Debra Darby

Debra Darby

Debra Darby

Speaker | Tetra Tech

Gloucester, MA |

Debra Darby is a client manager with 15 years of organics experience within the solid waste industry. She has garnered a reputation as a leader in her field through her extensive background working with organics and compostable materials and assisting clients through the design and implementation of organics diversion programs and management technologies, including composting and anaerobic digestion systems. In addition to her technical expertise, Ms. Darby is a U.S. Composting Council Certified Composting Professional (CCP) and has 20 years of experience in environmental marketing and has served as a strategic advisor in the public and private sectors.

As the organics lead, Ms. Darby is involved with consulting, compliance, permitting, and developing the operations of organics management systems and works in solid waste planning. Ms. Darby has provided PFAS awareness consultation and education as part of her work in finding cleaner production opportunities through toxics use reduction.

Session Code: B2

Track: Policy

Session Name: National Policy Work; PFAS Updates

Session Time: Wednesday, Jan 25, 1:45 to 3:15 PM

Presentation Title: PFAS in Organics and Materials Management

Presentation Description: The United States Environmental Protection Agency’s (US EPA’s) Waste Management and Food Recovery hierarchies prioritizes source reduction to reduce the amount of waste, with specific attention paid to wasted food.  Source reduction benefits include resource conservation, pollution prevention, and reduction of landfills air space utilization and the associated release of fugitive emissions, including methane – a potent greenhouse gas.

This presentation explores how such emerging contaminants as poly- and perfluoroalkyl substances (PFAS) are becoming a prevalent issue for the solid waste industry. We review how PFAS move through the waste stream and are detected in composting operations, limiting potential end-market uses and exposing composters and end-users to risks and potential environmental liability. Additional risks may arise due to plant uptake of PFAS. These multiple pathways for PFAS to move through the composting operation appears to indicate that composting is not as efficient in sequestering PFAS as are landfills. These issues are of concern as the USEPA implements the PFAS Strategic Roadmap and as an increasing number of states set environmental standards for drinking water, stormwater, and groundwater.

The collection and processing of organics waste streams (yard waste, food materials, biosolids, agricultural wastes, forestry and other compostable materials) and diversion from landfills and incineration can enhance nutrient deficient soils through the land application of compost as a soil amendment. Organics diversion, processing and end-market use can reduce solid waste disposal needs, thereby reducing costs, positively affect landfill leachate generation and greenhouse gas emissions, and ultimately the impacts of food waste reduction on climate change, including through enhanced carbon sequestration from crops grown in compost amended soils.