Solutions for Biscayne Bay: Sewage Leaks

Sewage Leaks

As one of the most populous counties in the United States, Miami-Dade County must grapple with the intricate task of maintaining a sewage system that effectively balances the demands of urban development and environmental preservation. Meanwhile, the system’s aging infrastructure makes it particularly vulnerable to malfunctions. Sewage spills are a common occurrence in Miami-Dade County. These spills, known as sanitary sewer overflows (SSOs), happen when untreated sewage is discharged from the wastewater treatment system. Within the last couple decades, SSO’s have spilled tens of millions of gallons of sewage into our waterways, contributing excess nitrogen, phosphorus, pharmaceuticals, and fecal bacteria–all polluting the bay and making our waters unsafe. There are various causes of SSO’s: stormwater and/or rising groundwater can overwhelm the system; people flush incompatible items–causing blockages and backups; contractors break infrastructure like force mains if they fail to adequately check the locations of lines before excavating; the lack of investment in maintenance and monitoring means that infrastructure malfunctions and corrodes. 

Miami-Dade County is currently under federally-mandated consent decree to (1.) improve the county’s wastewater collection and transmission system, (2.) eliminate SSO’s, and (3.) correct effluent limit violations. The 15-year term consent decree ends in 2028, and in that time, the County has committed over $1.6 billion to meet its obligations. 

According to the 2018 Biscayne Bay Task Force Grand Jury Report, approximately half of the water being treated at the wastewater treatment facilities consists of groundwater that has seeped into aging pipes through leaks and cracks. 

The County is also subject to  Ocean Outfall Legislation. Two of the three wastewater treatment plants dispose of waste via ocean outfall pipes leading three miles offshore and 100 feet deep (the third injects wastewater deep into the Floridan Aquifer).  While waste is treated before it is disposed into the ocean, the effluent still contains excess nutrients and other harmful substances, hence the state mandate to largely shut off these ocean disposal pipes by December 31, 2025 and to reuse at least 60% of the wastewater.  


  • Advanced Treatment and Resilience: Fortify sewage treatment plants to ensure they are  resilient to climate change impacts, with upgraded infrastructure that can withstand the challenges posed by rising sea levels and increased storm events
  • Infrastructure Capacity: Ensure that wastewater infrastructure, including treatment plants, have the capacity to handle present-day and future population demands, accommodating urban growth and preventing capacity-related overflows.
  • Storm Resilience: Increase capacity within the sewage system to prevent spills during storm events and heavy rains, reducing the risk of sanitary sewer overflows.
  • Real-Time Monitoring and Response: Enhance detection of and response to sanitary sewage overflows using advanced software for real-time monitoring of infrastructure, allowing for swift response to issues
  • EPA Consent Decree Compliance: Ensure Miami-Dade County meets the terms and conditions of the EPA consent decree, on time, demonstrating commitment to environmental protection and regulatory compliance.
  • Contractor Accountability: Increase enforcement of fines and penalties for contractors who cause repeat damage to sewage infrastructure, holding responsible parties accountable for their actions.
  • Infiltration Reduction: Line sewage pipes with carbon sheeting to reduce infiltration, preventing excess stormwater and groundwater from entering the system and alleviating treatment plant overloads.


  • Budgetary Investment: Ensure adequate Miami-Dade County water and sewer budget to address improvement and maintenance of the aging sewage infrastructure, which is vulnerable to increased sewage leaks.
  • Scheduled Operation and Maintenance: Prioritize conducting operation and maintenance activities on schedule, avoiding deferred maintenance, to prevent infrastructure deterioration and potential overflows.
  • Community Outreach and Engagement: Conduct educational campaigns aimed at deterring sanitary sewage overflows caused by the improper disposal of grease and other inappropriate items  into the sewage system. Promote responsible waste disposal practices.
  • Contractor Accountability: Enforce accountability on contractors responsible for sanitary sewer overflows during construction projects. Debar repeat offenders from doing business with the County to encourage responsible construction practices.
  • Grant Exploration: Explore grant programs to secure funding for the upgrade and modernization of outdated municipal sewage treatment plants. Utilize grants to improve treatment capabilities and reduce environmental impacts. (Biscayne Bay Task Force Recommendation 7G)
  • Ocean Outfall Inspection and Closure: Regularly inspect the length of ocean outfall pipes to identify and address potential issues or blockages, ensuring proper wastewater discharge. Establish a definitive timeline to close ocean outfalls by 2025, promoting alternative and environmentally friendly sewage discharge methods that reduce the impact on ocean ecosystems.
  • Illicit Discharge Detection:  Enhance efforts to detect and address illicit discharges and connections, which can introduce pollutants into the sewage system.
  • Sewage Spill Response: Develop and implement rapid response protocols to address sewage spills promptly and prevent further contamination. Ensure that immediate public notification of sewage spills is integrated into the response protocol.


  • Fort Worth’s illicit connection model ordinance: Fort Worth's ordinance has been used as a model by many other communities around the country and their illicit connection detection program has been recognized nationally.
  • EPA model illicit connection and discharge model ordinance: The model ordinance in this section includes language to address illicit discharges in general, as well as illicit connections from industrial sites. The language is borrowed from a number of ordinances and communities will need to assess what enforcement methods are appropriate for their area.

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