Skip to main content


Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


A previous presentation (Witzgall, et. al., 1998) compared design features and construction costs of new anaerobic digesters at the Los Angeles Hyperion Treatment Plant, the Greater Vancouver Regional District's (GVRD) Annacis Island Wastewater Treatment Plant and the Sacramento Regional Wastewater Treatment Plant (SRWTP). This paper focuses on the comparative performance and operation and maintenance experience of new fixed cover and egg-shaped digesters at these three large primary/secondary wastewater plants following approximately five years of operational experience with the new and upgraded digestion systems. The following information is presented in this paper:

Description of facilities.

Digester operations (feedstock characterization, feed rate, solids loading rate, method of feed and withdrawal).

Digester performance (volatile solids reduction, gas production, and quality, and product pathogen content)

General condition of digesters (grit build-up, scum or foam on surface, corrosion/struvite issues).

Comparisons and conclusions.

Basic design data and process flow diagrams for the three anaerobic digester facilities are discussed. Each of the three plants has different anaerobic digester process features and operational strategies but all three process primary and waste biological sludges. The Hyperion plant has operated a 2-stage mesophilic operation in recent years, but is currently operating an innovative thermophilic Class A digestion process in egg-shaped digesters. The SRWTP has been operating in a mesophilic mode using a blending/storage digester at the end of the process. The GVRD Annacis Island WWTP is operating a unique staged thermophilic process to produce Class A biosolids.

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 These proceedings are not peer reviewed.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