The design and installation of an on-site sewage system is dependent on many factors. The size and shape of the lot, the size of the residence and the results of the soil test. There are instances when a system described in our rules cannot be designed and an alternative on-site system is needed. Alternative systems must be approved by the DEQ prior to the system installation. For additional information concerning the types of alternative systems available and the application/approval process for alternative systems, please contact your local DEQ office or Matt Pace at 405/702-6100.