1. USEPA. USEPA NPDES Permit Writers’ Manual; Report EPA-833-B-96-003;USEPA Office of Water:Washington, DC, 1996.
2. USEPA. Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus; EPA Region 10, Report EPA 910-R-07-002;USEPA:Washington, DC, 2007.
3. WERF Nutrient Challenge – Nutrient Regulations, Treatment Performance, and Sustainability Collide
4. USEPA. Ecoregional Nutrient Criteria Factsheet; EPA-822-F-02-008;USEPA:Washington, DC, 2002.