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After seven months of searching for the source of water contamination in Millsboro, the Delaware Department of Natural Resources and Environmental Control (DNREC) narrowed it down to a former poultry vaccination lab off Route 113.
DNREC investigators sampled water throughout the Millsboro area during the past seven months searching for the source of trichloroethylene (TCE), which contaminated the water supply in October.
Residents of Millsboro were forced to use bottled water when the TCE contamination was discovered.
The site tagged as the source of the contamination used to operate as a poultry health laboratory, where chickens were vaccinated. TCE used in the operation spread into the groundwater.
Kathy Stiller-Banning, site investigator for DNREC, said cleaning up the site could cost in the millions of dollars, a price tag that may be hard for Millsboro officials to swallow. Officials said the cleanup may require federal help.
Contamination time line
“High pollution levels in town wells prompted health officials in October to warn against drinking any water from a system that serves Millsboro and part of Dagsboro,” said Stiller-Banning. “Some of the 3,000 residents affected by the pollution episode relied on bottled water or supplies from emergency tanker trucks for weeks, with service restored only after the installation of a chemical filtration system.”
The investigation of the source did not technically start until December, two months after the contamination was found. Private wells, including those operated by Tidewater Utilities, were not affected by TCE, said DNREC officials.
DNREC lifted restrictions on drinking the water, starting Nov. 28 for certain areas of Millsboro and Dagsboro. But even into December, some residents were still advised not to drink the water.
Paul Will of DNREC said the delay allowed enforcement officials to get permits to investigate wells in the area.
As of Nov. 21, levels of trichloroethylene (TCE) were still above the required 5 parts per billion (ppb).
“The levels are significant at the property,” Stiller-Banning said. “Our goal is to try to figure out how to clean it up and to remove any potential continuation” of the well contamination. She added that a cleanup could cost “several million” dollars, with the bill ultimately going to those responsible.
What is TCE?
Trichloroethylene is a nonflammable, colorless liquid with a somewhat sweet odor and a sweet, burning taste. It is used mainly as a solvent to remove grease from metal parts, but it is also an ingredient in adhesives, paint removers, typewriter correction fluids and spot removers.
TCE is a clear liquid used as a solvent by industries and also by dry cleaners. If ingested, it affects the central nervous system and can cause dizziness, vertigo, headaches and even coma.
According to the Environmental Protection Agency (EPA) there are over 2,000 known TCE-contaminated sites throughout the country.
“It is a World Trade Center in slow motion,” said Boston University epidemiologist and TCE expert David Ozonoff in a recent press release about the possibility that thousands of birth defects and cancers every year may be due to TCE exposure.
United States senators recently wrote letters to the EPA, demanding harsher regulations on TCE.
In a 2001 EPA document assessing the risks of TCE, officials noted that exposure can cause both short and long term health effects.
“TCE exposure is associated with several adverse health effects, including neurotoxicity, immunotoxicity, developmental toxicity, liver toxicity, kidney toxicity, endocrine effects, and several forms of cancer,” reads the report. “ Under EPA’s proposed (1996, 1999) cancer guidelines, TCE can be characterized as ‘highly likely to produce cancer in humans.’”
The allowable level of TCE in water is regulated at five parts per billion (ppb), but water tested in the Millsboro and Dagsboro area had almost 15 times that in October.
Water tested at the Dagsboro town hall measure 72.7 ppb of TCE, while a test at a Millsboro fire hydrant measured 39.3 ppb, and a test at one well in Millsboro reached 91.6 ppb, according to Heidi Truschel-Light of the Delaware division of public health.
For Millsboro, the next task will be getting the money to clean up the contamination. Early in May, the town held a referendum that would allow the use of bonds to help cover some cleanup costs.
The Delaware State Revolving Fund will lend the town $200,000. Town officials estimate that the process up to this point has cost that much and further testing and removal of contaminants will exceed the loan.
“Our Site Investigation and Restoration Branch systematically collected more than 300 ground water samples and 95 geo-probe borings in the Millsboro area to locate the source,” said James Werner, director for DNREC’s Division of Air and Waste Management. “From our results, it appears that the ground water contamination forms a relatively narrow and confined plume, which is most helpful in the final site investigation and clean up.”
The town of Millsboro has already installed carbon filtration systems throughout the water system to help reduce toxins entering the groundwater.
Now, further clean up is needed at the contamination site, said Werner, who said the responsible party will have to help fund the clean up.
“The Department will initiate cost recovery against the responsible parties under the polluter pays principle,” said Werner.
For more information about clean up efforts, contact Stiller-Banning or Will at 302-395-2600.
TCE’s effects on the human body
Exposure:
• Once a person is exposed to TCE, either by drinking, eating or breathing it in, the chemical travels through the circulatory system where it can accumulate in fat and other tissues
• There is evidence of heart abnormalities in human and animal offspring exposed to TCE while in the womb
Effect on organs:
• Brain: TCE can cause dizziness, headaches, sleepiness, nausea, confusion, blurred vision and weakness
• Lymphatic system: In humans, TCE was associated with an elevated, but not statistically significant, risk of non-Hodgkin’s lymphoma.
• Immune system; TCE is lined to immune system damage and increased incidence of autoimmune diseases
• Liver: TCE can be toxic to the live and has been linked to increased risk of liver cancer
• Pancreas: A possible increased chance of pancreatic cancer has been identified
• Kidney: Those exposed to TCE showed signs of kidney damage and an increased risk of cancer
• Reproductive system: Some male workers exposed to TCE showed possible reproductive effects, including reduced sperm counts. Links have also been drawn to cervical and prostate cancer.
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