A septic system consists of two main parts: a septic tank and a leach field. The septic tank is a water-tight tank and generally is made of concrete or fiberglass. Wastewater flows from the house to the tank. The tank treats the wastewater by holding it in the tank long enough for the solids to settle out of the effluent (water) and fall to the bottom of the tank. This is called “sludge”. The solids that are lighter than water (grease, oil, laundry lint, and garbage) remain floating on the top. This is the “scum” layer. The middle layer, which usually takes up most of the volume of the tank, is called “effluent”. It is a layer of cloudy water that flows into the leach field. The layers of scum and sludge remain in the tank where enzymes and bacteria work to break them down. The scum and sludge that cannot be broken down, remain in the tank until the tank is cleaned and pumped. 

When the cloudy water leaves the septic tank, it travels to the leach field. It flows from one pipe to a series of perforated pipes that take the water and distribute it to the field. The trenches are 5ft and deeper. They are filled with rock. The rock serves no purpose other than to hold the trench open. The water trickles down through the rock to the bottom of the trench. Millions of microbes work to process the pathogens (bacteria and viruses), thus breaking down the organic matter. The water is purified and returns to the aquifer.

There are areas in Sierra Vista and surrounding towns that have had septic systems installed in the 1970s. Most all systems installed in this decade have cast-on concrete inlet and outlet baffles. The outlet baffle deteriorates over the years from the hydrogen sulfide gas produced by the bacteria as they eat. This allows the scum on the top of the water to be taken into the leach field. If this is occurring, your system is doomed to fail unless these baffles are replaced. It is not necessary to replace the septic tank. There is a 95% chance that your baffle is deteriorated. This is why it is SO IMPORTANT TO have your tank pumped and inspected periodically. You don’t have to sit and wait for it to fail – take action. Out of sight-out of mind or “I have never had any trouble” is not the approach for preservation of your most costly system on the property.