US Federal Drinking Water Regulatory Update

Transcription

1 US Federal Drinking Water Regulatory Update November 2014 Bruce A. Macler, PhD USEPA Region 9 macler.bruce@epa.gov

2 All Quiet on the Regulatory Front Under way Unregulated Contaminant Monitoring Rule 3 Out for public comment Contaminant Candidate List 3 determinations In development Perchlorate Rule Carcinogenic VOCs Rule Lead and Copper Rule revisions 6-year Review Contaminant Candidate List 4 Arsenic, chromium IRIS risk reviews

3 Unregulated Contaminant Monitoring Rule 3 Results to date (August 2014) High levels of detections for strontium, chlorate, vanadium, chromium/cr6, molybdenum (42-98% detects) 1,4 dioxane frequently found (~20% detects) Perfluoro compounds; hormones; VOCs (including 1,2,3 TCP); pesticides seldom or not detected, nationally

4 UCMR3 Data vs. Risks Using a 1 cancer/ million people risk benchmark: 90% of systems have Cr6 above CA PHG ~7% of systems have 1,4 dioxane above EPA ~1% have 1,2,3 TCP above EPA For non-carcinogens: 35% have chlorate results above EPA benchmark ~3% with vanadium results above Everything else is a non-issue risk-wise

5 UCMR3 Metals, National Metal MRL Health Ref Conc PWS w/ Detects Above HR Chromium 0.2 ug/l 100 ug/l 69% 0% Cr (0.02 CA PHG) 90% (>90%) Cobalt % 0.1% Molybdenum % 0.5% Strontium % 1% Vanadium % 3.5%

6 Other UCMR3 Results, National Material MRL Health Ref Conc. PWS w/ Detects Above HRC Chlorate 20 ug/l 210 ug/l 69% 35% 1,4 Dioxane % 7% 1,2,3 TCP % 1% 1,2 DCE % 0%

7 But UCMR3 Results CA vs. National Material CA PWS w/ detects National PWS w/ Detects CA PWS above HRC Chlorate 97% 69% 50% 35% 1,4 Dioxane 31% 20% 15% 7% 1,2,3 TCP 7% 2% 7% 1% National PWS above HRC Cr6 96% 90% (>96%*) (>90%*)

8 What Does This All Mean? So what do we tell the public? It is heartening that we can now detect materials at levels well below harmfulness Almost all your drinking water has hexavalent chromium, a known carcinogen, above CA health goals! ATSDR has some good health risk communications materials

9 Carcinogenic VOCs Rule EPA interested in regulating all cvocs as a group for ease and cost savings Common disease endpoint (cancer) Common MCLG (i.e., zero) Common analytical method Common treatment Incorporate existing cvoc MCLs Add unregulated cvocs Use total risk reduction approach, not chemical by chemical May also be appropriate for DBPs, nitrosamines

10 cvoc Workgroup Activities Not much is happening right now Efforts to define a VOC ongoing Not all VOCs are VOCs Occurrence data getting vetted Of the regulated cvocs, only TCE and PCE occur with any frequency UCMR 3 will provide more information Treatment approaches being tested Packed tower aeration Granular activated carbon

11 Group cvoc MCL ideas A single standard for multiple cvocs: Aggregate of analytical limits Aggregate of treatment feasibility levels Aggregate risk at feasible levels But 1,2,3 TCP would likely dominate Highest risk, by far

12 Perchlorate Rule EPA is moving ahead with a MCL for perchlorate Need to come up with risk assessments to set the Maximum Contaminant Level Goal MCLG will determine MCL options Exposure assessments needed for how much different subpopulations get Both will influence go/ no go options

13 Perchlorate Health Risk Issues 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 and USDA are modeling exposures, risks Pregnant women, fetuses Infants on breast milk and formula May have results in 2015

14 Perchlorate Mode of Action Pituitary Perchlorate TSH THYROID GLAND Iodide T4 and T3

15 Perchlorate Exposures to Sensitive Subpopulations Relative Source Contribution is how much perchlorate comes from DW vs. other exposures CDC research shows DW perchlorate relatively insignificant Adults (including pregnant women) get most perchlorate from leafy greens DW perchlorate low on list Infants get most from breast milk Formula is fortified with iodide

16 Contaminant Candidate List 3 Regulatory Determinations Proposal in Federal Register on Oct 20, 2014 FR 79: 202, pp Strontium to go forward for regulation 1,2,3 TCP being considered with the cvocs Nitrosamines (NDMA) and chlorate will be considered in 6-Year Review of DBPRs These to be dropped as not being DW problems 1,3 Dinitrobenzene Dimethoate Terbufos & Terbufos sulfone Others on CCL3 need more health or occurrence information

17 What CCL3 RD Didn t Do 1,4 dioxane Waiting for UCMR3 occurrence data Perfluro compounds Need health risk assessments Vanadium, molybdenum Need health risk assessment

18 Contaminant Candidate List 4 Soon to be proposed 100 chemicals 12 microbials Expect to see the remaining CCL 3 members Plus, perhaps, manganese and nonylphenol

19 Lead & Copper Rule Long-term Revisions EPA has been evaluating all aspects of the current rule Does partial lead service line replacement make a difference? Can monitoring be improved? Sample site selection Lead vs copper Tap sampling issues Water quality parameters Lead in schools and day care facilities Is copper really a problem worth regulating?

20 LCR Revisions Timeline Initial ideas for revisions made Rule very complex and unworkable, so scrapped Pretty much starting over Stakeholder meetings were held Nothing profoundly helpful Unclear when, or if, a proposal will appear 20

21 6-Year Review of Regs Major focus on DBPs Adding nitrosamines, chlorate from CCL3 Will need new risk assessments This is going slow SWTRs also to be reconsidered Fluoride being actively discussed Chromium, arsenic and nitrate/nitrite need new risk assessments

22 Fluoride EPA MCL is 4 mg/l; 2 o MCL is 2 mg/l Based on skeletal fluorosis CDC says fluoridation one of the great health benefits Reduction in dental caries by hardening teeth Optimal level ~0.7 Mg/L EPA says it is toxic and can damage teeth Change of adverse endpoint to dental fluorosis Risk assessments may go below 0.7 mg/l Searching for a middle ground

23 IRIS Risk Reviews for As, Cr EPA s Integrated Risk Information System will be reviewing the current assessments for arsenic and chromium Will likely take approaches different from CA OEHHA s Oct DC stakeholder meeting informed risk process Cytotoxicity vs. genotoxicity big issue Problems with NTP data

24 Other EPA Activities Focus on distribution system issues Storage tank inspection and cleaning requirements? Water reuse (indirect and direct potable) Regs considered adequate Operator certification will be emphasized Legionella (premise plumbing) Need R&D on monitoring and control Will provide guidance eventually

25 More EPA Activities Algae, algal toxins and nutrient control Sampling and analysis issues Health advisory expected spring 2015 Nutrient control (esp N) is important Ebola advice for wastewater workers Climate change impacts on resources and water quality DWSRF, WIFIA administration

26 Drink Your Water Good for you Cheap, too