Environment |

How a toxic chemical infiltrated the Floridan Aquifer, tainting Seminole County tap water

The toxic chemical in the drinking water of thousands of Seminole County homes has properties that can seem sinister.

1,4-dioxane turns water into its Trojan Horse. Colorless and smelling mildly sweet, it does that because it is infinitely soluble, or entirely dissolvable in water.

With that trick, it masquerades among crystalline currents deep underground in the Floridan Aquifer where Lake Mary, Sanford and Seminole County obtain drinking water.

In its cloak of aquifer water, the chemical sticks to nothing, not sand, rock or clay. It won’t be deterred, except by costly intervention, en route to kitchen faucets and showers.

The chemical also is known to flood into tiny pores of underground aquifers and then bleed back out for decades as a continuing problem for generations to come.

Lastly, the contaminant resists breaking down into less harmful substances, earning it the “forever chemical” label.

“1,4-dioxane is a pervasive and persistent contaminant that is both recalcitrant and highly mobile,” said Tom Mohr, a California-based engineer who began to study and publish on the chemical nearly 20 years ago and provides expert testimony in legal proceedings.

There is no ordinarily affordable way to remove the chemical from the Floridan Aquifer. Typical water treatment plants are vastly outmatched by 1,4-dioxane, which is classified by the U.S. Environmental Protection Agency as likely to cause cancer.

Precisely how 1,4-dioxane could have escaped from a shuttered Siemens factory in west Lake Mary, infiltrated deeply into the Floridan Aquifer and then tainted water supplied to Lake Mary, Sanford and northwest Seminole County involves overlapping factors.

Rain barrel

The Floridan Aquifer is fragile yet formidable, amounting to a gigantic underground rain barrel. It is one of the most productive aquifers in the nation, according to the U.S Geological Survey, and provides the Orlando region nearly 100 percent of its drinking water.

The aquifer is clean, for the most part, despite the countless chemical contaminations that occur above it on the surface of the ground. The aquifer attracts bottled-water companies to set up pumping plants to extract millions of gallons daily.

The Floridan Aquifer is robustly protected from toxic chemicals – solvents, fuel, pesticides and others – by overlying layers of rock and clay and its sheer size.

But in some places, the aquifer is vulnerable to poisoning, including, it turned out, the geology beneath the factory that once was Seminole County’s largest employer.

120 drums

Nearing the end of its life in the early 2000s, the telephone systems factory now owned by Siemens in Lake Mary had been probed and fined for improper handling of chemicals.

Seminole County authorities logged complaints about the plant, including “dying trees, odors and rusty barrels.” One caller, identifying only as a former worker, said chemical drums had been stacked for years behind a building.

Field notes from a state investigation in 1988 of the “Stromberg-Carlson Drumsite,” taking the name of the factory when it first opened in 1968 under the ownership of General Dynamics, describe a noxious wasteland.

One 55-gallon drum was “laying on its side with 2/3 of the drum missing, heavily rusted.” Another rusted drum contained “brownish-orange liquid, almost full.” Also noted was “underneath drums #10 and #11 there were several drums which one could not gain access to.”

That fits with a former worker’s experience.

“We would stack them up, two high and then build them up higher,” said the ex-employee, who spoke to the Sentinel several times but asked not to be identified because of nondisclosure agreements in his lawsuit settlement with Siemens. “When there were too many, they were moved farther out.”

In 2015, an environmental assessment by the state highway department, in preparation for widening the adjoining Interstate 4, noted that 120 metal drums were found at the site.

“There is no available record of the site being cleaned or the drums being removed,” the report states. “This site is rated high risk based on vague records.”

Sinkholes

Siemens workers described to the Sentinel and in court documents that solvent chemicals were being carelessly handled and often puddling on the factory floor and outside where the chemical drums were stacked. Some described smelling fumes after a heavy rain.

But it’s not entirely clear from records how 1,4-dioxane escaped into the soil and underlying aquifer at the plant campus. There were many possibilities apart from shoddy drum storage.

Some workers said in civil lawsuits and to the Orlando Sentinel that it wasn’t uncommon to flush solvents down drains. In 2011, more than three dozen former factory workers combined their lawsuits and settled their multi-million dollar legal battle against Siemens and General Dynamics, alleging that the companies’ careless handling of the solvents with toxic chemicals caused them to develop cancer.

One of those lawsuits alleged in 2006 that 1,4-dioxane was “disposed of by placing the waste on the ground outside the plant and allowing it to evaporate … as the method of disposal that was specifically recommended by chemical manufacturers.”

However the chemical was released, investigators ultimately found that the plant property was perforated with new and ancient sinkholes able to serve as funnels for chemicals plunging into the Floridan Aquifer.

Nobody checked

1,4-dioxane was confirmed in 2001 to be part of hazardous pollution at the factory.

The highest concentrations of toxic chemicals would be located in plumes beneath the factory floor.

It’s possible the chemical already had migrated into the Floridan Aquifer and drinking water by then. But utility officials say they have little evidence as to the timing.

Nobody thought to check for 1,4-dioxane in drinking water in 2001 and nobody would for another dozen years.

Toxic Secret: Our series about 1,4-dioxane in Seminole water

• Part 1 – A toxic chemical, 1,4-dioxane, has infiltrated waters of three utilities
• Part 2 – Local water utilities have struggled with how to address 1,4-dioxane, a likely carcinogen
• Part 3 –  1,4-dioxane has a seemingly sinister ability to invade the Floridan Aquifer
• Part 4 – 1,4-dioxane in Seminole water has been a virtual secret. How one family found out

Know more about this issue?

Do you have pertinent information about the 1,4-dioxane contamination in Seminole County water you would like to share with us for our reporting? If so, please email us at toxicsecret@orlandosentinel.com.

About the journalists who reported this series

• Kevin Spear is the Orlando Sentinel’s environmental reporter. He has been with the newspaper for 34 years and for most of that time has covered key issues relating to water, wildlife and land use. He can be reached at kspear@orlandosentinel.com 
• Caroline Catherman is the Orlando Sentinel’s health reporter. She joined the newspaper in 2021 after previously working in public health research. She can be reached at ccatherman@orlandosentinel.com
• Martin E. Comas is the Orlando Sentinel’s Seminole County reporter. He started at the newspaper in 1988 and has covered key Seminole stories including the death of Trayvon Martin and its aftermath, and the controversies surrounding disgraced Tax Collector Joel Greenberg. He can be reached at mcomas@orlandosentinel.com
• Joe Burbank is the Orlando Sentinel’s senior photographer. He joined the newspaper in 1988 after working for Agence France-Presse news.  He has spent more than three decades covering Central Florida with his visual reporting. He can be reached at jburbank@orlandosentinel.com
• Rich Pope is the Orlando Sentinel’s videographer. He joined the newspaper in 2003. He has received Emmy nominations, along with recognitions from the Online News Association and Florida Society of Newspaper Editors. He can be reached at rpope@orlandosentinel.com

Help support our investigative reporting

Contributions to the Orlando Sentinel’s Community News Fund helped us produce this series. Please consider supporting our reporting by donating to the fund at OrlandoSentinel.com/donate