An environmental engineer wants to evaluate three different methods for disposing of a non-hazardous chemical waste: land application, fluidized-bed incineration, and private disposal contract. Use the estimates below to help him determine which method should be chosen at i = 12% per year, on the basis of annual worth. AOC stands for annual operating cost First cost, $ AOC, S/year Salvage value, $ Land Incineration -150,000 -900,000 -95,000 -70,000 25,000 300,000 4 6 Contract 0 -150,000 0 2 Life, years