Although rarely mentioned these days, an East Austin factory was the source of one of the country’s most spectacular fish kills, which wiped out wildlife for hundreds of miles down the Colorado River.

The story of Acock Laboratories’ “insect powder” and its role in the 1961 fish kill has been widely available since 1962, when Rachel Carson published her groundbreaking, best-selling book “Silent Spring.”

Her carefully documented investigation tracked for the first time the effects of DDT — which was banned by the U.S. Environmental Protection Agency in 1972, two years after the agency was founded — and other pesticides on wildlife, livestock, pets and humans. Public response to the book helped launch the modern environmental movement.

Last year, the Library of America republished “Silent Spring.” In this edition, Austin first appears on page 128, in a chapter titled “Rivers of Death.”

“Shortly after daylight on Sunday morning, Jan. 15, dead fish appeared in the new Town Lake in Austin and in the river for a distance of about five miles below the lake,” starts Carson’s account, which is based on evidence laid out in the Fish and Game Commission’s “Report of Investigation of the Colorado River Fish Kill, January 1961.”

By Monday, dead fish had been reported 50 miles downstream of Longhorn Dam, which was completed the previous year to impound Town Lake, now known as Lady Bird Lake.

It did not take much expertise to surmise that something poisonous had entered the water. “By Jan. 21, fish were being killed 100 miles downstream near La Grange,” the book continues. “And a week later, the chemicals were doing their lethal work 200 miles below Austin. During the last week of January, the locks on the Intracoastal Waterway were closed to exclude the toxic waters from Matagorda Bay and divert them into the Gulf of Mexico.”

Not unlike some of Austin’s other water-quality problems — such as the boil-water notices of 1935 and 2018, as well as the recent stinky water complaints blamed on zebra mussels — the look and smell of the water were key indicators. Back then, officials said the strong odor they detected was associated with the insecticides chlordane and toxaphene.

“It was especially strong in the discharge from one of the storm sewers,” Carson writes. “The sewer had in the past been associated with trouble from industrial wastes, and when officials of the Texas Game and Fish Commission followed it back from the lake, they noticed an odor like that of benzene hexachloride at all openings as far back as a feeder line from a chemical plant.”

That benzene hexachloride smell likely came from lindane, a related chemical commonly used in pesticides, including those manufactured and bagged in East Austin.

Which plant? Carson doesn’t say.

Contemporary newspaper accounts, citing the same Game Commission report, flagged Acock Laboratories, which manufactured insect powder that was used on cotton crops. Among the main products of the Acock plant was DDT, along with the other chemicals mentioned in the investigation.

DDT builds up in the fatty cells of animals that ingest it, so the higher up on the food chain an animal feeds, the greater its risk of exposure to high concentrations of the chemical. Some studies have shown that humans can be harmed by DDT, even without eating animals contaminated by it, if the exposure is repeated over a long time.

“The manager of the plant admitted that quantities of powdered insecticide had been washed into the storm sewer recently,” Carson writes, “and, more specifically, he acknowledged that such disposal of insecticide spillage and residues had been common for the past 10 years.”

Fishery officials found that other local insecticide plants used Austin sewers as industrial drains. Not only that, but the whole storm sewer system had been recently flushed out by high-pressure water, which could have forced years of dumped toxins into the river.

“As the lethal mass drifted down the Colorado, it carried death before it,” Carson writes. “For 140 miles downstream from the lake the kill of fish must have been almost complete, for when seines were used later in an effort to discover whether any fish had escaped, they came up empty.”

Officials identified as many as 27 species among the dead, with a total of 1,000 pounds of carcasses pegged to a mile of riverbank. A giant dead blue catfish was recorded weighing 84 pounds.

Game and Fish officials predicted that the fish population would be altered for years and that some species might never return. This also might explain why a federal fishery was located on Town Lake in the 1960s.

At least the closure of the Intracoastal Waterway protected the vast oyster beds and shrimp stock in Matagorda Bay.

Tainted lands?

A civil jury later declined to pin exclusive blame for the big 1961 fish kill on Acock Laboratories, which operated at 2700 E. Fifth St. However, the Texas Fish and Game Commission, with forensic help from city of Austin drainage experts, had no problem citing and fining Acock as the primary culprit.

Almost 60 years later, the former Acock site now is virtually clean.

“The good news is that the lab analysis of the soils and groundwater collected at the site showed only minor concentrations of various substances well below regulatory levels,” the property’s current owner, Jim McCurry, said, “and that no action is required.”

The Acock site is hardly the only former industrial site in Austin, especially in East Austin, that might be considered a "brownfield," one that, because of past use, needs careful study or environmental remediation. As East Austin rapidly gentrifies, redevelopment of those sites means confronting a toxic past.

Nearly century-old city zoning policies gave largely minority East Austin a disproportionate share of the city's industry. Almost any open spot located next a freight rail line might have hosted industrial activities at one time or another. Indeed, chemical plants, mines, quarries, dredging operations, iron and steel mills, cotton gins, and factories that processed food or leather, or made plastics, fabric, tools or furniture operated all around Austin.

Generations of East Austin activists have pushed for the removal of industrial sites from their neighborhoods, such as fuel storage facilities, better known as "tank farms," in the 1990s, as well as Arnold Oil Co. in the 1970s and again in the 1990s, and, for decades, the now shuttered Holly Street power plant.

McCurry told the American-Statesman he was surprised to hear about the pesticide dumping in the 1950s and 1960s. The Austinite has been investing in old industrial properties for a while and had hoped to do something creative at the former Acock site.

“I really liked the size and shape of the old warehouse on that property from the first time I saw it, and was interested in trying to save it if I could,” McCurry said. “And when I bought the property from Union Pacific Railroad in 2005, the environmental report didn’t provide any indication or evidence of any toxic or hazardous materials-type incidents on the site.”

That report determined merely that the primary use of the site for the previous 30 to 40 years had been as a construction and storage yard, same as it is today.

“The historical reports of Acock’s activities indicate they actually disposed of, or dumped, chemicals directly into the storm drain(s), which unfortunately was the most direct path into the river, and that was terrible and mindless and incredibly destructive to the aquatic life and ecosystem,” said McCurry, who ordered a more thorough analysis after the Statesman's questions. “But we don’t have reports that they dumped the chemicals onto the ground at the warehouse property, so it’s possible these chemicals were never introduced into the soil in a major way.”

One more twist

The story of Austin pesticides and fish kills does not end there, however, or when Acock closed its plant in 1975 and moved to Houston.

In 1979, the state ordered two cleanups of serious pesticide pollution mixed in the soil at Mabel Davis Park in Southeast Austin and on nearby land owned by Property Management Inc.

“We don’t know for sure how it got there,” said Fred Rogers of the Austin-Travis County Health Department. “But they’ve agreed to remove the contaminated soil or cover it with topsoil. We still sample the water out there when it rains, but the latest sample showed the pollution well under health limits.”

Mabel Davis Park sits on top of one of the city’s 10 old landfills, which were closed in the 1950s. The city kept no records of what was dumped there.

Yet the name Acock shows up again.

“The Mabel Davis problem surfaced, literally, in May when about 200 fish in a nearby pond on Country Club Creek were found belly up,” wrote Statesman reporter Dick Stanley. “City and state officials concluded that the fish had died from pesticides washed into the creek by storm runoff unwittingly uncovered, and spread around, by construction activity in the park.”

The pesticide? A combination of DDT, toxaphene and lindane discovered in dozens of torn bags labeled “Acock,” for “Acock Laboratories.”

“Though the landfill beneath the park was closed in 1958, the pesticide powder hardly was decomposed,” Stanley wrote, describing how the contaminated soil was moved to other locations. “No one knows for sure how the pesticide bags wound up in the landfill under the park, whether they were dumped there by the company or a customer.”

This cache of Acock poisons might not have decomposed very quickly because it was still encased in plastic bags.

“We might never have known about it,” said Stephen Cook with the city’s Water Resources Department, “had the city not begun digging there. The other landfills should be checked, but if they’re not leaking anything toxic, then they ought to be left alone. Resecuring them could be expensive and dangerous.”