Results in from Major Study of Connecticut River Water Quality
Date: February 3, 2005
For more information: contact Adair Mulligan, CRJC Communications Director
Phone: 603-795-2104
Email: contact@crjc.org
Web site: http://www.crjc.org
Charlestown, NH: Results of the most comprehensive river water quality assessment undertaken in New Hampshire were delivered to the Connecticut River Joint Commissions by the New Hampshire Department of Environmental Services in Lebanon on January 31st. Ted Walsh, Coordinator of DES' Volunteer River Assessment Program, presented the results of this major study, undertaken last summer at forty five sampling locations.
Under the microscope was the safety of the Connecticut River for recreation, including swimming, and the conditions for aquatic life. Results indicate a river that is largely in fine condition, especially for dissolved oxygen, although there are several areas of concern for harmful bacteria in some of the most popular canoeing waters in the North Country. DES undertook this ambitious study at the request of the Connecticut River Joint Commissions, who are engaged with their five local river subcommittees in updating the Connecticut River Management Plan. CRJC learned that the state had little or no information about the safety of swimming and other river recreation, or about the quality of aquatic habitat, for over 100 of the 275 miles of river in New Hampshire, and asked for help in filling this knowledge gap.
DES responded with a well-organized and intensive effort during the summer of 2004, sampling five times at each of 45 different locations for the presence of E. coli bacteria, and testing 12 times at each site for dissolved oxygen, temperature, pH, and conductivity. Walsh noted that the study collected 50,000 data points, all of which had to be double checked for accuracy. Because bacteria samples had to be rushed within six hours to the DES lab in Concord, the handling of water collected from Fourth Connecticut Lake at the end of a trail on the Canadian border, for example, required some careful advance planning.
"This effort has been quite a demonstration of choreography, including arranging for quality control, sampling timing, and transport to the lab," observed Sharon Francis, CRJC Executive Director. "CRJC is very grateful for this work."
Swimming safe in most of the river - In most places, and at most times, the river today is clean enough for swimming, but there are still areas and weather conditions where swimming is not advised. Bacteria can reach rivers through poorly functioning septic systems or drainage from areas where animals are concentrated, whether they are moose or cows, especially where they have direct access to a tributary or the river itself. Bacteria can also reach rivers through runoff, such as stormwater washing over a city street where dog walkers do not pick up after their pets, and especially through combined sewer overflows, where runoff from heavy storms can overwhelm a wastewater treatment plant and send untreated sewage into the river. Bacteria counts are likely to be higher in the river after a heavy storm.
On the Connecticut River in 2004, researchers found high bacteria levels in undeveloped parts of the Connecticut Lakes region on a single day, just after a heavy rain. Walsh guesses that these results reflect the flushing of wetlands and other wildlife habitat areas after a long dry spell. However, consistent bacteria problems appeared a few miles downstream, from Bishop Brook to Canaan Dam in Stewartstown and in the Colebrook area. The Commissions are especially concerned at dangerous bacteria levels found in the 19 miles from Bloomfield to Groveton, a particularly beautiful stretch popular with canoeists, kayakers, and swimmers that includes the state-designated "Natural Segment." CRJC will be conferring with both states and investigating possible causes for this unexpected contamination.
Elsewhere, the river is safe for swimming and other recreation, except at times in the 14 miles from the White River to Cornish and Windsor. This stretch of river passed the bacteria tests this year but still may receive untreated sewage during and right after big storms, due to Lebanon's remaining combined sewer overflows.
"For thirty years, wastewater treatment plants have been key to the return of the river's health," notes River Commissioner Henry Swan of Lyme. "We must be certain that, as they age, these plants continue to operate effectively and that the funds are there for maintenance and improvements."
Water quality variable for aquatic life - The river demonstrated its ability to hold enough oxygen for fish and other aquatic life throughout its length. Dissolved oxygen never dropped below the state standard anywhere during the study, even at the very bottom of 100' deep Comerford Reservoir.
Acidity was a different story, with a number of readings in the river's first hundred miles showing pH below the state standards. Walsh pointed out that where the river is smaller, it has less ability to bounce back from the damaging effects of acid rain that regularly falls in its watershed. Surprisingly the opposite result was found at the North Stratford Bridge, where the river's pH threatens aquatic life because it is so high. The cause is unknown, but Walsh guessed that new riprap placed just upstream might have come from a limestone area, and suggested looking into this. Otherwise, pH was within accepted limits.
DES also measured "specific conductance," a test that indicates various kinds of pollution, such as road salt runoff. Researchers found a clear increase in specific conductance of river water as they traveled downstream. For unknown reasons, a few sites also tested high for aluminum, a metal that is leached from soil subjected to acid rain. At one station at the confluence of the Black River in Springfield, aquatic habitat is considered impaired due to the presence of milfoil.
The study's results are generally encouraging news for aquatic life, but they shed light on just four aspects of the underwater world, notes Adair Mulligan, CRJC Communications Director. "Mercury and other metals, automotive oils, and pesticides can lurk in the sediments or the bodies of fish and their food, and never appear in a bucket of river water." An extensive study of Connecticut River sediments by EPA in 2000 found contaminants from parking lot and road runoff at a number of locations as far north as Pittsburg village, and traces of copper from the mines high in the Waits and Ompompanoosuc watersheds of Vermont. At some sites, the contaminants were in levels high enough to threaten aquatic life.
Funds for the water quality study came primarily from DES and the U.S. Environmental Protection Agency. The Connecticut River Joint Commissions contributed to the cost of processing bacteria samples. DES hired four interns to conduct the study, who went through a detailed training program before their work began. Vermont Commissioner of Environmental Conservation Jeffrey Wennberg said he would like to have Vermont's water quality program coordinate with New Hampshire's to help answer questions on the shared river.
CRJC carries information on the safety of various parts of the river for recreation at http://www.crjc.org/swimming.htm and has already updated this page with the new data. Complete results will be posted on the DES web site at http://www.des.state.nh.us/asp/wmb/AU/connrb.asp. CRJC's site carries a direct link to this page.
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