When you pour yourself a cool, fresh glass of water, remember it comes out of an aquifer in the ground, sometimes not too far from where our household wastewater (sewage) ends up. Many of us moved to Mayne from a city where smelly waste is whisked away in big pipes and dealt with “Elsewhere”. If problems backed up the system, a call to the city engineering department or your local DrainPro usually solved the issue. Rarely would we have to consider the impact on our drinking water, as this is delivered to city homes through a different system of pipes.
Living on Mayne Island, things are different. You might have both a well and a septic system on your property, and many people live in districts with central water systems and shared septics. The location of a septic tank and field is very important, and should not be directly above a groundwater source. There are legal requirements for keeping water supplies away from septic disposal fields within and between properties that must be followed. Other conditions including percolation rate for a properly operating field are mandatory under BC law (link).
Septic Tanks: A Living System
If a septic system is improperly located or maintained, contaminants from wastewater can end up in ground reservoirs. Liquid wastewater leaves our homes via a drainage pipe and enters the septic tank, a buried, watertight container that holds wastewater for separation into solid sludge and oils which float to the surface as scum. Microorganisms liquify this waste and can even destroy some contaminants. This liquified waste is then sent to the drainfield before it percolates into the soil through a gravel filtration layer, and from there the water eventually works its way to the groundwater. You should not park or drive on your septic field, and plant trees away from it to avoid roots invading the system – it is important to keep the drainfield undisturbed. Soil microorganisms can remove many of the pathogens and excess nutrients, but cannot break down harmful chemicals which may contaminate lakes, streams and coastal waters. A septic system is more than a disposal system – it’s a living ecosystem.
Overloading the System
If a septic system becomes overloaded, it can surface in your yard and back up in the drainpipe into your home. Protect your system by paying attention to what goes down the drain. Using a sink disposal (garburator) is not a good choice. Only washing and kitchen water, human waste and toilet paper should be put down the drain. Waste food should be composted, and never pour oils, paints, solvents, harsh cleaners or medications down the drain. If you have a clogged drain, use boiling water, vinegar, and a drain snake to clear it. The term “flushable” is not currently regulated in Canada, and many items that seem “flushable” aren’t, such as diapers, wipes, feminine hygiene products, cotton swabs, cat litter, coffee grounds, cigarette butts and dental floss. Installing low-flush toilets is an excellent choice as they not only conserve water, but excessive water is a common cause of septic system failure.
Maintaining Your Septic System
A well-maintained system can last 40 years, but unmaintained systems commonly malfunction within 15 years. Septic maintenance should be done every 5 years, and homeowners are required to keep records and ensure that any system on their land is maintained. Septic systems fall under the B.C. Sewerage System Regulation which requires construction be done by a qualified “Registered Onsite Wastewater Practitioner.” More information can be found at the Ministry of Health website (link).
As a septic system owner, be aware that your system can have adverse effects on the natural water cycle. The wastewater from your septic tank eventually percolates into the soil and finds its way back in the natural water cycle. If you neglect your septic system, it can pollute the groundwater which will ultimately affect the quality of water in the cycle.
As an interesting aside, let’s take a wee look at the constituents that make up human urine. This waste product is sterile and rich in the nitrogen that plants need to thrive. Improperly functioning septic systems and the use of chemical fertilizers can result in algal blooms, oceanic dead zones, and contaminated drinking water. Meanwhile, we flush tons of naturally-created nitrogen down the toilet each year. Peeing on your compost is a way to add essential minerals like nitrogen to your soil and simultaneously divert excessive nitrogen from your septic system. To go one step further, put the ashes from your woodstove in your compost and pee on the whole mess, as research seems to indicate that wood ash and pee is a great combo for plants. A study at the University of Finland found that tomatoes fertilized with human urine and ash yielded four times more tomatoes than non-fertilized plants. According to the researchers, one widdle person has the power to fertilize 6,300 tomato plants a year, yielding 2 tonnes of tomatoes!