! Nitrogen (N) and phosphorus (P) concentrations at the Cornell University Ruminant Center (CURC) in Harford, NY, have been measured in ground and surface waters periodically since 1974. Here, I evaluate the effect of agriculture on groundwater from a farm located within two small catchments with two markedly different land use distributions. Groundwater nitrate (NO3-) concentrations are significantly higher in the more intensively farmed south catchment. There, mean monthly groundwater concentrations of NO3- have increased from 0.23 ± 12 mML-1 in 1974 to 0.94 ± 23 mM-L-1 in 2016. Groundwater NO3- concentrations in the smaller, less intensively farmed north increased from 0.27 ± 0.8 mM-L-1 in 1974 to 0.72 ± 0.12 mM--1 in 2016. Total Dissolved P was also measured, but has not significantly increased in either catchment over time, indicating that high soil sorption capacity continues to ensure applied P is retained in soils.