All along the sanitary sewer main, residences and business require services lines or ‘laterals’ gravity fed between the home/business and the main.
When preparing to install sanitary sewer service laterals, it is common to locate any working laterals (if existing) prior to installation of the new laterals. This may need to be done by videotaping or launching a camera up the laterals by way of the main. When attempting to locate existing sanitary services to tie onto, important factors to consider are whether the service is coming off a slab-on-grade/crawl space building structure or a building with a basement. Homes with basements (particularly with basement plumbing) may have deeper existing services.
When designing sanitary sewer systems, engineers typically avoid allowing sewage to drop longer distances. In a situation where the lowest floor is at grade, by the time the shallow sloped service lateral is run to the deep main, there is often a considerable drop-off between the 2 pipes. Engineers will typically require this drop to be broken somehow by an angled standpipe system consisting of bends or wyes which breaks the direct fall of the wastewater.
Along these service laterals it is common to find a ‘cleanout’ system which allows for maintenance access to the pipe for cleaning out and unclogging, between the home and the sewer main. This cleanout assembly typically consists of a tee or wye, a standpipe, a cap with a nut for opening and closing. It is common for the maintenance of service laterals past the right of way into private property be the responsibility of the building owner. It is commonly a plumber that will handle the actual tie in to the building’s main waste outlet pipe and any coring or sleeving through the foundation. A common slope requirement for lateral services coming off a property is 1% or 1/8” per foot.