Pretreatment Unit & Device Maintenance

Pretreatment Unit Maintenance & Supplemental Treatment Devices

Pretreatment Unit Maintenance will vary depending on the type of unit you have. Pretreatment can be accomplished several ways. One way is to inject a substantial amount of air into the wastewater in the pretreatment tank, creating an aerobic environment that will sustain high bacterial populations, which then actively digest organics in the aerated wastewater. The other method of pretreatment is to re-circulate wastewater over a filter medium frequently (several times/hour). A portion of the wastewater will go to another treatment component for dispersal and a portion will go back to the septic tank for redistribution over the filter medium.

Maintenance Intervals

Each type of pretreatment unit therefore will have its own required maintenance interval. It may be every four months, six months or once a year. Some pretreatment units will have chlorinating units or ultra violet lights as part of the system and will also have maintenance and replacement intervals of every one to two years for those components.

It is because of these additional components that additional consideration is given to septic tank maintenance and dose tank maintenance timelines for pumping intervals. The maintenance pumping intervals may be expanded because of the sensitive nature of the pretreatment unit used in the Private Onsite Wastewater Treatment System (POWTS) network of components

Report Form for Pretreatment Unit

All service event report data should be provided to this department after each service interval for the Pretreatment Unit and its components. The service event report data must be entered on and submitted via the Kenosha County Sanitary Maintenance Portal (KCSMP). Each maintenance company for the various Pretreatment Unit Systems on the market has their own service report form due to the individual characteristics of each particular unit. The data collected during the service event by the service provider must be entered into the KCSMP database and must be received by the Kenosha County to comply with the maintenance reporting requirements.

The owner of the POWTS is still responsible for making sure all completed service event data is submitted to this department as described above. This department will send notice to the property owners to remind them of this obligation. If the completed service report data has not been received by this department in the specified timeframe and means then corrective measures are taken to obtain compliance.


A citation is issued as a reminder to the POWTS owner of the maintenance obligation they have to the county to ensure proper operation of the POWTS.

It is important to remember that maintenance is the key to achieving design performance and extended use of each POWTS.