By Hank Lambert
The U.S. Environmental Protection Agency (EPA) recently implemented its third Unregulated Contaminant Monitoring Rule (UCMR 3), requiring public water systems (PWS) to conduct assessment monitoring for the presence of 28 additional chemicals and two viruses during a 12-month period beginning as early as January 2013. EPA will use the data from this and prior UCMR assessment phases to determine whether further drinking water regulations are in the public interest.
Nearly 40 years ago, the federal Safe Drinking Water Act (SDWA) made U.S. drinking water safety a priority for health officials. Under its authority, EPA sets standards to control contaminants in public drinking water. To date, EPA has identified nearly 90 contaminants whose concentrations in drinking water are regulated under its National Primary Drinking Water Regulations.
Detecting contaminants in trace amounts doesn’t alone imply risk to humans. Significant research is needed to understand both problem scope and its implications for public drinking water. To determine whether a contaminant should be regulated, the EPA analyzes peer-reviewed science, addressing variables that include contaminant occurrence levels in the environment, human exposure routes and potential health effects. In addition, the UCM program collects data on contaminants suspected as present in drinking water, but not currently regulated.
An overview of EPA’s UCMR 3 monitoring program for PWS begins with background information on EPA’s role in drinking water contaminant regulation. Details of the UCMR 3 program requirements, including substances subject to monitoring, sampling and testing methods and program schedules and deadlines, are discussed. In conclusion, considerations are laid out for PWS regarding compliance with UCMR 3, as well as recommendations on test laboratory selection for UCMR sample testing.
Importance of drinking water
EPA estimates Americans drink more than 1 billion glasses of tap water per day. Although drinking water safety is largely taken for granted, natural and man-made factors affect water quality. These include naturally occurring chemicals and animal waste, pesticides, chemical byproducts of manufacturing processes and improper chemicals disposal. Improperly treated or disinfected water, or water passing through a distribution system not sufficiently maintained, also pose potential health risks.
Federal efforts to control drinking water contaminants began in 1974 with SDWA passage. Under SDWA, EPA sets enforceable maximum contaminant levels (MCLs). The National Primary Drinking Water Regulations set maximum levels for 90 separate contaminants and require PWS to test system water samples to assure compliance with MCLs.
A rigorous process evaluates potential health risks from contaminant exposure and determines an MCL below that of potential risk. PWS ensure contaminant concentrations in water supplies comply with MCLs, most often using suitable water treatment technologies to minimize contaminant risk. EPA may also require PWS to treat water supplies in cases where an applicable MCL based on reliable detection of a particular contaminant isn’t feasible.
National drinking water regulations and standards apply to more than 170,000 separate PWS in the U.S., including approximately 54,000 individual community water systems. Regulations and standards are legally enforceable by both EPA and individual state water authorities. PWS that fail to monitor concentrations of regulated contaminants or treat water supplies as required are subject to administrative penalties, monetary forfeitures and other legal action.
EPA’s UCMR program
In addition to currently regulated contaminants, EPA maintains a Contaminant Candidate List (CCL) comprised of those that may be subject to future regulation. CCL-listed contaminants include those found in drinking water at PWS or identified through EPA research. Those listed are prioritized based on potential health risk as assessed by EPA’s Office of Water’s Office of Science and Technology.
EPA’s UCMR program is an important source of data on CCL unregulated contaminants. Established under the SDWA as amended in 1996, UCMR measures the occurrence and levels of specific contaminants found in drinking water at PWS. Data collected is stored in the National Contaminant Occurrence Database. EPA uses it to prioritize unregulated contaminants and determine whether further regulatory action is appropriate.
UCMR requires EPA to issue a list every five years of not more than 30 currently unregulated contaminants to be monitored by PWS. To date, EPA has conducted two separate rounds of UCMR drinking water monitoring. The first, UCMR 1, monitored 25 contaminants (24 chemicals and one bacterium) from 2001 to 2003. UCMR 2 monitored an additional 25 chemical contaminants from 2008 to 2010. UCMR 3 was published in April 2012, and will monitor 30 new additional contaminants (28 chemicals and two viruses) from 2013 to 2015.
Specific UCMR 3 requirements
The 30 different contaminants monitored under UCMR 3 are detailed below.
All PWS serving more than 10,000 people, along with 800 EPA-selected PWS serving 10,000 or fewer people, must monitor 21 separate contaminants (See table 1). The list includes seven different volatile organic compounds, six different metals, six perfluorinated compounds, one synthetic organic compound and one oxyhalide anion.
Contaminants must be monitored continuously for any 12-month period from January 2013 through December 2015. Water sample analyses for List 1 contaminants must use technologies commonly used by laboratories that evaluate drinking water.
All PWS serving more than 100,000 people, as well as 320 EPA-selected PWS serving between 10,000 and 100,000 people and 480 selected PWS serving 10,000 or fewer people, will monitor seven hormones (See table 2). Monitoring for these additional contaminants must be done continuously for any 12-month period from 2013 to 2015. Unlike List 1 contaminants, analysis of List 2 contaminants samples requires use of specialized technologies available only through selected testing laboratories.
For Pre-Screen Testing of List 3 Contaminants, the EPA will select 800 representative PWS serving 1,000 or fewer people with wells located in areas of karst or fractured bedrock, i.e., complex geographic environments with distinctive hydrologic features, and that do not disinfect drinking water.
Sampling and testing
Consistent with UCMR 2 practice, UCMR 3 sampling is to take place at all entry points to the PWS distribution system. However, PWS may sample at representative entry points when groundwater is collected from multiple sources, or when purchased water comes in through multiple connections from the same wholesale supplier. Representative sampling in these circumstances is subject to additional conditions.
Samples collected under UCMR 3 are subject to testing consistent with established EPA analytical methods, as follows:
• Volatile organic compounds — EPA Method 524.3, "Measurement of purgeable organic compounds in water by capillary column gas chromatography/mass spectrometry."
• Synthetic organic compounds—EPA Method 522, "Determination of 1,4-Dioxane in drinking water by solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring (SIM)."
• Metals (other than chromium-6)—EPA Method 200.8, Rev 5.4, "Determination of trace elements in waters by inductively coupled plasma – mass spectrometry."
• Chromium-6—EPA Method 218.7, "Determination of hexavalent Chromium in drinking water by ion chromatography with post column derivatization and UV-visible spectroscopic detection."
• Oxyhalide Anion—EPA Method 300.1, "Determination of inorganic anions in drinking water by ion chromatography."
• Perfluorinated compounds—EPA Method 537, Rev 1.1, "Determination of selected perfluorinated Alkyl acids in drinking water by solid phase extraction and liquid chromatography/tandem mass spectrometry."
• Hormones—EPA Method 539, "Determination of hormones in drinking water by solid phase extraction and liquid chromatography electrospray ionization tandem mass spectrometry,"
• Viruses—EPA Method 1615, "Measurement of enterovirus and norovirus occurrence in water by culture and reverse transcription-quantitative polymerase chain reaction."
Under UCMR 3, EPA is responsible for all cost associated with sample preparation and analysis for PWS serving 10,000 or fewer people. In addition, EPA arranges for sample collection for PWS participating in pre-screen testing of List 3 contaminants.
Reporting requirements, program deadlines and data on analyses of samples collected under UCMR 3 will be posted by testing laboratories to the EPA’s Safe Drinking Water Accession and Review System (SDWARS). This online database is accessible to registered PWS through the EPA electronic reporting system.
In addition to SDWARS reporting, PWSs are subject to agency public disclosure rules. Specifically, the Consumer Confidence Report Rule requires reporting of monitoring results when unregulated contaminants are detected. The Public Notification Rule requires PWS to provide public access to testing results.
By Oct. 1, 2012, for PWS serving more than 10,000 people, PWS contact information must have been reported to SDWARS and sample inventory locations and schedules must be updated in SDWARS.
The following UCMR 3 program deadlines apply to PWS and testing laboratories:
• Jan. 1, 2013—Water sampling commences
• 120 days from collection of samples—Laboratories must post sample analysis results to SDWARS
• 60 days from posting of laboratory assessment data—PWS serving more than 10,000 people must review laboratory data and take any necessary actions
• Dec. 31, 2015—All monitoring, sampling and reporting to be completed
Choosing a laboratory
EPA requires all samples collected under UCMR 3 be analyzed by a laboratory registered under its Laboratory Approval Program and approved by EPA for each specific test method. Laboratory approval to a specific test method is based on the laboratory’s successful completion of an EPA administered proficiency test study involving analysis of samples for each method approved.
Approved testing laboratories must also meet specified quality assurance and quality control requirements to achieve and maintain approval under the UCMR 3 program.
PWS operators should select a laboratory that holds EPA approval to test for all contaminants they are required to monitor. This approach is more efficient than dealing with multiple laboratories evaluating samples to different methods and should streamline the reporting process. For PWS paying for sampling and testing, working with a single laboratory is more cost-effective.
UCMR 3 is a key element of EPA’s efforts to monitor occurrence and levels of unregulated drinking water contaminants, and an essential part of the agency’s overall effort to protect the safety of U.S. drinking water. The data collected will be used in conjunction with research from the EPA, industry and the scientific community to determine possible future efforts to regulate additional contaminants.
UL has been approved by the EPA to analyze water samples collected under UCMR 3 for all 28 List 1 and List 2 contaminants and is the only testing laboratory in the U.S. certified in all 50 states for drinking water analysis.
For further information about the UCMR 3 program and UL’s water testing services, contact Nathan Trowbridge, customer experience manager, at [email protected].
Hank Lambert is general manager, Global Food and Water Businesses. UL is a premier global safety science company, providing a broad array of services in more than 100 countries with more than 10,000 employees worldwide and annual revenue in excess of $1 billion. Lambert joined UL in November 2010, bringing extensive food industry general management, supply chain management and business building experience. He holds a Masters in Business Administration from The University of Chicago, Booth School of Business and a Bachelor in Economics from Union College.