==== Secondary Treatment ====
Septic tanks alone are not sufficient to treat wastewater to the point where it can be safely discharged, so secondary systems are required. View a summary table of the [[Practitioner's Tool / Secondary_Treatment_Methods|secondary treatment technologies]].
*[[Practitioner's Tool / Constructed_Wetlands|Constructed Wetlands]]: Constructed wetlands are gaining in popularity as the wastewater system of choice in the Philippines for many point sources of sewage pollution, including those from public markets, hospitals and slaughterhouses. Constructed wetlands come in many shapes, sizes and flow patterns.
**[http://www.susana.org/en/resources/library/details/2470 Constructed Wetlands Tool (.xlsm, File 06)]
*[[Practitioner's Tool / Technology and Operation / Cocopeat Filters|Cocopeat Filters]]: Cocopeat is the dust from ground coconut shells once the fibers (coir) have been removed. It is generally considered to be a waste by-product from the coconut processing industry; therefore, in coconut producing areas, cocopeat is readily available at a low cost.**[[Practitioner's Tool / Case_Studies:_Cocopeat_Implementations_in_South-East_Asia|Case Studies on Cocopeat Implementations]]**[[Practitioner's Tool / Cocopeat_-_Selecting_Proper_Grades_for_Use_in_Biotreatment_Systems|Selecting Proper Grades for Use in Biotreatment Systems]]: Selecting the proper grade for use in bioreactors as components of wastewater treatment systems is important. Review this link for information on the different grades of cocopeat and steps for preparing cocopeat from dried coconut husks.
**[[:File:Septictanksizingtoolwithcocopeatmodule.xlsx|Cocopeat Sizing Tool (.xlsx)]]
*Aerobic Systems
**Activated Sludge: Activated sludge is a flow-through process during which wastewater passes through a series of tanks or basins where different processes treat the wastewater. After large solids and grit are removed through bar screens and grit traps, the wastewater undergoes primary settling to remove much of the settleable solids. Settled effluent then undergoes biological treatment in the next tank where oxygen and activated sludge containing billions of microbes act upon the organic material in the wastewater.
**[[Practitioner's Tool / Extended_Aeration|Extended Aeration]]: Extended aeration is a modification of the activated sludge process and was developed to provide a more stable treatment process for smaller and more variable flows for sources from schools, tourist facilities, shopping malls and similar facilities.**[[Practitioner's Tool / Sequencing_Batch_Reactors|Sequencing Batch Reactors]]: A sequencing batch reactor (SBR) is an aerobic treatment process that is highly efficient in removing organic matter, suspended solids and even nutrients in wastewater. Unlike the traditional activated sludge method that uses multiple tanks, the SBR treats each batch individually in a single tank.**[[Practitioner's Tool / Oxidation_Ditches|Oxidation Ditches]]: An oxidation ditch is a combination of extended aeration and activated sludge processes. An oxidation ditch is constructed as a large holding tank in a continuous oval-shaped ditch.**[[Practitioner's Tool / Fixed_Activated_Sludge_Treatment|Fixed Activated Sludge Treatment]]: The Fixed Activated Sludge Treatment (FAST®) process employs a unique hybrid combination of attached and suspended growth in an aerobic, packed-bed bioreactor.
*[[Practitioner's Tool / Rotating_Biological_Contactors|Rotating Biological Contactors]]: Rotating biological contactor (RBC), or biodisc, technology is a fixed-film aerobic treatment process that can be very effective in treating a variety of wastewaters. It is a secondary treatment process, meaning that grit removal and primary settling are required before the RBC process.
==== Disinfection ====
