Clean Water Act significantly reduces pollution in US waterways – ScienceDaily

The team analyzed data from 50 million water quality measurements collected from 240,000 monitoring sites in the United States between 1962 and 2001. Most of the 25 water pollution measurements showed improvement, including an increase in dissolved oxygen levels and a decrease in faecal coliform bacteria. The share of rivers suitable for fishing increased by 12% between 1972 and 2001.

Despite a noticeable improvement in water quality, almost all 20 recent economic analyzes believe that the costs of the Clean Water Act consistently outweigh the benefits, discovered a costly job. -written with researchers from Cornell University. These figures are in contradiction with other environmental regulations such as the Air Quality Law, which have far greater benefits than costs.

"Water pollution has dropped dramatically and the Clean Water Act has contributed significantly to these declines," said Joseph Shapiro, an associate professor of agricultural economics and resources at the College of Natural Resources in the United States. Berkeley University. "So we were shocked to find that the number of benefits measured was so low compared to the costs."

The researchers suggest that these studies overlook some benefits, including improving public health or reducing industrial chemicals not included in current water quality tests.

The analyzes appear in two studies published in the Quarterly Journal of Economics and in the Proceedings of the National Academy of Sciences.

Clean up our streams and rivers

Americans worry about drinking water. In Gallup polls, water pollution is consistently ranked among Americans' top environmental concerns – higher than air pollution and climate change.

Since its entry into force, the Clean Water Act has imposed environmental regulations on individuals and industries that dump their waste in waterways. It resulted in $ 650 billion in spending through federal grants to municipalities for the construction of sewage treatment facilities or the upgrading of existing facilities.

However, comprehensive water quality analyzes have been hampered by the diversity of data sources, with many measurements coming from local organizations rather than from national organizations.

To perform their analysis, Shapiro and David Keizer, assistant professor of economics at Iowa State University, had to compile data from three national water quality data repositories. They also found the date and location of each municipal grant, an undertaking that required three requests under the Freedom of Information Act.

"The measurement of air pollution and greenhouse gases is usually automated and standard, while water pollution is more often caused by a person coming out of a boat and diving something into the water. # 39; water. " Shapiro said. "It was an extremely tedious project of data and time to collect all these measurements of water pollution and then analyze them in a comparable way in time and in space."

In addition to the overall decrease in water pollution, the team found that water quality downstream of wastewater treatment plants had improved significantly after municipalities received subsidies to improve water quality. Wastewater. They also calculated that it costs about $ 1.5 million to fish a mile of river for a year.

Compare costs and benefits

The addition of all the costs and benefits – both monetary and non-monetary – of a policy is a means of assessing its effectiveness. The costs of an environmental policy such as the Clean Water Act may include direct expenditures, such as the $ 650 billion of municipal subsidy expenditures, and indirect investments, such as costs borne by businesses to improve the treatment of wastewater. Benefits may include increased prices for waterfront housing or decreased travel to find a good place to fish or swim.

The researchers conducted their own cost-benefit analysis of municipal grants under the Water Act, and combined it with 19 other recent analyzes by hydrologists and the LFS. They found that, on average, the measured economic benefits of the legislation accounted for less than half of the total costs. However, these figures may not paint a complete picture, Shapiro said.

"Many of these studies consider that cleaning up rivers, lakes and streams to serve human health has little or no benefit, because they assume that if we drink water it is subject to a separate purification process, no matter how dirty the water in the river is, it's not going to affect people's health, "said Shapiro. "The recent controversy in Flint, MI recently seems to go against this point of view."

"Similarly, drinking water treatment plants are analyzing a few hundred different chemicals and the US industry is producing close to 70,000. It is therefore possible that some chemical studies can not measure the adverse effects on the environment. people's well-being, "said Shapiro.

Even though the costs outweigh the benefits, Shapiro points out that Americans should not have to compromise their passion for drinking water – nor abandon the Clean Water Act.

"There are many ways to improve the quality of water, and it is quite plausible that some of them are great investments, and some are not worth it. Investments, "said Shapiro. "It is therefore plausible that it is important and valuable to improve the quality of water and that some investments made by the United States in recent years do not pass the benefit-cost test. . "