Water Quality Assessment of the Swamp River - Part I

This is the first in a three-part series that records the proceedings of an important gathering at The Inn at Dover Furnace in Dover on June 4, 2011 that addressed local water quality issues. Over 40 members of the public were in attendance and included a few municipal officials

The Housatonic Valley Association (HVA) sponsored this strategic meeting of Harlem Valley Communities to share in this forum, which included the results of important water studies and related information applicable to our public and private water supplies in the Harlem Valley. The Baseline Water Studies and the costs of the Forum, were funded by Iroquois Gas, Constellation Energy, Berkshire Taconic Foundation, Pawling Corporation, Benjamin Companies, and Cary Institute.

Presentations were made by Dr. Jim Utter of FrOGS, Drs. William Schlesinger, David Strayer and Stuart Findlay of the Cary Institute of Ecosystem Studies, Barbara Kendall of the Hudson Rover Watershed Alliance and Matt Alexander, Mayor of Wappinger’s Falls.

Tonia Shoumatoff, Director of the New York Office of HVA, made the introductions of the panel of distinguished experts. HVA, she explained, is the oldest watershed resource non-profit organization protecting water resources in this area. HVA operates in the several states into which the Housatonic River watershed extends. The New York State office opened in 2004 and HVA’s mission is to achieve a balance between development and resource protection.

Dr. Jim Utter, the chairman of Friends of the Great Swamp (FrOGS) was first on the agenda, with his talk on “The Interdependence of Man and Nature”.

Dr. Utter went on to explain the great size of the Great Swamp, which protects it to some extent, but it sprawls across 3 towns and one village, extending for about 20 miles in length. Because of this length, it has extensive edges, and it is these edges that are so vulnerable to degradation. The southernmost areas tend to be more acidic due to the bed rock conditions, but in the center of the Harlem Valley, conditions are very alkaline and rare plants abound in this environment. The south flow moves in a southerly direction, from Dutcher Avenue, located in the Village of Pawling. At Dutcher, on the western side of the road, the flow moves northerly. This is the divide area. In both directions, the gradient is very slight, which restricts the movement of the waters. It is the sluggishness of the flow that tends to retain the sediments and the pollutants, and transfer these to the groundwaters. Low gradient rivers like the Swamp River (which flows north) create great challenges to flush out the pollutants that they collect.

Dr. Utter spoke at length about the functions and values of the Great Swamp. He stressed the enormous flood stage capacity of the Swamp, and how it traps sediments.

The Great Swamp is the largest red maple swamp in New York. The Burton Brook Watershed, in Dover, is the largest drainage area in the North Flow. Any pollutant that enters a stream can find its way into the Swamp and pollute. Preventing pollutants from entering streams is the easiest way to protect the Swamp and the Groundwater.

FrOGS started a Biologic Stream Monitoring (Analysis of Macro Benthic Invertebrates) Project this past year, at 6 selected sites on the Swamp River and its tributaries. An analysis of certain stream insect larvae, like mayflies and caddis flies can tell us a great deal about the health of the water and its suitability for sustaining living organisms. In Pawling, results at Murrow Park and downstream at the base of Corbin Hill, the two the testing sites in Pawling, received passing grades, but showed some degradation.

Dr. William Schlesinger, President, Cary Institute:

Baseline water samples were taken at representative streams in the Great Swamp, from Spring to Fall during 2010. Five (5) sampling sites were chosen by an advisory committee, consisting of persons from the affected communities who were familiar with the science. The samples were tested for their water chemistry by the lab at Cary Institute and by a contract lab for controls: the results were very similar. This is a hard water system, with a high ph, in the North Flow. Allowing for the expected, due to this chemistry, there were a few surprises, related mostly to the salinity, which will be addressed by the reporter who follows, Dr. Findlay. Overall, the worst pollution, not surprisingly, was found in the Village of Pawling discharges, due to the urban run off, and the large amount of salting, and the reduced flows.

Dr. Schlesinger stated that tracking down the sources of pollution that were discovered should be undertaken to see how they can be addressed.

The reports of the presentations of the other speakers at the forum will follow in further issues of this newspaper.

The detailed results of the baseline water tests, can be obtained from HVA, toniashoumatoff@HVA.org

Contributed by Sibyll Gilbert, a member of the Baseline Studies Advisory Committee, Vice President of The Oblong Land Conservancy, and a member of the Pawling Conservation Advisory Board