as not a DW problem 1,3 Dinitrobenzene Dimethoate RDX Terbufos & Terbufos sulfone
Others may need more information
Unregulated Contaminant Monitoring Rule 2 Results
UCMR 2 data mostly in NDMA detected at ~25% of PWSs
Chloraminated SW>chlorinated SW> chloraminated GW>chlorinated GW
Some other nitrosamines rarely found Very few pesticide hits No flame retardant hits
Data are influencing CCL3 cut-down
N-Nitroso Dimethylamine NDMA is a known carcinogen
10-6 risk @ 0.7 ng/L Many other nitrosamines have similar risks
Formed from chlorination or chloramination of wastewater
UCMR 2 shows 25% of systems affected Controversy over relative contributions
from food vs water Hot prospect, singly or as “nitrosamines”
Other Possibilities1,2,3- Trichloropropane
Mutagenic carcinogen Likely pulled into carcinogenic VOCs reg
Chlorate DBP Thyroid effects; HRL @ 210 ug/L
Strontium Competes with calcium in bone HRL for child ~ 1700 ug/L
1,4-Dioxane
Considered a carcinogenRevised EPA IRIS risk assessment
estimates risk at 0.4 ug/LOccurrence data sparseLikely lack enough information to go
forward now
Perfluoro Octanoic Acid (C8)Perflurooctane Sulfonate
Used in making Teflon and related products Extremely persistent Occurrence largely unknown Provisional Health Advisory
PFOA = 0.4 ug/L PFOS = 0.2 ug/L General effects on liver, growth, development
Lack enough information to go forward now
CCL3 Pharmaceuticals One antibiotic (erythromycin) and nine
estrogens were added to the CCL3 Currently lack occurrence data Lack health effects information for exposures
at environmental levels EPA’s current take is that there is no
evidence that pharmaceuticals and personal care products in the environment cause human health effects Environmental levels typically <1/1,000,000 of
therapeutic dose
Estrogens in DWRecent report showed that natural
estrogens are far more prevalent than synthetic pharmaceutical estrogens Wise, O’Brien and Woodruff (2011) ES&T
45:51-60Pregnant women > women > men >
syntheticsCows and pigs >> people
EPA Drinking Water Strategy The EPA Administrator announced her DW
Strategy actions on February 2, 2011 Regulate perchlorate Regulate TCE, PCE, and possibly other
carcinogenic VOCs as a group Possibly revise existing MCLs for benzene,
carbon tetrachloride, 1,2-dichloroethane, 1,2-dichloropropane, dichloromethane, vinyl chloride
Possibly regulate aniline, benzyl chloride, 1,3-butadiene, 1,1-dichloroethane, nitrobenzene, methyl oxirane, 1,2,3-trichloropropane, urethane
Currently Regulated Carcinogenic VOCs Besides TCE and PCE, EPA has MCLs for
benzene, carbon tetrachloride, 1,2-dichloroethane, 1,2-dichloropropane, dichloromethane, vinyl chloride
Dichlorobromopropane (DBPC) and ethylene dibromide (EDB) may also be reconsidered
During the last 6-year review, EPA passed on revising these as “not worth the hassle” (too little benefit for the cost to change)
Unregulated cVOCsFrom the CCL3, aniline, benzyl chloride,
1,3-butadiene, 1,1-dichloroethane, nitrobenzene, methyl oxirane, 1,2,3-trichloropropane, urethane
1,1,1,2 tetrachloroethane, 1,1,2,2 tetrachloroethane other possibilities
What is a VOC?No clear definition or agreementHigh vapor pressure, low water
solubilityBoiling point <200oCHenry’s Law constant: > .01Analysis with purge/ trap, method 524.3Air stripped (PTA) with >90% efficiency
What is a VOC?These criteria would likely eliminate
aniline, benzyl chloride, nitrobenzene, methyl oxirane, 1,2,3-trichloropropane, urethane
Could eliminate 1,2,3-trichloropropane, 1,1,2,2 tetrachloroethane, DBCP
cVOC Regulation? Interest in regulating all these cVOCs as a
group for ease and cost savings Common analytical method Common treatment
Unclear what this rule would look like Treatment technique?
Also non-carcinogenic VOCs to consider? Workgroup just started
Will be awhile….
Perchlorate Regulatory Determination
Administrator Jackson announced that EPA would regulate perchlorate on Feb 2, 2011 FR 76 n 29, pp 7762-7767 (Feb 11, 2011)
EPA regulatory workgroup established Examining risks in detail Working up occurrence and exposure data Considering treatment approaches and
costs MCLG and possible MCLs will get vetted with
respect to benefits and costs A proposed MCL still a ways off
Perchlorate: Health Concerns Health concerns are for damaged thyroid
and brain development in fetuses and infants Perchlorate interferes with iodide uptake ~20% of women are deficient in iodide
EPA has reconsidered perchlorate risks to focus on infants and toddlers, as well as pregnant women Risks run from 1-5 ug/L
CA OEHHA proposed lower PHG on 1/7/11 at 1 ug/L Based on infants (6 ug/L level was for pregnant women)
Blue-Green AlgaeNutrients appear to be contributing to
algal bloomsCause problems for DW treatment
Daily pH shifts Filtration problems Taste and odor complaints
Some species produce toxins sometimes Not easy to predict Seems like there are more lately
Blue-Green Woes GI upsets from oral ingestion Rashes and allergic reactions from dermal
exposure Headaches, fever, fatigue Poisoning from toxins
Microcystis: microcystin Liver damage
Anabaena: anatoxin-a Neurological damage
Can be lethal to dogs
UCMR 3UCMR 3 list proposed March 3, 2011
FR 76, #42, pp 11713-11737List of methods and chemicals as
previously described Implementation much like UCMR 2Took comment on substituting
hexavalent and total chromium (Method 218.6) for one of the proposed methods Most responders said yes
Method 200.8
VanadiumMolybdenumCobaltStrontium*
May require both source and distribution system monitoring
Method 300.1
Chlorate*Will require collection of
chlorination information as wellGaseous chlorinePotassium hypochloriteSodium hypochlorite
Method 522
1,4 Dioxane*
Method 524.31,1 Dichloroethane1,2,3 Trichloropropane*1,3 ButadieneChloromethaneBromochloromethaneBromomethanePropylbenzeneChlorodifluoromethane (Freon 22)sec Butylbenzene**
Method 537
Perfluoro octane sulfonic acid (PFOS)* Perfluoro octanoic acid (PFOA)* Perfluoro nonanoic acid (PFNA) Perfluoro hexane sulfonic acid (PFHxS) Perfluoro heptanoic acid (PFHpA) Perfluoro butane sulfonic acid (PFBS)
Method 539Estriol (16-hydroxy-17-estradiol)17- Estradiol17- EthynylestradiolEquileninEquilinTestosterone4-Androstene-3,17-dione
Finally, FundingThe deficit is the big issue in DC
House, especially, wants to cut EPABut State Revolving Funds help locally
Likely to stay funded about the same Streamlining the process desired
No Congressional earmark projects Apparently Maybe through the Corps of Engineers
Will be lean for travel and outreach
Final Thought:
Drinking water from a public supply is about the safest thing you do
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