Bacteria in both surface water and groundwater can adversely impact human health. Different levels of bacterial contamination will generate different degrees of health risks to humans and thus, different use restrictions for the waterbody. Greenwich Cove is currently closed to shellfishing due to high amounts of bacteria. A combination of increased nutrients and algal blooms in a water system can render the system eutrophic. Increased development, malfunctioning septic systems, fertilizer runoff, and sedimentation can increase the risk and rate of eutrophication.
Eutrophication is a natural process that usually takes place over thousands of years.
When human activities accelerate the process it is termed cultural eutrophication. Due to human use in the densely populated Maskerchugg watershed, Greenwich Cove and ponds within the watershed are threatened by eutrophication. Excess nitrogen is a concern in coastal waters, like Greenwich Cove, while excess phosphorus is a concern in freshwater, such as ponds within the Maskerchugg watershed. Nitrogen is the limiting nutrient in a coastal ecosystem, which means the amount of nitrogen in coastal water determines or limits productivity of marine life. These systems can be over-enriched with the addition of nitrates.