Septic Effluent Disposal versus Septic Effluent Treatment

  • DISPOSAL vs TREATMENT - CONTENTS: Distinguishing between septic effluent disposal and septic effluent treatment . "Getting rid" of septic effluent by soil absorption does not assure sanitary treatment of septic effluent. What is a septic effluent treatment failure? Definitions of septic failure for each component
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This article explains steps for distinguishing between septic effluent disposal and septic effluent treatment among the types of septic system failure in the drain field, leach field, seepage bed, or similar component. We list the causes of each type of septic component failure, and list the septic component failure criteria or in other words what conditions are defined as "failure"?

How can you distinguish between a blocked pipe, a septic tank that needs pumping, and a clogged drainfield that needs replacement? This is an important question as it distinguishes between relatively low cost maintenance or repair task and a costly septic leach field replacement.

We also discuss what can be planted over and near a septic drainfield and what should be avoided. Also see SEPTIC DRAINFIELD LOCATION: how to find the septic drain field or leaching bed.

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What is Onsite Septic Effluent Disposal, Graywater Disposal, or Wastewater Disposal?- Disposition & Transpiration

Wastewater is disposed-of on-site. We "get rid of" the liquid. This means that the liquid portion of waste piped from a building is released into the soil, typically at a drainfield or soakaway bed or leachfield (these are synonyms). There most of the water eventually joins groundwater in the soils around or passing through the property. See SEPTIC DISPOSAL FIELD CLOGGING INSPECTION.

A portion of effluent or wastewater is also released through evaporation, or transpiration. Moisture moves naturally upwards through soil to the more dry air above. Preserving transpiration or evaporative transpiration is one of the reasons that we don't want to pave over a drainfield nor cover it by plastic or insulation or anything that blocks moisture movement out of the soil into the air.

What is Onsite Septic Effluent Treatment?

Sketch of a septic drainfield showing clearance from grund water tableSeptic effluent that leaves a septic tank is treated by various processes so that when it is released to the environment the wastewater is sufficiently sanitary. A properly functioning septic system should not carry pathogens, chemicals, or other contaminants to the environment.

Septic effluent is the liquid portion of sewage waste that passes out of a septic tank into a disposal system such as a drainfield or leach field.

Sewage is partially treated in the septic tank (the level of treatment varies depending on the type of septic system and septic tank). In the septic tank effluent is separated from most solids.

Solids remain in the tank and effluent passes out of the septic tank to the soil absorption system: the drainfield. In the drain field, septic effluent is further treated by soil filtration and bacterial action in the drainfield.

However there can also be treatment failures.

Effluent may not back up or appear on the surface, but if insufficiently treated effluent reaches a private well or any stream or waterway, the environment is being contaminated -- this is an unacceptable condition.

Onsite Sewage DISPOSAL vs Sewage TREATMENT - Successful Wastewater Disposal Does Not Necessarily Mean Successful Treatment

Historically many people have just worried about wastewater disposal. That is, we don't want to see wet smelly areas of sewage water in our yard.

But we should also be concerned about wastewater treatment. As the quality of drinking water deteriorates in many areas and as population grows in many previously thinly-populated areas, proper wastewater treatment has become the real concern for everyone's health.

For example, if there is not sufficient soil between the bottom of the soil absorption system trenches and the local groundwater, the local environment is being contaminated.

Drywells and cesspools or deeply-buried drainfields may successfully dispose of wastewater or septic effluent, but because of the lack of oxygen deep in soils, the effluent may be insufficiently treated before it is released to the environment.

This distinction has been recognized in the United States by some state sanitary codes such as Massachusetts Title 5 that, through its provisions, requires that a septic system treat effluent not just dispose of it.

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