There is no one septic system suitable for all sites. They vary according to geology, lot size ad percolation time.
With proper care, a septic tank/field sewage treatment and disposal system will do its job for a long time. However any system will fail prematurely if taken for granted and neglected. The consequences of a failed system can be a serious health hazard caused by contaminated groundwater, streams and marine waters. Also, landowners may be faced with a septic field replacement cost of up to $25,000 or with having to install an expensive alternative package plant or engineered system. It pays to care for your sewage treatment/disposal system.
Fortunately, it is not difficult to take the care necessary to have an effective long-lived field. All you have to do is protect it against damage caused by abuse of the system, vehicular damage or plugging by roots from adjacent trees, particularly cedars. The less apparent and, therefore, the greatest threat occurs when the effluent does the damage because it has not been treated adequately in the septic tank. As a result, inadequately digested particles in the effluent are too big and therefore plug the pores in the soil. This is progressive and has two consequences. It impairs field effectiveness by cutting off air to oxygen dependent bacteria which are what treat the effluent by destroying pathogens. When the plugging of the pores becomes advanced, the resulting impermeability of the field causes ponding or seepage of untreated effluent, polluting adjacent surface and subsurface waters.
Proper digestion in the septic tank requires three measures:
1. Regular pumping of the septic tank (every 3 to 5 years)
This will prevent the settled sludge and floating crust from growing to the point where these take up so much room that the effective volume in the tank becomes too small. If this happens, the liquids pass through the tank too quickly thus providing inadequate time for digestion of solids and settlement necessary to produce effluent with very small suspended particles.
2. Minimizing the volume of water drained to the septic tank.
This can be done by installing water conservation devices and generally minimizing the amount of water used, particularly when there are large numbers of people in the house. If excessive volumes enter the tank, these displace effluent from the tank to the field before there is adequate time for proper digestion and settlement of the harmful larger particles. Obviously the greater the time it takes to pass through the tank, the higher the quality of the effluent and, therefore, the longer the life of the field. As a conservative rule of thumb, volumes to the tank should be managed so that there is an average minimum retention time of 5 days. For example, if the tank has a capacity of 600 gallons, then maximum daily discharge to it should be 120 gallons.
3. Avoid the use and disposal of products harmful to bacteria
Hazardous materials ranging from household cleaners to paint thinners, and including unused antibiotics, should not be allowed to drain to the septic tank. These weaken or kill the treatment bacteria and , of course, end up in the groundwater and possibly the stream and marine environments.
Hornby Water Stewardship asks all owners and renters of homes with septic tank/field sewage treatment/disposal systems to take a moment to consider the above and to think about the attention and care currently given to their system. A properly cared for system will reduce the risk to family, friends and visitors and result in very compelling financial benefits.
The Hornby Water Stewardship Project can assist you in protecting your system. we have an ongoing program of producing and updating brochures on water conservation and groundwater protection. You can refer to these for information on measures and devices which will reduce the volume of water wasted to septic systems and in the use of appropriate environmentally friendly cleaners. As a first step we suggest you:
- Consider installing good quality two-flush or low flush toilets.
- Use only full loads for dish and clothes washers and make sure use is limited to one load of either laundry or dishes per day. Also, be sure to add no more than the manufacturer’s recommended amount of soap or detergent.
- Don’t allow buildings, vehicles or activities on your septic field that could compact the soil or damage the pipes.
- Keep shrubs and trees and particularly cedars away from your field and do not water your field
- Use cleaning products that are “environmentally friendly” for laundry, dish washing and plumbing. Again, do not use more than the recommended amount.
- Avoid the use of any products which claim to improve septic tank performance as these can be harmful.
Georgia Strait Alliance has excellent advice on how to keep your home and environment toxic free.