In this article, we investigate disparate impact analysis as a validation tool for understanding the local effects of writing assessment on diverse groups of students. Using a case study data set from a university that we call Brick City University, we explain how Brick City's writing program undertook a self-study of its placement exam using the disparate impact process followed by the Office for Civil Rights of the US Department of Education. This three-step process includes analyzing placement rates through: (1) a threshold statistical analysis; (2) a contextualized inquiry to determine whether the placement exam meets an important educational objective; and (3) a consideration of less discriminatory assessment alternatives. By employing such a process, Brick City re-conceptualized the role of placement testing and basic writing at the university in a way that was less discriminatory for Brick City's diverse student population.