Annual Nitrogen Load Estimates from Six Nonpoint Sources on Long Island, New York, from 1900 to 2019

This data release contains annual estimates of nitrogen load from six non-point sources across Long Island, New York, over a 120-year period (1900-2019). Estimated loads are gridded at a 500 x 500-foot square resolution and represent the total mass of nitrogen (N), in kilograms (kg), from six major sources—septic systems (SS), residential fertilizer use (RF), agriculture crop fertilizer use (AG), livestock waste (LS), pet waste (PET), and atmospheric deposition (AD) applied to, or just below, the land surface annually. These annual estimates are considered unattenuated as they do not reflect the various mechanisms of nitrogen loss, such as plant uptake, overland runoff, and chemical transformations in the soil and unsaturated zones that likely reduce the amount of nitrogen that reaches the water table.