Saturday, March 7, 2009

Swimmin' in the septic system

Regular readers of this blog may remember a post about fishing last September. I described my device for gathering water samples from the discharge of our septic system, and how we are required to submit a sample at least once a year. We submitted a sample last September. It failed. We added chlorine to the discharge and sampled again. It also failed. We flushed the chlorinator and contact tank, added chlorine, and sampled again. It also failed. I've lost count of how many times we've flushed, sampled, and failed, but evidently the County Health Department hasn't lost count. They sent a representative out to take a look on Friday.

Taking a look at the contact tank in our system involves removing about a foot of earth on top of the 24" diameter concrete tank lid, and of course, removing the lid itself. The expert recommended we pump the contact tank, which if everything is working correctly, should only contain relatively clean and clear water. Ours was pretty muddy. After pumping about 40 gallons of water out of the tank, it was apparent that our pump was ingesting sediment, and that we needed a different method to remove water and muck from the tank. Being short on industrial pumping equipment and long on dim wits and energy, yours truly took a bucket into the hole. Even though water continued to trickle into the hole from the inlet and outlet tubes, I was able to stay ahead of the inflow and remove most of the sediment on the bottom of the tank. Photographic evidence of the adventure is included below for your enjoyment.

This was our routine: I would gather as much sediment and water in my little bucket as I could, while Karen's dad lowered a larger bucket into which I could empty mine. Because of the tight quarters, he would need to raise his bucket above my head so I could stoop back down to get another collection, stand up, direct the second bucket down in front of me, empty into it, repeat ad nauseum.

This demonstrates how far I could bend over inside the contact tank: just far enough to scrape my pail on the bottom while wedging my body against the sides of the tank, and trying to keep the inflowing water from running into my boots.

"Sure it's comfortable down here, why do you ask?"

Why am I smiling? Because I'm finally out of the hole!

Evidently tucking my pants legs inside the boots was not the way to keep the water out....


  1. Beautifully written and totally puzzling?
    With a "normal septic system" the tank using a anaerobic air less process turns our toilet to mainly water/liquid and methane and carbon dioxide gasses.
    Then the liquid moves into the drain field where the aerobic process takes place where the liquid is finally processed with the result clean water that then joins the local aquifers.
    Question, your article seems to indicate that you are sampling the liquid as it comes from the septic tank and before it goes through the final aerobic process?
    Why is that, and what are you looking for?
    Keeping in mind that, what you put down the sink or toilet effects what comes out of the septic?

  2. Perry, thanks for the compliment and comments. Our system does not have a drainfield but instead includes a sand filter (about 1,000 cubic feet of sand underground) downstream from the septic tank. Like you describe, we depend on anaerobic bacteria and the design of the septic tank to break down solids so liquid flows to the sand filter. The sand filter apparently serves the same purpose as a conventional drainfield and then discharges to a chlorinator where the fluid is exposed to chlorine, and then on to the contact tank which is pictured in the post. The discharge from the contact tank empties into a field tile that runs through several properties in our area. According to the County Health Department, since we have a "surface discharge" system, we must test it once a year to ensure the level of fecal contaminants at the outlet of the contact tank is lower than their requirement.

  3. That's a pretty crappy job...

  4. May I mention a few things that may help, sove your problem.

    I imagine that the septic is correctly sized for the number of people using it?

    A septic works best when the tank has at least eight feet between the inlet and outlet T's, when the sewage takes more than eight hours to transit the tank, when the tank sits idle and unused for a least eight hours a day/night, when very little cold water is allowed into the tank, as cold slows the process.
    Methane bacteria are pH sensitive they prefer pH6.8 to 7.4 lime can help if the process is too acid.

    Septic tanks work best when they are situated in full sun.
    The anerobic process works at its best at 95 degrees F.
    Therefore testing in early spring when the ground is cold is guarenteed to receive a poor result.

    It makes a lot of sense to build a green house over the septic, this will raise the ground temperature on most days and will enable the bacteria to work more efficently.

    There are certain products and situations that slow or stop the bacteria from working, cold I have already mentioned, all types of antiseptic, salt, sodium, alcohol, bleach, heavy metals can in quantity bring the process to a halt.

    If you do not keep a check on the contents of your septic, it is a good idea to open the lid and take a look from time to time.

    If you use a ten foot pole to ascertain the level of solids in the tank, say sample every few months (until you get the hang of it) you will see that the tank will fill during the winter cold period and empty again with the warmth of summer.
    On this point, a septic does not require emptying until the top of the solids is within twelve inches of the bottom of the outlet T.
    Checking two or three times a year means you chose when to empty the tank at a time thats conveinent to you.
    avoiding all types of antiseptic ie:Salt, sodium, alcohol, bleach etc;that will stop the anerobic process, a septic will only require emptying every 20 to 30 years.

  5. Thanks for the great advice Perry!