Guidance for Remediation Program Landfills and Open Dumps. MSECA s Quarterly Meeting February 19, 2019

Transcription

1 Guidance for Remediation Program Landfills and Open Dumps MSECA s Quarterly Meeting February 19, 2019

2 Remediation Program Landfills and Open Dumps Guidance Resource files/tech_guidance_landfill _opendump.pdf

3 Overview Waste content, design, and Risk Leachate Groundwater Methane Ancient Landfill Records

4 Waste Content and Design Pre-1969: Burn dumps burned everything, including liquid waste After 1969: Phased out burning of waste Waste decomposed, self-generating leachate and gas Wetter contents than burn dump waste Oversight for liquid waste was less stringent (pre-rcra) Applications for approval landfills 1971 State Board of Health issued landfill guidance

5 Approval Landfills 45 Years After Closing

6 1974 Indiana Stream Pollution Control Board Regulation SPC-18 Effective August 15, 1974 Requires a landfill permit from State Board of Health

7 SPC-18 Landfill Design Groundwater monitoring for some landfills VFC #

8 SPC-18 Landfills 40 Years Later Trees on Cover Ponded Water UST for Landfill Fleet Open Dump on Top of Closed Landfill

9 IAC 2 30 years groundwater monitoring Cover certification Bare Cover Overgrown Cover

10 Groundwater monitoring Cover certification Leachate and methane extraction Plastic liner and cover After 1996, plastic liners and dry entombment eliminated groundwater releases (so far) IAC 10

11 Municipal Solid Waste Conceptual Site Model (CSM) One person s household waste... Waste Characterization... joins everybody s waste

12 Municipal solid waste contains millions of objects and materials. Heterogeneity precludes waste characterization.

13 Drilling Through Waste Drilling through waste is NOT recommended, but if you MUST, then: Submit a HASP Intrinsically safe equipment Safety precautions (explosimeter) Boring log courtesy of Landfill Drilling and Piping, Inc. 3 borings per acre Material encountered Methane gas (if applicable) Elevation of standing leachate (if applicable) Consider sampling leachate Waste temperature (if applicable) Fill borings with hydrated bentonite Dispose of waste cuttings according to applicable rules

14 What if Municipal Solid Waste in the Context of Risk You sampled the liquid at the bottom of your kitchen trash can? AND you analyzed for all 807 Risk constituents? You filled up a lot of bottles

15 The liquid in your trash can will likely not exceed OLQ risk-based Screening Levels. Does that mean you can drink the liquid from your trash can? Risk-based screening levels pertain to chemical exposure, not biological.

16 MSW Leachate Leachate = water that has been in contact with waste Precipitation combines with waste, creating leachate and methane. Waste decomposition creates liquid, which becomes leachate. Waste is deposited with a moisture content, which becomes leachate. Methane gas forces an exit through the cover. Leachate then often follows the same path.

17 MSW Leachate May exceed MCL for nitrate (10 mg/l) May exceed U.S. EPA Advisory for ammonia (30 mg/l)

18 If you Analyzed MSW Leachate for ALL Risk Constituents Would that represent all the possible chemicals that could be in a landfill? All the per- and polyfluoroalkyl substances (PFAS)? All the potential herbicides and pesticides? All the pharmaceuticals and pathogens?

19 MSW Leachate Leachate fingerprint in groundwater: Secondary constituents without MCLs Usually below Screening Levels (except nitrate) Secondary refers to the established Secondary Maximum Contaminant Level (SMCL)

20 Secondary Constituents Ammonia Nitrate Chloride Sulfate Boron, Iron, Manganese, Sodium, Copper Fluoride Field ph

21 Industrial Waste CSM Limited types of waste Usually not a source of pathogens/biologicals (there are exceptions)

22 Industrial Waste Secondary constituents in groundwater represent leachate NOT an infinite universe of additional parameters (unlike MSW)

23 Groundwater Monitoring How long? How often? How many constituents? Closure?

24 How Long? 30 years from the date that the landfill ceased accepting waste, followed by a groundwater closure demonstration. If less than 30 years have passed since waste was accepted, then semi-annual monitoring until 30 years have passed.

25 How Often? IDEM recommends initial sampling before regrading/cover work/redevelopment. 8 semi-annual or quarterly events after receiving cover certification approval.

26 How Many Constituents? A comprehensive list for the first two events A shorter list for subsequent events

27 Solid Waste Groundwater Constituents VOCs SVOCs PCBs Arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver Ammonia, Nitrate, chloride, fluoride, sulfate Boron, Iron, Manganese, Sodium, Copper, Zinc Cyanide, Nickel, Phenols Field ph

28 Coal Ash Groundwater Constituents Chloride, fluoride, and sulfate Arsenic, barium, cadmium, chromium, lead, mercury, and selenium Antimony, boron, beryllium, cobalt, lithium, molybdenum, and thallium Radium 226 and 228 combined Site-specific COCs, as applicable

29 Evaluating Monitoring Results Groundwater affected by landfill leachate. Groundwater that requires a remedy.

30 Identify Leachate Footprint in Groundwater Wells with VOCs (svocs) Wells with metal and secondary constituents that statistically exceed background concentrations Dissolved metal analyses reduce variability

31 Groundwater with Detected VOCs Original map courtesy of IWM Consulting Group

32 Groundwater with Statistically Elevated Ammonia (UCL = 3.41 mg/l) Original map courtesy of IWM Consulting Group

33 Evaluate Whether Groundwater Needs a Remedy 1) Do nitrate or fluoride concentrations exceed the MCL or two times the background concentration, whichever is higher? (329 IAC 2-16) Fluoride has an MCL of 4 mg/l and SMCL of 2 mg/l Nitrate has an MCL of 10 mg/l 2) Do chloride, copper, iron, manganese, sulfate, or zinc concentrations exceed two times the SMCL or two times the background concentration, whichever is higher?

34 Evaluate Whether Groundwater Needs a Remedy 3) Do concentrations of ammonia or sodium exceed two times the background concentration? 4) Is field ph more than 10 or less than 5? 5) Do all detected concentrations indicate a statistically stable or decreasing trend?

35 Vinyl chloride concentrations > GWSL (2 µg/l) Original map courtesy of IWM Consulting Group

36 Ammonia concentrations > 2 X background (2 x background = 2 X UCL = 6.82 mg/l) Original map courtesy of IWM Consulting Group

37 Possible Groundwater Remedies Upgraded cover system Institutional Controls (IC) Consider leachate footprint Lines of Evidence (LOE) Groundwater extraction or containment Groundwater sampling may need to continue during remedy implementation

38 Approved cover certification Groundwater evaluation Extents Stability Exposure pathways 30 years passed since waste was accepted IC Closure Checklist Long-Term Stewardship Plan

39 Waste is not soil. Reports Leachate is not perched groundwater inside the waste. If you wish to compare waste and leachate sampling results to RCG Screening Levels, please consider a separate table for these results.

40 Applies to all decomposing waste MSW Landfill Methane Monitoring Methane Monitoring Program (NPD # Waste-0056) Open Dump with MSW Clean Fill often contains vegetative material Methane gas Ammonia in groundwater

41 Where to Screen for Methane Gas As close as possible to the waste boundary Monitoring wells Well screen should not be submerged Methane monitoring probes Borings VI equipment Entire vadose zone should be screened Field instruments, NOT summa canisters

42 Methane Can migrate in all directions Not dependent on groundwater flow direction Barrier to methane migration: Hillside Borrow area Surface water Methane Migration

43 Methane Contingency Plan Implement a Methane Contingency Program within 60 days after detecting methane gas exceedance: 25% of the lower explosive limit (LEL) (=1.25% methane by volume) in structures or, The LEL (5% methane by volume) at the facility boundary.

44 Ancient Landfill and Open Dump Records Old lists and landfill/dump county maps will be on the internet (soon) Ask IDEM if you cannot find information about a particular landfill or dump in VFC Historical newspapers

45 Ancient Landfill and Open Dump Locations IDEM rest service: LandfillBoundaries/MapServer ArcOnline data Search for LandfillBoundaries with IDEM logo (updates in real-time) IndianaMap Viewer

46 Ancient Landfills Locations

47 Historical Topographic Maps

48 What s Next? New CSM? PFAS Biological Research

49 Successful Redevelopment Future Redevelopment?

50 Questions? Suggestions? Thank You Kim Vedder Office of Land Quality (317)