The presence of hazardous materials within the East Bank Wastewater Treatment Plant was used to strengthen the case for mitigation at the EBWWTP. 44CFR part 9, Floodplain Management and Protection of Wetlands, § 9.11 Mitigation, outline the mitigative requirements and options available as protection from 100 years or 500 years storms.
Moreover, as in this case, with additional risks to the floodplain and to the community (such as the presence of hazardous materials), FEMA can use additional “discretionary” powers to provide additional level of protection.