We propose to develop a novel peptide tracer to be used for detecting and quantifying the relative contributions of the septic systems in lake communities to the nutrient loads to the lakes that lead to HAB and help prioritize the community efforts to improve nutrient treatments in those septic systems. We plan to apply this developed tracer for assessing the relative nutrient contributions of the septic systems that drains to the Cupsaw Lake, which is the direct intake to the Wanaque Reservoir, the drinking water source for nearly 3 million residents in North Jersey.