Sanitary sewer overflows

What are Sanitary Sewer Overflows? Why are SSOs a problem? A sanitary sewer overflow can spill domestic A key concern with SSOs entering rivers, lakes or wastewater out of manholes, onto streets and into streams is their negative effect on water quality. The stormwater systems or surface water bodies before it is overall impact of wastewater discharges to surface able to reach a treatment facility. waters is fortunately temporary. Our bays, rivers and gulf are constantly moving, which results in the dissipation Why Do Sewers Overflow? and dilution of wastewater contaminants in a few days. Although wastewater facilities are permitted and The Florida Department of Health issues health designed to safely and properly collect and manage a advisories when bacteria levels present a risk to human specified wastewater capacity, obstructions or extreme health, and may also post warning signs when bacteria conditions can cause SSOs. affect public beaches or other areas where there is the When the flow of wastewater is obstructed in the pipe, risk of human exposure. the wastewater may then back up and overflow through a manhole, cleanout, toilet, sink or drain. This Because SSOs contain partially treated (or potentially overflowing wastewater may then make its way into the untreated) domestic wastewater, ingestion or similar environment, a house or a business. contact may cause illness. People can be exposed through: Contributing factors may include: » Direct contact in areas of high public access » Too much rainfall infiltrating through the ground into » Food that has been contaminated leaky sanitary sewers, which are not intended to hold » Inhalation and skin absorption rainfall. Excess water also can flow through roof drains connected to sewers or poorly connected sewer lines. How Can SSOs Be Reduced? » Blocked, broken or cracked pipes and other SSOs can be reduced by: equipment or power failures that keep the system » Sewer system cleaning and maintenance. from properly functioning. Tree roots can grow into the sewer. Sections of pipe can settle or shift so that » Reducing infiltration and inflow through system pipe joints no longer match. Sediment and other rehabilitation and repairing broken or leaking lines. material can build up and cause pipes to break or » Enlarging or upgrading sewer, pump station or collapse. sewage treatment plant capacity and/or reliability. » A deteriorating or aging sewer system that can » Construction of wet weather storage and treatment be expensive to repair. Some municipalities have facilities to treat excess flows. found severe problems, necessitating costly correction programs. DEP has a State Revolving » A few SSOs may be unavoidable, including those Fund Program that provides low-interest loans for occurring from unpreventable vandalism, some investments in water and sanitation infrastructure types of blockages and extreme rain events. upgrades. » Permit holders do have bypass provisions when human health and safety are at risk and there is no feasible alternative. The utilities are required to notify DEP within 24 hours if they need to use those provisions.

continued Florida Department of Environmental Protection - Sanitary Sewer Overflow How does DEP respond to SSOs For example, DEP takes into account the severity of the rain event, was it a hurricane or a storm, or if the area had and resulting discharges to surface received an unusually large amount of rainfall beyond waters? historical averages. If the discharge was caused by an operator error, or lack of a certified operator on-site at the After DEP has received final data from the utilities time, the department may consider additional training for regarding their wastewater releases, environmental operators to prevent similar errors from occurring in the specialists will review the data to assess the situation and future. the overall impact to the environment when considering whether to take additional action. Specialists will be In some circumstances, the department will meet with evaluating many factors, including: utilities to discuss infrastructure repairs and process improvements the utility is making and planning to How serious was the violation? » implement in order to avoid further discharges. » Is it a first-time violator or a chronic offender? Most of the cities and counties that are having wastewater » Was the violation inadvertent or beyond issues are investing millions of dollars to upgrade their reasonable control? infrastructure, but these are complex and costly projects » Can any damage to the environment be undone or that take time to complete. remediated quickly?

Florida Department of Environmental Protection 10/16 dep.state.fl.us