Papers and Reports

This paper looks at the growing trend towards biosolids heat drying at small to medium size wastewater plants. Biosolids heat drying is gaining in popularity in North America due to its inherent ability to produce a Class A product thereby reducing the environmental and political risks, as well as its potential to reduce biosolids disposal costs. This paper addresses two key factors in selecting and designing a biosolids drying system–economics and safety. Case studies are presented for four plants ranging in average annual wastewater flow from 0.33 to 18 million gallons per day (mgd). A detailed economic analysis is presented for the Lakehaven Utility District in Federal Way WA.