The conventional wisdom about the US Clean Water Act (which I’ve always believed) is that it’s been a great success. Maybe not?
On the fortieth anniversary of the Clean Water Act this paper reports the first quantitative assessment of the aggregate trends in water quality in the U.S. using a single standard over the years 1975 to 2011. The analysis suggests that fresh water lakes for the nation as a whole are about at the same quality levels as they were in 1975. In short, viewed in the aggregate, nothing has changed.