Non-standard Onsite Wastewater Treatment System

Maintenance Guidelines

A non-standard onsite wastewater treatment system is typically one which uses something in addition to a septic tank to treat effluent and/or uses other than a gravity-flow drainfield. Such a system requires an operating permit and an inspection report every 3 years. The Humboldt County Division of Environmental Health Land Use Program recommends the following routine maintenance be practiced to prolong the life of these systems. Call staff at Environmental Health with questions.

Cross sectional diagram of 2 compartment septic tank

Septic Tank

  1. Check the lids and/or risers of the septic and pump tank to make sure they are water tight. It is recommended that risers be installed over access ports of the septic and pump tank in order to provide for easier access for pumping and servicing.
  2. Pump septic tanks on average, once every 5 years. Effluent filters are required to be on the outlet side of all new septic tanks and can be retrofitted to older tanks. If an effluent filter is present, it should be cleaned. This can be achieved by removing the filter and hosing the debris into the first compartment of the septic tank.
  3. Flush out the lateral lines once every 3 years to remove scum and solid in the lines. A handout on flushing can be obtained from our office.
  4. Check to see if alarm box functions. If it is not operable, it must be repaired or replaced. The alarm switch should always be in the “on” position and “sound” when activated. The alarm should sound when the alarm float is in an “up” position. If you have a pump control box, the dose counter and elapsed time should be recorded.

    Cross sectional diagram of pump chamber.

    Pump Chamber

  5. Keep large animals and vehicular traffic off the septic system and reserve area at all times, especially when the ground is moist. The impact of animals and/or vehicles may cause severe damage requiring repair or replacement of the system.
  6. For above-ground systems, check for erosion of soil resulting from seasonal rains. If significant erosion has occurred fill those areas with topsoil to bring the soil cover to its original shape.
  7. Remove deep-rooted plants including trees, shrubs, and blackberries from disposal field. Plant shallow rooted grasses or herbaceous plants over disposal field.
  8. Ground cover should be routinely cut and properly maintained. Protect irrigation can lids and sweeps and caps when mowing. Irrigation can lids and/or sweeps and caps must be replaced if broken and should be added if not present. Sprinklers and drip irrigation systems must not be placed over the disposal field.
  9. Should sewage backup into house, contact a service provider to determine if system is failing. Should sewage surface over disposal field contact the Humboldt County Division of Environmental Health to evaluate whether a repair is needed.
Diagram of a sample non-standard onsite wastewater treatment system.

Example of a non-standard onsite wastewater treatment system