Following extensive study, analysis and development, the Environmental Protection Agency has finalized an approach to disposal of wastewater that offers greater protection for underground sources of drinking water and potential savings for wastewater treatment facilities in Florida.
The Underground Injection Control (UIC) rule sharply reduces the possibility of contamination from wastewater injected into deep wells. Facilities may opt for one of several approaches as long as their action brings them into compliance with the Safe Drinking Water Act.
Those that use the UIC method must have industrial pretreatment so that various sources of effluent remove major contaminants before the water enters the wastewater treatment plant. Treatment facilities, in turn, add a secondary level of treatment and then high-level disinfection to inactivate pathogenic organisms. This results in water that meets the same standard as is required by the State of Florida for reuse water applied on lawns, golf courses and similar applications.
"This rule helps Florida continue to protect underground sources of
drinking water as well as aquatic ecosystems by strengthening pollution prevention and disinfection requirements," said assistant administrator of Water Benjamin H. Grumbles.
The rule is based, in part, on the findings of a comprehensive study called "Relative Risk Assessment of Management Options for Treated Wastewater in S. Florida." It demonstrated the feasibility and cost effectiveness of the approach. Some treatment facilities have been facing prohibitively expensive alternative disposal methods or perhaps even closing their operations.
For more than 20 years, some Florida municipalities have been using
underground injection as an alternative to surface disposal of treated domestic wastewater. These high-technology (Class I) wells have been drilled 1,000-3,000 ft deep. However, evidence has accumulated that some of the wastewater has been migrating into underground sources of drinking water.
The UIC rule provides wastewater treatment facilities with a solution that brings them into compliance with the requirements of the Safe Drinking Water Act. As a salutary side effect, treatment facilities may find there is a market for the treated water, which could reduce the need for injection.
EPA has also found that pretreatment programs and prohibitions on wastewater from significant industrial users have prevented contaminants from getting into wastewater in the first place, and that secondary treatment is a critical step in wastewater treatment prior to high-level disinfection.
The Florida Department of Environmental Protection (DEP) administers the UIC Program in the state. DEP will propose regulations that are at least as stringent as this new federal rule. Facilities in St. Petersburg already meet this standard and, improvements to meet the standard at Miami-Dade are underway.
The final rule, "Revision of Federal Underground Injection Control Requirements for Class I Municipal Disposal Wells in Florida" will be published in the Federal Register in the near future.