Thursday, August 21, 2014 / by Vanessa Saunders
(Depending on your point of view, this blog may or may not be acceptable for polite conversation, water cooler debates or dinner table discussion. It's about poo, and the problems we have getting rid of it. You have been warned.)
According to the EPA, one in four homes uses some kind of septic system to treat waste water in the United States. The EPA concluded in its 1997 Response to Congress
that "adequately managed decentralized waste water systems are a cost-effective and long-term option for meeting public health and water quality goals, particularly in less densely populated areas."
Unfortunately, far too many of these systems are installed and then forgotten until problems arise. The most common problem septic systems experience is the loss of the bacteria which breaks down solid waste. This situation came up recently in a home we listed for sale. It's a good learning project for buyers and sellers alike.
One of the most common causes of dead bacteria is the medications you and I take when we are sick.
Medicine gets into our septic systems one of two ways. Either it is flushed down a toilet when the meds are no longer needed, or it is present in our poo. Many prescription medicines are intended to kill bacteria, and most don't distinguish between the ones that make us sick and the ones we use to breakdown our waste products.
Surprisingly, one of the most toxic category of drugs for a septic system is cancer medicines. These powerful medications can kill a septic system's bacterial colonies if used over time.
If a system's bacteria are compromised, it can be fixed. Depending on the age and condition of the tank, the fix can be a simple pumping and replacement with new bacteria, or in the worst case, the removal and replacement of the entire system, a process which is costly and inconvenient.
The best solution for homeowners is to maintain their septic systems. Don't flush anything that isn't biodegradable, have it pumped regularly (usually every two or three years), and be especially careful not to flush medications. Expired or obsolete pills and medicine can be turned in to pharmacies, police departments or hospitals with programs for medical disposal. Doing so will guarantee a functioning system, and greener grass over the septic tank.
How a septic system works
A septic tank is simply a big concrete or steel tank that is buried in the yard. The tank might hold 1,000 gallons of water. Waste water flows into the tank at one end and leaves the tank at the other. The tank contains a vast army of microscopic bacteria who live on waste. Solid waste pumped into the tank sinks to the bottom where it is consumed by these little critters, which reduces its volume. Anything that floats rises to the top and forms a layer known as the scum layer. Anything heavier than water sinks to form the sludge layer. In the middle is a fairly clear water layer. This body of water contains bacteria and chemicals like nitrogen and phosphorous that act as fertilizers, but it is largely free of solids.
As new water enters the tank, it displaces the water that's already there. This water flows out of the septic tank and into a drain field. A drain field is made of perforated pipes buried in trenches filled with gravel called the drain field.
Sludge at the bottom of the tank will gradually build up to a point where it will need to be pumped out. (See video.)
The problems start when this sludge builds up too much and is not removed, or when the bacteria are no longer efficiently breaking down solid wastes. Either way can cause a clogged drain field and shut down the operation of the system.