Last Updated: 2011-03-10

Strong Waste Surcharge Program FAQ

What is a Combined Sewer Overflow?

Combined Sewer Overflow (CSO) is a discharge of untreated storm and wastewater from a combined sewer into the environment. CSOs typically occur when combined sewers fill up with too much water for the system to handle, most often during heavy rains, and the excess water is released into a stream or river.

What is a Combined Sewer Overflow (CSO)?

Like many older cities throughout the Eastern U.S., Richmond's sewer pipes carry a combination of sewage from homes and businesses and rainwater runoff to the city's Wastewater Treatment Plant. That works just fine in dry weather, but when heavy rains come, to keep the sudden onslaught of water and sewage from backing up into homes, it is necessary to release some of the combined sewage into local waterways. This release is called a Combined Sewer Overflow, or CSO.

Is the city of Richmond, Va, the only city that has CSOs?

No. More than 950 of the nation's older Northeast, Great Lakes and mid-Atlantic cities have CSOs.

Why does this happen?

Before indoor plumbing and wastewater treatment, cities built sewer systems to carry stormwater away from homes, businesses and streets. As the population grew and modern bathrooms came into existence, plumbing was hooked into the these existing storm sewers, making them "combined" sanitary and stormwater sewers. Even today, during dry weather, the combined sewer pipes are no problem. They carry water to the city's wastewater treatment plant to be treated and released into the James River. However, during heavy rains, the volume of water is too great for Richmond's interceptor system and treatment plant to process, and the combined system overflows by design into rivers and creeks.

Since CSOs only happen during heavy rains, are they really a serious issue?

Yes. Because CSOs carry raw sewage with the stormwater, disease-causing organisms and other pollutants can enter into our area waters.

Has Richmond warned area residents about these health hazards?

Yes. Richmond has posted signs at every outfall, alerting people to the presence of CSOs and warning against swimming during and after rain events. A contact phone number is provided for additional information

Why can't we just separate the sanitary sewage from the stormwater run-off?

We might be able to, but the cost to channel the two types of flow into separate pipes would be enormous. As you can imagine, we would need to excavate much of the city streets to duplicate the piping, and this still would not solve the problem of chemicals and other debris that enter our waterways in stormwater

If we separate the sanitary sewage and stormwater, and catch debris from stormwater run-off, would that make our waterways safer and cleaner?

Not completely. Our water will still be polluted from stormwater sources upstream. That is why it's important that this be recognized as a regional watershed issue that will require regional cooperation

What about the cost? Who pays?

The city of Richmond's CSO system is financed through three sources: State and Federal grants, state low-interest loans and rate payers.

What are EPA's Nine Minimum Controls?

Richmond has already implemented the Nine Minimum Controls required by EPA; they are:

  1. Proper operation and regular maintenance programs for the sewer system and the CSOs.
  2. Maximum use of the collection system for storage.
  3. Review and modification of pre-treatment requirements to ensure CSO impacts are minimized.
  4. Maximization of flow to the city's wastewater plant for treatment.
  5. Prohibition of CSOs during dry weather.
  6. Control of solid and floatable materials in CSOs.
  7. Pollution prevention.
  8. Public notification to ensure that the public receives adequate notification of CSO occurrences and CSO impacts.
  9. Monitoring to effectively characterize CSO impacts and the efficacy of CSO.

RVA Impact Map displays projects (i.e. gas, water, paving, etc.), events (i.e. parades, races, block parties, etc.) and right of way impacts (i.e. detours, partial and full lane closures, barricades, parking restrictions, etc.) as an interactive map for informational and navigational purposes. Data displayed is refreshed as changes are made.

Contact Information:

Public Utilities
City of Richmond
900 E. Broad St.,
Room 115
Richmond, VA
23219 USA
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Phone: (804)646-4646
Interested in learning about how our award winning water is treated and transported to your home or how the water that leaves your home is treated and placed back into the James River? Request a tour of our Water Treatment Plant or Wastewater Treatment Plant. Click here to fill out the form.

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