HOW IS A SEPTIC SYSTEM DESIGNED?
HOW DOES A SEPTIC SYSTEM WORK?
WHO CAN INSTALL A BASIC SEPTIC SYSTEM?
HOW OFTEN SHOULD I PUMP OR MAINTAIN MY SEPTIC SYSTEM?
SHOULD I USE SEPTIC TANK/SYSTEM ADDITIVES?
TYPES OF SEPTIC SYSTEMS

 
HOW IS A SEPTIC SYSTEM DESIGNED?

A Private Onsite Wastewater Treatment System (POWTS) or septic system is sized and designed by the completion of a site & soil evaluation. From this evaluation report a loading rate is determined and type of system. The size of system is calculated by the number of bedrooms [150 gallons per day of waste water (toilet, kitchen, shower, laundry, etc.)/bedroom]. Dividing the gallons per day by the loading rate you can calculate the square footage needed for the type of system being installed (Example: 450 gpd / .7(loading rate) = 642.857 sq. ft.). The septic tank size is determined by the number of bedrooms for residential or gallons per day for commercial and using a POWTS Treatment Tank Capacity Determination formula.

There are several types of septic systems out there. Conventional, At-Grade, Mound, Holding Tank, In-ground Pressure and Pre-Treatment. Once again the type of system is determined by a site & soil evaluation.

 
HOW DOES A BASIC SEPTIC SYSTEM WORK?

Waste water flows from the building into a septic tank. The septic tank acts as a settling chamber, separating liquids from solids. Exiting the septic tank the effluent passes through a filter, which doesn't allow solids 1/8 inch or larger to pass. The effluent then goes to the cell (absorption area) and is treated by passing through the soil.

 
WHO CAN INSTALL A SEPTIC SYSTEM?

You must be a licensed Master Plumber or Master Plumber Restricted Service (MPRS) individual, to contract or permit for work, by the WI Dept. of Commerce. You can search to see if the company you're looking at hiring is licensed with WI Dept of Commerce.

License search: http://apps.commerce.state.wi.us/SB_Credential/SB_CredentialApp

 
HOW OFTEN SHOULD I PUMP OR MAINTAIN MY SYSTEM?

County zoning sends out inspection or pumping cards every 3-years from date the system was installed. Septic tanks don't need to be pumped until solids reach 1/3 or more volume of the tank. Although some tanks may need pumping more often, most do not. Studies show a septic tank servicing a family of four under normal usage may only have to be pumped every 4-5 years. In fact, pumping a tank too often can do more harm than good.

Newer systems have effluent filters required by code (after July 1st 2000), to be installed in the tank on the outlet side. Filters keep solids and particles 1/8 inch or larger from exiting the tank and going into the cell (absorption area). If you have a filter, it should to be cleaned every 6 months to 1 year, depending upon the size of the filter and usage of water (see picture).

A licensed Master Plumber (MPRS) should be hired to clean the filter and check the (cell or absorption area) to make sure everything is working properly on a yearly basis. If the tank needs to be pumped, you will be referred to a local pumper.

POWTS Treatment Tank Capacity Determination formula

 
SHOULD I USE SEPTIC TANK/SYSTEM ADDITIVES?

A homeowner does not need to add a stimulator or an enhancer to a septic tank that is designed, operated, and maintained properly—naturally occurring bacteria are already present within human fecal matter. Contrary to popular belief, yeast, dead chickens, possums, or raw hamburger do not need to be added to the septic tank. Chemical additives, such as caustic hydroxides and sulfuric acid, should never be added to a septic system. Adding these products will destroy the bacterial population in the septic tank, change the permeability characteristics of the soil absorption system, and may cause groundwater contamination. Often, manufacturers of biological additives market their use to restore the bacterial balance in a septic tank on a monthly basis as part of a routine maintenance program. This is not necessary because these bacteria already reside in human feces. There are special instances when the use of a biological additive may be warranted, such as when homeowners take antibiotics or other prescription medications. However, it should be noted that research is still needed in this area. Claims made on the effectiveness of additives to either eliminate pumping of a septic tank or restore permeability of the soil absorption system are unsubstantiated. No product will allow a homeowner to escape a regular septic tank pumping and maintenance schedule. The debate on the issue of using an additive can be resolved only through a cooperative research effort from independent/unbiased researchers (such as universities and research centers) and additive manufacturers to determine their true effectiveness and reveal their limitations. If you have additonal questions about septic tank additives, call NSFC at (800) 624-8301 or (304) 293-4191.

 
TYPES OF SEPTIC SYSTEMS