FAIRBANKS — Alaska health officials are warning North Pole residents to avoid using well water on their gardens after tests showed traces of an industrial chemical.
About 200 wells in and around North Pole are contaminated with sulfolane, an industrial solvent used to refine oil.
Gasoline spills that occurred at a North Pole refinery more than a decade ago, during previous ownership, are believed to have caused the contamination.
Flint Hills Resources, which bought the refinery in 2004, discovered the groundwater contamination in 2009. Since then, the company has put several million dollars toward solving the problem.
On Tuesday, the Alaska Division of Health and Social Services released a report that advised North Pole residents not to use sulfolane-tainted water in their gardens.
Lettuce, tomatoes, snap peas and other plants can store the chemical sulfolane in their fruits, leaves, roots or flowers, The Fairbanks Daily News-Miner reported.
“It’s not just the leaves. We found it in all different parts of plants,” said Nim Ha, acting program manager for the public health division.
Health officials said the levels are unlikely to pose health risks. But a person’s exposure depends on many factors, such as how much water a garden receives and how much homegrown food a person eats.
“We can’t say for all gardeners it would be completely safe to use the well water without knowing more, because of these unknowns,” Ha said. “We’re just being very conservative.”
No studies have been conducted on the long-term effects of low levels of sulfolane on humans. High levels have been shown to harm or kill animals but in doses at least several hundred times higher than those in North Pole wells.
Samples came from 23 plants in seven North Pole gardens last summer, including beets, broccoli, cabbage, romaine lettuce, Swiss chard, tomatoes and rhubarb.
Sulfolane was detected in about half the types of plants, including snap peas, tomatoes, zucchini and green leaf lettuce. The amount and location of the chemical varied by plant.
Half the plants contained no sulfolane, including cucumbers, green onions, summer squash and string beans.