Renea Hall, US EPA Region 4

Thomas Speth, PhD PE, US EPA Office of Research and Development

EPA ORD-Region 4 Small Drinking Water Systems Meeting

October 15, 2020

Session 8: An Overview of PFAS within Region 4 and Treatment Options

Region 4 PFAS Overview (Renea Hall)

• PFAS Action Plan Updates• Regional Technical Assistance provided to states

• Case Study: PFAS Characterization Study• EPA PFAS Grants & Funding• Regional System Treatment Updates

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PFAS Action Plan• EPA’s PFAS Action Plan (Feb 2019) aims to accomplish three main

goals: • Demonstrate federal leadership on this critical issue• Provide a multi-media, multi-program, unified approach to addressing

PFAS• Respond to the extensive public input the Agency has received and

encourage continued partnerships with federal agencies, states and communities

• Over the past year and half, EPA has made significant progress under the Action Plan to help states and local communities address PFAS and protect public health

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Drinking Water• In February 2020, EPA issued preliminary determinations to regulate PFOA and PFOS in

drinking water• EPA is also asking for information and data on other PFAS substances, as well as seeking

comment on potential monitoring requirements and regulatory approaches the Agency is considering for PFAS chemicals

• In December 2019, EPA published a new validated method to accurately test for 11 additional PFAS in drinking water bringing the total to 29 PFAS

• Method 533 focuses on “short chain” PFAS, complements EPA Method 537.1

Monitoring • In July 2020, EPA transmitted the Unregulated Contaminant Monitoring Rule 5 (UCMR 5)

proposal to the Office of Management and Budget for interagency review. EPA anticipates proposing nationwide drinking water monitoring for PFAS that uses new methods that can detect PFAS at lower concentrations than previously possible

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PFAS Action Plan: Drinking Water Updates

Cleanup• In December 2019, EPA issued Interim Recommendations for Addressing Groundwater Contaminated

with PFOA and PFOS, which provides guidance for federal cleanup programs (e.g., CERCLA1 and RCRA2) that will also be helpful to states and tribes

• The recommendations provide a starting point for making site specific cleanup decisions and will help protect drinking water resources in communities across the country

• In July 2020, EPA submitted the Interim Guidance on the Destruction and Disposal of PFAS and Materials Containing PFAS to OMB for interagency review. The guidance would:

• Provide information on technologies that may be feasible and appropriate for the destruction or disposal of PFAS and PFAS-containing materials

• Identify ongoing research and development activities related to destruction and disposal technologies, which may inform future guidance

• EPA is working on the proposed rule to designate PFOA and PFOS as hazardous substances under CERCLA. In the absence of the rule, EPA has used its existing authorities to compel cleanups

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PFAS Action Plan: Cleanup

1 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)2 Resource Conservation and Recovery Act (RCRA)

• Removing PFAS from Drinking Water – Researchers are studying how effective various technologies are at removing PFAS from drinking water. This includes studying how well the technologies work and whether they can remove different types of PFAS. Researchers are also studying household water filters so that you have the information you need to protect the water in your own home

• Managing and Disposing of PFAS – Researchers are working hard to help understand how materials that contain PFAS should be safely managed and disposed. EPA researchers are doing tests to figure out the best ways to dispose of PFAS (e.g., incineration, landfilling, composting) and to understand how PFAS at a contaminated industrial site may move into the nearby environment

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PFAS Action Plan: Treatment and Disposal

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Regional Technical Assistance Provided to StatesWater Division – Laboratory Services and Applied Sciences Division

Multimedia Testing: Provided support to various state agencies to sample drinking water, landfill leachate, effluent, downstream surface waters upon request

Sample Collection Training:Provided training to sample collectors on best field techniques to reduce risk of cross-contamination and/or quantify & account for secondary sources

Chattooga River

Coosa River

Weiss Lake

Water Divison-Laboratory Services and Applied Science Division Studies (2008-2020 Summary)

• Point sources & non-point sources

• PFAS Characterization in: • Surface water (current)• Sediment (legacy)

• Lake profile

Case Study – PFAS Characterization Studies (GA EPD1 & ADEM2)

1 GA Environmental Protection Divison (GA EPD)2 AL Department of Environmental Management (DEM)

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PFAS Characterization

• Surface water provides a current snapshot

• Sediments provide a legacy perspective

• Greater diversity

Composition of Detected PFAS - Surface Water Composition of Detected PFAS - Sediment

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Lake Profile

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EPA PFAS Grants and Funding

• In May 2019, EPA awarded $3.9M through two grants for human and ecological exposure• In September 2019, $6M was awarded to gain a better understanding of the environmental risks

posed by PFAS in waste streams• In August 2020, EPA awarded $4.8M in funding to identify potential impacts of PFAS to farms,

ranches and rural communities

• In March 2020, EPA Region 4 awarded $984K in supplemental FY2020 Public Water System Supervision (PWSS) Grant funding to the 8 Southeastern states and one tribal organization for activities:

• Sampling influent and effluent of drinking water systems• Increased state-wide sampling (including systems not sampled UCMR3)• Laboratory equipment purchase• Source delineation (near known areas such as DoD facilities)

NATIONAL

REGIONAL

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EPA Region 4 – System Treatment Updates

System State Treatment Option Timeframe

West Morgan-East Lawrence AL GAC InstallationReverse Osmosis

November 2016TBD

Gadsden AL GAC Installation November 2018

Centre AL GAC Installation November 2020

Stuart FL Ion exchange May 2019

Summerville GA GAC1 Pilot Testing Fall 2020

Cape Fear Public Utility Authority NC GAC Installation May 2022

1 Granular Activated Carbon

PFAS Treatment Updates (Tom Speth)

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EPA’s PFAS Drinking Water ResearchProblem: Utilities lack treatment technology cost data for PFAS removal

Actions: • Gather performance and cost data from available sources (DoD, utilities,

industry, etc.)• Conduct EPA research on performance of treatment technologies including

home treatment systems• Update EPA’s Treatability Database, Treatment Models and Unit Cost Models • Connect EPA’s Treatability Database to EPA’s Unit Cost Models for ease of

operation• Model performance and cost, and then extrapolate to other scenarios• Address treatment impact on corrosion• Evaluate reactivation and incineration of spent granular activated carbon and

incineration of spent ion exchange resins

Impact: Enable utilities to make informed decisions about cost-effective treatment strategies for removing PFAS from drinking water 14

Model Scenarios

• Variable source waters

• Variable PFAS concentrations in source water

• Alternate treatment goals

• Changing production rates

• Document secondary benefits

• Different reactivation/disposal options

Cost Models

To provide tools to accurately predict the performance and cost of treating PFAS in drinking waters

Treatability Database

Suite of Tools

Performance Models

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Cost ModelsTreatability Database

Performance Models

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To provide tools to accurately predict the performance and cost of treating PFAS in drinking waters

Suite of Tools

Interactive literature review database that contains 123 regulated and unregulated contaminants and covers 35 treatment processes commonly employed or known to be effective (thousands of sources assembled on one site)

Currently available:PFOA, PFOS, PFTriA, PFDoA, PFUnA, PFDA, PFNA, PFHpA, PFHxA, PFPeA, PFBA, PFDS, PFHpS, PFHxS, PFBA, PFBS, PFOSA, FtS 8:2, FtS 6:2, N-EtFOSAA, N-MeFOSAA and GenX

Treatment Information

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Access EPA’s Drinking Water Treatability Database.

Publicly Available Drinking Water Treatability Database

Contains treatment information to be used in performance or cost models

Treatability Database

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Agency Landing Page Database Homepage

Access EPA’s Drinking Water Treatability Database.

PFAS Treatment

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PFAS Treatment: Activated Carbon

Matrix of conditions and results from treatment references that can be downloaded into a spreadsheet

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Effective Treatments Percent Removal• Anion Exchange Resin (IEX) 90 to 99 • High Pressure Membranes 93 to 99• Powdered Activated Carbon (PAC) 10 to 97 • Granular Activated Carbon (GAC)

• Extended Run Time 0 to 26 • Designed for PFAS Removal > 89 to > 98

PAC Dose to Achieve50% Removal 16 mg/l90% Removal >50 mg/LDudley et al., 2015

Ineffective Treatments• Conventional Treatment• Low Pressure Membranes• Biological Treatment (including slow sand filtration)• Disinfection • Oxidation • Advanced Oxidation

Drinking Water Treatment for PFOS

- Effective- Effective- Effective for only select applications

- Ineffective - Effective

Drinking Water Cost Models

Access the Drinking Water Treatment Unit Cost Models and Overview of Technology webpageor search EPA WBS. 22

Adsorptive mediaAnion exchangeBiological treatmentCation exchangeGACGreensand filtrationMicrofiltration / ultrafiltrationMulti-stage bubble aeration

Non-treatmentPacked tower aeration

Point of Use (POU)/Point of Entry (POE)*

Reverse Osmosis / NanofiltrationUV disinfection

UV advanced oxidation

*POU/POE temporarily taken off web. Please contact Rajiv Khera

Various Models are Available

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Costs for PFAS Treatment: One GAC Example

Primary Assumptions:• Two vessels in series• 20 min Empty Bed Contact Time

(EBCT) Total• Bed Volumes Fed

1,1-DCA = 5,560 (7.5 min EBCT)Shorter Chain PFCA = 4,700Gen-X = 7,100Shorter Chain PFS = 11,400PFOA = 31,000PFOS = 45,000

• 7% Discount rate• Mid-level cost

Costs can be generated for various sizes, contaminants, and even POU scenarios

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Costs for PFAS Treatment: One IEX Example

Primary Assumptions:• Two vessels in series• 3 min EBCT Total• Bed Volumes Fed:

Shorter Chain PFCA = 3,300Gen-X = 47,600Shorter Chain PFS = 34,125PFOA = 112,500PFOS = 191,100

• 7% Discount rate• Mid-level cost

Costs can be generated for various sizes, contaminants, and even POU scenarios

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Cost Models

To provide tools to accurately predict the performance and cost of treating PFAS in drinking waters

Treatability Database

Performance Model Demonstration

Performance Models

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Environmental Technologies Design Option Tool (ETDOT)

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ETDOT is a series of treatment models, data sets, and parameter estimation tools developed by National Center for Clean Industrial and Treatment Technologies at Michigan Technological University (MTU)• The models were sold as a package for many years• In 2019, EPA signed an agreement with MTU to make this suite of water and air

treatment models available to the public at no cost

Expected interested users:• State primacy personnel interested in evaluating data sets• Water utilities with experience in running models• Consulting engineers• University academicians

Access the ETDOT software, manuals and more at the ETDOT GitHub site.

Available Modeling Tools

Access the Environmental Technologies Design Option Tool (ETDOT) or search EPA ETDOT.

GitHub Site

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The engines are written in FORTRAN with a Visual

Basic front end

Available Modeling Tools

Models available at the GitHub site:• Adsorption Design Software for Windows (AdDesignS) Version 1.0• Advanced Oxidation Process Software (AdOx) Version 1.0.2• Aeration System Analysis Program (ASAP) Version 1.0• Biofilter Design Software Version 1.0.27• Continuous Flow Pore Surface Diffusion Model for Modeling

Powdered Activated Carbon Adsorption Version 1.0• Dye Study Program (DyeStudy) Version 1.0.0• Predictive Software for the Fate of Volatile Organics in Municipal

Wastewater Treatment Plants (FaVOr) Version 1.0.11• Ion Exchange Design Software (IonExDesign) Version 1.0.0• Software to Estimate Physical Properties (StEPP) Version 1.0

29Access the Environmental Technologies Design Option Tool or search EPA ETDOT.

Incorporation of Complex Mechanisms

Flow

Surface diffusion

Film transfer resistance

Pore diffusion Instantaneous

kinetics

With fouling/preloading that reduces capacity and slows down kinetics

Example: GAC Model

The models range from simple to complex 30

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North Carolina Case Study

• Two phases (~125 days & ~225 days)• Five carbons, three anion exchange resins• Two feed waters (raw and post-treatment)• 10- and 20-min Empty Bed Contact Time (EBCT) • Measured a range of PFAS analytes

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Model FittingVary K and 1/n for each Carbon/PFAS combinationSelect the pair that minimizes sum-of-squared difference Example of best fit for PFHpA/Calgon F400

Model Application

Model Full-Scale Treatment from Pilot-Scale Fit• Establish overall treatment performance

• Treatment goal for 6 PFAS• Select influent for PFAS chemicals

• Average experienced at site for a period• Test other values of interest

• Input proposed design of GAC bed• Bed Height• Bed Area or Dimensions• Mass of Carbon• Type of Carbon• Flow Rate(s) of Interest

• Model extended operations• Predict multi-bed operation/bed replacement

frequency under different conditionsExample Output

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Predictions Allow for Design Evaluation

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Multiple CarbonSingle InfluentSingle Flow Rate

Simulated Single Bed

Simulated Multi-Bed Blended Scenario

Single CarbonMultiple InfluentMultiple Flow Rates

Take an effluent profile for a single GAC bed and extrapolate to multi-bed performance

Projected effluent for 8 beds with 2 beds per replacement cycle

19 MGD @ Average Concentrations

Impact of Varying Feed Concentrations

020406080

100120140160180

0 50 100 150 200 250 300

Conc

entr

atio

n (p

pt)

Time (days)

1/2 Initial Conc. (C1-F400) Sum - EBCT20 (C1-F400) 1/2 Initial Conc. (C2-F300)Sum - EBCT20 (C2-F300) 1/2 Initial Conc. (C3-PF-F400) Sum - EBCT20 (C3-PF-F400)1/2 Initial Conc. (C4-PF-AC1230) Sum - EBCT20 (C4-PF-AC1230)

Example: What would happen if the influent concentration changes?• The models can predict breakthrough for various influent concentrations

0

20

40

60

80

100

120

0 5 10 15 20

Spec

ific

Thro

ughp

ut (m

3 /kg

)

EBCT (minutes)

Relationship Between Specific Throughput and EBCT

PFOA

PFOS

PFBS

PFHpA

PFHxA

PFPeA

PFBA

Co = 100 ng/L, Cto = 2 ng/L

Predictions Allow for Design Evaluation

Example: EBCT Choice• Can evaluate EBCT for various PFAS for different conditions

such as influent concentration, effluent goal, etc.

0

50

100

150

200

250

0 5 10 15 20

Spec

ific

Thro

ughp

ut (m

3 /kg

)

EBCT (minutes)

Relationship Between Specific Throughput and EBCT

PFOA

PFOS

PFBS

PFHpA

PFHxA

PFPeA

PFBA

Co = 10 ng/L, Cto = 2 ng/L

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Georgia Case Study

PFAS Levels• 100 ppt PFOA and PFOS influent concentration• 70 ppt PFOA and PFOS treatment goal

Current Infrastructure • Ten total filters• 18 and 24” GAC carbon cap options• Powdered activated carbon (PAC) option

Design/Operation Evaluations

Example: How should the beds be deployed and replaced? The models can evaluate

how many and how often beds need to be brought online or replaced for various bed depths (EBCTs).

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Example: How many beds be deployed and replaced at a time? The models can evaluate how many and how often beds need to be brought online or replaced

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Design/Operation Evaluations

Lead/Lag Operation Evaluations

Example: What advantage can be gained with a lead/lag configuration? The models can predict this increased carbon use rate Note: Lead/lag operations can complicate modeling efforts, especially for those that take

NOM fouling/preloading into effect

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#2#1 #3#2 #4#3

After a certain breakthrough (1st

or 2nd column), a fresh column is added to the back of the train.

After a similar breakthrough point, a fresh column is added to the back of the train again.

In an ideal situation, the first column would be completely saturated to maximize the use of the carbon.

Single use: Time to 70 ppt breakthrough (PFOA & PFOS) 154 days (based on 1st column)

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Lead/Lag: Time to 70 ppt breakthrough (PFOA & PFOS) 236 days (based on 1st column)

Lead/Lag Operation Evaluations

Ultimate Goal

For the treatment/cost models housed at EPA…

• Environmental Technologies Design Option Tool Models or search EPA ETDOT

• Drinking Water Treatability Database or search EPA TDB

• Drinking Water Treatment Cost Models or search EPA WBS

• Provide tools and approaches to accurately predict the performance and cost of treating PFAS in waters

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Contacts

Thomas Speth, PhD, PEAssociate DirectorCenter for Environmental Solutions and Emergency Response US EPA Office of Research and Development Speth.Thomas@epa.gov513-569-7208

Renea HallEnvironmental EngineerWater DivisionUS EPA Region 4Hall.Renea@epa.gov404-562-8397

43The views expressed in this presentation are those of the authors and do not necessarily reflect the views and policies of the US EPA.