One of the greatest pollution concerns when living by water are septic systems. Recognition that septic systems need space and the filtering properties of the soil to function fully is a primary reason for increased setbacks of the system and the building from the water. Although septic systems can be extremely useful, there are the malfunctions to consider. A buffer distance in the soil, and a buffer strip of vegetation, are vital to protecting the quality of lake and river water.

The septic system works mainly on biological processes. The septic tank biologically treats raw sewage and waste water in a low oxygen environment, and then the material is deposited into the tile bed. Underneath the tile bed, bacteria in the soil feed on the waste water, removing contaminants. The water eventually percolates downward and intercepts the groundwater. If everything is working properly, the water is clean before it gets to the ground water. That is very important, because that ground water is very often the source of supply of drinking water in rural areas, and cottages.

Figure 7: Septic System Pollution
Used with permission from Charleston Lake Association (from Healthy Shoreline Review Handbook.)

Although this method does work, a tank may become too full and produce too much material for bacteria to treat. To ensure that you are not causing any detrimental effects on the lake system, have your septic system inspected regularly and pump your system on a routine basis as sludge builds up. Although the frequency of pump-outs depends on the size of the tank and the amount of people using the facilities, it is recommended that tanks be pumped out every 3 to 5 years. This will increase the lifespan of your septic system and will preserve the water quality in the ground, and in rivers and lakes.

Holding Tanks

Holding tanks do not treat wastes and other wastewater, but merely contain it until it can be pumped out and taken elsewhere for treatment. They are no longer common, as they are always at risk from damage and aging, and may develop leaks. Holding tanks are simply 1500 gallon (or larger) water-tight tanks. The waste builds up inside the tank until it is 75% full and an alarm, which must be installed, sounds meaning that the tank needs to be pumped. If your tank is not suited with an alarm it must be pumped before the ground starts freezing. This can be a costly, as holding tanks need to be emptied as often as once per week, depending on the size of the tank and how much wastewater the household generates. New holding tanks are not usually permitted for this reason, and do not qualify for permits for new buildings on lots. However, there are still some used on existing, older lots too small for a septic system. In this area, the authority and source of information and advice is the Leeds, Grenville and Lanark Health Unit, 458 Laurier Boulevard, Brockville, at 613 345-5685.

There are new technologies being developed that require less space than the standard septic beds. Permission for their use again depends on the assessment of the County Health Unit. However, remember that waste disposal systems are only one part of the water quality issue, and that there is still nothing so effective in cleansing and purifying runoff to the water as nature’s own buffer of native ground and forest cover.