Former regional EPA manager Richard Pepino was studying biology in college in the 1960s. He remembers one of his professors sending his class onto the river to measure the oxygen levels.

“We were getting no readings,” he said. “And so they said, ‘Somebody’s got to tell the professor the machine is broken.’ The machine wasn’t broken. There was no oxygen. How can you support an ecosystem where the amount of oxygen was too low to measure?”

The answer was: you couldn’t. The dead zone on the river ran from Philadelphia to about 25 miles down river in Marcus Hook, Pa. That made it impossible for migratory fish like shad to breed. They would die on their journey upstream before they could lay their eggs in the upper Delaware.

Once plentiful caviar and sturgeon also disappeared. Combined with losses of shad and other fisheries, that spelled the death of a regional industry once worth hundreds of millions of dollars.

But even for people who didn’t fish, Pepino said for decades, the river just wasn’t a place people wanted to be.

“You look out on the river today, it looks appealing. It did not look appealing in those days.”

The decomposing bacteria gave off noxious hydrogen sulfide fumes. Some shipping vessels refused to dock in Philadelphia because it smelled so bad.

An infamous news article from 1923 reported that a seafarer from Calcutta, India was said to have exclaimed, “Phew! Mates, I’ve been in all the principal harbors of the world, I’ve seen—and smelled—some mighty filthy ones. But Philadelphia is the worst. No wonder you have no buzzards flying about the harbor. Their hardened stomachs could not stand the strain of the nauseating odors which would assail their nostrils here.”

Another article documented the claims by a World War Two army pilot that he could smell the river from five thousand feet in the sky.

Fumes would regularly react with the lead paint on ship hulls and turn them black.

Various clean water campaigns gained support but then sputtered out. In 1936, New York, Pennsylvania and New Jersey joined together to form the Interstate Commission on the Delaware River Basin (Incodel). Delaware joined in 1938. The group had no powers, but it was seen as a way to develop joint plans and programs for the Delaware. Their first priority was addressing water quality.

The group rolled out water quality standards, but its efforts were scuppered by the onset of World War Two. Cleaning up the river was going to be expensive, and the country’s money was tied up in the war effort.

In 1961, President John F. Kennedy signed the Delaware River Basin Compact creating the Delaware River Basin Commission, which was a more sophisticated and formal version of Incodel. The commission included all four states — Pa., N.J., N.Y., and Del. — as well as the federal government and sought to address river planning, development and regulation, with a specific eye on water quality.

The group made some progress, but funding continued to be an issue.

Then something started happening.

“The people were fed up,” Pepino said.