Researchers at the University of California Berkeley and Iowa State University studied the effects of water pollution after the enactment of the 1972 Clean Water Act in the U.S.
A team of researchers analyzed the conditions and quality of water pollution in and around the sites of water distribution in the U.S. They collected samples from around 50 million water quality measurements collected at 240,000 monitoring sites throughout the U.S. between 1962 and 2001. The team comprehensively observed the data of those sites and concluded that most of the 25 water pollution measures depicted improvement. This included an increase in the level of diffused oxygen and reduced concentration of fecal coliform.
The analyses found the water quality improved by a large margin, however, the economic analyses estimates of recent years (almost all 20) suggests costs of the Clean Water Act outweigh the benefits. Joseph Shapiro, an associate professor of agricultural and resource economics in the College of Natural Resources at UC Berkeley, said, “the Clean Water Act contributed substantially to the declines of water pollution, so we were shocked to find that the measured benefit numbers were so low compared to the costs.”
The findings of the analyses were published in the Quarterly Journal of Economics and the Proceedings of the National Academy of Sciences. The team compiled data from three national water quality data repositories. “It was an incredibly data and time-intensive project to get all of these water pollution measures together and then analyze them in a way that was comparable over time and space,” adds Shapiro.
The researchers proposed that the economic analyses might have overlooked the industrial chemicals and public health in current water quality testing. They conducted cost-benefit analysis of the Clean Water Act municipal grants and found that on an average the measured economic benefits was far below than the average cost.