Question

Lake Springfield in the city of Springfield, Illinois, is a busy place where people swim and fish. The lake also supplies drinking water for Springfield residents and cooling water to a nearby coal-fired power plant. Beautiful homes surround most of the lake. Over the past 15 years, the bacterium Leptospira, commonly found in agricultural animal waste, has been detected in this lake water, and some people have become sick. The contamination of the lake by Leptospira may best be prevented by

Select one:
a. doubling the amount of fluoride added to the city's public water supply.
b. requiring the power company to find another source for its cooling water.
c. restricting swimming in the lake to only weekends.
d. better control of agricultural nonpoint source pollution of the lake.

Answer 1

As in this case tracing contamination cause back to a single source is difficult. So the bacterium Leptospira can be prevented by the better control of agricultural non point source pollution of the lake. Non point source pollution (NPS) is the pollution that results from many sources, in contrast with point source pollution that results from a single source. As people do swimming and fishing there, their homes are surrounding the lake, using the lake water for drinking and also it's water is provided to the coal power plant, so their might be many sources that are causing the contamination. So the best option is d.

d. better control of agricultural nonpoint source pollution of the lake.