1. Leachate Treatment at Virginia Landfills By: Bob Gardner, PE, BCEE Senior Vice President SWANA Old Dominion Conference Wintergreen, VA August 7, 2014

2. Leachate Leachate is defined as “liquid that has passed through or emerged from solid waste and may contain soluble, suspended or miscible materials”. 2

3. Treatment Goal 3 Undesirable Acceptable Undesirable

4. Unique Issues Variable quantity 4

5. 5 Source: NASA

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8. Leachate Generation Geographical/Climatic factors Seasonal factors Operational factors Cover design 8

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10. Unique Issues Variable quantity Variable quality 10

11. Samples from Six VA LFs 11

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15. Unique Issues Variable quantity Variable quality Treatment & pretreatment constraints 15

16. 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. 16

17. Federal Requirements 17 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

18. Fundamental Issue 18 Conveyor with food

19. Fundamental Issue 19 Conveyor with food Are there enough of us here to eat all this?

20. Fundamental Issue 20 Conveyor with food What’s the quality of the food?

21. Fundamental Issue 21 Will my Mom let me eat this? Conveyor with food

22. Fundamental Issue 22 Can I or do I want to eat what’s on the plate passing by me? Conveyor with food

23. Treatment Requirements Varies by locality Varies by time of day – Hydraulic loading – Pollutant loading Varies by type of treatment plant Varies by discharge limitations 23

24. 24 Source: VDEQ for MSW LF’s Only

25. Unique Issues Variable quantity Variable quality Pretreatment constraints Geographic constraints – Rural – Urban 25

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28. Key Components Raw leachate storage Treatment (full or pretreatment) Treated effluent storage Discharge (onsite or to POTW) 28

29. 29 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

30. 30 Leachate Hauling Fill Stand Hillsborough County, Florida

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34. 34 Leachate Storage and Pretreatment Basins Escambia County, Florida

35. Typical Leachate Characteristics for MSW LFs 35 ConstituentConcentration (mg/l) pH4.5 – 9 Alkalinity300 – 11,500 Calcium10 – 2,500 Magnesium40 – 1,150 Chloride100 – 5,000 Sodium50 – 4,000 Sulfate70 – 1,750 Ammonia Nitrogen30 – 3,000 BOD520 – 40,000 COD500 – 60,000 Source: Ehrig, 1989

36. Leachate Management Options Discharge to POTW – Pretreatment – Direct, no pretreatment Onsite – Evapotranspiration – Land application – Recirculation – Onsite leachate treatment 36

37. Overview of Treatment Processes Biological treatment – Aerated lagoons – Activated sludge – Rotary contactors – Anaerobic digesters Chemical treatment – Precipitation/coagulation – Ion exchange 37

38. Overview of Treatment Processes (Cont.) Physical Treatment – Screening – Settling – Filtration Disinfection (Ultraviolet) Membrane and Evaporation Processes (e.g., Reverse Osmosis) 38

39. Key Points to Remember Highly strategies are site and facility specific. Treatability studies needed. System must be robust. 39

40. Thank You! Bob Gardner, PE, BCEE Senior Vice President SCS Engineers Norfolk, VA rgardner@scsengineers.com 40