2013 acuity es case study reduced

µg/L

In-Situ Remediation of Hexavalent Chromium, Antimony and Nickel with Sub-Micron (Nano)-Scale Ferrous Sulfide Slurry

Jim V. Rouse, Richard H. Christensen, PhD LPG,

& Steven R. Irvin (AcuityES, Fishers, IN)

© AcuityES 2013

Company’s Primary Focus: • Environmental Liability Consulting (how to manage liabilities) • Site Investigation – Soil, Groundwater, Air • Remediation of contaminated Sites • Expert Witness Testimony

Company’s Secondary Focus: • Environmental Permitting – Air, Water, Waste • Environmental Compliance

Acuity Environmental Solutions

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Presented At: • International Seminar on Remediation and Redevelopment of

Contaminated Sites, Sao Paulo, Brazil • AEHS West Coast Conference, San Diego, CA • USEPA’s Sustainable Remediation International Conference, Amherst, MA • AWPA National Conference, Ft. Lauderdale, FL & Nashville, TN • Midwest States Environmental Consulting Assoc., Indianapolis, IN • Battelle Conference, Monterey, California

In-Situ Remediation of Hexavalent Chromium, Antimony and Nickel with Nano-Scale Ferrous

Sulfide Slurry

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Case Study In… In Situ Geochemical Reduction

Stabilization (i.e., immobilizing) of metal constituents by chemically reducing the metals of concern to less soluble forms through the manipulation of geochemical factors such as:

• pH • Oxidation potential (Eh or ORP) • Complexation • Sorption • Ion exchange

Resulting in the elimination of metallic contaminants by: • Precipitation • Dissolution • Oxidation • Complexation

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Key Project Considerations Competitor’s Proposals for Project included: • Off-site disposal of hazardous soils • 15 - 20 year pump and treat remedy for groundwater • >$8 Million

Note: original estimates based on >50% smaller source area Our Solution: • In Situ remediation of impacted soils and groundwater • Goal: 2 year total remedy - 1/8th the time - • Cost: $4.5 Million - Nearly 50% below competitor’s bids -

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Chrome Plating

Gone Wild!

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First things first…

Interior Building Decontamination

Segregation of Waste for Disposal

Building Demolition

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Soil Boring & Well Installation

Groundwater Sampling

Soil Sampling

First things first…

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Site Location -- Muncie, IN

Source Areas

GW Impacts

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Site Plan for X-Section Line

Site Conditions First investigation – 2005 AcuityES - 2009

A’

A

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Geologic X-Section

FORMER BASEMENT

SOURCE AREA

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Hydrogeology

Unconfined Aquifer Clay to 15 feet (w/stringers) Sands & fine gravels Static Water at 15’ bgl Saturated thickness 5’ in SE to > 25’ in NW

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Soil Impacts

• Two Adjacent Source Areas • 5,400 cubic yards of impact • Perched water sand stringers

7,900 mg/Kg maximum Cr+6

3,600 mg/Kg Cr+6 at 12’ bgl

State Cleanup Goal - 38 mg/Kg

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Groundwater Impacts

Groundwater COCs Cr+6, Sb, As, and Ni

On-Site Cr+6

800,000 µg/L

9,700,000 µg/L

66,000 sq ft (320 ft long) Plume Offsite Cr+6 at 58,800 µg/L

State Cleanup Goal- 100 µg/L Cr+6

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In Situ Chemical Reduction

•Ferrous Sulfate : FeSO4·7H2O

•Ferrous Sulfide : FeS

•Calcium Polysulfide (CPS) : CaSx

•Sodium Thiosulfate : Na2S2O3

•Sodium Metabisulfite : Na2S2O5

•Sodium Sulfite : Na2SO3

•Zero Valent Iron

BENCH TESTED CHEMICALS REDUCTANTS

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Selected Ferrous Sulfide (FeS)

FeS, Hybrid Form (aka precipitated pyrite)

Liquid suspension of 7% FeS FeS, hybrid - With additional 2% free Sulfide to simulate CaSx Nanoscale: 98% crystals <5 microns Cationic (Iron) 4 H2O + Cr04

2- + 3 Fe2- + 4 OH- 3 Fe(OH)3+ Cr(OH)3 (Solid) Anionic (sulfide) 17 H2O + 8 Cr04

2- + 3 HS- 3 S + 8 Cr(OH)3 (Solid) + 12 OH-

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In Situ Soil Blending

Dual Axis Blender – 15’ Plunge Total Area – 130’ x 110’

GPS Grid Network – 10’ x 10’ (100’ x 70’ to 15’) & Shallow to 5’

Computerized Dosing

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In Situ Soil Blending

Dual Axis Blender

FeS injection/mixing

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In Situ Soil Blending

Thorough Mixing to 15’ BGL

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In Situ Soil Blending Completed in 2 weeks Total FeS = 78,300 gallons Subsequent stabilization with aglime required

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Confirmation Sampling

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Groundwater Injections – FeS

THE NUMBERS

155 Inject Pts

15 ft ROI

6 wks complete

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Groundwater Injections

Difficult Injections

Boulder Fields

6’ caliche

(calcified silt)

Lodgement till

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Groundwater Injections

FeS Injection Totes 35,385 gallons injected

Rotosonic Drilling Top Down Injection – 5ft intervals

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Groundwater Injections

Sensitivity to the Community

Required

Residential Hours

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Preferential Flow Paths 15 – 20’ bgl Sand Unit

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Preferential Flow Paths 20 - 25’ bgl Sand Unit

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Pre-Treatment Cr+6

State Cleanup Goal of

100 µg/L

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FeS Reductant Injection

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1st Q Post-Treatment Cr+6

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2nd Q Post-Treatment Cr+6

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3rd Q Post-Treatment Cr+6

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1st Supplemental Injection

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4th Q Post-Treatment Cr+6

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5th Q Post-Treatment Cr+6

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6th Q Post-Treatment Cr+6

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7th Q Post-Treatment Cr+6

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2nd Supplemental Injection

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8th – 10th Q Post-Treatment Cr+6

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Antimony Treatment Antimony Concentrations: Detected in 25 monitoring wells on-Site up to 30,000 µg/L off-Site up to 4,700 µg/L State Industrial Cleanup level - 41 µg/L State Residential Cleanup Level - 6 µg/L Goal for Antimony: Fixate onto Goethite (FeO(OH)) or Precipitate as stibnite (Sb2S3)

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Pre-Treatment Antimony

State Cleanup Goal of 6 µg/L

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FeS Reductant Injection

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1st Q Post-Treatment Antimony

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2nd Q Post-Treatment Antimony

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3rd Q Post-Treatment Antimony

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1st Supplemental Injection

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4th - 10th Q Post-Treatment Antimony

All results less than method

detection level of

6 µg/L

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Nickel Treatment Nickel Concentrations Detected in 10 wells exceeding cleanup levels off-Site up to 4,100 µg/L on-Site up to 50,000 µg/L State Industrial Cleanup level – 2,000 µg/L State Residential Cleanup Level - 730 µg/L Goal for Nickel: Fixate as: westerveldite ([FeNiCo]As) or pentlandite (FeNiS)

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Pre-Treatment Nickel

State Cleanup Goal of

730 µg/L

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FeS Reductant Injection

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1st Q Post-Treatment Nickel

All results less than method

detection level of

50 µg/L

No subsequent detections

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Arsenic Arsenic – Pre-treatment As detected in 13 wells @ concentrations of 11 µg/L to 360 µg/L 10th Quarter Sampling results: only 2 wells @ 11 & 12 µg/L Goal for Arsenic Fixate as: orpiment (As2S3) or arsenopyrite (FeAsS)

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The Site Today

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ISCR Benefits 1. In situ soil blending eliminated need for off-Site

hazardous waste disposal. (> 10,000 Tons)

2. In situ groundwater geochemical reduction eliminated need for prolonged pump and treat.

3. In situ geochemical reduction reduced time period of remediation from > 15 years to about 2 years.

© AcuityES 2013

CONTACT Richard H. Christensen, PhD, LPG – [email protected]

Steven R. Irvin – [email protected] Jim V. Rouse – [email protected]

317-570-4919

Past Teaming Partners

CDM Mundell & Associates Burns & McDonnell CALIBRE Professional Engineers MWH Global Malcom Pirnie V3 Consultants

www.acuityes.com © AcuityES 2013