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Residential septic system (pressurized)

Residential septic system (pressurized)

Residential septic system (pressurized)

I have a client whom plans to install his septic system drainfield up hill from his house elevation. therefore I know I am in need of a two tank system, one to house the sewage flow and the other to pump the effluent to the drainfield. In return, the homeownwer want to install a bathroom in the basement level of the home. Would this involve an additional pump? does this pump need to be a grinder pump ?

Or shall 2 sewage pumps suffice, one at basement level to pump to septic tank, then one pump from pump chamber to drainfield.

Is there a more economical solution. ie) the use on one (1) pump instead of two? without having to install the tanks more than 10 ft below grade ?

Basement elevation = 436.0
elevation of drainfield = 440.0 approx. 200 lf. from pump chamber.

Any comments or recommendations are greatly appreciated.

Thanks in advance for your comments.


RE: Residential septic system (pressurized)

It would help if you supplied a sketch.

Your first floor elevation is estimated at EL 446. That would put the building sewer at approximately EL 444. If you allowed 4-Feet of slope from the building to the drain field, the system should work by gravity.

For the basement bathroom, use an sewage ejector pump with an overhead sewer line. For most applications, the correct choice is a sewage ejector pump. Applications where a sewage ejector pump should be used are when pumping sewage to a septic tank, when pumping sewage short distances (750 feet or less) and when there is a low vertical distance to lift the sewage.

Applications where a sewage grinder pump should be used include when pumping to a pressurized sewer main, when pumping a long distance (1,000 feet or more), and when there is a high vertical distance to lift the sewage (at least 30 feet). A note here in the case of vertical lift: Depending on the specific application, either an ejector or grinder pump might be the proper choice.

You probably want to add soil around the house so that water will drain away from the house.

RE: Residential septic system (pressurized)

thanks for your response, FFE = 445, drainfield is approx. 200 lf away, it is planned for a force main to the leaching field, but I will entertain trying to do it by gravity. Therefore, a sewage ejector pump to pump the sewage to septic tank shall suffice, then I planned to pump effluent to field by force main. So my main concern was whether or not I needed to "grind" the sewage. My thoughts are as long as the home owner takes caution on what enters the sewage stream, a regular sewage pump should be fine, then let the septic tank separate the solids from the wastewater.

Thanks again for the input.


RE: Residential septic system (pressurized)

Along with this system, the client requested a basement bathroom, therefore, we used an ejector sewage pump for this. Does this need its own lateral to the septic tank, or may it be combined with the gravity lateral we have currently designed going to the septic tank ?

Thanks in advance for your responses and comments.

RE: Residential septic system (pressurized)

No, I would advise an overhead sewer. Basically, pump it up to the bottom of the floor joists, and pump it into the building sewer.

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