What is inflow & infiltration?

Inflow and infiltration (I&I) are terms for the ways that stormwater runoff and groundwater (clear water) make their way into sanitary sewer pipes. With inflow, stormwater rapidly flows into sewers via roof drain downspouts, yard drains, storm-sewer cross connections and faulty manhole covers. Inflow is greatest during major storm events and can more than triple wastewater volumes. Infiltration occurs when groundwater water seeps into sanitary sewer pipes through cracks, leaky pipe joints and/or deteriorated manholes.

Why I&I Matters

Excessive I&I in the sewer system creates multiple problems:

• Expensive Treatment: Once stormwater and groundwater mix with wastewater, all the water is treated. This is expensive and impacts the regional system. Reducing excessive I&I in the system saves millions of dollars.
• Reduced System Capacity: Additional water that enters the wastewater system through I&I flows within fixed-capacity sewer pipes. The additional flow consumes capacity that was built to accommodate wastewater flows from existing properties and new developments. During major rain events, the additional flow can exceed the available sewer system capacity, causing overflow issues.
• Water Quality: Exceeding the capacity of the sewer system can result in wastewater overflows and spills into nearby waterways, affecting the water quality.

Reducing Excessive I&I

The City of Fort Lauderdale has prioritized increasing the efficiency and capacity of its sanitary sewer collection system by reducing I&I. The City is implementing a citywide cost-effective I&I reduction program over the next five years to significantly reduce the amount of surface stormwater and subsurface groundwater that enters the City’s sanitary sewer system.

Inflow & Infiltration Reduction Program: Sewer Smoke Testing 

The City of Fort Lauderdale is working with Ardurra Group Inc. to conduct smoke testing throughout Fort Lauderdale over the next three years. This common procedure involves blowing smoke through sewer pipes to locate defects that would allow stormwater and groundwater to enter the sewer system.

Approximate Testing Schedule

Smoke testing will take place Monday through Friday between 8 a.m. and 5 p.m. This schedule is subject to change based on inclement weather or other unforeseen circumstances.

Review the following materials to learn more about upcoming sewer smoke testing:

For more information or questions about smoke testing, contact:

Inflow and Infiltration Program Hotline
877-332-4037 or ftlii@ardurra.com

Inflow & Infiltration Reduction Program: Overnight Wastewater Flow Analysis

The City of Fort Lauderdale is working with Ardurra Group Inc. to study the flow of wastewater throughout the City’s sewer system over the next three years. This flow analysis is part of the City’s ongoing efforts to identify portions of the sewer system where stormwater and groundwater are possibly entering the system, which leads to problems such as increased treatment cost and reduced system capacity. The results of this analysis will be used to plan future sewer system improvement projects.

Approximate Testing Schedule

Inspections will take place Sunday through Thursday evenings between 11 p.m. and 7 a.m. This schedule is subject to change based on inclement weather or other unforeseen circumstances. Crews will be accessing sewer lines through sewer manholes. Therefore, no heavy machinery will be on site and minimal noise and lighting impacts are expected.

Review the following materials to learn more about upcoming overnight inspections:

For more information or questions about overnight wastewater flow analysis, contact:

Inflow and Infiltration Program Hotline
877-332-4037 or ftlii@ardurra.com

How can the community help with I&I reduction efforts?

A significant level of I&I occurs on private property. The City will be engaging in efforts to involve and educate neighbors on how they can help reduce I&I within the sanitary sewer system.

1. Avoid planting trees and shrubs over sewer lines on private property (known as sewer laterals). The roots can damage the structure of the sewer pipes and cause leaks.
2. Make sure that sewer cleanouts are properly capped. The plastic caps tend to be broken by lawn mowers. Replacement lids are available at local hardware stores.
3. Proactively replace any known broken, leaky or problem sections of sewer pipe that are located on your property.

For more information or questions, contact:

City of Fort Lauderdale Customer Service Center
954-828-8000 or lauderserv@fortlauderdale.gov

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