Water Quality Improvement Act Of 1970

Water quality sucked. At least in the post-WW2 era, when America thought its resources were endless, and that it could just crap all over the place with no recourse.

Mercifully, somebody finally took notice and started regulating the pigs.

One of the many regs that hit was the Water Quality Improvement Act of 1970, which gave the U.S. federal government more room to lay down the law (and created more laws, i.e. provisions) in terms of water pollution. The main issue was oil contaminating water, which was creating negative externalities from firms to humans, marine life, and other wildlife. See the more modern BP Oil Spill for details.

Fun fact: Politicos knew we had slob issues ages ago; they just didn't do much about it. Anemic laws started to come into existence as early as the 19th century, with an 1886 edict that created the River and Harbor Act. They were before their time.