Depending on the terrain of your lot, you may be able to install an onsite system that discharges effluent to the
drainfield via a gravity system. As wastewater flows into the tank at the inlet, it pushes out clear effluent at the
outlet. A Biotube Effluent Filter on the outlet of your septic tank will protect the drainfield from particles that
could clog and damage it.
Other onsite systems discharge effluent to the drainfield using an effluent pumping system. This is necessary
when the drainfield is not downhill of the septic tank. One advantage of an Orenco pumping system is that it
delivers wastewater to the drainfield in small, uniform doses throughout the day. This keeps the drainfield in a
consistently moist condition favorable to the growth of treatment organisms.
In Orenco’s effluent pumping systems, the pump is protected by a Biotube Effluent Filter and operated by a
control panel. The panel may activate the pump based on demand, when the effluent in the tank reaches a
certain level. Or it might activate it on a timed schedule.
If your site’s not suitable for a drainfield of conventional size, or if your site has poor soils or is in an
environmentally sensitive area, you’ll need a secondary or advanced treatment system. These systems treat
household waste to very high, advanced (secondary) treatment levels: 10 mg/L BOD and TSS, or better.
Many wastewater treatment organisms need oxygen to do their work. In a conventional municipal wastewater
treatment plant and in some advanced treatment systems, machinery or blowers continuously aerate the liquid
effluent to supply the necessary oxygen. This process requires a lot of energy.
However, a more stable and energy-efficient practice is to trickle the effluent over a bed of porous material,
called a media filter. The filter media develops a thin coating of microorganisms. Nutrients continuously wash
over them, and oxygen from the air passively permeates the thin layer of moisture. Periodically trickling effluent
with a small pump uses much less electricity than continuously aerating liquid with a blower. This process also
provides more efficient treatment and reduces the amount of biosolids produced.