Septic Tank FAQs

What is a septic system?

A septic system is a small onsite sewage treatment and disposal system buried in the ground in which waste matter is decomposed through bacterial action.

How do septic systems work?

  1. Household waste flows out of the house via a connecting pipe to the primary chamber of the tank. Organic solid material floats to the surface and forms a layer of what is commonly called “scum.” Bacteria in the septic tank biologically convert this material to liquid (effluent.) Inorganic or inert solid materials and the byproducts of bacterial digestion sink to the bottom of the tank and form a layer commonly known as “sludge.”
  2. As the primary chamber of the septic tank fills up, this digested material or effluent flows though a connecting pipe to a secondary chamber. This is where the final settling and digestion process in the tank takes place. From the secondary chamber, the effluent passes through an outlet pipe into the leach field for the final purification process. Only clear water (effluent) should exist between the scum and sludge layers. It is this clear water (effluent) – and only this clear water – that should overflow into the soil absorption area.

How do I know if my septic system is unhealthy?

There are a few ways to tell if your system has become unhealthy. If you notice any of these symptoms, call PRS immediately, before it gets worse!

  • Sewage is backing up into your toilets, sinks, or showers.
  • The household drains are draining slowly, especially after it has rained.
  • You notice a sewage smell in the leach field or the nearby area.
  • You see sewage in ditches or the soil is very soggy (even when it hasn’t rained) in your leach field.
  • Water tests in nearby streams or ponds test positive for biological contamination or organic chemical contamination.
  • There is an alarm in your house that is flashing which means the septic tank needs attention. (Some systems have alarms, some don’t—it depends on when it was installed and what type of system you have.)
  • There is sewage seeping up from the septic tank or vault lid.

How do I care for my septic system?

Septic system maintenance means two simple things. First, the sludge that accumulates in the bottom of the tank must be pumped out periodically. How frequently depends on the size of the tank, the use it gets, and the condition of the system. There is no additive that you can put in the tank that will deal with the sludge. IT MUST BE PUMPED. If not pumped, the sludge will eventually overflow into the soil-absorption area. This will clog the system, and it will need to be replaced, at enormous expense and inconvenience.

The second part of septic system maintenance involves the bacteria necessary for the digestion of the solids. If bacteria-killing products are used in the home – as they usually are – the bacteria should be replenished. If the bacteria level is too low, the solids may not be digested properly causing the solids to build up too much and overflow into the soil absorption area. This again can clog the system, requiring repair or replacement. Use only USDA approved bacteria replenishment products that are engineered specifically for septic tank maintenance.

See our Do’s and Don’ts list for more information about how to prevent a system failure.

How often should I get my tank pumped?

Frequency of pumping depends on the capacity of the tank and the number of people in the house. If your house has a standard 1,250-gallon tank and you have 3 to 4 people, the tank must be pumped every 2 to 3 years. Note: if you use a garbage disposal, it’s like adding another person to the equation and accelerates the buildup of sludge.

What does pumping a septic tank entail?

Pumping involves vacuuming the wastewater sludge and scum out of the tank chambers with a large tank truck equipped with a high capacity vacuum pump system. The waste is then transported to a designated municipal wastewater treatment facility for processing. In some rural areas, septic tank contents can be applied directly to the land if treated properly.

How long do septic systems last?

With proper septic tank maintenance your system should last between 20 and 30 years.

I’m thinking of buying a house, what should I know about its septic system?

It is necessary to have a licensed technician or plumber inspect the tank and leach field before you close on a property.