THE AFFECTS OF ROAD SALT ON TWO SMALL NEW HAMPSHIRE LAKES

Northern New England states use deicing agents on the roadways during winter months to keep the roads clear and safe for travel. Sodium Chloride (NaCl), the most commonly used deicer in New Hampshire, may have environmental ramifications to surface and ground water near treated roads. Two lakes are investigated in this study. Saco Lake is located just north of Crawford Notch in the White Mountain National Forest and is a small roadside pond along NH Route 302. Saco Lake is seasonally impacted by road salt runoff and is the headwaters for the Saco River watershed. Ammonoosuc Lake is located across Highway 302, 130 m west of Saco Lake. Ammonoosuc Lake, a headwater pond of the Connecticut River watershed has an elevation greater than Highway 302, and is therefore not affected by the road salt contaminated snow melt and serves as a control during the snow melt season.

Previous work by Dennehy (2008) showed conductivity levels in Saco Lake to be more than twenty times that of Ammonoosuc Lake during the snow melt season. Preliminary data collected in fall 2009 has consistently shown a greater conductivity level in Ammonoosuc Lake over Saco Lake up and down the water column. With the exception of during the snow melt season, the last three years have shown conductivity levels to be greater in Ammonoosuc Lake than Saco Lake.

This study is a part of a five year long project funded by the White Mountain National Forest. Ammonoosuc and Saco Lake shall be monitored through the 2010 snow melt season for road salt induced ramifications. This study shall also investigate the influence of the bedrock and surficial geology on which these two lakes lie as an explanation for the greater conductivity levels in Ammonoosuc Lake during the non-snow melt season.