WHAT IS A SEPTIC SYSTEM?
A septic system is used to treat liquid wastes to prevent contamination of drinking water wells, groundwater, and nearby lakes and streams.
A septic system typically consists of:
- A septic tank, which is a watertight, buried tank made of concrete, fiberglass or plastic;
- A distribution box
- A leaching field (also called a bed, soil drainfield, disposal field, or absorption field), typically consisting of perforated pipe laid in gravel-filled trenches
All of which are connected by pipes, called conveyance lines.
HOW DOES A SEPTIC SYSTEM WORK?
- Wastewater flows from the house into the septic tank.
- The septic tank holds the water long enough for the solids to either be digested, or settle out as sludge.
- Scum and grease float on the top of the liquid, and submerged baffles prevent the floating scum from being discharged.
- Liquid wastes overflow into the distribution box, which evenly separates the effluent into the network of distribution lines in the leaching field.
- In the leaching system, which may consist of a leaching field, trenches, dry wells, beds or galleries, the trickling water is further purified by filtration and decomposition by soil microbes, before it percolates into the groundwater.
- Properly designed, installed and maintained septic tank/leaching field systems provide excellent treatment, purifying wastewater into drinking water within a short distance. A conventional septic system should last about 30 years.
COMMON CAUSES OF SEPTIC SYSTEMS FAILURE
- Leaking fixtures or overuse of water.
- Neglecting to regularly inspect and clean the septic tank. If sludge or scum is allowed to escape into the distribution box, and from there into the leaching field, the soil will quickly become clogged. If this happens, the liquid will no longer be able to soak (percolate) into the soil. Broken baffles in the septic tank can cause this condition. Failure to have the tank pumped can also lead to a situation where the sludge and scum overwhelm the baffles.
- Lack of understanding on proper use of the system. A septic system is not designed to handle solids. If solids overflow from the tank into the leaching system, they will clog the holes.
- Poor soil conditions and/or faulty design or installation. A leaching system placed in unsuitable soil, a system that is too small for the house it serves, or an improperly constructed system, can lead to early failure. High Water Table. During wet, or abnormally wet seasons, groundwater may rise into the leaching field and force sewage upward to the ground surface. This may mean the system needs to be re-installed at a higher level. It may also be possible to intercept the high groundwater with a series of drains around the system called “curtain drains.”
HOW CAN YOU AVOID PROBLEMS?
Over time, solids will settle out in the bottom of the tank. If they are not pumped out, they can plug up the leaching field, requiring costly repairs, impairing the ability of the soil to effectively treat septic tank effluent, and causing pollution. A regular cleaning is not that expensive (about $130 to $200). While the tank is open, the service technician can also run some water from a hose into the distribution box to determine whether the leaching field is still functioning. Ask if the company offers this service. Keep accurate records in a permanent house file on the location of the system, permits, and cleaning, inspection and repairs. If you sell your home, pass this information on to the next owner.
Have your septic system inspected and pumped regularly.
Most problems can be prevented through simple maintenance by a licensed inspector/contractor.
All Northumberland County
4142 Harwood Rd.,
Baltimore, ON K0K 1C0