Introduction

TR-16 Guides for the Design of Wastewater Treatment Works is one of the most requested documents produced by the New England Interstate Water Pollution Control Commission. However, there is a need for supplemental information to address the design of sequencing batch reactor (SBR) wastewater treatment facilities. SBRs are becoming popular wastewater treatment options in New England and across the country due to their ability to treat varying flow rates and allow control flexibility. In addition, they have a small footprint and are potentially less expensive to construct and operate.

Recognizing the need to address issues associated with the design and operation of SBR facilities, the Massachusetts Department of Environmental Protection Technical Assistance Section requested that NEIWPCC initiate this guide. NEIWPCC began by developing a 40-question survey and sending it to SBR facility operators in New England and New York. The survey questions covered design parameters, methods to improve overall plant function, type of discharge permit, and plant set-up. Responses received from the survey verified state concerns that there is no general design that is common to SBR facilities.

After the survey results were compiled, the next step in the development of this guide was to visit five SBR facilities in New England. The plants visited were chosen based on their unique characteristics, which included:

  • A newly designed plant
  • A plant at full capacity
  • A plant with a varying wastewater flow rate
  • A larger SBR plant with steady flow
  • A plant receiving seasonally varying flows

At these facilities, operators, superintendents, design engineers, and laboratory technicians were interviewed. These visits provided valuable first-hand information on how these plants were operating and the types of adjustments made to operate at optimal conditions.

The goal of this document is to provide design considerations and operational information to enhance SBR performance. The guide is also an attempt to optimize SBR design and describe specific configurations and processes that will enhance treatment performance.