1. The Environmental Trading Network, Water Quality Trading: State Trading Programs. http://www.envtn.org/water-quality-trading/state-programs. Accessed 02 March, 2019
2. The Environmental Trading Network, Water Quality Trading: Trading Programs Outside the United States. http://www.envtn.org/water-quality-trading/programs-outside-us. Accessed 02 March, 2019
3. 25 Pa. Code §96.8. Use of offsets and tradable credits from pollution reduction activities in the Chesapeake Bay watershed
4. 33 U.S.C. §1342. National pollutant discharge elimination system
5. Anastasiadis S, Kerr S, Nauleau M-L, Cox T, Rutherford K (2014) Does complex hydrology require complex water quality policy? Aust J Agric Resource Econ 58(1):130–145