Septic Tank Maintenance A septic tank is an underground sewage-collection system. The tank itself is a watertight container constructed of a sound, durable  material resistant to corrosion or decay. With proper care and maintenance, a septic system will provide many years of trouble free service.

How does a Septic Tank work? As the septic system is used, there is an accumulation of solids in the tank, which is sometimes referred to as sludge.  The septic tank removes solids by holding wastewater in the tank for at least 24 hours, allowing the solids to settle  and scum to rise to the top. This is accomplished by a series of baffles inside the tank.  Up to 50 percent of the solids retained in the tank will decompose over time. Due to the soil conditions and high water table  in the Cayman Islands, treated effluent water discharges from the tank through a 4"-6" drain pipe that is 40-60 feet deep where it  drains safely into the saline water below the water table.

Septic Tank Maintenance As you use your septic system, sludge will accumulate in the tank. Properly designed tanks have enough space  for up to three years of safe accumulation. Once the sludge has reached this level, the separation of solids and scum no longer takes place,  and sewage may overflow into the absorption area. This can be prevented by periodically pumping the accumulated sludge.

How often should you pump? This depends on the following: * Capacity of septic tank * Flow of wastewater * Volume of solids in wastewater Volume of wastewater flow is determined by the type and frequency of common household activities. Water conservation practices in the  home will help to limit the flow into the system. Use of an in-sink garbage disposal will increase the volume of solids.  Care should be given to the type and amount of solids disposed of through a garbage disposal. Please note that biological and chemical  septic tank additives are not necessary and do not eliminate the need for pumping.

Safe use of septic systems Do not put substances such as motor oil, gasoline, paints, thinners, and pesticides in drains. These materials may pollute the groundwater  and are toxic to the microorganisms that maintain an active septic system. Moderate use of household cleaners, disinfectants, detergents,  or bleaches will do little harm to the system, but remember that where there is a high density of septic systems there may be a cumulative impact on groundwater  from household cleaners. Fats, grease, coffee grounds, paper towels, sanitary napkins, disposable diapers, and other such items will clog your septic system.

Conserve water Remember to consider the capacity of your septic system when installing new appliances or plumbing. Limit the water entering the tank.  Use water-saving fixtures. Repair toilet float valves, leaks, and dripping faucets.

Avoid septic tank additives Yeasts, bacteria, enzymes, and chemicals are sold with the claim of helping septic systems work better; however, there is no scientific evidence  that additives are effective. In fact, some cleaners allow the solids in an overloaded tank to be re-suspended and clog the drainage lines.  Additives are not an alternative to proper maintenance and do not eliminate the need for routine pumping of a septic tank. Commercial biological  additives are not necessary for restarting decomposition after pumping because the sludge residue contains active microorganisms.

How to recognize problems Learn how to recognize problems with septic systems. For example, unusually lush and green grass over your drain field may indicate trouble.  Also, pay attention to slow-draining toilets or drains, sewage odors, or sewage backing up into the house or over the drain field.

Checklist for Good Septic Tank Maintenance * Check your system annually for leaks and sludge. * Have your septic tank pumped by a licensed pumping contractor. * Practice water conservation. Repair leaky faucets and toilets. Spread clothes washing over the entire week, and operate only with a full load of laundry. * Learn the location of your septic systems. Make a map and keep it handy. Keep a maintenance record.