Sampling Out: Regulatory Avoidance and the Total Coliform Rule

This paper investigates strategic noncompliance with the Total Coliform Rule (TCR) under the U.S. Safe Drinking Water Act. The structure of the TCR provides incentives for some piped drinking water systems to avoid violations by taking additional water quality samples. We estimate the prevalence of this behavior and its potential impact on violations using monthly data for more than 500 Massachusetts water systems, 1993-2003. We find evidence that strategic oversampling is occurring. Water systems most likely to avoid violations by oversampling are most likely to oversample. A significant number of additional violations would have occurred if systems had adhered to legal sampling requirements, rather than oversampling. Our analysis of potential impacts of regulatory avoidance under the current rule suggests that alternative policies for monitoring bacteria in drinking water should be considered.