46 Geosciences and Community

Friday, 21 March 2025
1:30 PM - 3:30 PM
Alleghany A

EVALUTION OF WATER QUALITY HOT SPOTS AND NITRATE LEVELS IN NAGS HEAD: POTENTIAL LIMKAGES TO WASTEWATER MANAGEMEN.

Paper number: 46-4
Program: Theme Sessions
Time: 2:15 PM – 2:30 PM

Authors

Abstract

The Outer Banks of North Carolina, a series of barrier islands composed primarily of sand, host over 5 million tourists annually. Recent water quality assessments in the region identified critical areas with elevated nitrate (NO₃⁻) levels in both surface and groundwater. These elevated levels are particularly pronounced during the months of May through August, coinciding with heightened human activity and intensive septic tank use. Our investigation confirmed that nitrate levels during this period significantly exceed baseline concentrations, primarily due to contributions from golf course fertilizers, effluent from the local wastewater treatment plant, and widespread septic tank usage in residential areas. Elevated nitrate levels are known to contribute to eutrophication, which depletes oxygen in aquatic ecosystems, and pose risks to public health, particularly when concentrations surpass 10 mg/L. While the acceptable range for marine biodiversity health is between 2 and 5 mg/L, concentrations exceeding this range can cause stress to aquatic life.

In addition to nitrate, our analysis detected a slight increase in ammonium concentrations in areas with elevated nitrate levels, further indicating nutrient enrichment. The study evaluated both seasonal and spatial variations in nitrate concentrations at surface and groundwater monitoring sites. Findings revealed clear correlations between land use patterns and wastewater inputs, underscoring the need for targeted management strategies. This research highlights the urgency of mitigating nitrate pollution to preserve biodiversity and safeguard public health. Based on our findings, we recommend implementing specific community actions, such as optimizing wastewater management systems, promoting the use of alternative fertilizers, and educating residents on sustainable practices. These measures aim to prevent further water quality degradation and ensure the long term health of the Outer Banks' ecosystems and communities.

Geological Society of America Abstracts with Programs. Vol. 57, No. 2

doi: 10.1130/abs/2025SE-408844

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