Septic System Questions
Septic System Questions
(OP)
I'm working on a project that involves a new building and parking lot. It's for a now-vacant lot that used to contain a single-residence. I suspect that the water-table is close to grade in this area (soil borings will be taken this month).
I was told that the septic tank was removed when the house was demolished. I assume there is a septic field the site somewhere that we will need to address. (Lord knows how it's been operating with the high water table). Neither the surveyor or I have had luck spotting evidence of it. I assume GPR may be necessary to locate the thing.
I know NOTHING about septic systems. Can anyone recommend a good read, that would cover the basics, or some general advice on the situation? Thanks.
I was told that the septic tank was removed when the house was demolished. I assume there is a septic field the site somewhere that we will need to address. (Lord knows how it's been operating with the high water table). Neither the surveyor or I have had luck spotting evidence of it. I assume GPR may be necessary to locate the thing.
I know NOTHING about septic systems. Can anyone recommend a good read, that would cover the basics, or some general advice on the situation? Thanks.





RE: Septic System Questions
RE: Septic System Questions
Here's a link to an EPA site with a little info...
http://cfpub.epa.gov/owm/septic/home.cfm
Also, to locate the septic tank, search the property appraiser's records for a sketch of the house on the lot. These are commonly available, even if the boundary survey did not locate the septic tank.
Depending on side setbacks, the septic tank was usually installed in the front or back yard. If large separation between houses, back yard was common. On tight lots with small side yard setbacks, front yard was often selected for ease of access for cleanout.
Tanks were usually no closer than 5 to 10 feet from the house. Could be farther, depending on lot size.
Using a probe rod (1/2" diameter straight steel rod, 4' to 6' long, preferably with a tee handle) probe a grid pushing the rod as deeply as possible. If there was no basement, the septic tank was probably installed less than 2' below grade. The higher the water table, the higher the tank.
Bottom of the drain field is usually a maximum of 18" below grade. With the probe rod, you'll hit gravel, drain tiles or both. Work your way back to the tank.
RE: Septic System Questions
http://www.epa.gov/seahome/septics.html
RE: Septic System Questions
Your primary concern should be the septic tank and/or drywells that may be still present on site. They could represent a collapse hazard in the future. You either need to locate and properly abandon them or get some sort of authoritative confirmation that they were removed or collapsed and filled.
As for addressing the septic field, I think you only need to worry about it if you plan on using it again. Otherwise all it represents is some stone and tile that you might run into during construction.
If you plan on using this septic field again, it's a whole different story.
RE: Septic System Questions
RE: Septic System Questions