Nitrate has been a ground water quality threat for many decades. Aquifer nitrate contamination continues to increase worldwide. This session provides an overview of activities related to monitoring, assessing, and regulating nitrate contamination. Presentations address aquifer vulnerability assessments as decision-making tools; occurrence of nitrates in domestic wells; fingerprinting nitrate/forensics to distinguish various sources; natural nitrate occurrence; assessment of long-term trends in ground water nitrate; denitrification processes, quantification/assessment/mapping of denitrifying zones in aquifers; nitrate and cocontamination with salts and pathogens; regulatory control of nitrate in ground water; remediation of nitrate in ground water; best/beneficial management practices implementation; monitoring of farm nitrogen impacts for compliance purposes or for source management purposes; animal and agricultural waste lagoon liners leaching from lagoons; and computer modeling of transport and fate/geochemistry of nitrogen at various scales (plot/field/farm/regional).