Skip to main content


Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


The Burlingame Wastewater Treatment Facility is a 5.5 million gallons per day secondary treatment plant owned by the City of Burlingame, CA, and operated by U.S. Filter Operating Services. The secondary treatment facility includes four rectangular aeration basins and four square secondary clarifiers. The air activated sludge plant has historically experienced sludge settleability problems, with a sludge volume index (SVI) averaging around 400 ml/g and occasional peaks exceeding 600 ml/g. The poor sludge settleability has had severe ramifications on plant operations, often mainfesting in solids washout from the secondary clarifiers. Plant staff had tried return activated sludge chlorination as an operational control measure, but found it to be costly and limited in effectiveness. Microscopic examination was performed and Type 021N and Type 1701 filamentous organisms were found to be the major cause of the bulking sludge. While waiting for long-term improvements (anaerobic selector and additional aeration capacity) to be constructed, plant staff implemented a diurnal peak flow equalization control strategy to help eliminate the Type 1701 filamentous organisms and improve sludge settleability. This paper will discuss the effect this control strategy has on SVI, filamentous organisms, and initial settling velocity of the sludge. In addition, the benefit this control strategy has on elimination of clarifier loading is illustrated via the use of a plant-specific State Point Analysis model.

Document Type: Research Article


Publication date: 2003-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more