A septic system includes a tank to collect and separate solids from household wastewater and a drain field to filter and biologically treat wastewater. Septic systems not functioning properly due to inadequate maintenance or poor design will produce untreated water containing pathogenic, or disease-causing, bacteria, nitrates, and phosphorus that will move into groundwater and the lake or will bubble to the surface. A well-designed, constructed, maintained, and properly located septic system minimizes pollution of aquifers and surface waters. Naturally occurring microorganisms (bacteria and fungi) digest wastes, thereby purifying the water before it flows into and merges with the groundwater. Regular pumping of the holding tank is important. A septic system consists of two components: the holding tank and the drain field.

The drain pipes of the household plumbing system lead to a large concrete tank buried near the house. The tank allows the solids to settle out and separate from the liquids. Solids settle to the bottom of the tank. Greases and oils float to the surface. Anaerobic bacteria (bacteria that thrive without oxygen) in the tank decompose the wastes into by-products such as carbon dioxide, methane and water. The microorganisms consume some of the solids; the solids remaining are disposed of by periodic pumping. However, if the tank is too full or if the microorganisms are dead, solids will overflow from the tank and clog the drain field.

The drain field is a grid of perforated drain pipes buried in gravel and covered with several feet of soil. The septic tank is designed so that as wastes in the septic tank break down into liquids, the waste water moves through an outflow pipe and flows into the drain field. There the waste waters soak into the gravel and migrate into the soil. In the drain field, another form of bacteria (aerobic or oxygen-using) continues to break down compounds in the waster water.

Since drain fields release large amounts of tainted waste water into the ground, they must be located far enough from the lakeshore to minimize the amount of contaminants that reach the open water. Contaminants in the wastewater are trapped in the subsoil as the water migrates from the drain field, so the distance the drain field seepage must travel is proportional to the amount of contaminants the soil can remove. Some septic systems use gravity to move the waste water from the holding tank to the drain field. In locations where the drain field must be located a distance from the holding tank, pumpback systems are required. The pumpback system collects the household wastewater in a separate holding tank near the house and pumps the waste to a drain field located where the seepage won’t harm the lake water quality.

Human waste, with its high nitrogen and phosphorus content, is a great fertilizer. If a septic system is not properly located, even a well-designed and maintained system may allow wastewater to carry nutrients, including phosphorus and nitrogen, into the lake via groundwater. These nutrients provide essential ingredients for the growth of weeds and algae. Larger weed beds and murkier waters are indicators of water quality deterioration. With proper care and maintenance, you can lower the nutrient release from your septic system.

Be a septic sleuth. Here are your clues:

• Foul odors around system
• Depression in ground around drain field or tank
• Lush green grass over drain field
• Soggy areas over drain field
• A sluggish toilet
• Algae growing in the lake near your shoreline

If any of these clues are present, you probably need help. Call your Benzie County Health Department at 231-882-4409 .

Service your system

If your septic tank is too full of sludge, solids will overflow into the drain field and clog the system. Should this happen, harmful bacteria, phosphorus, and nitrates can be flushed into the groundwater or rise to the surface and be carried into nearby water bodies. It is important to keep records of service. The average need is once every three to five years for both year-round and seasonal residents. A maintenance record should include the date, type of work done, and the name of the maintenance contractor.

Septic Systems
Best Management Practices Checklist

Septic systems that are not properly designed and maintained may leak bacteria and nutrients such as nitrogen and phosphorous into the water table and ultimately into the lake, resulting in increased and unwanted plant growth or algae bloom, or even a health risk. Familiarize yourself with the location, operation and design of your septic system. The less water used, the better a septic system will function. The more water that flows through the septic system, the faster and more intense will be the release of nutrients into the ground. Do not place things into the septic system which will over-burden the system.

1. Check your septic tank sludge depth annually. If the sludge depth is within 6 to 12 inches of the outlet baffle, the drain field may be clogged with sludge and require replacement. If the depth is within 12 inches of the outlet baffle, the tank requires pumping/cleaning. Also, if the bottom of the scum layer is within 6 inches of the outlet baffle, the tank should be pumped.
2. Pump the tank at regular intervals (usually 3 – 5 years) or measure scum and sludge depths to determine need for pumping.
3. The use of additives to help maintain the system is not recommended. Additives will not extend the amount of time required between pumping, and, although they may not harm the septic tank, they could contaminate the soil. As mentioned earlier, the most effective method of breaking down the solid matter in the sewage is allowing the naturally present bacteria to digest it. Avoid chemical agents and additives to clean the system.
4. Learn the location of your system drain field and keep the area clear. Keep all automobiles and heavy vehicles off of the area. Do not plant trees. Root systems will clog and interfere with the flow through the pipes.
5. Never build or pave over a drain field or septic tank.
6. Dense, shallow-rooted plants are beneficial over a drain field. Deep-rooted plants (trees and shrubs) may clog drain tiles.
7. Down spouts and drains should be directed away from drain field areas. Puddles or standing water over drain fields disrupt proper function.
8. Stockpiled snow, soil, or other debris should be stored away from drain fields because they require free air circulation for proper evaporation and treatment of wastewater.
9. Washing machines with lint traps are the best. Front loading washing machines use less water than top loaders.
10. Distribute laundry and dishwasher loads throughout the week to avoid overloading the system.
11. Always use detergents without phosphates.
12. Run your dishwasher or clothes washer with full loads.
13. Repair leaking faucets and toilets.
14. Garbage disposals use large volumes of water. Ensure that your septic system has the capacity to accommodate disposal wastes.
15. Conserve water usage in the bathroom. Low-volume toilets and showerheads are an excellent way to reduce the loading of your septic system. Change the way you do things: take shorter showers, put less water in the tub, and turn off the water while you shampoo, brush your teeth and shave.
16. .Avoid running water continuously while shaving, brushing teeth, or washing hands, or washing the dishes.
17. Avoid over-burdening your system with solids. Products that fill up a septic system and cannot be easily broken down are cigarette butts, fats, paper towels, “Kleenex” tissues, diapers, sanitary napkins, grease, and coffee grounds.
18. Septic systems cannot handle harmful materials that kill natural bacteria, such as solvents, oils, paints, strong cleaning agents (drain cleaner, bleach, etc.), and pesticides.
19. Besides using a large amount of water, garbage disposals often add enough solids to septic systems to reduce the interval of pump-outs Compost as many of your vegetable food scraps as you can.