in situ thermal treatment– lessons...

22nd Annual NARPM Training Program 1 22nd Annual NARPM Training Program 22nd Annual NARPM Training Program

In Situ Thermal

Treatment– Lessons

Learned

Jim Cummings

Technology Innovation and Field Services Division OSRTI/OSWER/USEPA

2 22nd Annual NARPM Training Program 2 22nd Annual NARPM Training Program 22nd Annual NARPM Training Program

Organization of Presentation

National Perspective on In Situ Thermal Treatment

Lessons Learned


In Situ Thermal Treatment

Electrical Resistance Heating (ERH)

Thermal Conductive Heating (TCH)

Steam Enhanced Extraction (SEE)

• * * * *

• Radio Frequency Heating (RF)

• * * * *

• Self Sustaining Technology for Active Remediation (STAR)

• Gas Thermal Remediation (GTR)


National Perspective

+/- 100 Completed In Situ Thermal projects - domestic and international (# growing)

All vendors report being very busy

May result in few(er) bids in response to RFPs

(Grants, NM dry cleaner project had one bidder)


National Perspective (cont.)

Variety of contaminants Low boiling point solvents Petroleum hydrocarbons High boiling point coal tars and PCB’s

Variety of unconsolidated and consolidated lithologies (Fractured rock, the Last Frontier…)

Variety of conditions/situations Beneath (inhabited) buildings Considerable depth (c. 130’) Below the water table


Attributes

Effective across a wide range of permeabilities

Thermal conductivity varies +/-2 over 106

permeability contrast

Significant shortening of remedial timeframes

In Situ Process Control

Possible beneficial impacts on downgradient contamination

No evidence of (dreaded) ‘rebound’


‘Sampler’ of Completed In Situ Thermal

Projects at NPL and NPL-caliber sites

Visalia, Ca NPL wood treater - SEE

Delisted from NPL

Pemaco, Ca Solvent NPL Site - ERH+

Camelot Cleaners, Fargo ND - ERH

Tight clays

Groveland Wells, Ma - ERH+SEE

Silresim, Ma - ERH

Grants, NM Drycleaner - ERH+


‘Sampler’ – On-

Going/Planned/Prospective NPL caliber

In Situ Thermal Projects

Frontier Fertilizer, Ca (pesticides) - ERH

SRSNE, Conn - TCH

S Muni Water Supply Well site,

Peterborough, NH - ERH+

Carter Carburetor, Mo. – PCB - TCH(?)

Wyckoff, Wa., wood treater - SEE/TCH


ERH Innovations


Angled Electrode Boring – AF Plant

4

Photo Courtesy

URS


Sheet Pile Electrodes


Horizontal Electrodes


Lessons Learned

Actual performance often exceeds cleanup goals

For ERH, need to add water adjacent to electrodes to prevent soil drying and ensure current flow

Media conductivity (e.g., fill) may affect ERH applicability/performance

For SEE, ensure proper closure of existing monitoring wells, etc. in treatment volume prior to heating (NOT hypothetical)


Lessons Learned

Possible to heat discrete zones – horizontally and vertically – reduce treatment volume

Systems can be installed entirely below grade

No conflict w/ facility operations or pedestrian/vehicular traffic

Subsidence rarely a problem But see Fargo, ND dry cleaner as main/only(?) exception

Buried utilities, etc., usually not a problem (but see SRSNE)


Naphthalene Pipe Clogging


Lessons Learned

‘Step 1…’ – Check with local utility regarding power and equipment availability (and KEEP checking)

Especially in areas undergoing development

If there is a lot of contamination in the ground, you will recover it Have the (big) catcher’s mitt ready

Cummings’ rule of remediation – mass = 2-5X estimated


Lessons Learned

Specifying generic ISTT in RFP for CVOC sites will allow both ERH and TCH vendors to bid

‘Hot sampling’ allows discontinuing heating of zones which have met cleanup goals

• Don’t have to wait 12-18 months for site to cool before demobilizing treatment equipment

Concentrate power in zones not cleaning up as quickly

A point about sustainability: Carbon footprint for electrically heating 1 yd3 of contaminated soil

digging and hauling it 65 miles (source: Terratherm)


Resources


EPA-542-R-04-010 –

Mar 04


Resources/Contact Information

Jim Cummings [email protected] 703-603-7197

Eva Davis

[email protected] 580-436-8548

Web-based resources www.cluin.org www. Frtr.gov

In Situ Thermal Treatment of Chlorinated Solvents: Fundamentals and Field Applications – EPA 540-R-04-010 Mar 2004

In Situ Thermal Treatment – Lessons Learned – In preparation

mailto:[email protected]


http://www.cluin.org/


Selective Heating – Memphis Depot

22


Dunn Field,

Memphis Depot,

TN

8 DNAPL

source areas,

CVOCs

49,800 cubic

yards

(Semi-) Surgical

remediation

(Heron et al. 2009)


Aerial View of Memphis Site (During Demob)

367 heaters

68 extraction wells

367 heaters

68 extraction wells

Central Treatment

Equipment


New Kids on the Block


STAR – Self-Sustaining Technology for

Active Remediation

In Situ Combustion Exothermic reaction converting

carbon compounds CO2 + H2O

-Take advantage of BTU content of wastes

Smoldering Flameless

Occurs in porous materials

Temperatures typically 400 – 800 oC

Propagation typically 5 ft/day

Oxygen-limited, thus controllable


HEATER OFF

Heating

Element

AIR

SUPPLY

NAPL

SOIL GRAINS

GROUNDWATER

NAPL Smoldering

27


STAR Application

28


Post-pilot Soil Sampling

Pilot Results – Pitt Consol DuPont

Facility in NJ

29

Before

After

22nd Annual NARPM Training Program 30 22nd Annual NARPM Training Program 22nd Annual NARPM Training Program

Post-pilot Soil Sampling

Average

Concentration

Reduction = 99.72%

Approximately

10,000 # of coal tar

destroyed in situ

Proceeding to full-

scale

STAR Pilot Results

Before STAR TreatmentCombustion Zone

T > 600 oC

2,4-Dimethylphenol 635 1

2-Methylnaphthalene 7,900 10

2-Methylphenol 475 3

4-Methylphenol 595 5

Acenaphthene 3,950 6

Acenaphthylene 295 1

Anthracene 16,700 10

Benzene 36 0

Benzo(a)anthracene 775 2

Benzo(a)pyrene 505 1

Benzo(b)fluoranthene 640 2

Benzo(g,h,i)perylene 255 1

Benzo(k)fluoranthene 240 1

Carbazole 6,750 2

Chrysene 870 3

Dibenzo(a,h)anthracene 60 0

Dibenzofuran 3,850 7

Ethylbenzene 40 0

Fluoranthene 3,750 11

Fluorene 5,150 7

Indeno(1,2,3-cd)pyrene 220 1

Naphthalene 29,500 63

Phenanthrene 10,850 21

Pyrene 2,550 8

Toluene 130 0

Xylenes (total) 225 0

TPH-DRO soil C10-C28* 118,000 243

TPH-GRO soil C6-C10 1,300 7

Compound

Average Concentration (mg/kg)


How it Works

More information at:

www.tpsthermal.com

Closed-loop in-situ

thermal conductive

heating system;

Co-located vapor

extraction and heating

wells;

Treatment

temperatures from

~100°C to >400°C

Small Case Study: ISTT Underneath Building

Contaminants : Petroleum and Heavy Hydrocarbons

Max. Concentration: 15,000 mg/kg Depth: 21 ft bgs

Geology: Sand, silt Volume: 400 m3

Treatment Time: 25 days Target Temperature: 200°C

Challenges: Difficult access in basement; Rapid schedule RE transaction

Remedial Goal: < 300 ppm Remedial Result: Avg. Concentrations < 90 ppm

Both Performance and Time Guarantees Achieved Turnkey ISTD Cost: $168 / cu yd (note: larger areas generally less costly)

Reuse of TCH Wells: Geothermal Heat Storage

34

Water in

Water out

When the commercial building was

redeveloped to residential apartments, the

heating wells were left in place and converted

to geothermal heat storage wells with PTFE

tubing. The system harnesses the constant

temperature of the subsurface to preheat

municipal water prior to the building’s boiler

system. The use of the wells in this manner

also contributes to a more rapid reduction in

in-situ soil temperatures.

Current, Select “Small” Projects (North America)

Chlorinated Solvents: 900 cu yards ISTD (indoor installation) San Francisco 3,100 cu yards ISTD (active facility) Toronto

BTEXs 2,700 cu yards ISTD (former petrol station) Sacramento 3,000 cu yards Ex-Situ Thermal Treatment in Wyoming

PCBs 1,300 cu yards ISTD (to residential goals) in California

Dioxins 1,900 cu yards Ex-Situ Thermal Treatment near Phoenix

Coal Tar 2,500 cu yards ISTD (to residential goals) in Illinois

35

Part II: ISTD of PCBs at a Former Electrical Substation (Initial Pilot Study Results)

36

PCB Pilot Study (Commenced June 2012) Initial Soil Concentrations: Average 5,900 mg/kg (Aroclors 1242, 1260)

Design Remedial Goal: Average samples < 10 mg/kg

Design Duration > 250° C: 72 hours (64 days total heating duration)

CEM: ambient air and emissions monitoring (reason for tent)

Full Scale: project is > 10,000 cubic yards (combination of in situ and ex situ soils); estimated start date January 2013.

PCB Pilot Study (Vadose + Saturated Zones) Three Phases of Thermal Conduction Heating: First: Heating from ambient to boiling point of water (100°C) Second: Boiling, evaporation of groundwater in TTZ (steam stripping and removal of mobile DNAPL) Third: Superheating from 100°C to 250°C (thermal destruction of residual DNAPL)

PCB Pilot Study (Initial Results) Final results will be published in a scientific journal Spring 2013.

Lessons Learned:

1. High temperature hydrolysis effected significant dechlorination of PCBs during remediation and likely acts as a positive polishing effect (more in our article).

2. Significant mass was extracted as NAPL and vapour off-gas. C3 Technology vapor condensation system specified for full scale treatment.

3. ND levels of dioxins and furans measured (low potential for indoor air quality impacts). Levels of dioxins and furans are now being measured in soil and groundwater for pre- vs. post-treatment quantification.


Cool (or Hot) New Idea

Post-Remediation use of ISTT Infrastructure to support Geothermal Heat Pump for HVAC

Considered for Frontier Fertilizer site but big box retailer decamped

Reportedly part of plan post-ISTT at industrial facility in Bordeaux, France


Vendor Contact Information –

Additional Case Studies

Terratherm

- terratherm.com

- Ralph Baker – 978-730-1200

Thermal Remediation Services

thermalrs.com

David Fleming – 425-396-4266

Current Environmental Solutions

Cesiweb.com

Joe Pezzullo – 215-262-7855

McMillan-McGee

Mcmillan-Mcgee.com

Bruce McGee – 403-569-5101


Vendor Contact Information (cont.)

RF Heating Ray Kasevich [email protected] 413-528-4651

STAR Technology Gavin Grant, Geosyntec [email protected] 919-822-2230

Gas Thermal Remediation TPS Tech America Grant Geckeler [email protected] 858-603-1838



in situ thermal treatment– lessons...

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