Todd Williams

Todd Williams

Todd Williams

Speaker | Jacobs Engineering

Sunset Beach, NC |

Mr. Williams has a 42-year career in environmental engineering with experience and specific emphasis in the biosolids and residuals management field. Mr. Williams is a recognized biosolids composting expert having supported the development and operation of over 100 biosolids composting projects. Mr. Williams has delivered over 200 technical presentations specific to residuals management and is a contributing author for several articles and books significant to residuals resource recovery, residuals and municipal solid waste management, composting, and odor control. He is one of the principal authors of Biosolids Composting: Special Publication of the WEF Technical Practice Committee Task Force in 1995.  He is the compost chapter author of the WEF Manual of Practice No. 8 Design of Wastewater Treatment Plants released in 2008. He was one of the principal authors of Environment Canada’s Technical Manual on Municipal Solid Waste Organics Processing released in 2012.

Session Code: A3

Track: Current Research (hosted by CREF)

Session Name: PFAS and Air Emissions

Session Time: 4:15 to 5:45 PM

Presentation Title: Predictability of PFAS Concentrations in Biosolids Composts

Presentation Description: Per- and Poly-Fluoroalkyl Substances (PFAS) are a large family of organic compounds, including more than 4,000 synthetic fluorinated organic chemicals used since the 1940s. Conventional sewage treatment methods do not efficiently remove PFAS which are resilient to degradation and tend to sequester to the treated solids produced and the resultant biosolids.

Jacobs has analyzed data from testing of several biosolids composts produced with non-industrially impacted solids and biosolids to assess the concentration of PFAS compounds in biosolids based compost products.  Samples of input solids, bulking agents and finished composts were analyzed for 24 PFAS compounds utilizing Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS).  Jacobs evaluated the impact of various wastewater treatment processes on concentrations of various PFAS analytes in the resultant solids which was subsequently composted.  PFAS precursor analyte presence and concentrations in the input wwtp solids were compared.  Based on the type of solids treatment used and the input solids PFAS analyte makeup and concentrations, the general impact on output compost concentrations (will PFOS and other PFAS analyte compound concentrations found in input solids result in an increase or decrease in concentration after composting?) may be predicted.
This presentation will provide information regarding the measured concentrations of PFAS in the wwtp solids, bulking agents, and biosolids based compost products.  PFAS precursor analyte presence and concentrations in the input wwtp solids as well as the wastewater treatment process used to generate the compost will be presented. This information will be useful for those considering composting their own wastewater solids or other input wastewater solids at existing or planned composting operations to ensure the lowest feasible PFAS concentrations in compost can be achieved.