2013 acuity es_casestudy
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Transcript of 2013 acuity es_casestudy
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
© AcuityES 2013
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
© AcuityES 2013
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
© AcuityES 2013
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 -
© AcuityES 2013
First things
first…
Interior Building Decontamination
Segregation of Waste for Disposal
Building Demolition
© AcuityES 2013
Soil Boring & Well Installation
Groundwater Sampling
Soil Sampling
First things
first…
© AcuityES 2013
Site Plan for X-Section Line
Site Conditions
First investigation – 2005
AcuityES - 2009
A’
A
© AcuityES 2013
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
© AcuityES 2013
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
© AcuityES 2013
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
© AcuityES 2013
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
© AcuityES 2013
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-
© AcuityES 2013
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
© AcuityES 2013
In Situ Soil Blending Completed in 2 weeks
Total FeS = 78,300 gallons
Subsequent stabilization with aglime required
© AcuityES 2013
Groundwater Injections
Difficult
Injections
Boulder Fields
6’ caliche
(calcified silt)
Lodgement till
© AcuityES 2013
Groundwater
Injections
FeS Injection Totes
35,385 gallons injected Rotosonic Drilling
Top Down Injection – 5ft intervals
© AcuityES 2013
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)
© AcuityES 2013
4th - 10th Q Post-Treatment Antimony
All results less
than method
detection level
of
6 µg/L
© AcuityES 2013
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)
© AcuityES 2013
1st Q Post-Treatment Nickel
All results less
than method
detection level
of
50 µg/L
No
subsequent
detections
© AcuityES 2013
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)
© AcuityES 2013
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 Smith Mundell & Associates
Burns & McDonnell CALIBRE
Professional Engineers MWH Global
Malcom Pirnie Carndo MMA
www.acuityes.com
© AcuityES 2013