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Combined Sewer Overflows (CSO)
To better understand Combined Sewers we also need to know what other types of sewers we have in Cumberland. Besides Combined Sewers we also have Sanitary Sewers and Storm Sewers:
What CSOs Are
CSOs are the discharge of untreated wastewater from Combined Sewers directly into a waterway. They usually occur as a result of heavy rain that causes the capacity of the sewer to be exceeded, and are discharged by a control structure such as a Diversion Manhole or a Regulating Chamber.
Why CSOs Happen
Like many cities established in the 1800's, the 1st sewers developed in Cumberland were combined sewers. All wastewater and surface runoff went directly to the rivers and streams through these collector sewers. Some of the streams such as Dry Run, Sulphur Hollow Run, Mill Race, and others where later encased by conduits or lined with sewer pipes before being covered. As our city grew, it become clear that there wasn't enough water in the streams to assimilate our wastewater.
Existing Sewer Study
In the early 1900's the city began studies of its existing sewer and water systems in an effort to plan the utilities for it's continual expansion. During 1934 and 1935 an Interceptor Sewer System was constructed to collect the flow from sewers in North Cumberland, Downtown, West Side, and parts of South Cumberland. In 1936 and 1937 an "Outfall" or Interceptor Sewer was constructed from the Lindnerville area (Baltimore Avenue, Willowbrook Road, and Pine Avenue area) of Cumberland along Willow Brook Road and Evitts Creek to the mouth of Evitts Creek.
Then in 1957 the "Primary" Cumberland Wastewater Treatment Plant was constructed along with the Evitts Creek Pumping Station and several other interceptor sewers. The plant discharged the treated effluent to the Potomac River. In 1976, the City of Cumberland upgraded its "Primary" treatment plant to a "Secondary" Wastewater Treatment Plant utilizing the conventional activated sludge process. The City of Cumberland has continued to upgrade the Wastewater Treatment Plant and City forces are constantly engaged in preventive maintenance and improvements.
Collector Sewer Network
The City of Cumberland's existing sewer system includes a network of collector and interceptor sewers, over 105 miles in length and ranging in size from 4 - 60 inches. The collector sewers are usually combined (carrying both storm and sanitary), although some areas of Cumberland do have separate storm and sanitary systems. It is generally at the point where the combined systems enter the interceptor sewers that diversion manholes and regulating chambers are located. These points are the source of Cumberland's Combined Sewer Overflows and were designed to relieve the high flow, which occurs during heavy precipitation.
Where CSOs Occur
The City of Cumberland's existing sewer system includes a network of collector and interceptor sewers, over 98 miles in length and ranging in size from 8" to 60". The collector sewers are usually combined (carrying both storm and sanitary), although some areas of Cumberland do have separate storm and sanitary systems. It is generally at the point where the combined sewers enter the Interceptor Sewers that diversion manholes and regulating chambers are located. These points are the source of the city's combined sewer overflows and were designed to relieve the high flow that occurs during heavy precipitation.
Cost to Prevent CSOs
It is very expensive to prevent CSOs. In coordination with the National Park Service's (NPS) Canal Rewatering Project, the City of Cumberland has focused it's attention on the problems with it's Combined Sewer System (CSS) within the same area as the NPS Canal Rewatering Project. The city hired Whitman, Requardt, and Associates (WR&A) to do preliminary design for the CSO project. Phase I-A of the project complete, and the approximate cost of the project was almost $12,000,000. Funding included an EPA Grant in the amount $5,000,000 and several grants from the Maryland Department of Environment (MDE).
Estimated Cost
The estimated cost of the entire project in the area of the NPS Canal Rewatering Project is over $30,000,000. And while this should prevent the CSO's problems that have occurred in this area, it may not totally eliminate them and will not solve the problem in other areas of the City of Cumberland.
So as you can see, it is very expensive to prevent CSO's. And CSO's cannot be eliminated without the assistance of federal, state, and regional agencies. However, the City of Cumberland is taking steps to reduce the number of CSO occurrences, and you can help too. Please read the following sections for more information.
What the Public Can do About CSOs
Do Not Dump Into Catch Basins & Curb Inlets
A large portion of the curb inlets in Cumberland have previously been painted with the signs "Chesapeake Bay Drainage Area" and "Do Not Dump." This was accomplished by many volunteers. By not dumping items into the basins and inlets, it should reduce the amount of debris and floatables that sometimes get flushed through the system during a rain. This along with the city's efforts of Catch Basin Cleaning, Street Sweeping, and Reduced use of Gravel or Sand in Snow Removal, will prevent debris from getting into the sewer system and can reduce the frequency for the need of power cleaning of the sewers, and maintenance problems (associated with grit and debris) at the overflows, pumping stations, and Wastewater Treatment Plant.
This joint effort between the city and the public will minimize the amount of floatable materials and sedimentary problems in the adjoining streams. It will also ensure that the sewers can carry the maximum amount of flow without overflowing.
Report Overflows as Soon as They Occur
The City has placed the following signs at all the outlet points:
Help Your City
If You See Flow From
This Pipe in Dry Weather,
Please Call 301-759-6600
If you see an overflow and report it immediately, it will make the city aware of any overflows that occur between inspections. If the overflow occurs due to a blockage in the sewer, it will allow the city to quickly repair the problem and thus reduce the overflow to a minimum; and if it occurs due to wet weather, it will help the city estimate the duration of the wet weather overflow and thereby improve the accuracy of the quantity estimates of the overflow.
- Sanitary Sewers carry untreated human waste and wastewater from homes and business to the Wastewater Treatment Plant.
- Storm Sewers carry storm water (rain, melted snow, etc.) run-off from building roofs, streets, and parking lots to nearby streams, creeks, and rivers.
What CSOs Are
CSOs are the discharge of untreated wastewater from Combined Sewers directly into a waterway. They usually occur as a result of heavy rain that causes the capacity of the sewer to be exceeded, and are discharged by a control structure such as a Diversion Manhole or a Regulating Chamber.
Why CSOs Happen
Like many cities established in the 1800's, the 1st sewers developed in Cumberland were combined sewers. All wastewater and surface runoff went directly to the rivers and streams through these collector sewers. Some of the streams such as Dry Run, Sulphur Hollow Run, Mill Race, and others where later encased by conduits or lined with sewer pipes before being covered. As our city grew, it become clear that there wasn't enough water in the streams to assimilate our wastewater.
Existing Sewer Study
In the early 1900's the city began studies of its existing sewer and water systems in an effort to plan the utilities for it's continual expansion. During 1934 and 1935 an Interceptor Sewer System was constructed to collect the flow from sewers in North Cumberland, Downtown, West Side, and parts of South Cumberland. In 1936 and 1937 an "Outfall" or Interceptor Sewer was constructed from the Lindnerville area (Baltimore Avenue, Willowbrook Road, and Pine Avenue area) of Cumberland along Willow Brook Road and Evitts Creek to the mouth of Evitts Creek.
Then in 1957 the "Primary" Cumberland Wastewater Treatment Plant was constructed along with the Evitts Creek Pumping Station and several other interceptor sewers. The plant discharged the treated effluent to the Potomac River. In 1976, the City of Cumberland upgraded its "Primary" treatment plant to a "Secondary" Wastewater Treatment Plant utilizing the conventional activated sludge process. The City of Cumberland has continued to upgrade the Wastewater Treatment Plant and City forces are constantly engaged in preventive maintenance and improvements.
Collector Sewer Network
The City of Cumberland's existing sewer system includes a network of collector and interceptor sewers, over 105 miles in length and ranging in size from 4 - 60 inches. The collector sewers are usually combined (carrying both storm and sanitary), although some areas of Cumberland do have separate storm and sanitary systems. It is generally at the point where the combined systems enter the interceptor sewers that diversion manholes and regulating chambers are located. These points are the source of Cumberland's Combined Sewer Overflows and were designed to relieve the high flow, which occurs during heavy precipitation.
Where CSOs Occur
The City of Cumberland's existing sewer system includes a network of collector and interceptor sewers, over 98 miles in length and ranging in size from 8" to 60". The collector sewers are usually combined (carrying both storm and sanitary), although some areas of Cumberland do have separate storm and sanitary systems. It is generally at the point where the combined sewers enter the Interceptor Sewers that diversion manholes and regulating chambers are located. These points are the source of the city's combined sewer overflows and were designed to relieve the high flow that occurs during heavy precipitation.
Cost to Prevent CSOs
It is very expensive to prevent CSOs. In coordination with the National Park Service's (NPS) Canal Rewatering Project, the City of Cumberland has focused it's attention on the problems with it's Combined Sewer System (CSS) within the same area as the NPS Canal Rewatering Project. The city hired Whitman, Requardt, and Associates (WR&A) to do preliminary design for the CSO project. Phase I-A of the project complete, and the approximate cost of the project was almost $12,000,000. Funding included an EPA Grant in the amount $5,000,000 and several grants from the Maryland Department of Environment (MDE).
Estimated Cost
The estimated cost of the entire project in the area of the NPS Canal Rewatering Project is over $30,000,000. And while this should prevent the CSO's problems that have occurred in this area, it may not totally eliminate them and will not solve the problem in other areas of the City of Cumberland.
So as you can see, it is very expensive to prevent CSO's. And CSO's cannot be eliminated without the assistance of federal, state, and regional agencies. However, the City of Cumberland is taking steps to reduce the number of CSO occurrences, and you can help too. Please read the following sections for more information.
What the Public Can do About CSOs
Do Not Dump Into Catch Basins & Curb Inlets
A large portion of the curb inlets in Cumberland have previously been painted with the signs "Chesapeake Bay Drainage Area" and "Do Not Dump." This was accomplished by many volunteers. By not dumping items into the basins and inlets, it should reduce the amount of debris and floatables that sometimes get flushed through the system during a rain. This along with the city's efforts of Catch Basin Cleaning, Street Sweeping, and Reduced use of Gravel or Sand in Snow Removal, will prevent debris from getting into the sewer system and can reduce the frequency for the need of power cleaning of the sewers, and maintenance problems (associated with grit and debris) at the overflows, pumping stations, and Wastewater Treatment Plant.
This joint effort between the city and the public will minimize the amount of floatable materials and sedimentary problems in the adjoining streams. It will also ensure that the sewers can carry the maximum amount of flow without overflowing.
Report Overflows as Soon as They Occur
The City has placed the following signs at all the outlet points:
Help Your City
If You See Flow From
This Pipe in Dry Weather,
Please Call 301-759-6600
If you see an overflow and report it immediately, it will make the city aware of any overflows that occur between inspections. If the overflow occurs due to a blockage in the sewer, it will allow the city to quickly repair the problem and thus reduce the overflow to a minimum; and if it occurs due to wet weather, it will help the city estimate the duration of the wet weather overflow and thereby improve the accuracy of the quantity estimates of the overflow.