A complete layout of your site, including dimensions, is needed before designing a septic system. Every county has certain regulations concerning the location of septic systems. Consult your County Health Department for the regulations that apply in your county.
For example, your county's health department regulations may require that the drain field of a septic system be located a minimum of TEN FEET from the foundation walls of any buildings and that septic tanks must be at least FIVE FEET from foundation walls.
Your county's SANITARY CODE may require that the drain field be located some minimum distance from any water supply well. Don't forget your neighbor's well.
The Health Department may require that drain fields be set back a distance from property lines (e.g., no closer than TEN FEET).
Drain fields should be kept at a safe distance from lakes or streams. Site specific recommendations should be obtained from your County Health Department before planning construction.
Drain fields may have minimum set backs from any drop-off such as a ditch under the regulations of some health departments (e.g., no less than FIFTEEN FEET).
Some counties require a minimum distance from utility lines as well.
After accounting for all of these separation distances, you can determine the usable area remaining.
Don't forget to allow for any possible future construction. Don't locate your drain field in a location that would be ideal for a pool, deck, basketball court, or some other future additio