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EPA Drinking Water Regulatory Update (from a Wastewater Perspective) October 2011 Bruce Macler USEPA Region 9 (415) 972-3569 macler.bruce@epa.gov
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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
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EPA DW Regulatory Status Proposed (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
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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
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Acrylamide, Epichlorohydrin Both occur as left-over monomer in treatment polymers Treatment technique regulation Comply by certification from supplier 6-year Review revision decision Levels are lower now, so can Probably will comply as before Workgroup not yet established
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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
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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
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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
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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
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Arsenic Arsenic MCL currently at 10 ug/L NAS (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
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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
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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
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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
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Current CCL3 Data Availability Most 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 1 st cut No listed microorganism has adequate risk or occurrence data
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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
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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
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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”
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Other Possibilities 1,2,3- 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
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1,4-Dioxane Considered a carcinogen Revised EPA IRIS risk assessment estimates risk at 0.4 ug/L Occurrence data sparse Likely lack enough information to go forward now
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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
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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
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Estrogens in DW Recent report showed that natural estrogens are far more prevalent than synthetic pharmaceutical estrogens Wise, O’Brien and Woodruff (2011) ES&T 45:51-60 Pregnant women > women > men > synthetics Cows and pigs >> people
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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
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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)
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Unregulated cVOCs From 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
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What is a VOC? No clear definition or agreement High vapor pressure, low water solubility Boiling point <200 o C Henry’s Law constant: >.01 Analysis with purge/ trap, method 524.3 Air stripped (PTA) with >90% efficiency
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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
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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….
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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
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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)
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Blue-Green Algae Nutrients appear to be contributing to algal blooms Cause 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
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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
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UCMR 3 UCMR 3 list proposed March 3, 2011 FR 76, #42, pp 11713-11737 List of methods and chemicals as previously described Implementation much like UCMR 2 Took comment on substituting hexavalent and total chromium (Method 218.6) for one of the proposed methods Most responders said yes
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Method 200.8 Vanadium Molybdenum Cobalt Strontium* May require both source and distribution system monitoring
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Method 300.1 Chlorate* Will require collection of chlorination information as well Gaseous chlorine Potassium hypochlorite Sodium hypochlorite
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Method 522 1,4 Dioxane*
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Method 524.3 1,1 Dichloroethane 1,2,3 Trichloropropane* 1,3 Butadiene Chloromethane Bromochloromethane Bromomethane Propylbenzene Chlorodifluoromethane (Freon 22) sec Butylbenzene**
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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)
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Method 539 Estriol (16-hydroxy-17-estradiol) 17- Estradiol 17- Ethynylestradiol Equilenin Equilin Testosterone 4-Androstene-3,17-dione
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Finally, Funding The deficit is the big issue in DC House, especially, wants to cut EPA But 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
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Final Thought: Drinking water from a public supply is about the safest thing you do 41
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