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Clean Water Act (CWA) and CERCLA Hazardous Substance Lists

What is the relationship between the hazardous substance lists under the Clean Water Act (CWA) and under CERCLA?

All CWA hazardous substances and CWA toxic pollutants are CERCLA hazardous substances, whereas only some CERCLA hazardous substances are CWA hazardous substances. CERCLA section 101(14) defines “hazardous substance” by reference to lists, including the lists in CWA section 311(b)(2)(A) and CWA section 307(a).

  • CWA Hazardous Substances are designated under CWA section 311(b)(2)(A). CWA Hazardous Substances are listed in 40 CFR 116.4  in Table 116.4 A “List of Hazardous Substances” and Table 116.4 B “List of Hazardous Substances by CAS Number”. Additionally, Table 117.3 in 40 CFR 117.3 provides the CWA Reportable Quantities (RQs) for these CWA hazardous substances. 
  • CWA Toxic Pollutants are designated under CWA section 307(a). There are three lists of CWA Toxic Pollutants:
    • Toxic Pollutants listed in 40 CFR 401.15,
    • Priority Pollutants listed in Appendix A to Part 423, and
    • Toxics criteria for states not complying with CWA section 303(c)(2)(B) listed in 40 CFR 131.36. 

All substances listed in Table 116.4 A, Table 116.4 B, 40 CFR 401.15, Appendix A to Part 423, and 40 CFR 131.36 are also in the list CERCLA hazardous substances. The list of CERCLA hazardous substances can be found at 40 CFR 302.4.

Emergency Planning and Community Right-to-Know Act (EPCRA)

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Contact Us about the Emergency Planning and Community Right-to-Know Act (EPCRA)
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Last updated on January 14, 2025
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