The Arsenic Rule: Regulation and compliance in the United States Katherine Alfredo 1, Chad Seidel 2, Alan Roberson 3 (1) Earth Institute, Columbia Water Center / Columbia University, NY, 10027; (2) Corona Environmental Consulting, LLC / CO, 80027; (3) AWWA, Government Affairs Office / Washington, DC 20005
Arsenic regulation in the U.S. timeline 1970: USEPA Formed 1975 National Interim Primary Drinking Water Regulation MCL (interim) = 0.05 mg/l (50 µg/l) (40 FR 59566) 1988 USEPA Health Risk Assessment 1996 Safe Drinking Water Act (SDWA) Amendments (Section 142 (b)(12)(a)) 1 Develop As plan within 180 days 2 Propose regulation by Jan 1, 2000, final regulation Jan 1, 2001 2001 Regulation January 22: USEPA published final revised regulation March 23: Rule became effective Jan 2006: MCL becomes enforceable
Health Risk Reduction Cost Analysis National occurrence data Economic Analysis Regulatory Development REGULATION
Arsenic regulation in the U.S. Why investigate this legislation? To understand the complexities of data handling for large datasets as well as the data required to analyze nationwide contaminant occurrence To evaluate regulations in general (broad view) by targeting interim rules Alfredo, Seidel, & Roberson. 2014. Reviewing the occurrence data used in the revised Arsenic Rule. JAWWA. 106 (3): E139-E149
Arsenic Occurrence and Exposure Database (AOED) Data sources: SDWIS State compliance DB NIRS NAOS Metro USGS 1969 CWSS 1978 CWSS RWS NOMS Different reporting limits for As Not all states covered by compliance DB Only 25 states had suitable As compliance monitoring data and were used Used both CWS and NTNCWS systems
Second Six-Year Review (6YR2) Concurrently, USEPA was engaged in the second six-year review of water regulations Mandated by the 1996 SDWA amendments, USEPA reviews all existing drinking water regulations every six-years (USEPA 2009, 2003) Second six-year review (6YR2) collected data from 1998-2005 Data collection ended prior to the Jan 2006 enforceable deadline
Second Six-Year Review (6YR2) 45 states
Second Six-Year Review (6YR2) Used ¼ MRL Used the average, 75 th, and 95 th percentile value
Second Six-Year Review (6YR2) Used ¼ MRL Consider how datasets and data handling can impact regulatory determinations Used a 50 th, 75 th, and 95 th percentile value
How does aggregation influence data? Percent System Basis: How many utilities have arsenic concentrations C As? Percent Populations Basis: How many people consume water at arsenic concentrations C As?
How does aggregation influence data? The different achievable predictions using population estimates exemplifies the inherent uncertainty in these analyses even when using real arsenic measurements.
Arsenic contamination and system size The AOED database: predicted declining arsenic occurrence with respect to system size
Arsenic contamination and system size
Arsenic contamination and system size If the initially proposed MCL of 5 µg/l was adopted in the revised Arsenic Rule, a considerable percentage of systems in every size category unaccounted for in the AOED would have been affected.
Take-Aways Methods for nondetect handling can bias data depending on variation of MRL within dataset Only minimal differences were noted between the AOED and 6YR2 databases when analyzed on a percent systems basis Because many regulatory standards are aimed at reducing potential incidences of adverse health effects, population-based analyses should be included as part of future occurrence analyses. Obtaining more detailed identification and geospatial information regarding specific water utility sources would permit a source-based analysis rather than forcing the aggregation of samples on a utility basis.
How good is the regulation? (a) 6YR2 As Occurrence Currently, arsenic remains a leading public health and water utility regulatory compliance concern. Seven years after revision, 500+ systems remain out of compliance 20.1-50.0 µg/l >50.1 µg/l Very Very Small Large System Size (a) 6YR2 As Occurrence Arsenic Concentration 10.1-20.0 µg/l Arsenic Concentration 10.1-20.0 µg/l 20.1-50.0 µg/l >50.1 µg/l Very Very Small Large System Size Either there was a failure to predict occurrence or the burden placed on utilities to meet the revised arsenic threshold was underestimated (b) FY11 As Violations (b) FY11 As Violations
Number of CWS Arsenic violations 2006 2008 2010 2012 CA 4 134 104 117 NV 1 14 17 16 AZ 3 161 59 36 NM 0 7 24 23 TX 30 291 107 102 ID 48 128 31 17 How can utilities come into compliance?
CALIFORNIA Predicted non compliance by 6YR2 Was in violation in 2006, but compliant in 2012 2012 Violation EPA Sizes V. Small Small Medium Large V. Large
CALIFORNIA Predicted non compliance by 6YR2 Was in violation in 2006, but compliant in 2012 2012 Violation EPA Sizes V. Small Small Kern County Medium Large V. Large
CA CASE STUDY CA1510006 East Niles CSD 6RY2 estimate: 46 µg/l As Violation: 2010: 28.65 µg/l SDWIS Data SW (GW blended with SW) Large (Pop = 26,000) According to WQR (2009) East Niles C.S.D. exceeded the arsenic MCL in June 2009 and notification was provided to the area served. In November 2009 the State of California Department of Public Health approved the Kern Citrus Blending Treatment Plant. East Niles C.S.D has been in compliance with the arsenic MCL as of November 2009.
Funding mechanisms? State Drinking Water State Revolving Fund Established in 1996 More than 200 systems have applied for project funding to support arsenic compliance Grants or low-interest loans Funding = prioritized by health-based problems Allocation for the 2013-2014 fiscal year expected to reach $200 million By mid-2016, total funding could reach $878 million American Recovery and Reinvestment Act (ARRA) (2009) Revised SDWSRF (2013)
Funding mechanisms? Proposition Prop 13: The Safe Drinking Water, Clean Water, Watershed Protection, and Flood Protection Bond Act of 2000 $1.97 billion; $70 million for drinking water projects Proposition Prop 50: The Water Security, Clean Drinking Water, Coastal and Beach Protection Act of 2002 $3.44 billion; $485 for water security, water quality, and treatment technology Proposition Prop 84: The Safe Drinking Water, Water Quality and Supply, Flood Control, River and Coastal Protection Act (2006) $5.4 billion; $300 million for drinking water projects
Prop 84 Number of Funding Cycle Year Arsenic Projects Round 1 2008 15 Round 2 2009 20 Round 3 2011 42 Average Funded Cost by Project Type
Funding mechanisms? Water Bond Prop 1 (2014): Safe, Clean and Reliable Drinking Water Supply Act of 2014 included on the 04 November 2014 ballot---passed $7.545 billion; $455 SRF, $1 billion groundwater protection and cleanup Is this working? What approach maximizes the funding provided?
Continued Research Looking at each Prop 84 utility and understand the story Rates impacts? Arsenic violations? (Post intervention) Understand what pathways to compliance are most effective Texas & Arizona
Thank you. Katherine Alfredo ka2491@columbia.edu