Wastewater surveillance offers a powerful tool for understanding public health outcomes, including the transmission and risk of seasonal and emerging pathogens. As part of a surveillance system, wastewater samples are typically taken from wastewater treatment plants (WWTPs), which inherently exclude households not connected to sewer. Using New York State as a case study, we examined both the equity and inequity inherent in wastewater surveillance systems under different design conditions of WWTPs included in the system. We considered equity in terms of demographics (race, age, poverty) and incorporated the Environmental Justice Index (EJI) and the Social Vulnerability Index (SVI). Beyond evaluating who is included, we introduce two novel measures of equity in infectious disease surveillance: 1) equity of outbreak detection and 2) equity of disease forecasting.