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Summertime in the BelgradesContentsfor Printing Article Summaries |
Septic Systems and Lakesby Peter Kallin For as long as man has been living near the water, he has been disposing of wastewater nearby. Until at least the early 20th century this usually meant disposing of wastewater directly into the lake or stream with no treatment. As populations increased, this sometimes resulted in the spread of disease such as typhoid or cholera. Eventually, wastewater treatment became more sophisticated, such as digging a hole and placing an outhouse over it, and then digging a new hole once in a while. This method is still used on some Maine lakes where population is sparse and is still legal under Maine's plumbing code, but not really appropriate for more developed areas such as the Belgrade Lakes. The next level of sophistication was popular during the early to mid- 20th century, when many camps were built around the Belgrades. This was the cesspool, essentially a large underground hole, sometimes lined with bricks, sometimes just a buried steel drum, fed by a pipe coming from the residence instead of from a hole in the outhouse above. There are still a lot of these systems — one is too many! — in use today under Maine's "grandfathering" rules. In the middle of the 20th century, the system of choice for wastewater evolved toward a system developed in France at the end of the 19th century. This system consisted of an underground tank with two chambers that provided for digestion and settling of solids and a self siphoning outlet that drained liquids to a leach field for infiltration into the natural soils. This basic system, which became known as a "septic system," was actually modeled after the human digestion system and does a pretty good job of disposing of human waste in a sanitary manner. The tank itself is analogous to your stomach and provides an anaerobic environment — without oxygen — where digestion takes place and some solid matter is converted to liquid and gas, primarily carbon dioxide and methane, which is vented off, same as when you burp. The indigestible solids settle to the bottom where they are eventually pumped out — think large intestine and defecation. The liquids are distributed to a leach field that spreads them out over an area of several hundred square feet or more where additional purification takes place under aerobic conditions in a biomat of microbial activity — think kidneys — before draining into the native soils below to the groundwater table. These native soils are an extremely important and integral part of the system and are known as the "soil absorption system," or SAS. Like the urine you excrete, septic system leachate is not pure water but rather a fairly rich mix of dissolved nitrogen compounds, phosphates, metal salts, and other compounds that are difficult to break down such as prescription drug byproducts. Through the middle of the 20th century, many of these systems were installed throughout Maine under highly varying geological conditions. Some worked and some didn't. Many suffered hydraulic failures and leaked or backed up. In 1972, Maine implemented a statewide plumbing code that provides detailed guidance on how to assess the local soils and properly size and install a system to prevent hydraulic failure. This code does require inspections during the installation but unlike in most other states, Maine does not require any further inspections or maintenance after the system is installed, unless you live in the coastal zone. Maine relies on individual property owners to appropriately maintain and inspect their system to ensure proper operation. Next week we will discuss some common misperceptions about septic systems, explain what kind of maintenance is needed and how often, and provide some recommendations for making existing rules more protective of Maine lakes. Peter Kallin, Executive Director of the Belgrade Regional Conservation Alliance (BRCA), can be contacted at | ||