This research considers a system containing a manufacturing firm who generates waste material during manufacturing process, and a disposal firm who collects and disposes the waste material. Identification of the optimal number of pick ups and the amount of waste to be disposed at certain period of time in terms of cost minimization is studied. Two types of waste accumulation rates, constant and linearly increasing, are discussed and mathematical models are developed. It can be shown that the results for these two different types of waste accumulation differ in a wide range because of the difference in the way of how waste is accumulated, which disturbs the storage cost. An integrated model is also developed and discussed in which both the manufacturing firm and the disposal firm benefit from the coordination between the two parties. It is shown that the optimal policy adopted by the integrated approach can provide a strong and consistent cost-minimizing effect for both the manufacturing firm and the disposal firm over the existing approach. Finally, all the models are verified by a numerical example and the results are compared.