Book excerpt: This manual describes methods for diagnosing and rectifying activated sludge solids separation problems, which are one of the most common causes of permit violations in activated sludge wastewater treatment plants. The book is written in an easy-to-understand format that will help you resolve real-life problems. Lab techniques, theoretical considerations, design and control methods, and case histories are provided. The clear discussions make it ideal not only for practitioners and consultants, but also for students and professors. Every environmental consulting company, wastewater treatment plant, laboratory, and university should have at least one copy of this hands-on practical manual.