What is a CSO regulator?
Regulators control the amount of flow to a downstream point and provide an outlet for flows in excess of the sewer capacity. Vortex valves have been used to divert flows to CSO treatment facilities, control flow out of storage facilities, and replace failed mechanical regulators (U.S. EPA, 1993).
What is a combined sewer Overflow CSO )?
Combined sewer systems are sewers that are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. These overflows, called combined sewer overflows (CSOs), contain not only storm water but also untreated human and industrial waste, toxic materials, and debris.
What is a combined storm overflow?
Combined sewer overflows (CSOs) were developed as overflow valves to reduce the risk of sewage backing up during heavy rainfall. Overflows of diluted sewage during heavy rainfall are not a sign that the system is faulty.
How do I stop my combined sewer overflow?
Preventing combined sewage overflows
- Green infrastructure.
- Increased storage capacity in the collection system.
- Sewer treatment plant expansion or increased storage at the plant.
- Sewer separation.
- Infiltration and inflow reduction.
- CSO-related bypass of the secondary treatment step at the sewer treatment plant.
What is the difference between CSO and SSO?
Such events can result in either a Sanitary Sewer Overflow (SSO), a Combined Sewer Overflow (CSO), or both. While both situations act as a relief for the system, one is intentional and the other is not. An SSO is an unintentional discharge of wastewater to the environment or personal property.
How do you tell if you have a combined sewer?
Identifying Your Drainage System
- If you have a combined system, the dyed test water show up in the chamber from both foul and surface sources.
- If you have opened a surface only drain, the dyed test water will only show up when the dye is added to a surface drainage point.
Why are combined sewers a problem?
Combined sewers can cause serious water pollution problems during combined sewer overflow (CSO) events when combined sewage and surface runoff flows exceed the capacity of the sewage treatment plant, or of the maximum flow rate of the system which transmits the combined sources.
Where are combined sewer overflows?
These basins are located at original combined sewer outfalls located along the Detroit River and Rouge River within metropolitan Detroit. These facilities are generally designed to contain two inches of stormwater runoff, with the ability to disinfect overflows during extreme wet-weather rainfall events.
How do you know if you have a combined sewer?
Why are combined sewer overflows a problem?
Combined sewer overflows occur during storms when there is more stormwater flowing than the pipes leading to a treatment plant can handle. The excess runoff flushes human and industrial wastes, oil, toxic metals, pesticides, and litter into streams.
What is CSO in pump?
Combined sewer overflow (CSO) treatment facilities are designed to provide primary treatment (physical settling of solids), disinfection (usually chlorination), and dechlorination of CSOs.
What is CSO SSO?
Retention Treatment Basin (RTB), Combined Sewer Overflow (CSO), and Sanitary Sewer Overflow (SSO) discharges are described as discharges from a sewer system which contains untreated or partially-treated sewage.
What are combined sewer overflows and why are they important?
Combined sewer overflows, or CSOs, were built as part of sewer collection systems that were designed to carry both sewage and stormwater in the same pipe. Combined sewer systems have regulator structures that allow overloaded systems to discharge into rivers, lakes and coastal areas subjecting them to higher pollutant loads.
How are sanitary sewers different from combined sewers?
Sanitary sewers are different than combined sewers, which are designed to collect large volumes of stormwater in addition to sewage and industrial wastewater. Occasionally, sanitary sewers will release raw sewage. These types of releases are called sanitary sewer overflows (SSOs).
How does a combined sewer system ( CSS ) work?
A combined sewer system (CSS) collects rainwater runoff, domestic sewage, and industrial wastewater into one pipe. Under normal conditions, it transports all of the wastewater it collects to a sewage treatment plant for treatment, then discharges to a water body.
When do sewer overflows need to be controlled in Seattle?
In those agreements, both King County and Seattle are scheduled to have their overflows mostly controlled by 2025. Set schedules for completing CSO control projects. Set requirements for sanitary sewer overflows.