The online RCAP Resources Library has a variety of resources that are useful to small, rural drinking water and wastewater systems.
What is wastewater, and why do we treat it?
We all create wastewater multiple times a day – whenever we use the toilet, take a shower, or wash the dishes or our clothes. In general, residential wastewater is defined as any water generated by household fixtures. It’s what we dispose of down the drain at home.
In most cases, this used water needs to be cleaned before it’s put back into the environment or before we use it again. It’s for the benefit of the public’s health and the Earth’s health that we treat wastewater.
Of course, wastewater looks and smells bad. Beyond that, and more importantly, untreated wastewater can cause and spread disease. Untreated wastewater can have harmful effects to the water when it is returned to the environment. Sewage depletes oxygen in the water, is harmful to aquatic life and can result in excess nutrients being discharged into water bodies resulting in the growth of nuisance vegetation.
What is a septic system, and why is it important?
In many places, especially large cities, wastewater is collected from a large area and treated at a central treatment plant. In other places, including many rural areas, it is treated close to where it is generated – in a septic system.
A septic system is an underground system that treats wastewater from an individual home. If your home is not connected to a public sewer, then it has or ought to have some sort of a septic system. Septic systems are regulated at a minimum by the state or the local health authority. Different states have similar but not identical requirements.
Reasons to understand septic systems:
Another reason to understand septic systems is that they can cause harm when they don’t function properly:
Finally, septic systems are regulated, so it is important to understand the laws you must follow. Your state sets minimum standards, but other regional or local authorities may set standards at a more stringent level. You may be required to keep records, permits or other documentation to show the system has been inspected and has been functioning properly. In some states, an inspection may be required upon transfer of property. Realtors need to be aware of any requirements involving septic system condition disclosure requirements.
There are three main processes in wastewater treatment, whether in a septic system or at a central sewer system. The liquids and solids that make up wastewater are treated and disposed of separately.
The diagram below shows the components of a typical septic system:
Functions of the major components:
If you are installing a septic system on your property, there are many factors to consider for each of these components for proper installation and efficient operation of your system. These factors are not discussed here, but experienced and reputable installers will know how to properly install the system or what factors are causing an existing system to not function properly.
The diagram below shows inside the septic tank.
In this diagram, wastewater enters through the inlet (to the left). It immediately hits an obstruction, called a baffle, which intentionally slows the flow. This causes the solids to drop out more readily, and they settle to the bottom of the tank as sludge. Oils and greases – cooking oils, for example – float to the top of the tank as scum. Another baffle at the outlet blocks any floating solids from exiting the tank along with the settled wastewater. Baffles are important and may be one of the first things to wear out in an aging tank. Replacing them is cheaper than replacing your tank, or worse, the entire absorption system if it becomes irretrievably clogged.
The second article in this series on septic system basics identified the major physical parts of a septic system and what they do but did not explain any particular things to consider about those parts. Here are a few considerations:
There are many more considerations, and a qualified installer will know about them and the specific regulations of your area.
Ways homeowners and business owners should be caring for and maintaining their systems
Throw-aways like cigarette butts, kitty litter, coffee grounds, tampons, diapers and baby wipes will clog your system. Some household chemicals can wreak havoc with a system, but usually not unless they are used excessively. If a system is having problems that are not obvious, a good question for the homeowner to ask is: What kinds of cleaners do you use and how often?
High-strength wastes from some activities should be kept out of the system because they can cause damage. Examples of activities that may produce substances that should not go down the drain:
High water usage can cause problems. A system can be overloaded if, for example, the size of the house or number of occupants has outgrown the original system. Other behaviors that can overload a system: doing many loads of laundry; taking long or many showers; multiple-jet showerheads; hot tubs.
Protect your soil-absorption system:
Periodic inspections and pumping the solids and greases out of the tank help keep your system running well. Some states certify septic-system professionals. Your local health department or building-codes division can tell you more about licensing requirements in your area. If there are no obvious problems and the system appears to be operating well, an inspector might just open up the septic tank to make sure there are not too many accumulated solids. An inspection of the entire system might be necessary when there are problems with the system and may involve uncovering other parts of the system (the distribution box and leach field). It is wise to determine exactly what an inspection will cover and what it will cost up before agreeing to the service.
Typical signs of problems in your system are:
It is important for homeowners to keep and update maintenance records on their septic system. Keep records on inspections and on the history of pumping and repairs. Keep sketches of the system and the location of its components. Some states or management entities may require records to verify the system is functioning. They may need to see them periodically or when your property is transferred or sold.
The bottom line is that you should respect your septic system. Take care of it, and it will take care of you. Call on a reputable maintenance/repair company when necessary, and pay attention to the rules and regulations.