=== Features of ABR Systems ===
When adequately reinforced, ABR systems may be installed under driveways, parking areas, play grounds or other open spaces. The tanks are usually constructed completely underground with manholes or access ports as the only protrusions. ABRs, being passive systems requiring no electricity to operate, are truly low-cost technologies. However, ABRs, while more efficient than septic tanks, will still require secondary treatment to provide a quality of effluent suitable for discharge. Secondary treatment may be in the form of soils treatment (leach trenches if soils are adequate), constructed wetlands, sand or media filtration. Some designers will combine ABRs with mechanical treatment such as sequencing batch reactors to provide a highly treated wastewater effluent. Visit our [[Sequencing_Batch_Reactors|page on sequencing batch reactorsSequencing Batch Reactors]] for more information on these systems.
=== The Tank ===
#Backfill the rest of the way with clean soil and manually compact as above. Mound soil slightly around the tank to shed surface water and to avoid ponding of surface water over the tank.
#Check the soils over the tank frequently. Over the weeks or months after tank installation, some soils settling will occur. Fill depressions or fissures as soon as possible.
''NOTE: As soon as possible after the tank has hardened, add water to the tank and begin the backfilling procedure. This provides weight that can counteract buoyancy forces. This is especially important in areas where groundwater is high or surface waters can fill in tank holes.''
''[[Primary Treatment MethodsAnaerobic Baffled Reactor (ABR) 1| Back to Primary Treatment MethodsAnaerobic Baffled Reactor (ABR) 1]]''
''[[Practitioner's Tool / Technology and OperationPrimary Treatment Methods|Back to Technology and OperationPrimary Treatment Methods]]''
