Skip to main content

High Biosolids Costs? – Reduce Volume, Starve the Bugs!

The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

or click here to sign up for a free trial


The Springfield Water and Sewer Commission (SWSC) operates a 67 million gallons per day (MGD), regional activated sludge wastewater treatment facility (SRWTF) located on Bondi's Island in Agawam, Massachusetts. The facility began secondary treatment in 1977 and recently upgraded its mechanical, surface aeration system to fine bubble diffusion through a 10.8 million dollar SRF loan.

Over the last few years the SWSC has been developing a more competitive operation at the SRWTF. One major component is cost reduction, especially for Biosolids management which normally represents about 50% of a facility's budget. The new aeration system provides process flexibility to address secondary sludge production issues, which are an important part of the longterm Biosolids management program. Secondary sludge dewaters poorly; is unstable with respect to organics, oxygen demand, and odors; and is expensive to manage.

As part of the short-term Biosolids program, it was decided to examine cost reductions associated with lower waste activated sludge WAS production levels and associated downstream solids handling. Equipment and process modifications were made to the secondary system to allow operation in the traditional extended aeration range of organic and solids loadings, i.e. long solids retention times (SRT). The presentation will discuss the following aspects of the two year field study:

equipment modifications necessary for higher final clarifier solids loading rates (SLR)

changes in microbiology at mixed liquor suspended solids (MLSS) levels of 4000 mg/l and SRT values of fifteen (15) to twenty-five (25) days

operational procedures developed for high flow, wet weather operation

reductions in WAS volumes and associated savings in solids management costs

dewatering improvements resulting from improved primary/secondary sludge ratios

seasonal effects involving foaming and settling

Document Type: Research Article


Publication date: January 1, 2001

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.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial 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