Discuss on the three types of septic tank upgrade recommendations need to be made for the Australian local government and meet certain conditions. At the same time, for the three proposals, it is necessary to compare the funds of each aspect (Capital cost, Operating cost, Simplicity, Serviceability, Life span) and the weight ratio of each aspect in the plan (the reason needs to be explained and a certain reference is provided). The final result is similar to the examle1&2 given.