CERCLA section 103 release reporting requirements apply to "hazardous substances." How are CERCLA hazardous substances defined?

CERCLA section 101(14), as amended, defines "hazardous substance" by referencing other environmental statutes, including:

• CWA sections 311 and 307(a);
• CAA section 112;
• RCRA section 3001; and
• TSCA section 7.

CERCLA section 102(a) also gives EPA authority to designate additional hazardous substances not listed under the statutory provisions cited above. There are currently about 800 CERCLA hazardous substances. In addition, there are approximately 1,500 known radionuclides, approximately 760 of which are listed individually.