Choice Home Inspections
Providing Experience, Integrity, & Knowledge
TYPICAL SEPTIC SYSTEM OPERATION
There are a wide variety of types of private onsite wastewater treatment (septic) systems. These include both below and above-ground systems, media systems using media such as sand and peat, drip irrigation systems and constructed wetlands. This article will deal with the type most commonly found in Pennsylvania.
1. Septic tank:
Waste enters the tank through an inlet pipe from the home. Tanks typically have two chambers. Solids settle out into the bottom of the first chamber and are broken down by bacterial action. Liquid (called "effluent") moves to the second chamber before exiting the tank through the outlet pipe.
Baffles (short sections of vertical pipe or a similar device) prevent the scum from entering the inlet and outlet pipes and clogging the pipes and leach or drain field.
Sludge will need to be pumped from the tank occasionally. The frequency of pumping will depend on the tank size, the type and number of plumbing fixtures in the home and the manner in which these fixtures are used.
Because bacteria in the tank are crucial to proper operation, limit or avoid flushing cleaners, grease, solvents, oil or other strong or harmful chemicals. Products that claim to improve your tank's function by boosting bacterial action are not typically recommended. Your system doesn't need any chemicals added, it just needs to be treated with some consideration.
Consideration means...
- If it won't rot, keep it out of the septic system. You may understand what kinds of things will break down, but take the time to explain it to family members and guests who may not.
- If it kills bacteria, keep it out of the septic system. Is your hand soap anti-bacterial? Do you use sterilizing cleaners? Non-toxic soaps and cleaners are available and effective. Their use is recommended for septic systems.
2. Leach field or commonly called a drain field:
After leaving the tank, the effluent is routed into a series of pipes which are perforated to allow the effluent to soak into the soil. Bacteria in the soil break down the pollutants and soil filters out pathogens, organic matter and suspended solids.
Inspection of septic systems is beyond the scope of the General Home Inspection.
Flood and dye tests are not conclusive and those offering them are not professionals. Don't pay anyone to inspect your system or make purchase decisions based on flood or dye reports. Tanks should never be pumped before they're inspected. Low effluent levels are a sign that the tank is cracked. Cracks are impossible to spot visually after the tank has been pumped. Although I may make some cursory observations, you should realize that evaluation of the septic system requires a professional inspection by a Pennsylvania Septage Management Association (PSMA) specialist and if you choose to not to have that inspection performed, you do so at your own risk.
A septic system can be a very expensive home system to replace and diagnosing problems can be difficult because most of the components are located underground. I strongly recommend having them inspected in homes older than 10 years, homes that have been significantly expanded or homes with symptoms that indicate problems.
For more information about septic systems and septic system inspections, please go to http://www.psma.net/
Karl V. Orwig, Home Inspector & Certified Radon Tester
Providing Experience, Integrity, & Knowledge