Easy access to sewage tanks makes onsite system management a much easier task
Over the years I have seen a lot of access problems associated with sewage tanks, including septic, pump and aerobic tanks. As a part of any management program, regular maintenance of tanks must be performed. Some regulatory agencies require either periodic inspection or regular solids removal. To clean a septic tank properly requires access through a manhole or manholes that allow access to all corners or compartments of the tank.
This requires an opening that is at least 20 inches in diameter, allowing the ability to clean and inspect the tank as a part of regular maintenance. In addition, there should be the ability to access and inspect tank baffles. In most areas now it is required to have an effluent screen at the outlet baffle of the septic tank. I have had the opportunity to be with service providers on more than one occasion where we see that the outlet baffle and effluent screen are under the lid, so the only way to clean the screen is to remove the lid. Fortunately, this happens less often these days — but it still happens. As an installer, working with the tank manufacturers to make sure the tanks have access to the baffles is important. By choosing tanks that offer this feature you can directly impact the products in your area.
Providing access to tanks also means that the service provider does not have to hunt for an hour to find the tank and access points. To me this means bringing access points to the surface using risers and lids. Remember though that while the goal is to provide access to service providers, it is important that the lids be secure and prevent entry by unauthorized persons such as kids and homeowners. Every year you read in the news about a child who accidently fell into a septic tank and was seriously injured or even died.
Securing lids if they are plastic products means that all the lid screws are in place, including the one “safety screw that is different from the others.” The weight of concrete lids is somewhat of a deterrent but not enough; they should be chained and locked to prevent entry. It is also good to have an additional safety device or net inside the risers above the tank. There are numerous products on the market that will keep people or items from falling into the tank itself.
Similar situations to the effluent screen occur in pump tanks. In order to service or replace a pump or control floats in a system they must be accessible, so it’s important to use a pump tree for the pump and floats with a chain or rope attached so they can be removed from the tank for maintenance. This also means that the piping has quick disconnect connections so the service provider does not need to cut the supply pipe to remove the pump.
About the author
Jim Anderson is connected with the University of Minnesota onsite wastewater treatment education program and is an emeritus professor in the university’s Department of Soil Water and Climate. Send him questions about septic system maintenance and operation by email to firstname.lastname@example.org.
This article is part of a series about designing and installing onsite septic systems with future management in mind.