Final answer:
The statement about Pennsylvania having the best record for toxic discharges into surface water by the end of the 20th century is false. Industrial pollution of water bodies was a widespread problem in the U.S. and significant improvements were only achieved after the enactment of the Clean Water Act in 1972.
Step-by-step explanation:
By the end of the 20th century, Pennsylvania did not have the best record in the country for toxic discharges into surface water; that statement is false. The question relates to environmental history, particularly the industrial impact on water quality in the United States. In fact, water pollution was a significant issue throughout the country due to industrial practices. For example, the Cuyahoga River in Ohio was so polluted from industrial waste that it actually caught fire multiple times, with the most famous incident occurring in 1969. The water pollution problem was widespread during the early 1900s, and it wasn't until the Clean Water Act of 1972 that substantial progress was made in improving water quality in the United States.