Here is a collection of links and useful documents:
EPA – Background and Use of Onsite Wastewater Treatment Systems – A brief history on the history of wastewater treatment systems.
”10-State Standards” – Recommended Standards for Wastewater Facilities
Sequencing Batch Reactor Design and Operation Manual - Offers an in-depth overview of the factors in designing and operating an SBR system.
PA DEP F:M Ration Calculator – A calculator to determine the F:M ratio of an activated sludge system.