SOURCES OF NUTRIENT POLLUTION IN FALLS LAKE

This study is designed to determine the source of one of the most important nutrients, nitrogen, in Falls Lake which is the main water supply for Wake County. Elevated nutrient concentration in drinking water supplies is a problem across the United States. High nutrient concentrations are detrimental to both drinking water quality and are harmful to the ecosystem. They can cause excess algae growth which depletes oxygen levels in the water (eutrophication), causing harm or death to marine and plant life, and requires the need for more treatment which degrades drinking water quality.

To determine the source(s), we sampled all the major tributaries of Falls Lake for nitrogen concentration (TKN and Nitrate). Initial results indicate that streams that have discharge from waste water treatment plants (WWTP) have higher nitrogen concentrations than streams that do not. This suggests that reduction of nitrogen discharge from WWTP would be the most effective way of reducing nitrogen load to the lake. However, further analysis would have to be done to confirm this prediction.

The samples were analyzed by the EAD Lab at the Biological, Agricultural, and Engineering Department at NCSU.