Digging a new drain field

For those of you unfamiliar with a septic system, when your house is too far away from city sewer services, you have a septic tank. It is a concrete tank that is located underground not too far from your house. They hold anywhere from 750 to 1500 gallons or more. The drain line from your house goes into the tank (the inlet baffle), and then from the tank there is another line (the outlet baffle) that goes to your drain field. The inlet baffle and the outlet baffle are not at the same level so that the only thing that goes out the outlet baffle is liquid. A layer of scum floats on the top (like the small amounts of grease that you can't help send down the drain) and the solids sink to the bottom of the tank. The liquids that come out of the tank go to the drain field, which is some perforated pipe embedded in small rocks that causes the liquid to be filtered and eventually end up back in the water table as clean water. Every few years you have the tank pumped and the solids and liquids removed so, hopefully, it is like starting over. Every so often, though, the drain field will fail because the soil stops draining, or the drain lines become clogged. According to a few of the people we talked with, a drainfield's lifespan can be as little as 15-20 years. Ours was 32 years old, but we have fantastic sandy soil about 6 feet down because our land is old river flood plain. We decided to install a new drain field because the old one was too close to the location of our new addition. We oversized it by over 50% so we can add extra bedrooms down the road (the health department gauges the size needs by number of bedrooms, not number of bathrooms).

This is the location of the new drainfield before the digging began.

Sorry for the fuzziness but I took this through the window screen. Just beginning the digging.

Working their way west to finish digging the hole. They put the drain rock and pipe in the first half before they finished digging because the track hoe couldn't reach that far, though.

Preparing the bed for the perforated pipe. It's several inches of drain rock.

Half of the drain field pipe. The other side is a mirror image but they worked so quickly I wasn't able to get a picture of the entire thing.

They covered the pipe with more rock before they put felt over it and backfilled with dirt. This picture was taken in the evening after they'd left for the day. It's my husband, me holding the baby and the camera, and my brother-in-law.

The second half of the pipe is all covered and ready for felt.

We ended up waiting for the inspector before they could backfill. So they started demolition while they waited.


Now it's a big dirt field. We're waiting to reseed the lawn until the big machinery is done driving through the yard and we had to turn off the sprinkler lines before they got munched by the trackhoe so it will be a dirty summer. Anyone want to come sweep for me multiple times per day?