As part of the International Watersheds Initiative through the oversight of the International Joint Commission (IJC), the St. Croix International Waterway Commission conducted routine surface water sampling at stations throughout the St. Croix Watershed with a focus on nutrient levels. Samples were submitted to Environment and Climate Change Canada's (ECCC's) Atlantic Laboratory for Environmental Testing (ALET) and the Quebec Laboratory for Environmental Testing (QLET). Sampling occurred throughout the mainstem of the St. Croix, the headwater lakes, and many major tributaries to represent spatial coverage, and also occurred throughout the seasons to represent temporal variance.