Sewage treatment plants use chlorine to kill these harmful organisms. In a properly functioning septic system, soil and soil organisms effectively remove these disease causing bacteria and viruses from the wastewater. Nutrients like nitrogen and phosphorus are also found in domestic wastewater. Nitrogen, in the form of nitrates, poses a health threat to infants if the wastewater becomes part of the ground and surface water supplies. These nutrients also fuel the growth of algae in lakes and shallow Puget Sound bays. These “algae blooms” can cause serious water quality problems including loss of oxygen resulting in fish kills.

   Avoiding Septic System Failures

Poor design, construction, or maintenance will cause your septic system to fail. Design is generally best left to a professional. County health departments require a percolation (“perk”) test before a septic system is built. The test determines how fast the soil absorbs water. Waterfront and island septic systems demand special consideration. In these instances and in other unusual sites, soil examination by a professional soil scientist can provide a more reliable assessment of the capacity of soil to accept wastewater.

New septic system designs and entirely new technologies for dealing with human waste and wastewater are now emerging. In the resource section below, you’ll find several publications that can start your search for alternatives. If you are thinking of a “non- standard” system, begin a dialog and information exchange with your county health department to assure your system meets their approval.

Select a reputable firm to install your septic system. Tile or perforated pipe laid on improper grades, incorrect joints and alignments between system components, and tiles or pipes broken or crushed during the building process can all cause system failure.

Signs that may indicate septic system failure include:

• Ponded water or damp places in your yard, foul odors, and/or dark gray or black color to the soils indicate septic drainfield failure. These signs are particularly noticeable at the bottom of slopes draining away from the drainfield, and in drainage ditches.

• Areas where water comes to the surface, particularly after heavy rains or during activities which increase wastewater production such as doing the laundry.

• Toilets that flush slowly or drains that back up.

If you notice any of these signs, contact your local health department or a septic system pumping service for information and assistance. Some septic tank pumpers provide free inspection of your septic tank provided you uncover the clean-out opening.

Landscaping for a Healthy Sound