As we come to the holiday season, we don’t normally think of what’s necessary to keep operations on an even keel at our school’s package treatment plant. I got a call about the holiday break, and the operator’s supervisor wanted to confirm what the operator told him (Yes, the operator was right.).
The operator told him that they should “feed” the plant and run some water regularly through the plant to keep the bacteria alive. Since I agreed with the operator, the supervisor asked what to “feed.”
I suggested dried sorghum from a farm store. It’s cheap, readily available and a good energy source for the bacteria as it is a fairly simple sugar. There should also be some water run through the plant regularly to keep an active hydraulic movement in the plant. We discussed maybe reducing the amount of air added to the plant during the break. By adjusting the timers on the blowers for this plant, they may be able to lower the electric bill for the month. DO NOT SHUT OFF THE AIR!!!!! The plant will go septic and be a real stinky mess when you get back to it.
If you do lose the bacteria during the break from lack of attention or other problems, you can repopulate it in a couple of ways to return to treatment quickly. One way is to call a septic hauler to bring a load of mixed liquor from a neighboring wastewater plant to reseed your plant with their bugs. Since this can get expensive, smaller plants (less than 25,000 gpd. design size) can add a couple of five-gallon buckets of clean (no straw) horse manure. This will sometimes do the trick. Just add it to the aeration section of the plant and feed.
If you have septic tanks with a sand filter and disinfection and discharge at your school, this holiday break is a great time to do maintenance on the sand beds. Determine how deep the sand is above the collection system, and then roto till well above the pipes to break up the sand and allow for better filtering.
The supervisor’s call prompted this blog post to remind you to care for your plant during the break. It also gives me a chance to say Happy Holidays to everyone.