A great place to start research on this topic is on the Civil and Construction Engineering page on the Alumni Library website. Go to "Research by Subject" and drill down to Civil and Construction Engineering. Start your search in any of the core resources listed. You will find many articles from periodicals. There are also many ebooks on the subject via these resources. Try Academic Search Premier - found under General Resources to find articles on waste water management.
Look for the quick links I've provide to these resources in the box below this answer.
Stop the Reference Desk or contact a librarian, if you have further questions.