Is a comparison of costs and benefits always an effective method for choosing among alternatives? Why or why not?

In generating electricity, a power plant produces heat. To cool the operating machinery, the plant can use water pulled from a nearby source through a cooling water intake structure. The structure affects the environment by squashing aquatic organisms against intake screens or sucking the organisms into the cooling system. The Clean Water Act mandates that “cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.” For more than thirty years, the EPA made the “best technology available” determination on a case-by-case basis. In 2001 and 2004, the EPA adopted “Phase I” and “Phase II” rules for power plants.