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Water: Dioxin/Furans

Approval of EPA Method 1613 for Analysis of Dioxins and Furans in Wastewater

Fact Sheet; July 1997

This regulation would establish test procedures for the analysis of 2,3,7,8-substituted dibenzo-p-dioxins and dibenzofurans (CDDs/CDFs) under section 304(h) of the Clean Water Act. EPA Method 1613 contains test procedures for determination of the 17 tetra- through octa-chlorinated, 2,3,7,8-substituted CDDs/CDFs using high resolution gas chromatography coupled with high resolution mass spectrometry. This regulation would make available at 40 CFR part 136 an additional, more sensitive test procedure for measuring 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) in wastewater and would make available a new test procedure for measuring the 16 other CDDs/CDFs in wastewater. Method 1613 measures into the low part-per-quadrillion (ppq) range and would be the most sensitive analytical test procedure approved under the Clean Water Act for the analysis of CDDs/CDFs.


The U.S. Environmental Protection Agency (EPA) has previously approved a test method for the determination of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) in wastewater, but it became apparent that the sensitivity of this method was not suitable for some of EPA's analytical needs. A lower detection limit for 2,3,7,8-TCDD was necessary to monitor and control the discharge of this pollutant from a variety of industries regulated by EPA. In addition, the toxicological significance of the 16 other 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and dibenzofurans (CDDs/CDFs), a class of compounds consisting of 17 isomers, started to raise some concerns. Based on these needs, EPA Method 1613: Tetra- Through Octa- Chlorinated Dioxins and Furans by Isotope Dilution High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS), EPA 821-B-94-005, is being approved to augment the currently approved dioxin method. EPA developed Method 1613 for determining all 17 CDDs/CDFs with greater sensitivity, precision, and accuracy.

The promulgation of Method 1613 is pursuant to the authority of Sections 301, 304(h), and 501(a) of the Clean Water Act. Test methods are promulgated at 40 CFR part 136.

The Clean Water Act classifies 2,3,7,8-TCDD as a priority pollutant. The 16 other CDDs/CDFs are regulated as nonconventional pollutants in many National Pollutant Discharge Elimination System (NPDES) permits. Method 1613 provides permitting authorities and the regulated community with a scientifically valid tool to measure pollutants in the environment at lower concentrations and with greater precision and accuracy than could be measured by the previously approved method.

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Method 1613

Method 1613 extends minimum levels of quantitation of CDDs/CDFs into the low parts-per-quadrillion range for aqueous matrices and the low parts-per-trillion range for solid matrices. The method specifies the use of HRGC/HRMS for detection and quantitation of CDDs/CDFs. The method's use of isotope dilution techniques, internal standard calibration, and the 1600 series method quality control protocol, results in improved sensitivity, precision, and accuracy. These improvements have been validated through both intralaboratory and interlaboratory validation studies.

Method 1613 encourages advances in technology and reductions in the cost of analysis by allowing the use of alternate extraction and clean-up techniques. The analyst is permitted to modify the method to overcome interferences or lower the cost of measurements, provided that all method equivalency and performance criteria are met. By allowing the use of alternate extraction procedures that reduce the solvent volumes required during analysis, Method 1613 supports EPA's pollution prevention initiative.

The method also is consistent with EPA's ecosystem protection objectives and directive to base environmental policy on scientifically sound and credible approaches to reducing risk.

Requirements of the Regulation This regulation amends the Guidelines Establishing Test Procedures for the Analysis of Pollutants under Section 304(h) of the Clean Water Act (40 CFR part 136) to augment currently approved dioxin test procedures with EPA Method 1613 for determination of the priority pollutant 2,3,7,8-TCDD. Method 1613 also is being promulgated for the determination of all other CDDs/CDFs, which are regulated as nonconventional pollutants. This rule is necessary to support effluent limitations guidelines development and compliance monitoring requirements under the Clean Water Act.

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Regulatory Impacts

In 1994, under the Safe Drinking Water Act (40 CFR parts 141 and 142) EPA promulgated a version of Method 1613 consistent with the version of the method approved in this rule. With this rulemaking, the same version of Method 1613 applies to the analysis of wastewater and drinking water. Moreover, EPA's promulgation of Method 1613 does not repeal currently approved CDD/CDF methods but offers Method 1613 as another CDD/CDF approved testing procedure. Each permitting authority must decide which testing procedure is appropriate for its needs.

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More Information

Additional Information and copies For additional information concerning this action, please contact the U.S. Environmental Protection Agency, Mail Code 4303T, 1200 Pennsylvania Avenue NW, Washington, DC 20460.

The Federal Register notice contains instructions on how to obtain additional information and how to review the public record for this rulemaking.

The complete text of the Federal Register notice (September 15, 1997) containing the final rule and the full text of Method 1613.

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