Septic Systems - Clara Walker

Septic systems are a great way to treat wet waste from a household and then return the safe waste to the groundwater system. The systems are comprised of two main areas, the septic tank, and the leaching bed. 1

The general processes of the system. 2

Septic Tank
The separation of liquids and solids occurs in the septic tank. 3 The tank is a watertight container buried underground, and provincial regulations impose the size specifications. 4 As the waste water enters the tank, the solids (sludge) sink, and the lighter materials (scum) rise to the surface. Some of this organic matter is eaten by anaerobic bacteria. Then the partially treated wastewater is displaced, by new waste, into the leaching bed to continue in the purification process. 5

Components of a tank. 6

Leaching Bed
The leaching bed, or septic field, is a soil filter made up of a network of trenches and distribution pipes. A biomat layer (bacteria slime) in the trenches consume the organic matter. This bacteria also reacts with the ammonia nitrogen to form nitrate nitrogen, which is less harmful and less toxic. Other viruses and bacteria in the waste are simply filtered out. 7 Oxygen plays an important role in these processes, so to ensure proper circulation nothing can be built on top of the septic field. 8 From here, the water seeps through the soil and into the water table for reuse. 9

The location of the leaching bed. 10

Did you know?
1) Roughly a quarter of Canadian homes use a septic system, mostly in rural areas. 11
2) Most septic system failure occurs when the soil will not allow any more moisture to pass through. To avoid this, divert run off water away from the septic field. 12
3) Trees planted on top of the septic field can damage the filtration system, but the nutrients are beneficial to smaller plant life. 13

Issues
Clogging: When the slime and sludge build up and interfere with the system flow, the septic tank will need pumping to remove the clog. It is recommended that this happens every five years. 14
Freezing: With little usage in the colder months, the tank can freeze. To prevent this, insulate the tank, or maintain a consistent level of water flow. 15
Water supply contamination: Do not place the septic system near a water supply, like a river or a well. 16


Sources:

1. Canada Mortgage and Housing Corporation, "Your Septic System," 2008, http://www.cmhc-schl.gc.ca/en/co/maho/gemare/gemare_009.cfm (accessed October 25, 2009).

2. Image: Ibid

3. Ibid

4. Prince Edward Island Department of Environment, Energy and Forestry, "Septic Systems," October 20, 2006, http://www.gov.pe.ca/envengfor/index.php3?number=43823 (accessed October 25, 2009).

5. Canada Mortgage and Housing Corporation

6.Image: http://www.esse-environmental.com/images/septic_system.jpg

7. Canada Mortgage and Housing Corporation

8. Corey Tournet, "Septic Secrets," July 2000, http://www.elements.nb.ca/Theme/health/corey/septic.htm (accessed October 25, 2009).

9. Canada Mortgage and Housing Corporation

10. Image: Ibid

11. Corey Tournet

12. Ibid

13. Prince Edward Island Department of Environment, Energy and Forestry

14. Corey Tournet

15. Ibid

16. Prince Edward Island Department of Environment, Energy and Forestry