Sewer pumping station encountered during building survey.
We recently completed a full building condition pre-purchase survey for a client and they were surprised to see in their report that a sewer pumping station was installed to the drive of the property under consideration. We think it important that potential house buyers fully understand why these systems are installed and what can go wrong.
Wherever possible, we will always test for foul drain leaks using pneumatic drain bungs but in this particular case we quickly realised that this wouldn’t be possible because on lifting the inspection chamber cover we noted that an underground sewer pumping station (sometimes called a lift station) was installed. These stations are used to transport wastewater to higher ground where the waste can then be further transported by gravity flow. These lift stations are generally designed to handle raw sewage where the site topography is too low to allow the transfer of effluent to the main sewer under natural gravity flow.
The basic design principle for these systems is that raw sewage is fed to an underground pit or ‘wet well’, where it is stored until the effluent reaches a predetermined level, at which point the effluent pump kicks in and pumps the effluent to the main sewer. The pump will run until the level in the wet well reaches its predetermined minimum level. These minimum and maximum levels are determined by float valves in the wet well that are linked to an alarm system in the electronic control panel. The sewage pumps are generally open end suction centrifugal pumps, often macerator pumps to break down solids into a more fluid sludge.
Read the blog…Sewage pumping stations