Out of Sight, Out of Mind - A Wastewater Primer

Maintaining a Healthy Septic System
What You Should Do...

• Know the location and size of your tank, drainfield and distribution box. To find this information, you may need to check with the health department for septic system records

• Monitor your septic tank yearly (see next page or see the "Resources" section) and have a reputable contractor remove the sludge and scum every three to five years depending on usage. Keep records of the pump dates. Regular pumping helps prevent solids from escaping into the drainfield and clogging soil pores which can lead to costly system failure.

• Reduce the volume of wastewater the system must handle by employing the water conservation techniques described in the water uses chapter. If you expect very large crowds, consider renting a construction outhouse. In some areas, waterborne "outhouse boats" are available for hire for your beach parties.

• Distribute laundry chores throughout the week to balance water use and keep from overloading the septic system.

• Divert roof drains and stormwater runoff away from the drainfield area. Excess water reduces the capacity of the drainfield to absorb effluent.

• Dispose of household chemicals as described in the hazardous waste chapter - do not pour them down the drain or toilet; they can destroy the bacteria in the tank and enter groundwater through the drainfield.

• Use biodegradable soaps and the alternatives to hazardous cleaning compounds discussed in the hazardous waste chapter.

Here's How to Monitor
Your Septic Tank

When half of the capacity of the tank is taken up by solids, it's time to have the tank pumped out. For a fee, your septic tank pumper will perform a yearly inspection for you.

You can perform the inspection yourself using these instructions.

To measure the scum accumulation, nail a three inch square block to a pole and poke the block through the scum layer. Carefully move the pole up and down to feel the resistance as you move the block up against the bottom surface of the scum layer. Mark that place on the pole which is ground level. Then feel around for the bottom of the outlet pipe and mark that level on the pole. If the two marks are three inches or less apart, your tank needs to be pumped out.

Next, wrap an old towel around the bottom of the pole and fasten it with string or tape. Push the towel down to the bottom of the tank and twirl it around several times. Mark the pole at ground level. After a minute or so, pull it out and measure the distance between the top of the sludge layer (the top of the black material on the towel) and the bottom of the outlet pipe. If the distance is 12 inches or less, your tank needs to be pumped out.

A Word of Caution...
• Avoid the use of garbage disposals; they add grease and solids to the system which shortens its life. If a garbage disposal is used, septic tanks should be cleaned every other year.

• Do not flush material into the septic tank which may not readily decompose or may clog the system (diapers, plastic, etc.)

• Avoid parking, building or housing animals on your drainfield. Such uses compact the soil and reduce the capacity of the soil to absorb and treat sewage.

• Don't cover the surface of the drainfield with concrete or other impermeable materials. Such coverings reduce the supply of oxygen to the soil and the soil's evaporation capacity, which will in turn cause improper functioning of the drainfield.

• Don't rapidly drain hottub water to septic systems. They are not designed to handle large volumes of chlorinated water in a short period of time. Before draining, allow chlorine level to drop to .5 or lower and the water temperature to fall to 70ºF. Drain slowly over a period of three to four days.