PFAS in Landfill Leachate

Viraj deSilva, PhD, PE, BCEE

July 16, 2019 Outline

• PFAS Overview • Chemistry • Sampling • Sources • PFAS Regulations • Treatment Options • PFAS Waste Management • Summary

2 PFAS is Everywhere

Source: Green Science Policy Institute

3 PFAS related Health Effects Studies have shown: • Increased Cancer risk: •Colon •Kidney •Pancreatic • Affect the immune system • Increase cholesterol

4 PFAS Levels measured in Parts per Trillion • PPT = ng/L • 10 -12 • 1 drop of water (0.05 mL) in 2 Olympic size swimming pools

= +

5 PFAS Structure

PFOA kJ/mol of bonds C-F 485 C-H 436 C-C 346 C-Cl 339 Strong C-N 305 PFOS C-F bonds C-Br 285 C-S 272

Sometimes you may hear C8 Chemicals- That’s PFAS.

6 Limited Analytical Methods

EPA 537.1 • SPE LC-MS/MS • 18 Compounds • For drinking water • Holding time: 14 days for extraction • Typical RL: 5 - 25 ppt • ~ $250-350/sample • Approximate 40 laboratories

7 Sampling Considerations

• Sampling objectives • Cross contamination • PPE • Drilling • Sampling Equipment • Shipping • Food packing • Surroundings • QAQC samples Knowledge evolves quickly! • Filtering & Rinsate Need living sampling guidance to staff! Develop sampling and analysis plan! 8 PFAS Transport Pathways

Source: MI DEQ (2018)

9 PFAS in Drinking Water Supplies

From Hu et al. 2016. Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants. ES&T Letters. 2016, 3 (10) pp. 344-350 (open access article).

10 PFAS Sources: Landfills

• Consumer products • Industrial waste • Construction debris • Biosolids from WWTPs • Landfill leachate • a source of PFAS for WWTP • Landfill gas condensate • Ambient air around landfills

11 PFAS Levels (PPT) from Landfill Leachates

PFAS Compounds Minimum Maximum

Michigan Landfills (32) PFOA 16 3,200 PFOS 9 960 USA PFOA 30 5,000 PFOS 3 800 Europe PFOA ND 1,000 PFOS ND 1,500 Australia PFOA 17 7,500 PFOS 13 2,700 China PFOA 281 214,000 MWRA Report, PFOS 1,150 6,020 March, 2019 PFAS Cycle between Landfills and WWTPs

Biomass containing PFAS

Leachate containing PFAS

13 PFAS Regulations • 2016 EPA issued Health Advisory for PFOA and PFOS limit of 70 ppt • 2019 EPA has developed PFAS Action Plan to begin developing a Drinking Water Standard for PFAS • Several States have established PFAS drinking water limits / advisories

14 PFAS Regulations

Water

15 PFAS Treatment

• GAC (Granular Activated Carbon) • IX (Ion Exchange) • RO (Reverse Osmosis) • Concentrate/Waste Management • Evaporation • Deep well injection

16 PFAS Treatment - GAC Adsorption by Pores inside Carbon

17 Typical GAC Process • Influent GAC vessel • “Lead” • Second GAC vessel • “Lag” • Monitoring • Influent • Mid-point • Effluent • Carbon Change Out • Lead to reactivation • Lag to lead • New to lag Diagram courtesy of Calgon Carbon

18 PFAS Treatment: GAC • May require pretreatment • Effectiveness depends on: • pH • Temperature • contact time Oakdale, MN • NOM • Chlorine • Better for long-chain PFAS • No brine and chemicals • GAC may be cost- effective Oscoda, MI

19 PFAS Treatment: Ion Exchange (IX)

PFAS free Treated water PFAS in water

Short Contact Time ~3 mins Incineration or other disposal alternative

Illustrations courtesy of Purolite, Inc.

20 PFAS Treatment: Ion Exchange (IX)

• PFAS are anions - IX can remove • Longer PFAS chains preferred over shorter chains • Resins disposed offsite (incineration)

Army Aviation Centre, Australia

21 PFAS Treatment: Reverse Osmosis (RO)

22 PFAS Treatment: Reverse Osmosis (RO)

Effective for PFAS • High pressure membrane • High energy usage • Reject water disposal • Typically used on lower flow rates • Questions about sustainability Removes a wide range of constituents: • Hardness • Dissolved solids • PFAS • Organics • Ammonia-N

23 PFAS Treatment using RO

New Hanover County, NC PFAS Treatment using RO

RO 1 RO 2 Compound (ng/l) Leachate Permeate Permeate Rejection

Perfluorobutanesulfonic acid (PFBS) 280 <2 <1.9 >99.3%

Perfluorobutanoic acid (PFBA) 1100 5 <1.9 >99.8%

Perfluoroheptanoic acid (PFHpA) 480 <2 <1.9 >99.6%

Perfluorohexanesulfonic acid (PFHxS) 690 <2 <1.9 >99.7%

Perfluorohexanoic acid (PFHxA) 2100 7.8 <1.9 >99.9%

Perfluorooctanesulfonic acid (PFOS) 200 <2 <1.9 >99.1%

Perfluorooctanoic acid (PFOA) 820 2.5 <1.9 >99.8%

Perfluoropentanoic acid (PFPeA) 880 2.7 <1.9 >99.8% Total 6550 18 0 >99.9% Incineration (PFAS Concentrate/Waste) • Thermal Method • High Energy Cost • Air Emissions • Limited Availability • Ash Disposal

26 PFAS Treatment Efficiencies

Treatment Method PFOA PFOS Considerations Requires regeneration or Granular Activated replacement and disposal. 48-90% 89-98% Carbon May release PFAS into the atmosphere Resins need to be Ion Exchange 51-90% 90-99% regenerated or replaced Waste stream contains Reverse Osmosis 90% 93-99% salts, and filtrate require disposal.

27 Evaporation • Thermal Method • Gas requirements • Air Permit • Air Emissions/Odor Issues • Concentrate/Sludge Disposal

28 Deep Well Injection

• Inject far below drinking water sources • Construction is Costly ~$4-6 M/Well • Clogging well during injection may be an issue • 3rd Party accepting 0.18-0.25/Cents Gallon

29 SUMMARY - PFAS Treatment

• Treatment is site specific(pilot testing) GAC  IX • PFAS removal may be Influenced by: • pH, water temperature, contact time, Organics and Chlorine compounds • Polishing Step may be required • Include PFAS in leachate treatment strategies in your future plans.

30 SUMMARY – PFAS Concerns

• WWTPs refuse accepting Landfill Leachates • Landfills cancel contracts receiving Biosolids and PFAS related waste • Land applied Biosolids is a potential source of PFAS impacts Surface water and groundwater

31 PFAS infiltrated our Food Supply

32 QUESTIONS?

PFAS in Landfill Leachates

Viraj deSilva, PhD, PE, BCEE [email protected] (813) 817-0766

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