Prior to the use of a Vactor truck to clean sewer lines, District staff would have to go down every manhole using a ladder to get to the bottom. Once at the bottom personnel would shovel material collected in the bottom of the manhole into a bucket. Material like rocks, sand, and other items needed to be removed as they in the sewer lines could clog the sewer line. Due to the depth of some of the manholes and the high concentrations of dangerous gas such as hydrogen sulfide that can build in
the pipes, this was very dangerous and could impact the health of District personnel. The Vactor truck now limits trips into the manhole by inserting a vacuum hose into the manhole and is operated from the surface to clean the sewer line. Along with the vacuum truck is a jetting hose. The jetting hose goes down a man hole and is forced by water pressure up a sewer line. Once the jetting head has reached the manhole upstream, the pressure on the jet is increased and pulled back slowly. This pushes all the unwanted solid materials that can build up the sewer line to the manhole where the vacuum is sitting, ready to remove the material. Our goal is to clean every line owned by the Iowa Great Lakes Sanitary District at least once every three years. This means we are cleaning approximately 20 to 25 miles of sewer lines a year.
The camera truck contains all the equipment for a wire controlled vehicle that is equipped with a video and digital camera, a distance measurement tool, a pipe size measurement tool, and other tools. After a sewer line has been cleaned by the Vactor truck, District Staff will run a camera in the line for inspection of maintenance issues and pipe conditions. The camera helps identify pipes that have roots growing into them, cracked pipes, separated pipes and broken pipes. We can see where water is coming into the sewer system and even if a private connection needs to be repaired. The camera is also used when we have a backed up sewer line to inspect what is causing the problem. This in turn allows staff to determine the location of the issue and what equipment is needed to resolve most problems.
This photo shows tree roots that come from a private sewer line. Tree roots are always looking for a water source and the sewer always has water in the pipes. The roots enter the sewer line through cracks in the pipe. These roots will eventually clog up a private sewer line and eventually the public sewer in this area. The private property owner is responsible for their sewer line from the house to the connection at the public sewer. The private property owner is also responsible for issues with the connection.
The Vactor truck is a large truck and all our manholes are not in an easily accessable location for a large truck. We can’t drive the truck up along every manhole and limit impact to private property. The easement machine is approximately 4 foot wide and has a smaller footprint and is easier to get between houses and around landscaping. This machine allows the District Staff to extend the hoses on the Vactor truck by connecting them to the easement machine so the truck can stay on a road or in a driveway. This greatly reduces the impact to private property and still gets the sewer lines cleaned.
We have 64 lift stations around the Iowa Great Lakes. One of the biggest threats to a lift station is the loss of power. In high collection areas, we have stationary generators to act as back up for a power failure. In 2012 generator plugs were added to all IGLSD lift stations for emergency situations. The generator plugs allow the District to bring in a portable generator and connect it to any lift station around the lakes area that may be without power. This is another way to limit impact to private property and water quality of the Iowa Great Lakes.