Small Lot and Failed Field
The residential lot in the below pictures had a failed septic field. The driveway on the left takes up a large portion of the lot so limited what treatment system and field could be installed. As the system was nearly 20 years old, the concrete septic tank was deteriorating. Hydrogen sulfide (H2S) is produced when organic materials decompose under anaerobic (without oxygen) conditions. Oxygen comes in with cold water draining from the house. H2S +2O2 = H2SO4, or sulfuric acid. Sulfuric acid slowly disolves concrete septic tanks necessitating replacement.

The customer had two options:

 1) Dig up the driveway, cut down the mature tree and, due to shallow soils, install a raised treatment system thereby converting the entire front yard to a sand mound.

 2) Install a Vegetative Tertiary Filter and have the treatment system in the front yard without disturbing the driveway or tree.

 Small front yard with little room for an onsite wastewater treatment system

Front yard open area approximately 12 m wide x 9 m deep (40' wide x 30' deep).

Nearby failing Type 1 septic system

Failing Type 1 (septic tank and dispersal field) systems draining from nearby properties.


The solution was to decommission the old septic tank and install a new tank with a Nayadic advanced secondary treatment plant, and a pump chamber.

The Vegetative Tertiary Filter constructed wetland before planting

Final polishing and dispersal is accomplished by a long-version Vegetative Tertiary Filter - VTF

An aesthetically pleasing constructed wetland

The final result is a small, esthetically pleasing peat gardening area for final polishing, and the surrounding dispersal area that contributes to property values while protecting public health and the environment.

Vegetative Tertiary Filter constructed wetland with different plant selection

Another picture of the finished VTF, with a differing plant selection.

The other option would have resulted in the loss of the driveway, loss of off street parking, and loss of the use of the car ports. With the losses in functionality, property values would likely go down.