Feature Article July 11, 2001
LAND O'LAKES NewsWeb HomeContact Us
The problem with water quality is US Part 1by Gray Merriam, professional ecologist, and Aileen Merriam, Kennebec Lake Steward
We place a high value on the water in our lakes, rivers and streams. We are interested in the quantity or levels of the water but we also are paying more attention to water quality.
When many people hear water quality, they think first about E. coli, but these bacteria are seldom the main problem. They can be serious if you get one of the rare strains that produce a toxin, as happened in Walkerton and in the various episodes of hamburger poisoning. However, finding E. coli usually just warns us that really serious disease organisms like hepatitis virus may be present, because they all come from the human gut. Thinking about water quality may remind some that 40% to 50% of the gas-and-oil mix used by two-cycle outboards ends up in the lake water. But the main way the quality of water in our lakes and rivers is degraded is by letting too much of the nutrients phosphorus and nitrogen get into the water.
The biggest source is from poorly operating septic systems. Every shoreline is fringed with septic systems. If they are not working properly, it is easy to see how we add nutrients. Today, efficient septic systems are available that remove a very high proportion of the phosphorus from our wastes. There no longer is any reason to let poor septic systems degrade our water quality. Not many of these new, high-efficiency septic systems are installed in our area yet. Quite the opposite. Most systems, both here and elsewhere, are low-tech and many are very old and ineffective. We have difficult terrain on our Precambrian bedrock for building good septic systems, and earlier systems often were somewhat makeshift.
How much maintenance our septic systems require depends on the system and the users. Small tanks with small tile fields and little soil can be overwhelmed by a huge group on a weekend visit. A tank filled with sludge up to the output will let that sludge out to clog the tile field. A clothes washer without a lint filter will add to the problem. In low-tech systems, solids that settle are supposed to stay in the tank until it is pumped out. The water, with its dissolved nutrients, is supposed to leach slowly from the tile field and move up through the soil. The vegetation on top of the tile field takes up this water, uses the nutrients and evaporates the water out through its leaves. Tile fields clogged with solids from an overfull tank fail to do this. The water carrying its nitrogen, phosphorus, bacteria and viruses finds a channel and flows into the nearby lake or river. The septic tank should have been pumped out sooner; now the tile bed may need to be replaced.
Since 1998 municipalities have been responsible for regulating septic systems, using the Ontario Building Code. Installation of new septic systems requires a permit and inspection; unfortunately municipalities are NOT required to carry out routine re-inspections of existing systems.
Prior to 1998, re-inspection of cottage septic systems was offered by the Ministry of the Environment. Its former Cottage Pollution Control Program had shown that about 30% of systems malfunctioned. This indicates that over a quarter of our existing septic systems could require repair or replacement if we wish to protect water quality. Some municipalities are beginning to re-inspect the septic systems under their jurisdiction and we should encourage others to do so. The Federation of Ontario Cottagers Associations is compiling information on septic re-inspection and hopes to complete and distribute a Road Map to Septic Reinspection in early 2002.
As well as pumping our septic tank when needed and inspecting our system regularly, we need to be careful about what we put into it. High phosphate detergents should not be used, and showers, dishwashing and laundry should be spread out in time to allow the system to effectively process the effluent. Dishwasher detergent is particularly high in phosphates.
In Part 2, the Merriams discuss what happens to lakes when too much of the nutrients phosphorus and nitrogen get into the water.