For some people served by private sewage systems the thought of an expensive system failure is never far from their minds. Advertisements for septic tank additives that can completely eliminate this worry looks tempting but these claims could be exaggerated.
Some advertisements for septic tank additives claim to completely prevent clogged drains, entirely eliminate the need for routine pumping, and rescue failing systems.

Introducing live bacteria or enzymes into a failing system may not offer much help because septic systems usually fail as a result of old age or neglect of clogged absorption fields, not from the lack of bacteriological action. Because septic systems are designed to catch solids, all tanks will eventually fill with indigestible solids (sludge). No chemical, enzyme or bacteria can digest sand, soil other inert materials. Indigestible solids that accumulate in the tank can wash into the soil absorption field if they are not pumped out. These solids can clog soil pores and prevent water from percolating through the soil absorption field. When the tank is more than half full of sludge there’s too little room for incoming wastewater to remain in the tank long enough to be treated properly. Grease and scum that accumulate on top of the wastewater must also be removed when the tank is pumped to prevent them from washing into the soil absorption field.

The Environmental Health Division recommends that a licensed pumper routinely pump your septic tank every 2-3 years even if additives are used. The cost of pumping a septic tank is often much less than you would pay for a year’s supply of septic tank additives.

While there is no accepted test method to prove septic tank additive products are effective, some products are actually harmful. In Wisconsin, all products claiming to aid digestion in septic systems must be reviewed prior to sale by the Department of Commerce for proof they do not adversely affect:

• The bacterial action in the private sewage system;
• The soil hydraulic conductivity in the soil absorption field; or
• The groundwater quality beneath the private sewage system.

There are no known chemicals, yeast, or other substances capable of eliminating or reducing solids in a septic tank so cleaning is unnecessary. The use of septic tank cleaners does not replace the need for regular pumping of the septic tank and general maintenance of the private sewage system.

The county reserves the right to question any soil test report submitted and require an on-site evaluation to verify the information submitted by the certified soil tester. Soil test reports submitted to the Waukesha County Environmental Health Division are reviewed shortly after being received for accuracy and completeness. Most questions are resolved shortly after submission and the soil test report is filed to await the submission of private sewage system plans.

Pre-1980 Soil Test Reports
Due to changes in soil test submission requirements, if your soil test report is pre-1980, you will need to provide additional information before a sanitary permit can be issued.

Soil Test Reports Dated between 1980 and 1991
If your soil test was conducted between 1980 and 1991 using the percolation test method, it can be used for septic system design and sizing if Environmental Health Division staff agrees with the information provided and it is complete.

Post 1991 Soil Test Reports
July 1991 changes in the Wisconsin Administrative Code prohibited the use of percolation tests to determine absorption area, and a new procedure for evaluating and reporting soil and site evaluation was put in place. Soil tests conducted from July 1991 to the present are acceptable and are expected to continue being accepted for years to come provided the site has not been altered by cutting and/or filling and there is no reason to question the soil conditions as they were reported.

Pre-1980 Soil Test Reports
Due to changes in soil test submission requirements, if your soil test report is pre-1980, you will need to provide additional information before a sanitary permit can be issued.

Soil Test Reports Dated between 1980 and 1991
If your soil test was conducted between 1980 and 1991 using the percolation test method, it can be used for septic system design and sizing if Environmental Health Division staff agrees with the information provided and it is complete.

Post 1991 Soil Test Reports
July 1991 changes in the Wisconsin Administrative Code prohibited the use of percolation tests to determine absorption area, and a new procedure for evaluating and reporting soil and site evaluation was put in place. Soil tests conducted from July 1991 to the present are acceptable and are expected to continue being accepted for years to come provided the site has not been altered by cutting and/or filling and there is no reason to question the soil conditions as they were reported.

The Wisconsin Administrative code establishes minimum isolation distances between the septic tank/soil absorption field and various improvements made on the property. A partial listing of some of the minimum isolation distances are as follows: