The most appropriate or effective options to treat wastewater will depend on a number of factors including the composition and volume of the wastewater, applicable legal requirements, and available external infrastructure such as off site treatment facilities.
- On-site Wastewater Treatment Only: Treatment performed onsite at a facility in a wastewater treatment plant used managed/operated by the facility. After on-site treatment, the wastewater is discharged to the environment.
- Zero-Liquid Discharge (ZLD): ZLD is a type of onsite treatment that is designed so no water leaves a facility in liquid form. At a facility with on-site ZLD treatment system, almost all wastewater is treated and recovered so that the only water discharged from the facility exists by evaporation or as moisture in the sludge from treatment plant operations. A facility is not considered to have a ZLD treatment system if there is any industrial liquid discharge.
- On-site Wastewater Treatment + Offsite Treatment: Treatment that is initially performed onsite at a facility before discharged to an offsite 3rd party treatment plant for additional treatment. This is also referred to as partial onsite treatment.
- Off-site Wastewater Treatment Only: Treatment that is performed offsite by a 3rd party wastewater treatment service provider that may be government or privately owned/operated. With off site treatment, the facility’s untreated wastewater is discharged directly to the off-site treatment facility.
- Septic System: Underground wastewater treatment structures that use a combination of natural and primary processes to treat wastewater. The process typically involves solids settling within the septic tank and ends with wastewater being discharged to the soil via a drainfield.