SSOs AND ZERO DISCHARGE: REVIEW OF RECENT PERMITTING AND CONSENT DECREE REQUIREMENTS

In an EPA enforcement notice, the EPA has stated that it wants zero sanitary sewer outflow (SSO) discharge from collection systems. However, this is not an absolute zero. For example, when there is local flooding, the EPA allows bypass discharge. While regulation of secondary treatment facilities requires the reduction of infiltration/inflows, the regulation does not require zero discharge. Further, peak excess flow treatment facilities (PEFTFs) have been developed to supplement secondary treatment facilities during periods of wet weather inflows. Lastly, the EPA's capacity, management, operations, and maintenance (CMOM) regulations contain no reference to zero discharge.