A septic system has two major components: a septic tank and a soil absorption system.
Waste water flows from the house to the septic tank. The tank is designed to retain waste water and allow heavy solids to settle to the bottom. These solids are partially decomposed by bacteria to form sludge. Grease and light particles float, forming a layer of scum on top of the waste water. Baffles installed at the inlet and outlet of the tank force the water to move slowly through it, and prevent scum from exiting the tank.
SOIL ABSORPTION FIELD (TRENCH):
A solid pipe leads from the septic tank to a distribution box where the waste water is channeled into one or more perforated pipes set in trenches of gravel. Here the water slowly infiltrates (seeps) into the underlying soil. Dissolved wastes and bacteria in the water are trapped or adsorbed to soil particles or decomposed by microorganisms. This process removes disease causing organisms, organic matter and most nutrients (except nitrogen and some salts). The purified waste water then either moves to the ground water or evaporates from the soil. Trench systems are the most common type of system used in new home construction.
An alternative to the common drain field is the Seepage Pit (Dry Well). In this type, liquid flows to a pre-cast tank with sidewall holes, surrounded by gravel. (Older versions usually consist of a pit with open-jointed brick or stone walls.) Liquid seeps through the holes or joints to the surrounding soil.
Another alternative is the Sand Mount System. These systems are used in areas where the site is not suitable for traditional septic systems. For instance, the soil may have too much clay to allow the water to seep through at a proper rate, or the water table may be too close to the surface. In these systems, the waste water flows from the septic tank to a storage tank. The liquid is then pumped from the tank to perforated plastic pipes buried in a mound of sand built on the original soil surface. This system provides a layer of suitable soil thick enough to ensure adequate time and distance for proper treatment of the waste water. Vegetation growing on the mound helps to evaporate some of the liquid. This is particularly important in areas with shallow water tables.
Cover your tank access at all times. A bright green spot on the lawn or strange odor may indicate your septic system is on the blink. Some of us have a direct line to the sewer. Others maintain our own septic systems. Whatever the method, pipes, tanks, drainfields, and other on-site sanitary disposal facilities can all back up or leak into waterways if poorly maintained.
· Pump every 3-5 years. Septic tanks that do not get pumped out will fail. You must rid your tank of solids and sludge that naturally build up. If these do not get removed on a regular basis they will get into the drainfield and clog the soil pores just like grease.
· Never use septic tank cleaning compounds which impair efficiency and damage the drainfield.
· Never flush toxic materials.
· Minimize water flow to the septic tank with low flow shower heads and toilet tank inserts.
· Don't plant trees or drive on or near your septic field.
· Do not dump cooking grease down the drain! Grease can clog septic systems, as well as municipal sewage systems, and interfere with their proper operation.
· Know the location of your tank and drainage field. Call your county or local Health Department for a copy of your septic system layout especially before you start any construction.
· Don't plant deep rooted trees or bushes over the drainage field. The roots could enter the field and clog the system.
· Don't drive or allow heavy vehicles on your septic system.
· Don't flush sanitary pads, tampons, paper, cigarettes, or disposable diapers. They do not decompose.
· Be on the lookout for signs of septic failure. These include visible drainage, strong odors, and the backing up of drains. Signs of failure are not always obvious.
· Don't use a garbage disposal if you are on a septic system. Compost kitchen scrapes or discard in the trash.
· Keep a cover on your septic tank access at all times.
· Attend a free University of Maryland workshop on Private Well and Septic System management.
· Water conditioners should not go to the tank because they kill the bacteria which naturally break down the solids and the backwash is briny which can deteriorate the concrete.
Septic Records and Maintenance Guidelines
Proper design, installation, and maintenance of your septic system will maximize your system's life. It will prevent failures that can be unsightly, foul-smelling, and threatening to your family's health. Good maintenance reduces the risk of contaminating your well water, and may save you from costly repairs of system replacement.
Possible Signs of Trouble:
· A wet area or standing water occurs above the absorption field. This situation can develop when sludge particles clog the absorption field, when tree roots or broken pipes keep the waste water from dispersing through the entire drain field, or when water use in the house regularly exceeds the design capacity of the system. When these conditions occur, waste water does not move through the soil as it should, and instead rises to the surface creating a serious health risk and odor problems.
· Toilets run slowly or backup: in the worst cases, the basement is flooded with sewage. This can be the result of plugged sewer lines to the tank, a plugged inlet or outlet pipe, a full septic tank, or a failed absorption field.
· Septic odors occur in the house, above the tank and absorption field, or escape from the vent pipe. If the system is operating properly, there should be no odors. If there are odors, it can be an early warning sign that the system is failing.
· The septic tank has not been pumped out in the last five years. Even if the system appears to be working well, sludge may have built up to the point where waste water is released without sufficient time in the tank for treatment and settling of particles. This situation may result in pollution of ground water or cause eventual clogging of the absorption field.
· Do not overload the system this is the primary cause of system failures. Early morning and bedtime are peak water use times in the bathroom. Run dishwashers and washing machines at other times of the day. Don't do all the family laundry in one day.
· Do not add "starter enzymes" or "yeast" to your system. Additives do not improve how well your system works. There are always plenty of natural bacteria available to do the job. In fact, additives can damage your system by breaking up the sludge and scum layers, causing solids to flush out of the tank and clog the infiltration bed.
· Only use normal amounts of detergents, bleaches, drain cleaners, household cleaners and other products. Avoid dumping solvents like dry cleaning fluid, pesticides, photographic chemicals, paint thinner, or auto products down the drain.
· Dense grass cover and other shallow rooted plants are beneficial over a septic field. However, do not plant trees because large plant roots can clog or break the pipes.
· For additional information on related topics, answers to questions, or comments, please contact:
· Nitrogen removal systems could keep 65,466 pounds of nitrogen per year from going into the coastal bays.
· Within the bays behind Ocean City and Assateague, 4,484 septic systems contribute more than 130,000 pounds of nitrogen annually.
· Properly functioning septic systems contribute an average of 29 pounds of nitrogen per household per year to groundwater.