Wet Drain Field

joeyd · Sep 4, 2012

New to rural living, my wife and I have been in our house for 5 years (new home but septic was in about 5 years before we bought the land). Just more that a year ago I noticed our drain field was soggy. I called a septic guy out to look at it and he said it was nothing to worry about. Today I used a string trimmer and cut down the grass and weeds growing over the drain field and as I was sloshing through wet areas I knew something wasn't quite right. Any one have any ideas or had a similar issue? Does it just need pumping or is something wrong with the drain lines or field? We do not have any other septic problems in the house and it has just been my wife and I in the house.

dave1949 · Sep 4, 2012

You do have a problem if your drain field is saturated.

Tanks should be pumped to prevent solids build-up that then enters the field, and that could have caused your problem, but pumping won't fix it.

You need a qualified person.

JD 4520 · Sep 4, 2012

I might recommend that you learn a bit about your system first so you know how it works. The most common type is a conventional gravity flow. They can be pretty basic so look it up and learn. Inspect your tank and see the best you can that it is flowing and not overflowing. You would certainly know if it were overflowing. A drain field needs to have length, depth and slope with adequate holes in the piping, usually PVC. Then the important thing is lots of river rock that will take the flow and gradually absorb it into the soil. Septics really are not difficult and you may need an expert but you should know the language and design so you know what someone is trying to sell you. It doesn't sound like you have an emergency rather something isn't working right so take the time to fix it.

Carl_NH · Sep 4, 2012

As JD 4520 says length width and depth - also the pipes and distribution should be level.

For a 2-3 bedroom house a septic field should be at least 15x40 to 20x50 area and reasonably level and layered with sand and stone about 3' deep or more is typical. If your wet area is smaller than this then you either have a smaller field or a poor draining/designed field.

What it sounds like is the septic was installed before the house was built possibly in a minimal fashion and never tested and approved.

If your field is smaller or not level the fluids will flow to the lowest point first or if on ledge with not enough base the waste wont percolate into the soil as intended.

Depending on where you are and your environmental conditions (lake or stream nearby and your land area - acreage and soils) then local laws you should do research to be septic aware before you apply for permits or replacement of a system.

I am not suggesting to skirt the law but become familiar with your system and determine your problem or issue. Replacing a leach field could be $5K or $25K depending on your situation.

dave1949 · Sep 4, 2012

It's going to be hard to learn a lot about your system. You can open up the tank and see what's going on there, maybe find a distribution box and check that if there is one. I am assuming you don't have any pumps or grinders involved, just a normal gravity system.

If one spot seems to be the source of wetness, that would be worth digging up, could be a crushed pipe, blocked or whatever. But, if your field is just failing in general, it could be like Carl said, the system could be undersized or poorly installed/designed.

I agree, it's good to learn what you can. If there was a permit filed for your system, it should be on file at your local code office. It should have a simple drawing of the system, that would help. If you need major work, you will probably need to see the permit folks anyways.

joeyd · Sep 15, 2012

Well I have learned a bit about my problem. First I had the field scoped with a video camera and it is saturated. That is not as bad as it sounds, the system is a cap and rock system and since my soil is clay it is designed for the water to evaporate off the top rather than seep into the clay. The field may always be damp but not as wet as it is now. The first advice for a repair is to add some loamy soil on the top to help absorb some of the wetness. It also looks as if I do not have the required 12-18 inches of soil over the top, more like 12" everywhere. Then re-seed the new soil to help retain it. We have identified a replacement area for any future drain fields. If I have to add it later I will add a diverter valve as my current drain field should repair or replenish itself in a few years. I could then alternate between fields to add to their longevity. We also decided that a culvert was misplaced, it diverts water towards my drainfield, that will be re-routed to help keep excess water out of the drain area. Initial estimate is about $2000 depending on how far the dirt spreads, it will be applied with a conveyer system to keep heavy vehicles off the field.

I will have two other opinions before I make the final choice, but it is not looking as bad as I first invisioned.