Moving right along with our Septic System conversation; pardon the pun about moving along.
Don’t forget that the first part of most septic systems is the Septic Tank, a 1,000 or 1,500 gallon tank that receives the Raw Sewage from your home. The point of a septic tank is that it is always 100% full. Every time you flush a toilet you are putting 1.6 gallons of effluent in the tank so exactly 1.6 gallons must leave the tank. For today’s conversation the effluent that leaves the tank will go to a Pumping Station; yesterday we talked about those pumping stations.
The float switches inside the tank will turn the pumps on, the effluent is then pumped upward to one of many types of Leach Fields. Today we are going to limit the conversation to the most common field, a Mound System.
As you drive around you have noticed many times a relatively large bump or mound in the yard. This “thing” is the Above Ground Septic Mound. Today’s photograph was the best we could find at the last minute but it clearly shows a mound. You’ve seen many of these; they all are fairly noticeable, especially the ones in the front yard. This mound which is carefully built and engineered is where the effluent is pumped.
Don’t confuse a septic mound with a Berm. Berms are a mound of dirt and often have shrubbery planted in them. Berms are used to create a green privacy wall. Septic mounds are built to deal with effluent and never have shrubbery planted in them; the roots would cause harm to the mound.
Septic mounds are fundamentally an engineered pile of sand. Buried inside the mound of sand are a series of pipes and then the entire mound is covered with top soil and grass is planted. 1) The pumping station pumps effluent into the mound, 2) the sand collects the “water”, 3) the pumps turn off, and 4) the mound then allows the effluent to either evaporate or percolate into the earth. The huge pile of sand acts as a sponge holding the waste water as it evaporates or percolates into the earth. Typically it will be several hours or more before the pumps turn on again allowing the mound to “rest.”
As I am sure you can quickly see the mound is far more than “just a pile of sand.” It is carefully calculated out to be of sufficient size to take care of the house’s effluent. It may not be a colorful and dramatic life but it surely is important.