ET septic systems

[Stephen Tashiro]

Do any members' houses have an "evaporation-transpiration" septic system? I'm curious how well they work.

Does the area of the yard used by the system have a distinct odor if the system is working properly?

[Bruce Wrenn]

I'm not sure if it's the same thing, but when I was doing septic systems, spray systems were used where soil wouldn't perk. Local state parks at the lake use this type of system, and they are located beside the entrance road, so odor would be noticed, if present. These systems first go thru septic tank, and then effluent is sprayed onto soil surface.

[Stephen Tashiro]

My understanding of the ET system is that a membrane keeps the liquids from soaking into the soil and they are taken up by the roots of plants and evaporated through the leaves. I think of it being like the drain field of a conventional septic system except that a membrane keeps the liquids from going deep in the ground.

[Bruce Wrenn]

Here we install LPP systems. LPP stands for low pressure pumped systems. You have conventional septic tank followed by a pump tank. The laterals are 1 1/4" PVC with holes drilled in them at designed spacing and size. The pump head is such that there is less than 2 feet of head on any lateral. When the float turns on the pump, all the laterals are filled, and then the fluid drains out over the entire field. The laterals are located about 12 - 16" below the surface, and are surrounded by stone. The fluid is picked up by the vegetation and transpired into the air. System won't work in areas that the ground freezes. By using pump, the complete field is flooded, not just the first few feet as in a conventional system. Google LPP septic systems for a better explanation.