The property owner will have to have another POWTS evaluation done because there is specific administrative code language that specifies when a POWTS evaluation is required. As part of those requirements, there is more detailed information that will need to be submitted to the permitting authority for review. Some of the required submitted information is soil test boring data that will determine whether the existing POWTS can meet the minimum depth of separation to limiting conditions. The typical limiting condition in this area is seasonal saturation depth (seasonal water table).
The seasonal saturation depth can be observed by specific soil feature characteristics found in the various layers found in the soil. A soil pit is typically required to perform a soil test. The soil boring will be dug near the existing POWTS (drain field), and the soil characteristics/properties will be described and recorded on a soil test report form. The evaluator who performs the soil test and provides the rest of the required information for the existing POWTS evaluation has to be licensed by the State of Wisconsin Department of Safety & Professional Services.
The POWTS evaluation for real estate sale transactions does not require licensure and does not have a specific set of standards or requirements to follow. The data in their reports can be less specific and more general. It is for these reasons – required standards & licensing, that another POWTS evaluation needs to be completed to obtain a permit for a building addition/renovation.