Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

The City of Los Angeles Hyperion Treatment Plant (HTP) completed the conversion of its anaerobic digesters to thermophilic operation in August 2002. Extensive monitoring of the digesters in 2003 indicated stable thermophilic digestion performance: pH of 7.5; 300 mg/L volatile fatty acids (VFA) as acetic acid; VFA to alkalinity ratio of 0.074; 61% volatile solids destruction. Since December 2002, the two-stage continuous-batch process has been certified as Class A under Alternative 3 of the U.S. EPA Part 503 Biosolids Rule. Salmonella sp., viable helminth and enteric viruses were not detected during monthly monitoring of the biosolids at the Truck Loading Facility and the farm for land application. Fecal coliforms were always at least ten times below the Class A limit, and often not detected. Hence, near complete disinfection of the biosolids was achieved, even though the holding time and temperature in the second stage (16 hours at 129.2°F) was well below the time-temperature requirement of Alternative 1. The City of Los Angeles Bureau of Sanitation aims to demonstrate that the process at HTP is equivalent to Processes to Further Pathogens (PFRP equivalency: Alternative 6). Detailed protocols have been developed to demonstrate a 2-log reduction of viable helminth ova and a 3-log reduction of enteric viruses, as required by U.S. EPA for Alternative 6. The experiments entail a laboratory setup with six 20-Liter digesters that will simulate the operation of HTP's second-stage batch digesters. The U.S. EPA Pathogen equivalency Committee gave final approval of the protocols in June 2004, and experiments are expected to start in 2005.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 01 January 2005

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 These proceedings are not peer reviewed.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