Nitrogen Loading in a Coastal Watershed: The Impact of Residential and Agricultural Land Use

Darcie Ritch
Department of Environmental Studies
Nitrogen loading is an issue facing much of the world, specifically affecting the Northeast United States with coastal over-enrichment, acid rain, and increased ground-level ozone. These conditions can cause human health issues, infrastructure deterioration, and negatively affect a major source of income for northeast coastal communities reliant on abundant fisheries. The watershed located in the town of Wells, Maine is a relatively healthy watershed. Land use, such as residential and agricultural uses, can impact the health of a watershed with increased nitrogen loading. This study sets out to discover if light agricultural and residential use is increasing the nitrogen load in the Maryland river/Branch brook/Little River watershed in Wells Maine. Nitrogen level is a determining factor of contamination due to human land use. The levels within this watershed were measured and compared to land use as well as physical and chemical stream properties, and population density. To determine if there was an increased level of nitrogen, data from developed areas was compared to data from forested areas within a single watershed. It was discovered that in this particular watershed the nitrogen levels in both forested and developed areas were negligible. Our data supports the idea that land use in combination with population density may affect the nitrogen levels of the watershed, while confirming the fact that low populated areas are resilient to nitrogen loading. The results of this study show that the potential for damaging nitrogen to infiltrate the studied watershed may be present; however there is currently no significant contamination. As long as management of the area and education of the residents is maintained with...