Re: New construction what is the best septic system for 4 people?
The septic design depends quite a bit on the soil and the lay of the land. To begin with, you'll need to dig a couple of test pits in the area where the drainfield will be, for a "perc test." This is a soil analysis to determine how porous the soil is. It is usually conducted by the local authority in charge of regulating septic systems. They will then give you the requirements for the septic system for your site, but they will probably stop short of designing it for you. You will need to present plans to the local authority that meet the requirements they set forth for your site in order to get a permit to build the thing.
(By the way, in a standard septic system, solids are separated from the liquids in the septic tank by microbial action and settling. Only liquid is supposed to flow to the drainfield, which disposes of the liquid more by evaporation than infiltration to the groundwater supply. If solids are permitted to enter the drainfield they will plug up the soil, which will require replacement of the drainfield in a different location. Septic tanks must be periodically pumped to remove the insoluble solids.)
Some other considerations besides soil permeability include the locations of nearby water wells, cut banks, groundwater, and streams.
Anymore, you can't just throw in a drainfield for a few hundred bucks, and there isn't a basic system that fits in most cases. Plan to spend some money on engineering by a qualified, licensed septic installer or engineer. For some strange reason, your neighbors are concerned for their health and quality of life, and an improperly designed septic system can be a major public health hazard. That's why the regulations on septic systems are so stringent, and that's why septic systems can be expensive to install. You can get an idea of what the cost might be by talking to neighbors with similar land who've had a septic installed in the last five or ten years (adjusting for the state of the economy, of course). Regulations haven't changed too much in that time frame.
Last edited by Fencepost; 09-13-2009 at 02:47 AM.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.