Septage: The story after the pump-out

It is recommended that septic tanks are pumped every 3-5 years, but have you ever wondered what happens after the pump out; where the sludge collected from your tank goes?

Photo credit: klamathriverkeeper

Material, both solid and liquid, pumped out of septic and holding tanks is generally referred to as septage. Septage may come from residential, commercial or institutional sources, but no matter where it comes from, it is raw and untreated. Given that septage is untreated, there are strict regulations in place that dictate how septage is disposed of. In Ontario, a few of the methods used to dispose of septage include:

Treatment at Sewage Treatment Plants (STP) – approximately 40% of Ontario’s septage is treated at a STP. A STP must be designed to accept septage and have capacity available. Many smaller STP are not designed to treat septage.

Dewatering trenches – are commonly used for disposal of septage in Northern Ontario. The septage is put into a series of trenches, similar to the runs in a traditional leaching field.

Waste stabilization lagoons – are designed to treat septage solids. These are generally found in rural areas where lots of land is available.

Land Applied – but this is coming to an end. The Ministry of Environment (MOE) has stated that it is committed to prohibiting the application untreated septage to land.

Certain times of the year, like in the winter, septage must be stored. Temporary storage of septage is permitted at Ministry approved sites, often in tanks or lagoons. These sites must meet stringent design and operation requirements and all must have a Certificate of Approval (CoA) from the MOE.

For more information on septage from the MOE please visit http://www.ene.gov.on.ca/envision/land/septage/septage.htm