The language of sanitation is a mystery to many. It is, however, a language we are likely to be hearing frequently in the future as the world’s water crisis becomes front page news. Since nearly half of all the homes in the United States are on septic systems it is also a language thousands of people hear used when their system has a problem.
Here are some of the words and what they mean.
Wastewater: all the water that comes out of the house or building is wastewater. It is sometimes referred to as “effluent.” In the codes governing sanitation all the water going into the structure must be treated or collected when it comes out of the structure.
Blackwater: sanitation discharged from the structure. In many states blackwater also includes what comes out of the kitchen sink and in some states may also include discharge from the washing machine.
Graywater: the rest of the water coming out of the structure that is not blackwater. Some jurisdictions do not distinguish between blackwater and graywater, requiring everything to be treated as sanitation.
Onsite treatment: just over half of the wastewater from homes and structures in the United States is discharged into collecting lines (sewer mains) that take it away to wastewater treatment plants, lagoons or other types of centralized treatment. “Onsite treatment” is the term used when this is not the case and, instead, the wastewater is treated at the point where it leaves the structure. The most common systems for onsite treatment are septic systems, called “onsite treatment systems.”
Septic systems: collect the wastewater in underground tanks. The wastewater is treated in the tanks and then dispersed, underground, through a series of lines that spread the treated wastewater out over a large area of land. These lines are called “leech lines.” They are pipes with holes in them designed to let the treated water flow out into the ground. The lines are typically several feet below the surface but not deep enough for the water leeching out to reach into the underground water.
Percolation: the term is often abbreviated to “perc.” Percolation refers to the process of water seeping into the ground from leech lines. In the presence of shale, rock, clay and high water tables percolation is slower or impossible. Slower percolation rates require more land and longer leech lines to absorb the wastewater. With high water tables the wastewater does not travel through the ground but goes directly into the underground water. This is never allowed because the nutrients in wastewater promote growth of organisms, which contaminates the groundwater. The primary nutrients are nitrogen, phosphate and potassium.
Mound systems: in some situations where the ground does not perc septic systems can be used by trucking in sand to create enough ground that will perc properly. The sand is used to form a mound for the leech lines.
Drip systems: another variation of septic systems where the groundwater is close to the surface is to run the leech lines just a few inches below the ground surface and let the effluent drip into the ground. The wastewater is absorbed by grass, plants and roots before it can get into the groundwater.
Alternative onsite treatment systems: are designed as alternatives to septic systems. There are a wide variety of alternative treatment systems, all of which are divided into two categories: discharge systems and non-discharge or zero-discharge systems.
Discharge systems: are designed to both treat wastewater and put it into the ground differently than septic systems. The two most common types are aerobic systems and microbiotic systems.
Aerobic systems: spray the treated wastewater onto the surface of the ground.
Microbiotic systems: add microbes to the treatment process in order to speed up the decomposition of organic matter in the wastewater.
End of part One