It's All About Clean Water

Part 1 of 3 - Septic Systems

"It's all about Clean Water" is a recurring column in the Moultrie news exploring issues tied to water quality in our community. The following is the first in a three-part series on septic tank systems and how they impact our environment.

Septic Systems: the Good, the Bad and the Ugly

The Good

• The first record of a septic system was in France in 1870. The typical septic system design has changed very little since first introduced in the US in 1884.
• About one-third of all U.S. households utilize septic systems to dispose of sewage.
• Well constructed and properly maintained septic systems in proper soil conditions provide a good means of wastewater disposal.
• A septic system provides a "holding tank" where natural bacterial action decomposes human waste products into water, and nutrients. These end products are then discharged to the soil.
• From the septic tank, the segregated liquid flows into a small distribution box where it then flows to several perforated pipes or field lines. These perforated pipes then distribute the liquid to a large sub- surface area, called a leach field, or absorption trench. The soil also acts as a filter to remove any small amounts of solids that may be carried along with the liquid. For the soil to properly do its job it needs an aeration zone between the leach field and the saturated ground or groundwater table.
• Sludge forms at the bottom of the tank and a scum layer at the top. These should be periodically pumped out and properly disposed. Regulations
• To install a septic tank, a home owner must get a permit from the South Carolina Department of Health and Environmental Control (DHEC). That process includes a soil composition test to determine if a septic system would function properly.
• All new septic systems are inspected, however, DHEC does not require any annual inspections, follow-up permitting or maintenance reporting.
• A license is required for construction, repair, or cleaning of on-site sewage treatment and disposal systems or cleaning of self-contained toilets in SC.

The Bad

• A properly installed septic system should last about 30 to 50 years. Unfortunately, most old systems were poorly installed. During several septic removal programs in recent years, we have found systems dating back more than 40 years. We have even discovered a few active pit privies.
• It costs between $125 and $225 for a licensed contractor to pump out tank sludge, which should be done about every three to five years.
• If a septic tank needs to be replaced - and the leach field is still undamaged - the cost will range from $1,000 to $2,500.
• If a new leach field is needed, the total tab will run $2,500 to $5,500 depending on conditions.
• If there is not sufficient room for a new leach field, the existing field, including the clogged soil, must be removed and a completely new system must be installed. Such an effort can easily exceed $8,000.
• Lack of maintenance may lead to system failure or malfunction. Some families simply cannot afford the costs of pumping and inspection and systems go un-maintained for years.

The Ugly

• Our region’s high water table rises even more during heavy rain storms and extreme high tides,, forcing excess water into the leach field and sewage upward to the ground surface. And it gets real ugly when this raw sewage finds its way to drainage canals, storm drains, marshes, estuaries and waterways. Ground water quality is also affected if there is an insufficient aeration zone.
• Solids that are not decomposed eventually have to be removed from the septic tank or else the septic tank fills up and wastewater discharges directly to the drainage field. Not only is this bad for the environment, but if the sludge overflows the septic tank into the leach field, it may clog the leach field piping requiring expensive repairs.
• Some pollutants, especially nitrates, are not decomposed by septic tanks but in the leach field. In areas with high population density, groundwater nitrate levels may exceed acceptable limits. Nitrates are the leading drinking water contaminant in South Carolina with malfunctioning septic systems as one source of this contamination.
• Sewage that bubbles to the surface harbors vectors, potential pathogens, and the chance of human contact and contamination and that is downright ugly.