Friday, May 4, 2012

What the heck is a perc test?

After we bought our land and decided we wanted to build a modular home, we realized the land did not have a valid perc test and therefore, we had to get this done.

Wikipedia defines:

A percolation test (from percolation, colloquially called a perc test) is a test to determine the absorption rate of soil for a septic drain field or "leach field". The results of a percolation test are required to properly design a septic system. In its broadest terms, percolation testing is simply observing how quickly a known volume of water dissipates into the subsoil of a dug hole of known surface area. While every jurisdiction will have its own laws regarding the exact calculations for the length of line, depth of pit, etc., the testing procedures are the same.

In general, sandy soil will absorb more water than soil with a high concentration of clay or where the water table is close to the surface.

In our county, you have the option to dig the holes yourself.  The county gave us a detailed description of what needed to be done, but if my memory serves me correctly, you dig three holes, in a triangle pattern, where you want your septic system to be.  Ours were about 2 feet deep.  After about 12 inches in, we hit clay, so that was fun, and rather disturbing (see the definition)!  This hole had to drain water and drain it fast for us to pass the perc test and put in the septic system!  Anyway, after you dig the holes, you have to bring a gigantic container of water to your property for the engineer to fill the holes with.  Ideally, that water will drain at a rate that is acceptable and you get your septic system approved.

So, as I remember, I was digging madly, sweat running off my brow - no, wait, that was my husband.  I was standing by, offering support and encouragement.  After the three holes were dug, the heavens opened and we had three days of torrential rain.  (On the 3rd day, we had scheduled for the county to come and perform the test. I don't have to tell you that this was not the ideal for passing the perc test.)

We knew we had to do something before the test, cuz there we were with three large holes, full of mud water.  My hubby is pretty smart, so he had the idea to use a trowel to scrape up the sides and the bottoms of the hole, so that the water would sink into the ground easier.  Brilliant!  So, I lie down on the muddy ground, armed with my trowel, and plunge my hand and arm into the murky mud water.  I didn't think of this at the time, but as you can imagine, after a few days of rain, not only do the holes fill up with water, they fill up with other things.  Like dead frogs!  And dead bugs, dead worms, and one live toad!

But, I'm a trooper!  I screamed, threw the trowel to the ground, and ran for the relatively clean and safe truck!  My brave husband, shook his head, and continued with the job he knew he'd end up doing anyway.

Well, we didn't pass that perc test.  That water just didn't want to drain!  To our relief, it seems the county where we live is fairly relaxed and the woman who performed the test rescheduled for the following week, when we hoped, the ground would not be so sodden.

As luck would have it, the wind blew and the holes dried up, and we passed the perc on the second try.  Phew!