BANGOR, Maine — More than a dozen people armed with nets waded into Birch Stream on Saturday morning in search of bugs as part of Healthy Streams Healthy Community, a fledgling effort to track the stream’s water quality.
Their work involved lowering nets into the water to capture insects and small crustaceans, said Wendy Warren, the city’s environmental coordinator.
The bugs then were compared with an illustrated chart which divided the creatures into three groups: those that can live only in clean water, those that can tolerate some pollution and those that can survive in almost any quality of water, Warren said.
Among the creatures the group hoped to find during Saturday’s survey — sponsored by the Maine Air National Guard, Bangor Land Trust and the Bangor Clear Streams Project — were caddisflies, mayflies and stoneflies, which are insects that can survive only in clean water and, as such, are considered indicators of good health.
“Certain bugs are sensitive to pollution,” said Mark Whiting, a biologist with the Maine Department of Environmental Protection, who has been working with city staff and volunteers to conduct similar surveys of other Bangor streams and brooks.
“If you find them in a stream, it’s an indication of good water quality,” he said. “Those are what the fishermen use for trout bait so they are indicators of good trout habitat,” which in turn indicates good water quality.
For the assessment, the bugs are cataloged and scored, and the results are an indication of the water quality.
Birch Stream is one of five water bodies in Bangor that the Maine Department of Environmental Protection has deemed impaired or polluted. The others are the Penjajawoc Stream, Shaw Brook near Birch Street, Arctic Brook along Valley Avenue and Pushaw Stream near the Glenburn town line.
Birch Stream first came under scrutiny in 2003, when the DEP began investigating contamination of the stream by a de-icing agent used on military and commercial aircraft at Bangor International Airport.
Some residents of the nearby Griffin Park housing complex complained that the propylene glycol antifreeze used in the de-icer caused headaches and other ailments, although there were no scientific data to support those claims.
The DEP, however, did determine that Birch Stream was heavily polluted, though it also concluded that runoff from the airport and the nearby Maine Air National Guard base was only part of the problem.
The waterway runs underneath a dense commercial district along Union Street, including the Airport Mall.
Since then, the city and airport have been working with the Air Guard and numerous other stakeholders to implement a comprehensive watershed management plan designed to improve water quality in Birch Stream, Warren said.
BIA and the Air Guard recently installed a de-icer collection system, which diverts the fluid from the stream to the city’s wastewater treatment facility. They also have teamed up to clean debris from some sections of the stream.
More recently, three windmills were installed at the airport to power an air compressor that aerates runoff stored in an underground basin.
The effort to improve the condition of Birch Stream and other problem water bodies in Bangor appears to be paying off.
“Just five years ago, it was atrocious,” Whiting said. “There was sewer bacteria covering every surface. It stunk. The neighbors were complaining.
“[Now,] the Penjajawoc is able to support some of these critters, and we’re hoping to see that in Birch Stream, especially now that it’s turned around,” he said. “Really, it’s improved a lot.”
Warren said Saturday’s survey results will provide valuable baseline information to help show if watershed improvement efforts are making a difference.
Though the results were still being cataloged, Warren said the array of life found in the samplings at four sites along the stream yielded mixed results, with two of the sites earning a fair ranking, one site deemed good and one being rated as excellent.