Implementing the Arsenic Rule May 23, 2006 Bill Goss DHS Drinking Water Program Revised MCL The new MCL of 0.010 mg/L or 10 ppb became effective Jan. 23, 2006. The new MCL applies to Community and NonTransient NonCommunity public water systems. Sampling Requirements All Community and NTNC systems must sample during the 2005-2007 compliance period For GW systems, one sample per entry point is to be collected for the 2005- 2007 compliance period Sampling and Compliance for GW systems If a sample was collected between Jan. 1, 2005 and Jan. 22, 2006, samples collected in 2008-2010 will determine compliance. If a sample was collected after Jan. 23, 2006 and is over the new MCL of 10 ppb, the PWS must collect a confirmation sample and start quarterly monitoring. When is a system in violation? After the running annual average (RAA) over four quarters is > MCL, or if one sample would put the RAA over the new MCL (42 ppm) If no quarterly results are available, use the average of available results. Violations are issued by the DWP. Alerts A water quality alert will be generated if a sample result exceeds the new MCL. The system will be required to begin quarterly monitoring. Public Notice An MCL violation requires a Tier 2 notice – distribute within 30 days of the violation. May require publication in local newspaper. Special language must be included in the Consumer Confidence Report if Arsenic is between 5 and 10 ppb, stronger language if over 10 ppb. When will a system become a Significant Non-Complier? A system will become an MCL SNC if the running annual average for Arsenic exceeds the unreasonable risk to health value of 2 x MCL or 0.020 mg/L. SNC’s may require an Administrative Order if they fail to take action to come into compliance. Investigate Systems on a Case by Case Basis Review historic data Is the source high in Arsenic still in use? Has a source been designated as an emergency source? Has the system changed the entry point configuration to blend sources? Has treatment been installed? Systems should take action sooner rather than later! Begin dialogue with system’s management regarding plans and options. Systems that make little or no effort to address the issue should receive an informal enforcement letter and a draft compliance schedule. Transient Systems The new MCL does not apply since long-term exposure is required. Those people who may have long-term exposure to drinking water above the MCL should at least be advised of the health risk. Plan Review Systems must go through the DWP plan review process before installing treatment, drilling a new well, or blending existing sources. Note that the plan review fees have increased. Schools are Important! Waivers Systems will be eligible to reduce monitoring to once every three years if three rounds have been collected using correct lab methods with results to three decimal places. Review eligibility when conducting sanitary surveys. Resources EPA Arsenic website http://www.epa.gov/safewater/arsenic/index. html EPA “Learning Portal” http://www.arsenictradeshow.org EPA Simple Tool for Effective Performance (STEP) guide http://www.epa.gov/safewater/arsenic/pdfs/a rs_final_app_f.pdf Resources Consulting Engineers Product Vendors Drinking Water Program staff Questions?
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