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Leachate Treatment at Virginia Landfills. By: Bob Gardner, PE, BCEE Senior Vice President SWANA Old Dominion Conference Wintergreen, VA August 7, 2014. Leachate.
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Leachate Treatment at Virginia Landfills By: Bob Gardner, PE, BCEE Senior Vice President SWANA Old Dominion Conference Wintergreen, VA August 7, 2014
Leachate • Leachate is defined as “liquid that has passed through or emerged from solid waste and may contain soluble, suspended or miscible materials”.
Treatment Goal Undesirable Acceptable Acceptable Undesirable
Unique Issues • Variable quantity
Leachate Generation • Geographical/Climatic factors • Seasonal factors • Operational factors • Cover design
Unique Issues • Variable quantity • Variable quality
Unique Issues • Variable quantity • Variable quality • Treatment & pretreatment constraints
9VAC25-31-770. National pretreatment standards: prohibited discharges • General prohibitions. A user may not introduce into any POTW any pollutant or pollutants which cause pass through, interference or violation of water quality standards.
Federal Requirements • Title 40 of the Code of Federal Regulations, Parts 122, 123, 124, and 403, and chapter I, subchapter N. • Subpart B of 40 CFR Part 445 “RCRA Subtitle D Non-Hazardous Waste Landfill Subcategory
Fundamental Issue Conveyor with food
Fundamental Issue Are there enough of us here to eat all this? Conveyor with food
Fundamental Issue What’s the quality of the food? Conveyor with food
Fundamental Issue Will my Mom let me eat this? Conveyor with food
Fundamental Issue Can I or do I want to eat what’s on the plate passing by me? Conveyor with food
Treatment Requirements • Varies by locality • Varies by time of day • Hydraulic loading • Pollutant loading • Varies by type of treatment plant • Varies by discharge limitations
Unique Issues • Variable quantity • Variable quality • Pretreatment constraints • Geographic constraints • Rural • Urban
Key Components • Raw leachate storage • Treatment (full or pretreatment) • Treated effluent storage • Discharge (onsite or to POTW)
60,000 GPD Onsite Leachate Storage, Treatment & Disposal Facility Hillsborough County, Florida 750,000 gal. storage Treatment Unit Nitrification/Denitrification Office, equipment, and lab building
Leachate Hauling Fill Stand Hillsborough County, Florida
Leachate Storage and Pretreatment Basins Escambia County, Florida
Typical Leachate Characteristics for MSW LFs Source: Ehrig, 1989
Leachate Management Options • Discharge to POTW • Pretreatment • Direct, no pretreatment • Onsite • Evapotranspiration • Land application • Recirculation • Onsite leachate treatment
Overview of Treatment Processes • Biological treatment • Aerated lagoons • Activated sludge • Rotary contactors • Anaerobic digesters • Chemical treatment • Precipitation/coagulation • Ion exchange
Overview of Treatment Processes (Cont.) • Physical Treatment • Screening • Settling • Filtration • Disinfection (Ultraviolet) • Membrane and Evaporation Processes (e.g., Reverse Osmosis)
Key Points to Remember • Highly strategies are site and facility specific. • Treatability studies needed. • System must be robust.
Thank You! Bob Gardner, PE, BCEE Senior Vice President SCS Engineers Norfolk, VA rgardner@scsengineers.com