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WallyPop 08-27-2012 06:48 AM

Septic field "perc" test, Sq. Hole digging suggestions.
In upstate NY need to excavate (3), 12"x12" square holes, 30" deep in my backyard to evaluate soil for septic tank drain field via "Perc" (percolation) test. This will determine amount of area needed to lay required quantity of 4" dia perforated pipe per Dept of Health specs.
Doing the test is "easy" for an old codger like me, but I'd appreciate some creative, experience-proven, suggestions on digging the holes. Each hole has to be flat walled, non-crumbly, etc per NYS guidelines.
I own a 4" wide-bit long-handled cold-chisel and post-hole digger; have lots of time but much fewer $. Wondering if some sort of powertool (akin to a battery-powered drill with long bit) is available for one-person use that would do the bulk of the excavation, with my hand labor finishing off the four vertical sides, etc.?

nealtw 08-27-2012 10:06 PM

I don't think there is a trick to it. Anything you can find to make it easier is a bonus.
Good luck.:rolleyes:

BridgeMan 08-30-2012 12:57 AM

Dig your round holes to the required depth using the clam-shell, then clean up the sides using a flat (rectangular) garden spade. Depending on the type of soil you have, squaring up the corners with a spade should be relatively easy. Take small, gentle stabs at each corner, removing the dirt that falls to the bottom with the clam-shell until you get all the way to the bottom. They don't have to be perfect.

Been there, done that, more than once.

WallyPop 08-30-2012 07:35 AM

Bridgeman: Thanks for reply. Giving myself 2 more days for responses and then will use the coming long weekend for my manual labor. Since you speak from experience, should I soak the ground, which is dry and hard to ease my digging chore?

Still grasping at straws, I'm considering using an 18v Lithium battery powered hammer drill? (with a sacrificial extended drill bit) to pave the way for the clam shell. Any thoughts?

Again, appreciate your response, plus words of reality and encouragement.


BridgeMan 08-30-2012 11:59 AM

Soaking the soil can work both ways--too many silty fines (P-200s, passing a No. 200 sieve) could result in a thick, heavy clay gumbo. It will stick to every shovelful of material, causing you to talk to yourself a lot while trying to unstick it. If your soil has a high enough amount of coarser (granular) fines, soaking would definitely help. Never used a battery-driven hammer drill, so I can't speak about its effectiveness. With hard, dry soil, my guess would be not enough oomph to do much good. Unless you go slow, and/or have standby batteries on the charger.

Another option would be to hire a few strapping high school kids in your area. For the price of a slice of home-made pie your Mrs. makes, with ice cream, they could have the holes dug in less than an hour. Trick--make it a contest, to see who is the strongest by being able to dig their hole fastest (you'll need a stop watch to make it official, while hiding your real intent of getting the darn holes dug).

nealtw 08-30-2012 05:42 PM

A five foot digging bar, goes a long way to loosen things up for the clam shell.

mudmixer 08-30-2012 08:13 PM

Who is responsible for determining the size of a tank and amount of pipe to install?

I had a system installed by a local contractor that did a lot of work in the area and knew the soil and water table conditions. He gave me a decent price on Tuesday night and I said O.K. I lived 140 miles away and went up on Thursday afternoon from the lake home I was building and spent the week-end pounding nails.

When I got there, I found a couple of holes (very, very roughly square) that were dug by the contractor and a note to the inspector of when they were dug (time and date). On Friday, an inspector was out there dumping in water and measuring and then left. The next Thursday the contractor called and said everything was done and approved and it would be good to go then. It pays to have someone do the specialized work that knows the inspector and what is required. A month later, I got a gold edged certificate from the county describing the perk results, size of the tank, distribution box, length and size of pipe used the paper over the drain field and the amounts of gravel and sand used.

When I built the 1850 sf masonry home, I needed only 2 inspections (septic because it was on a lake and electrical). I did the electrical after having underground service brought in, which I did myself with help from my 12 year old son that made all connections/grounds after I ran the wires (separate in conduit or Romax on the interior walls).

I tried to get a building inspection, but it was not possible because I was in an "unorganized area" and no inspectors were available even if it was at a premium and not really required.


WallyPop 08-30-2012 08:20 PM

Bridgeman & Nealtw: Thanks both. Time to stop pussyfooting around and get to work. I'll save the ice cream as an incentive for me.

I'll report back with my trials, tribulations and results after Labor Day.



WallyPop 08-30-2012 08:55 PM

MudMixer: Just as I submitted my reply to Bridgeman & Nealtw, lo and behold your reply popped up. Thank you.

This is not a new installation, but a planned rehabilitation of my 50 year old original drain field and a replacement of my second 25 year old steel tank, this time with a longer-lived poly blow-molded tank + new distro box.

The "perc" test will determine how many Infiltrator poly leach field modules I'll need to purchase in preparation for my tank installation contractor to install and connect.

The latter is way beyond my DIY aspirations, but keeps me knowledgeable about my septic system details and future upkeep.


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