Sewer Line Cleaning Applications

sanitary sewer line cleaningCommon to municipalities around the world is the need to maintain a clean and sanitary environment suitable for humans to live and work. This responsibility includes providing a system for efficiently moving both wastewater (sewage) and stormwater along with the solid materials through a collection system from the source to an environmentally safe place of treatment and disposal. A wastewater collection system is typically a network of pipes, manholes, cleanouts, traps, siphons, lift stations and other required structures to collect all the wastewater from an area and transport it to a treatment plant or disposal system. Some systems are “combined systems” which are designed to collect both sanitary wastewater and storm or surface water runoff. Stoppages are caused by obstructions in the pipe, such as roots, grease, debris, broken pipe or a joint failure. Partial or complete interruption of the flow may result from an obstruction in a sewer. When a stoppage occurs, the material will backup and eventually overflow the system up to the point of the blockage. Streets, homes, and businesses can be damaged from the debris as well as freshwater resources. Human health is threatened with unsanitary conditions and the spread of germs and disease. Sanitary sewer overflow (SSO) is a condition whereby untreated sewage is discharged into the environment prior to reaching sewage treatment facilities. The main causes of SSO are:

  • Infiltration/Inflow of excessive stormwater into sewer lines during heavy rainfall
  • Rupture or blockage of sewerage lines
  • Malfunction of pumping station lifts or electrical power failure
  • Human operator error at treatment plant facilities.

SSO is distinct from a combined sewer overflow (CSO), a similar problem of untreated sewage discharges, but which occurs only in a municipal system specifically designed with a combined sewer.Stormwater run-off often carries gravel, sand, leaves and other street debris. This material often runs down the system after it has rained, creating build up within the storm sewer system. When the rainwater can no longer flow down a system because pipes and culverts are blocked, streets will become flooded which creates hazardous or impassable travel conditions. The best way to keep a sewer or storm system working properly is to perform routine inspection and cleaning. The objective of a Sewer Cleaning and Maintenance Program is to operate and maintain the wastewater collection system so it will function as well as:

  • Minimize the number of stoppages per mile of sewer pipe
  • Minimize the number of odor complaints
  • Minimize the number of lift station failures
  • Maintain intended flow in the system
  • Protect freshwater resources.

Systems around the world vary in many details. Type of material for the pipe, shape, size, and location all differ. Regardless of these variables, these systems must be routinely cleaned to ensure safe, consistent movement of the material.

Catch Basin Cleaning

Catch basins allow surface wateCatch-Basinr runoff to enter the stormwater conveyance system while trapping solids and sediments that might otherwise end up polluting the receiving water bodies.  Catch basin cleaning is an efficient and cost-effective method for preventing flooding as well as removing the sediment and pollutants before they can get into the waterways.  A regular schedule of catch basin cleaning improves both aesthetics and local water quality. The Vactor 2100 Series CB catch basin cleaner is equipped with a highly maneuverable boom and a powerful vacuum source to quickly and efficiently move from basin to basin, cleaning out rocks, dirt, leaves, litter and other debris that can clog storm sewers and prevent proper operation during rain events.

treatment plantsTreatment Plants

Built-up sludge found in pits and wells at treatment plants can negatively impact the wastewater treatment process. Combination machines are used to clean pits and wells at treatment plants to remove sludge build up over a period of time. The material is flushed to a vacuum tube to remove material that affects the productivity of the wastewater treatment process. Periodic cleaning is requires based on system design.

Jet Flushing and Jet Rodding

jet roddingBoth the Vactor Ramjet jetter and the Vactor 2100 Series combination sewer cleaner are used for jet flushing and jet rodding applications to clean sewer lines and remove built-up debris. With jet flushing, loose debris from sanitary sewer lines is collected and flushed back to the manhole for retrieval by either vacuum loading or screening. A typical flushing operation involves jetting a nozzle up the entire length of the sewer line and flushing material back to the manhole in one pass. This works for lines filled with light debris. Heavier or more substantial debris may require multiple passes or step-cleaning where the operator uses the sewer nozzle to flush the first portion of a line, then goes in further for the next portion, and repeats this step until the entire line is completely cleaned. Similar to jet flushing, jet rodding uses a sewer nozzle to scour the walls of the sewer line to remove built-up debris or grease. Rotating heads or special spray pattern nozzles are used to ensure the entire inside surface of the line is cleaned. This operation typically takes longer than simply flushing the line. Proper nozzle selection is critical for effective jet rodding.

Wet Wells/Lift Stations

wet wellsWet wells are the holding sump for gravity-flow sewer systems. As sewage enters the wet well and the water level rises, pumps are engaged to pump out the sewage to a forced main, or the sewage is lifted to a higher grade to continue the gravity flow to the outlet point. Solid material will accumulate in the bottom of the wet well and incoming sewage lines. Lift stations are low points in a gravity-flow sewer system where incoming sewage is pumped from a well to a higher grade to continue the gravity flow to the treatment plant. As solid material, such as rags, enter the lift station, buildup will occur on the bottom of the well and in other components within the station. Solid materials can often plug or damage pump impellers, so periodic cleaning is required to remove the solid material from the lift station.