In numerous engineering applications, ranging from wastewater treatment and disposal to drinking water treatment or contaminated site investigations, a pivotal question revolves around the underlying aquifer: "Is the aquifer confined or unconfined?" This determination fundamentally shapes an engineer's design direction, influencing decisions on the level of protection against surficial contamination, the feasibility of effluent disposal to the ground, the need for significant groundwater treatment for drinking water purposes, and the potential impact of drawing water from the aquifer on surface water sources. While traditionally, professionals rely on well logs to identify a thick clay unit for this determination, hydrogeologists employ a diverse array of clues and methodologies to make this crucial distinction. This tutorial will delve into a comprehensive range of tips and tricks that provide early indications of whether an aquifer is confined or unconfined, along with insights into the methodologies employed by hydrogeologists to make the final determination. Anticipate an engaging discussion led by an enthusiastic self-described groundwater nerd, with ample opportunities for interactive discourse, particularly focused on northern aquifers.
