Among the many services the City provides, the Sewer Maintenance Section is responsible for the 'hidden' services that we have all come to rely on as part of our daily lives whether at work or play. The Sewer Maintenance Section is responsible for inspecting and repairing storm and sanitary sewers, opening stoppages and replacing sewer mains as needed on a routine basis. The City's sewer and drain collection system consists of separated and combined sewers. The Sewer Section maintains 189 miles and of storm sewer, 240 miles of sanitary sewer and six (6) miles of combined sewer. Other functions of the Sewer Section are Hydrant Maintenance and repair, Best Management Practices and Inspections (BMPs), and catch basin maintenance and repair. PWS uses a combination of Vactor Trucks, Jet Trucks, Flush Trucks, and CCTV Vans to inspect, maintain and clear pipes of any obstruction throughout the City.
An important component of the Storm & Sanitary Sewer Section's work is to inform residents, business owners, and citizen groups to advise them of the best known methods to avoid sewer backups and to define the responsibility of the City and the homeowner regarding sewer connections. The ultimate goal is to reduce the number of flooding by decreasing mainline blockage, minimize the infiltration and inflow of storm water in the sanitary system, and evaluate structural integrity of the entire sewer system. This Section also assists with the development and management such as combined sewer overflow monitoring.
The Sewer Maintenance Section maintains 189 miles of storm water mains. Stormwater mains transport stormwater to a receiving body of water such as a river, lake or ocean. The City's stormwater mains discharge to the Potomac River. The Sewer Section also works with the Department of Environment Protection (EPA), Department of Environmental Quality (DEQ), and local community groups to improve the water quality of the Potomac River.
Combined Sewer Overflows
The City owns and operates a combined sewer system (CSS) that discharges combined sewer overflows under wet weather conditions to waters of the Commonwealth of Virginia. The City is authorized to discharge wet weather overflows from its CSS under the Virginia Pollutant Discharge Elimination System (VPDES) Permit No. VA0087068 (permit) issued by the Commonwealth of Virginia Department of Environmental Quality (VDEQ). During significant rain storms combined sewer systems may fill up beyond their capacity with a mixture of sanitary waste and rain water. A combined sewer overflow (CSO) acts like a relief valve allowing sewerage to discharge into waterways instead of backing up into the homes and businesses, and into the streets.
How does it work?
A combined sewer is a sewage system that collects and disposes of both sanitary sewage and storm water runoff into sewage treatment works. Is it called combined because in some more modern sewage systems, sanitary sewage and storm water runoff are not handled by one system but rather by two distinct pipes. The purpose of this system is twofold. One, it safely disposes of pollutants swept by a storm that are found on the ground, like pesticides, oil, and grease into treatment facilities. This system is also responsible for collecting domestic and industrial sewage. Under normal circumstances, the sewage is moved to a sewage plant and then safely disposed in a body of water. During particular rainfall events, the capacity of the CSS may be exceeded and this excess flow, which is a mixture of stormwater and sanitary wastes, is discharged directly to Hunting Creek, Hooffs Run, or the Potomac River (Oronoco Bay) through the City's four permitted CSO outfall Structures. The following out falls are regulated under the City's VPDES Permit as point source discharges of combined sanitary sewage and stormwater overflow from the City's CSS.
001 - Pendleton Street CSO
002 - Royal Street CSO
003 - Duke Street CSO
004 - Hooffs Run CSO
The City continues to practice and extensive program of sewer preventative maintenance. Focusing or preventative maintenance has helped the City reduce the need for corrective and emergency maintenance. The City's current preventive maintenance program includes the following activities:
- Monthly Problem Area Grease Flushing
- Flushing of the sanitary sewers, storm sewers, and combined sewers in the CSS
- Internal Sewer CCTV Inspections
- Inlet and Catch Basin Cleaning
- Sweeping and Cleaning of the Streets
The activities performed under the City's preventative maintenance program help maintain the capacity of the CSS in addition to maximizing the storage of the collection system. See more information on the City's combined sewer system.
Property Owner Responsibilities
Sewer laterals are pipes that carry sanitary sewage from buildings to the City's sewer mains. It is the responsibility of the individual property owner to maintain and repair laterals installed before July 1, 1955 from the curb to the property. The maintenance and repair of laterals installed on or after July 1, 1955 are the responsibility of the property owner from the infrastructure to the actual sewer main. Stormwater laterals are pipes that carry stormwater from buildings or land to the City's stormwater mains. These pipes are typically between four inches and twelve inches in diameter and are made of concrete, clay, plastic or cast iron. The maintenance and repair of stormwater services are the responsibility of the individual property owners.
Preventative Maintenance Program
The City's Sanitary Sewer Maintenance Program consists of inspections of the sewer pipes and manholes with the City wastewater collection system. This initiative investigates the City sanitary sewer system in order to protect public health and the environment, ensure compliance with state and federal requirements and ultimately renew aging infrastructure.
PWS is using robotic technology with closed-circuit television (CCTV) cameras to determine which sewer lines need to be rehabilitated or repaired. This technology is used to investigate emergency overflows, maintenance problems, identify infiltration and inflow problems and flooding issues and to provide information to prioritize projects and sanitary sewer replacements.