U.S. Water News Online
AMHERST, Mass. --Over the course of a year, an average of 136 million gallons of water a day flows from the Quabbin Reservoir to 49 Massachusetts communities. That water is known for its pristine quality. And environmental engineers from the University of Massachusetts (UMass) are helping to keep it that way, studying whether seagulls who roost on the water in late autumn and early winter affect the water's quality.
As the weather gets colder, "seagulls eat and congregate in landfills, then roost just before dusk," explained John Tobiason, of the university's civil and environmental engineering department. The problem is where the gulls roost: on the Quabbin, where they may deposit contaminants. "They like open water," said Tobiason, "and the Quabbin has lots of it."
The two-and-a-half million people in the eastern part of the state who rely on Quabbin for drinking water are not affected by potential contaminants from the seagulls. Their water comes from another section of the reservoir.
But three local communities do receive water withdrawn from the southwestern basin of the reservoir: Chicopee, Wilbraham, and South Hadley. Tobiason heads a research team from the university which is studying the impact wildlife has on the cleanliness of the water supplied to those municipalities, via the Chicopee Valley Aqueduct.
Researchers say there is no immediate threat to human health. The water is generally so clean that it needs only a small amount of chlorine to disinfect it. Typically, it has a fecal coliform level between zero and one per 100 milliliters of water. The U.S. Environmental Protection Agency requires filtration of reservoir water if fecal coliforms exceed 20 parts per 100 milliliters in greater than 10 percent of the samples measured.
Strict guidelines on recreational activities, combined with the watershed's impressive size -- 38 square miles of water surrounded by nearly 150 square miles of woodlands -- help ensure a clean drinking water supply. Local water officials said water samples are taken and regularly tested to assure that state and federal health standards are met.
But waterfowl contaminants may slightly elevate coliform levels in southern areas of the reservoir during this time of year, say researchers, and this is a concern because very high levels of coliform and fecal coliform -- bacteria that originate with birds and mammals -- can be associated with organisms that cause illness in humans. Sharon Long, a microbial ecology specialist, is studying the amount and types of coliforms in the reservoir during the fall season.
UMass researchers are undertaking a complex study of water flow and how coliform bacteria travel through the Quabbin by dividing the reservoir into segments, and creating a computer model of the water body. The team is using floats and nontoxic dye to determine the reservoir's currents. The aim is to try to understand the water's surface level and flow, and predict how the bacteria will travel.
The researchers are working in conjunction with the Massachusetts Water Resources Authority (MWRA), which distributes the water, and the Metropolitan District Commission (MDC), which manages the watershed. The information gained from the study will help the MDC in making the best possible decisions regarding the watershed's management.
Meanwhile, UMass researchers are pondering these questions: "How much work should be done to scare off the gulls? How many gulls are too many, and how far away should they be from the intake?"
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