ROAD SALT RUNOFF AND ACCUMULATION IN FRESHWATER MARSH ECOSYSTEM AND ITS POTENTIAL CONSEQUENCES WITH IRON CORROSION OF SUBMERGED RAILROAD TRACKS

In 1972, the U. S. Department of the Interior designated Reedy Meadow Marsh, also known as Lynnfield Marsh, as a National Natural Landmark. This marsh is located primarily within the town of Lynnfield, Massachusetts. Recently, the towns of Lynnfield and neighboring Wakefield have proposed extending a rail trail through Reedy Meadow. For this project, I examined the monthly variability of dissolved ions commonly linked to road salt, in water collected within the Reedy Meadow Marsh in an attempt to quantify the relative health of the marsh along the proposed rail trail. Road salt application creates potential risks to fresh water marsh ecosystems through runoff and accumulation of dissolved ions. Sodium Chloride (NaCl) and Calcium Chloride (CaCl₂) are commonly used on roadways in Massachusetts with NaCl most abundantly used, as it is a less expensive option. I found the ionic concentrations within the marsh were found to predictably change with local changes in water discharge. An expected increase of dissolved ions was also seen during winter months. I also examined total dissolved iron, another common component of freshwater. The results indicate that the highest levels of dissolved iron were found at a site directly downstream from partially-submerged, abandoned railroad tracks. The other sites with high dissolved iron were found in close proximity to roadways and/or parking areas. Given the focus of this study on water it is difficult to determine the overall health of the marsh. I would recommend extensive examination of the underlying sediments and vegetation.