Axiomatic Design provides a set of axioms and corollaries to help make system design decisions. In this paper, the independence axiom is applied to evaluate alternate low pressure air (LPA) distribution system designs to serve the aeration basins of a wastewater treatment plant. The airflow to each air zone is defined as a functional requirement (FR) in the functional domain. A design parameter (DP) in the physical domain is selected to achieve each FR. The DPs include the LPA motor operated valve (MOV) damper positions and a process air blower inlet guide vane (IGV) position. Three design alternatives are developed and evaluated with the respect to the independence axiom. Each subsequent alternative attempts to reduce the amount of functional coupling. Reduced functional coupling in an LPA system results in a more stable treatment process and greater system longevity through reduced component wear.