In the US, the Environmental Protection Agency (EPA) has responded to environmental and health concerns by strengthening regulation of CAFOs under the Clean Water Act (CWA). Some states have imposed their own regulations as well. Due to repeated overflows and resultant health concerns, North Carolina banned the construction of new anaerobic lagoons in 1999. There has also been a significant push for the research, development and implementation of environmentally sound technologies (ESTs) which would allow for safer containment and recycling of CAFO waste.