NATO/CCMS
Third International Conference
Demonstration of Remedial Action Technologies
for Contaminated Land and Groundwater
APPENDICES 	
&EPA
iHiviRfi) w
Montreal, Canada
6-9 November 1989

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Regional Center for Environmental Information
US EPA Region III
1650 Arch St.
Philadelphia, PA 19103
	J
This report 1s not an official document of the
NATO/CCMS Pilot Study program.

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NATO/CCMS
Third International Conference
Demonstration of Remedial Action Technologies
for Contaminated Land and Groundwater
APPENDICES
IfWfRfil	()
Montreal, Canada
6-9 November 1989

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Abstract
In November 1986, the NATO Committee on Challenges of Modern Society (CCMS)
formally adopted a United States proposal for a five-year pilot study to
demonstrate technologies for cleaning up contaminated land and groundwater.
The participating NATO countries are Canada, Denmark, Federal Republic of
Germany, France, the Netherlands, and the United States. Japan 1s also
participating. Norway and the United Kingdom are observer countries. The
Pilot Study Director 1s from the United States; the co-directors are from
the Federal Republic of Germany and the Netherlands.
The Third International Conference was held 1n Montreal, Canada, on 6-9
November 1989. Reports on 12 projects (final and Interim) were prepared,
Including the following types of treatment: pump and treat (2 projects),
microbial treatment (3 projects), thermal (2 projects), solidification/
stabilization (1 project), electroklnetlc (1 project), chemical (1
project), and soil extraction (2 projects). The discussions at this
meeting also included recent developments in the regulations and remedial
technology research and development 1n the attending countries. The next
meeting will be a workshop held 1n Oslo, Norway on 13-15 March 1990.

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Table of Contents
Page
ABSTRACT			 J1
APPENDICES
A List of Attendees at NATO/CCMS Third International
Meeting, Montreal, Canada, 6-9 November 1989	 A-l
B Presentations by NATO/CCMS Guest Speakers
Alain Jollceur (Canada) - Groundwater management 1n
Canada	 B-l
Art Stelzlg and Brett Ibbotson (Canada) - Decom-
missioning and clean-up criteria of Industrial
facilities in Canada; The development of soil
clean-up criteria 1n Canada; and AERIS, an expert
computerized system to aid 1n the establishment of
clean-up guidelines	 B-31
Rene Kleijntjens (The Netherlands) - Technological
and kinetlcal aspects of microbial soil decon-
tamination in slurry reactors on mine-plant scale	 B-81
Colin Mayfield (Canada) - Anaerobic degradation	 B-89
C Papers by Continuing NATO/CCMS Fellows
Reset Apak (Turkey) - Heavy metal removal from
contaminated groundwater by the use of metallurgical
solid wastes and unconventional materials	 C-l
Robert Bell (United Kingdom) - Plant uptake of non-
toxic organic chemicals from soils	 C-27
Thomas Dahl (United States) - Environmental problems
at the Strlngfellow Site			C-55
James Gossett (United States) - B1odegradat1on of
dlchloromethane under methanogenlc conditions	 C-87
Robert Olfenbuttel (United States) - The status of
the NATO/CCMS pilot study report	 C-105
Wayne Pettyjohn (United States) - Hydrogeology of
f1ne-gra1ned materials	 C-115
Sjef Staps (The Netherlands) - Evaluation of research
projects concerning biological in-situ treatment of
contaminated soil and groundwater	 C-143
i i i

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Table of Contents
(Continued)
Aysen Turkman (Turkey) - Cyanide removal from
contaminated groundwater			 C-171
Peter Werner (Federal Republic of Germany) - Aspects
of in-situ removal of hydrocarbons from contaminated
sites by biodegradation	 C-189
D Final Paper on a Project Presented at an Earlier
Conference
Soil Treatment by Extraction - High-pressure soil
washing (scrap metal and copper refinery; Berlin,
Federal Republic of Germany)	 D-l
iv

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APPENDIX A
NATO/CCMS Pilot Study
Demonstration of Remedial Action Technologies
for Contaminated Land and Groundwater
LIST OF PARTICIPANTS
Third International Conference
Montreal
Canada
6-9 November 1989

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PILOT STUDY PARTICIPANTS
CANADA
Don Bartkiw
Assistant Director
Ontario Ministry of the Environment
Waste Management Branch
40 St. Clair Avenue, W.
Toronto, Ontario
Canada M4V 1P5
OFFICE TEL. 416-323-51-51
FAX	 416-963-3109
Robert Booth
Senior Process Development Engineer
Environment Canada
Wastewater Technology Centre
P.O. Box 5050
867 Lakeshore Road
Burlington, Ontario
Canada L7R 4A6
OFFICE TEL. 416-336-4689
HOME TEL... 519-623-8139
FAX	 416-336-4765
Maria Dober
Waste Treatment Coordinator
Environment Canada
Contaminants and Assessments Branch
5th Floor, Queens Square
45 Alderney Drive
Dartmouth, Nova Scotia
Canada B2Y 2N6
OFFICE TEL. 902-426-6141
HOME TEL... 902-477-7401
TELEX	 019-21565
FAX	 902-426-2690
Ruth Drouin
Ingenieur Charge de Projets
Ministrie de L'Environnement du Quebec
3900 Rue Marly
Ste-Foy, Quebec
Canada G1X 4E4
OFFICE TEL. 418-644-3389
HOME TEL... 418-832-5547
FAX	 418-646-0001
A-2

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Tony Fernandes
Scientific Officer
Alberta Environment
Industrial Branch, Wastes and
Chemicals Division
A820-106 St.
5th Floor
Edmonton, Alberta
Canada 15K 2J6
OFFICE TEL. 403-427-5847
HOME TEL... 403-435-7620
FAX	 403-422-5120
Bernard Gaboury
Ingenieur Charge de Projets
Ministrie de L'Environnement du Quebec
3900 Rue Marly
Ste-Foy, Quebec
Canada G1X 4E4
OFFICE TEL. 418-644-3403
HOME TEL... 418-871-5030
FAX	 418-646-0001
Pierre J. Gelinas
Professor
Department of Geology
University Laval
University City, Quebec
Canada G1K 7P4
OFFICE TEL. 418-656-2411
HOME TEL... 418-832-0123
TELEX	 051-31621
FAX	 418-656-2603
Marc Halvey
Process Development Engineer
Wastewater Technology Centre
P.O. Box 5050
867 Lakeshore Road
Burlington, Ontario
Canada L7R 4A6
OFFICE TEL. 416- 336-4698
HOME TEL... 416- 639-7364
FAX	 416- 336-4765

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J. Peter Jones
Full Professor
Department of Chemical Engineering
Universite de Sherbrooke
2500 Boulevard Universite
Sherbrooke, Quebec
Canada J1K 2R1
OFFICE TEL. 819-821-7165
HOME TEL... 819-563-9980
FAX	 819-821-7855
Jean-Paul Lanctot
Project Manager
SNC Inc.
2 Place Felix-Martin
Montreal, Quebec
Canada H2Z 1Z3
OFFICE TEL. 514-866-1000
HOME TEL... 514-486-8132
FAX	 514-866-0795
Suzanne Lesage
Senior Groundwater Chemist
National Water Research Institute
Environment Canada
RRB, CCIW
Burlington, Ontario
Canada L7R 4A6
OFFICE TEL. 416-336-4587
HOME TEL... 416-560-7396
FAX	 416-336-4989
Richard Martel
Hydrogeologist
Environment Quebec
Groundwater Branch
2360 Chemin Sainte-Foy
Sainte-Foy, Quebec
Canada G1V 4H2
OFFICE TEL. 418-646-7688
HOME TEL... 418-688-0819
FAX	 418- 643-9591
Andre Pelletier
Project Engineer
Environment Canada
Conservation and Protection
1179 de Bleury Street
Montreal, Quebec
Canada H3B 3H9
OFFICE TEL. 514-283-7309
HOME TEL... 514-524-7951
FAX	 514-283-4423

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Charlie Riggs
Environmental Engineer
Departement of Environment
Government of Newfoundland, Canada
Department of Environment and Lands
Industrial Environmental Engineering Division
P.O. Box 8700
St. John1s, Newfoundland
Canada A1B 4J6
OFFICE TEL. 709- 576-6771
HOME TEL... 709- 579-6113
FAX	 709- 576-1930
James W. Schmidt, P. Eng.
Head, Physical/Chemical Processes Section
Wastewater Technology Centre
Environment Canada
P.O. Box 5050
Burlington, Ontario
Canada L7R 4A6
OFFICE TEL. 416-336-4541
HOME TEL... 416-827-2139
TELEX	 0618296
FAX	 416-336-4765
Pierre Sylvestre
Graduate Student
Centre St. Laurent
Environment Canada
105 McGill Street
8th Floor
Montreal, Quebec
Canada H2Y 2E7
OFFICE TEL. 514-283-4252
HOME TEL... 514-333-0532
DENMARK
Neel Stroback
Msc. Engineering
National Agency of Environmental Protection
Waste Division
Strandgade 29
1401 Copenhagen K
Denmark
OFFICE TEL. 31-57-83-10
HOME TEL... 31-31-41-47
A-5

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r
DENMARK
Dr. Steen Vedby
Ph.D. Geology
Technical University of Copenhagen
Dept. of Environmental Engineering (LtH)
Building 115
2800 Lyngby
Denmark
OFFICE TEL. 45 2 884200 x 5092
45 2 884444
HOME TEL... 45 2 872258
TELEX	 37529 DTH-DIA
FAX	 02 882239
Troels Wenzel
Hojgaard & Schultz a/s
Jaegersborg 4
DK 2920 Charlottenlund
Denmark
OFFICE TEL. 01-67-20-00
TELEX	 21288 hands dk
FAX	 01-56-56-28
FEDERAL REPUBLIC OF GERMANY
Dr. Wolfgang Sondermann, Dr.-Ing.
GKN Keller GmbH
Spezialtiefbau
Kaiserleistrasse 44
D-6050 Offenbach 12
Federal Republic of Germany
OFFICE TEL. 069-8051-213
HOME TEL... 060-7431-815
TELEX	 4-152-616
FAX	 069-8051-244
Klaus Stief, Dipl.-Ing.
NATO/CCMS Pilot Study Co-Director
Umweltbundesamt
Bismarckplatz 1
D-1000 Berlin 33
Federal Republic of Germany
OFFICE TEL. 030-8903-2253
HOME TEL... 030-721 1576
TELEX	 183 756
FAX	 030 89 03 22 85
A-6

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FRANCE
Rene Goubier
Head of Hazardous Sites Team
Agence Nationale Pour la Recuperation et
1'Elimination des Dechets (ANRED)
2 Square la Fayette
BP 406
49004 Angers Cedex
France
OFFICE TEL. 41-87-29-24
HOME TEL... 41-73-22-32
TELEX	 721325 F
FAX	 41872350
NORWAY
Morten Helle
Senior Executive Officer
Hazardous Waste Section
Statens Forurensningstilsyn
P.O. Box 8100 Dep
N-0032 OSLO 1
Norway
OFFICE TEL. 472-678-120
HOME TEL... 472-490-656
TELEX	 76684 SFTN
THE NETHERLANDS
Merten Hinsenveld, Ir.
University of Cincinnati
Department of Civil and Environmental Engineering
741 Baldwin Hall (ML #71)
Cincinnati, OH 45221-0071
United States
FAX	 513-556-2599
Dr. Reinout Lageman
Hydrogeophys i c i s t/Hydrogeologist
Geokinetics
Poortweg 4
2612 PA Delft
The Netherlands
OFFICE TEL. 31-15 61 06 37
HOME TEL... 31-15-61-48-33
FAX	 31-15-62-20-56
A-7

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Esther Soczo, M.SC.
NATO/CCMS Pilot Study Co-Director
Rijksinstituut voor volksgezondheid
en milieuhygiene (RIVM)
Laboratory for Waste Material and Emissions (LAE)
Antonie Van Leeuwenhoeklaan 9
Postbus I, 3720 BA Bilthoven
The Netherlands
OFFICE TEL. 31-30-74-27-75
31-30-74-30-65
HOME TEL... 31-33-75-71-23
TELEX	 47215 RIVM NL
FAX	 31-30-742971
UNITED KINGDOM
Dr. R. Paul Bardos
Warren Spring Laboratory
Department of Trade and Industry
Gunnels Wood Road
Stevenage SGI 2BX
United Kingdom
OFFICE TEL. 44-438-74 11 22
HOME TEL... 44-438-85 606
TELEX	 82250 WSLDOIG
FAX	 44-438-36 08 58
UNITED STATES
Edward Burk, Jr.
On Scene Coordinator
U.S. Environmental Protection Agency
Response Section I
9311 Groh Road
Grosse lie, MI 48138
United States
OFFICE TEL. 313-675-3146
FAX	 313-675-3677
Douglas Downey
Chief, Environmental Engineering Branch
U.S. Air Force
Air Force Engineering and Services Laboratory
HQ AFESC/RDVW
Building 1117
Tyndall Air Force Base
Panama City, FL 32403
United States
OFFICE TEL. 904-283-2942
HOME TEL... 904-871-5775
TELEX	 904-283-6499
A-8

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Margaret Guerriero
Remedial Project Manager
U.S. Environmental Protection Agency
230 S. Dearborn
5HS-11
Chicago, IL 60604
United States
OFFICE TEL. 312-886-0399
HOME TEL... 312-775-2910
FAX	 312-886-4071
Herbert King
Environmental Engineer
U.S. Environmental Protection Agency
26 Federal Plaza
Room 747
New York, NY 10278
United States
OFFICE TEL. 212-264-1129
HOME TEL... 914-666-3511
FAX	 212-264-8100
Walter W. Kovalick, Jr., Ph.D.
Deputy Director, Office of Emergency
and Remedial Response
U.S. Environmental Protection Agency
401 M Street, S.W. (OS-200)
Washington, DC 20460
United States
OFFICE TEL. 202-382-2180
HOME TEL... 703-323-6078
TELEX	 892 758 EPA WSH
FAX	 202-382-7884/7883
Norma Lewis
Environmental Scientist
Superfund Technology Demonstration Division
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
26 W. Martin Luther King Drive
Cincinnati, OH 45268
United States
OFFICE TEL. 513-569-7665
HOME TEL... 513-831-9029
FAX	 513-569-7274
A-9

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Dr. Robert F. Olfenbuttel
Director, Waste Minimization and Treatment
Battelle, Columbus Division
505 King Avenue
Columbus, Ohio 43201
United States
OFFICE TEL. 614-424-4827
HOME TEL... 614-481 3172
TELEX	 24-5454 BATTELLE COL
FAX	 614-424-3321
Mr. Thomas H. Pheiffer
Environmental Scientist
U.S. Environmental Protection Agency
OS110
4th and M. Streets, S.W.
Washington, , DC 20460
United States
OFFICE TEL. 202-382-4477
HOME TEL... 301-263-5741
Donald Sanning'
NATO/CCMS Pilot Study Director
Chief, Emerging Technology Section
U.S. Environmental Protection Agency
Risk Reduction Engineering Laboratory
Superfund Technology Demonstration Division
26 W. Martin Luther King Dr.
Cincinnati OH 45268
United States
OFFICE TEL. 513-569-7875
FAX	 513-569-7274
A-10

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NATO EXPERT GUEST SPEAKERS
Brett Ibbotson
Senior Environmental Engineer
SENES Consultants Limited
52 West Beaver Creek Road
Unit #4
Richmond Hill, Ontario
Canada L4B 1L9
OFFICE TEL. 416-764-9380
FAX	 416-764-9386
Alain Jolicoeur
Director/Technology Development and Technical
Services Branch
Conservation and Protection
Environment Canada
Ottawa, Ontario
Canada K1A 0H3
OFFICE TEL. 819-994-2103
FAX	 819-953-9066
Colin Mayfield
Professor
Waterloo Center for Groundwater Research
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
OFFICE TEL. 519-889-4640
HOME TEL... 519-884-1912
FAX	 519-746-2543
Art Stelzig
A/Chief Chemical Industrial Division
Industrial Programs Branch
Environment Canada
Ottawa
Canada K1A 0H3
OFFICE TEL. 819-953-1131
HOME TEL... 613-592-3640
FAX	 819-997-0547
Ir. Rene Kleijntjens
Department of Biochemical Engineering
Delft University of Technology
Julianalaan 67
2628 BC Delft
The Netherlands
OFFICE TEL. 015-78 16 18
HOME TEL... 015-13 22 07
FAX	 015-78 23 55
A-11

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NATO/CCMS FELLOWS
Sjef J. J. M. Staps/ Ing.
Rijksinstituut voor volksgezondheid
en milieuhygiene (RIVM)
Grontmij n.v.
P.O. Box 203
3730 AE De Bilt
The Netherlands
OFFICE TEL. 31-30-20-79-11
HOME TEL... 31-33-80-51-72
TELEX	 47215 RIVM NL
FAX	 31-30-20-02-94
Dr. M. Resat Apak, Ph.D.
Associate Professor
Istanbul University
Faculty of Engineering
Department of Chemistry
Vezneciler 34459
Istanbul
Turkey
OFFICE TEL. 520 75 50 EXT: 56
HOME TEL... 337 68 62
Dr. Aysen Turkman
Associate Professor
Dokuz Eylul University
Faculty of Engineering and Architecture
Department of Environmental Engineering
Bornova Izmir
Turkey
OFFICE TEL. 51 18 21 08
HOME TEL... 51 18 45 48
Dr. Robert Bell
Managing Director/Environmental
Advisory Unit
Liverpool University
131 Mount Pleasant
Liverpool L3 5TF
United Kingdom
OFFICE TEL. 051-709-1377
TELEX	 627095
FAX	 051-709-4536
A-12

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Michael A. Smith
Clayton Bostock Hill & Rigby, Ltd.
68 Bridgewater Road
Berkhamsted
Hertfordshire HP4 1JB
United Kingdom
OFFICE TEL. 021-359-5951
0442-871500
HOME TEL... 0442-871500
TELEX	 337273
FAX	 0442-870152
Thomas 0. Dahl
U.S. Environmental Protection Agency
National Enforcement Investigations Center
Denver Federal Center, Building 53
Denver, Colorado 80225
United States
OFFICE TEL. 303-236-8358
HOME TEL... 303-235-0284
FAX	 303-236-5116
Dr. James Gossett
Associate Professor
School of Civil and Environmental Engineering
Cornell University
Hollister Hall
Ithica, NY 14853-3501
United States
OFFICE TEL. 607-255-4170
HOME TEL... 607-257-3385
TELEX	WUI-6713054
FAX	 607-255-9004
Dr. Wayne A. Pettyjohn
Regents Professor, Sun Chair and Head
School of Geology
Oklahoma State University
105 Noble Research Center
Stillwater, OK 74078
United States
OFFICE TEL. 405-744-6358
HOME TEL... 405-372-1981
FAX	 405-744-7074
A-13

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ON-SITE SUPPORT STAFF
Chamaine C. Commins
Marketing Associate
JACA Corp.
550 Pinetown Road
Fort Washington, PA. 19034
United States
OFFICE TEL. 215-643-5466
HOME TEL... 215-763-2071
TELEX	 846-570
FAX	 215-643-2772
Virginia R. Hathaway
Director of Communications
JACA Corp.
550 Pinetown Road
Fort Washington.PA 19034
United States
OFFICE TEL. 215-643-5466
HOME TEL... 215-643-4643
TELEX	 846-570
FAX	 215-643-2772

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Appendix B
Presentations by
NATO/CCMS Guest Speakers

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GROUNDWATER MANAGEMENT IN CANADA
Alain Jolicoeur, Director
Technology Development & Technical Services Branch
Conservation & Protection
Environment Canada
Ottawa, Ontario
Presented at the Third International Meeting of the NATO/CCMS
Pilot Study Demonstration of Remedial Action Technologies
Contaminated Land and Groundwater - Montreal, Quebec
November 5-9, 1989
B-3

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GEOGRAPHICAL DETAILS
CANADA HAS:
	LAND AREA 9.97 MILLION SQ. KM.
	POPULATION 25.1 MILLION PEOPLE
CO
	MAJOR GEOGRAPHICAL DIFFERENCES

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POPULATION DISTRIBUTION
	MAJOR PART INHABITS A NARROW BELT
ALONG THE US/CANADA BORDER.
	53% LIVE IN THE FERTILE SOUTHERN PARTS
OF ONTARIO AND QUEBEC. THIS AREA IS
ONLY 1.8% OF CANADA'S TOTAL LAND AREA.
	15% LIVE IN SOUTHERN PRAIRIE PROVINCES
WHERE WHEAT IS GROWN.

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 32% IN THE ATLANTIC AND PACIFIC
COASTAL REGIONS.
VAST NORTHERN PARTS OF CANADA ARE
IMPORTANT FOR NATURAL RESOURCES AND
WILDLIFE.
CO
o

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STATISTICS ON GROUND WATER USE
IN CANADA
	IN 19811.5 BILLION m3 OF G.W. WAS USED, 4%
OF ALL WATER WITHDRAWN.
	LARGEST G.W. USER IS THE MUNICIPAL
SECTOR.
	DEPENDENCE ON G.W.:
RURAL SECTION - 82% OF ITS REQUIREMENT,
AGRICULTURAL SECTOR -13%, MUNICIPAL
SECTOR - 9% AND INDUSTRIAL SECTOR
ABOUT 1%.

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IN 1981, 26% OF POPULATION, RELIED ON G.W.
	SMALL MUNICIPALITIES (UNDER 10,000 )
RELIED ON G.W.
	G.W. IS NOT SIGNIFICANT IN IRRIGATION USE
( 3%):
87% OF THE LIVESTOCK WATER
CONSUMPTION COMES FROM G.W.
 IN COASTAL AREAS WHERE FISH FARMING IS
SIGNIFICANT, ALL NEED COMES FROM G.W.

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GROUNDWATER QUALITY CONCERNS
MAJOR CONCERNS ARE:
	11,000 ACTIVE LANDFILL SITES ARE IDEN-
TIFIED. 700 REQUIRED DETAILED INVESTIGA-
TION.
	CHEMICAL CONTAMINANTS OF CONCERN
ARE:ORGANIC SOLVENTS. SPECIALLY
CHLORINATED HYDROCARBONS AND PCB'S.
	LEAKING UNDERGROUND STORAGE TANKS:
THERE ARE 200,000 TANKS FOR GASOLINE
AND DIESEL FUEL, 5 TO 20% MAY BE LEAK-
ING.

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	SEPTIC TANKS AND SEWAGE TREATMENT
SYSTEMS:
-	2 MILLION SEPTIC TANKS
-	CAN BE SOURCE OF MICRO-ORGANISMS,
NITRATE AND ORGANIC SOLVENTS
	FERTILIZERS, PESTICIDES AND FEEDLOT
OPERATIONS CONTRIBUTE TO CONTAMINA-
TION OF G.W. IN 1981,17 MILLION HECTARES
OF FARMLAND WERE TREATED WITH
PESTICIDES.
	PESTICIDES IN G.W. IN REGIONS WITH PERME-
ABLE SOILS AND HIGH RAINFALL. OFTEN
REPORTED PESTICIDE IS ALDICARB.

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 SURFACE IMPOUNDMENTS:
LAGOONS AND PONDS FOR STRAGE AND
SETTLING SOLIDS, CAN CONTRIBUTE TO G.W.
CONTAMINATION.
TAR PONDS HAVE BEEN THE OBJECT OF
CLEAN-UP ACTIVITY.
	SPILLS AND LEAKS-ROAD SALT:
PETROLEUM PRODUCTS, DRY CLEANING
SOLVENTS, PCB'S AND WOOD
PRESERVATIVES SEEP INTO G.W.
	ROAD SALT USE IN WINTER TIME, HAS BEEN
A SOURCE OF WELL CONTAMINATION

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	DEEP WELL INJECTION
THIS TECHNIQUE IS USED IN OIL AND OIL
SANDS.
G.W. CONTAMINATION MAY OCCUR DUE TO
PRESSURE INJECTION.
	BASE METAL, COAL & URANIUM MINING:
SOURCE OF ACID DRAINAGE AND CAUSE OF
CONTAMINATION BY METALS AND
RADIONUCLIDES. G.W. CONTAMINATION
COULD BE A PATHWAY TO SURFACE WATER.

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	DISPOSAL OF NUCLEAR (URANIUM) WASTES:
CANADA OPERATES 14 COMMERCIAL AND 15
RESEARCH REACTORS. ELEVEN (11)
LICENSED TEMPORARY STORAGE FACILITIES.
LOCALISED LEAKAGE AT SOME SITES.
STUDIES ARE BEING CONDUCTED TO ESTAB-
LISH ACCEPTABLE SITES. DEEP DISPOSAL IN
IGNEOUS ROCK IS PREFFERRED.
I
M
CO
	COAL-FIRED POWER PLANTS:
COAL AND ASH PILES, SLURRY PONDS
FROM THE 26 PLANTS CAN BE A SOURCE OF
G.W. CONTAMINATION. ACID DRAINAGE,
HEAVY METALS, ARSENIC, SELENIUM AND
BORON ARE OF CONCERN.

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	COASTAL REGIONS:
SEAWATER INTRUSION INTO G.W. IS A FUNC-
TION OF G.W. USE. PROPER WATER SUPPLY
MANAGEMENT IS ESSENTIAL.
	NATURALLY PRESENT CONTAMINANTS SUCH
AS ARSENIC, URANIUM, FLUORIDE, IODIDE,
NITRATE, CHLORIDE AND SULPHATE LIMIT
USE OF G.W. SALT CONCENTRATIONS IN
PRATRTE REGIONS PREVENT THE USE OF G.W.
FOR IRRIGATION

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GROUNDWATER MANAGEMENT
CANADA HAS 10 PROVINCES AND 2
TERRITORIES. UNDER THE CONSTITUTION THE
PROVINCES HAVE JURISDICTION OVER
"PROPERTY AND CIVIL RIGHTS". THIS HAS
BEEN INTERPRETED AS MEANING THAT
"REGULATION AND DISTRIBUTION OF WATER
RESOURCES IN A PROVINCE FOR DOMESTIC OR
INDUSTRIAL PURPOSES ARE - WITH SOME
QUALIFICATIONS - WITHIN EXCLUSIVE
PROVINCIAL COMPETENCE".
PROVINCES DELEGATE RESPONSIBILITY FOR
SAFE DRINKING WATER TO MUNICIPALITIES.

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CANADA'S CONSTITUTIONAL STATEMENTS
HAVE BEEN INTERPRETED AS FOLLOWS WITH
REFERENCE TO ENVIRONMENTAL MANDATE
OF THE FEDERAL GOVERNMENT.
1. PARTICULAR MANAGEMENT RESPON-
SIBILITIES RELATING TO NAVIGATION, FISH
HABITAT, NORTHERN RESOURCES,INTER-
JURISDICTIONAL WATERS.
2. PROMOTE RESOURCE CONSERVATION AND
DEVELOPMENT IN THE LONG TERM ECONOMIC
AND SOCIAL INTERESTS OF CANADIANS.
CONCERN FOR ENVIRONMENTAL PROTECTION
AND RESOURCE DEVELOPMENT.

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3.	LEADERSHIP IN RESOLVING PROBLEMS OF
AN INTERJURISDICTIONAL NATURE AND BE A
CATALYST FOR ADDRESSING PROBLEMS OF
NATIONAL DIMENSION.
4.	RESPONSIBILITY TO IMPROVE KNOWLEDGE
ABOUT WATER RESOURCES AND DEVELOP
SCIENTIFIC CAPABILITY FOR MANAGING SUCH
RESOURCES.
FEDERAL WATER POLICY OF 1987 HAS
REFINED THESE ROLES:

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	DEVELOP, WITH CO-OPERATION OF
PROVINCIAL GOVERNMENTS, APPROPRIATE
STRATEGIES, NATIONAL GUIDELINES FOR
G. W. ASSESSMENT AND PROTECTION.
	CONDUCT RESEARCH AND UNDERTAKE
TECHNOLOGICAL DEVELOPMENT FOR
SOLVING G.W. PROBLEMS.
	DEVELOP G.W. MANAGEMENT PRACTICES
INVOLVING FEDERAL LANDS, FACILITIES
AND FEDERALLY FUNDED PROJECTS.
	DEVELOP MEASURES FOR G.W. QUALITY IN
TRANSBOUNDARY WATERS.

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WITH REGARD TO G.W. MANAGEMENT,
RESPONSIBILITY OF THE FEDERAL
GOVERNMENT OF CANADA, ARE:
1. MANAGEMENT OF RADIOACTIVE WASTE
FROM THE NUCLEAR FUEL CYCLE.
2. CONTAMINATION WHERE G.W. IS MAINLY A
CONDUIT TO SURFACE WATER AND MAY
AFFECT FISHERIES.
3. CONTAMINATION WHICH AFFECT
INTERNATIONAL WATERS. NEARLY 300
WATERWAYS AND AQUIFERS CROSS THE
BORDER BETWEEN CANADA AND THE U.S.

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4.	MANAGEMENT OF FEDERAL LANDS AND
FACILITIES.
5.	MANAGEMENT OF TERRITORIES HELD IN
TRUST FOR THE NATIVE PEOPLE OF CANADA.
6.	ENVIRONMENTAL MANAGEMENT IN THE
YUKON AND N.W.T.
7.	REGULATIONS ON PESTICIDE APPLICATIONS.
8.	REGULATIONS OF TOXIC COMMERCIAL
CHEMICALS.

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RESPONSIBILITY IS SHARED WITH PROVINCIAL
GOVERNMENTS.
as
i
PO

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TP,GAT, MANAGEMENT
IN CANADA, FEW LEGAL INSTRUMENTS ARE
DIRECTED SPECIFICALLY TOWARDS THE
PROTECTION OF G.W. RATHER, THE LEGAL
PROTECTION IS DIRECTED TOWARDS:
1.	PROTECTION FROM ALL WATER
POLLUTION WITHIN SPECIFIC GEOGRAPHIC
BOUNDARIES (e.g. PROVINCE, FEDERAL
LANDS...).
2.	PROTECTION OF ALL WATER RESOURCES
FROM INDUSTRIAL SOURCES.

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3. PROVISION OF SAFE DRINKING WATER FROM
GROUND AND SURFACE WATER.
4.	MANAGEMENT OF G.W SUPPLIES WHICH
IMPLIES PROTECTION OF QUALITY (e.g. WELL
DRILLING).
5.	MANAGEMENT OF LAND, WHICH AS A
RESULT PROTECTS G.W. ALSO.
ALL PROVINCES HAVE LAWS AND
REGULATIONS. IN THE ABOVE MENTIONED
AREAS WHICH HAVE A BEARING ON G.W.
MANAGEMENT.

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MANAGEMENT INSTRUMENTS
00
1
ro
4*
AN IMPORTANT FEATURE OF G.W.
MANAGEMENT IS THAT IT AFFECTS MANY
DIFFERENT ACTIVITIES AND CONCERNS.
THEREFORE, AUTHORITY IS WIDELY
DISTRIBUTED AMONG MANY DIFFERENT
ORGANIZATIONS.
NO SINGLE CO-ORDINATING BODY IN CANADA
EITHER AT FEDERAL OR PROVINCIAL LEVELS
FOR G.W.MANAGEMENT. IN THE U.S. THERE IS A
CENTRAL G.W. OFFICE AT THE EPA.

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LINES ALONG WHICH, THE FEDERAL AND
PROVINCIAL ORGANIZATIONS ARE DIVIDED:
CO
I
ro
	INSTITUTIONS FOR WATER SUPPLY
MANAGEMENT.
	CONTROLLING THE DISCHARGE FROM
.SPECIFIC SOURCES AND ACTIVITIES (e.g.
WASTE MANAGEMENT, PESTICIDES).
	SAFE DRINKING WATER.
	MONITORING WATER QUALITY.

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 RESEARCH AND TECHNOLOGY
DEVELOPMENT.
THE EXTENT OF CO-ORDINATION, BETWEEN
GROUPS DEPENDS ON THE CIRCUMSTANCES
AND NEEDS OF THE PARTICULAR SITUATION.
WITHIN THE FEDERAL GOVERNMENT,
G.W. MANAGEMENT IS DISTRIBUTED AMONG
SEVERAL DEPARTMENTS. ENVIRONMENT
CANADA HAS AN ADVISORY ROLE IN ALL
MATTERS AFFECTING THE ENVIRONMENT.

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BECAUSE OF OVERLAPPING RESPONSIBILITIES
OF THE FEDERAL AND PROVINCIAL
AUTHORITIES AND BETWEEN CANADA AND
THE U.S., JOINT COMMITTEES HAVE CONSIDER-
ABLE IMPORTANCE. A HEALTHY DEGREE OF
CO-OPERATION EXISTS BETWEEN THE DIF-
FERENT JURISDICTIONS.
03
I
ro
VI

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OTHER MANAGEMENT INSTRUMENTS
THE PROVINCIAL GOVERNMENTS, TO VARYING
DEGREES:
1.	MONITOR QUANTITY AND QUALITY OF G.W.
2.	COLLECT RELEVANT DATA.
3.	MAP PROVINCIAL HYDROGEOLOGY.
4.	CLASSIFY SENSITIVE ZONES OR ATTEMPT
WELL HEAD PROTECTION ETC.

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5,	PROVIDE TRAINING AND PUBLIC EDUCA-
TION.
6.	ENGAGE IN A VARIETY OF SPECIAL MANAGE-
MENT PROGRAMS.
THE FEDERAL GOVERNMENT PLAYS A
CO-ORDINATING ROLE IN DEVELOPING
GUIDELINES AND CODES OF PRACTICE. THE
FEDERAL GOVERNMENT PLAYS A ROLE IN RE-
SEARCH AND TECHNOLOGY DEVELOPMENT.

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Art Stelzig and
Brett Ibbotson
B-31

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DECOMMISSIONING AND CLEANUP
CRITERIA OF INDUSTRIAL
FACILITIES IN CANADA
NATO/CCMS MEETING
NOV. 6-9 1989
MONTREAL
B-33

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OVERVIEW OF NATIONAL
PROGRAM
 OBJECTIVE
 CCME
 HISTORY & BACKGROUND
 STATUS OF CURRENT PROGRAM
DECOMMISSIONING
OBJECTIVE:
Establish uniform approaches
on decommissioning of
industrial plants, storage
facilities and waste disposal
sites.
B-34

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Canadian Council of Ministers
of the Environment (CCME)
- WASTE MANAGEMENT COMMITTEE
-Responsible for the Hazardous
Waste Action Plan
-Added decommissioning of
industrial sites to action
plan Sept/66.
-Environment Canada and
Quebec identified as lead
agencies.
-Objective (established by
waste committee):
"Establish uniform approaches
on decommissioning of
Industrial plants, storage
facilities and waste disposal
sites."
INDUSTRIAL DECOMMISSIONING
TASKS
 DEVELOP CLEANUP CRITERIA
INCORPORATING SITE SPECIFIC
CONSIDERATIONS
 DEVELOP NATIONAL GUIDELINES
FOR DECOMMISSIONING
INDUSTRIAL SITES
B-35

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HISTORY AND BACKGROUND
	Decommissioning guide
-consultants report
	National workshops
and proceedings
- recommendations
steering committee
	Quebec & Ontario
Regulatory Initiatives
	Inventory of cleanup
criteria and
methodology	May 87
A: DECOMMISSIONING GUIDE
April 85 by Monenco Consultants Ltd.
	SCOPE AND PROBLEM DEFINITION
	GENERAL PRINCIPLES
-Planning
-Site Assessment
-Site Investigation
-Cleanup Criteria
-Site Cleanup
-Cleanup Confirmation
-Long Term Monitoring
-Regulatory Agency Involvement
-Public Relations
-Preventive Measures
	CASE HISTORIES
B-36
	CONCLUSIONS
1985
1985
June 86

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B: WORKSHOPS
Calgary Nov. 85
Ottawa Dec. 85
STEERING COMMITTEE
-Industry/Gov't
-Define Objectives
-Manage Workshops
OBJECTIVES
Advance state of the art
level of understanding
Exchange information
-Share expertise and
experience
-Identify needs
CONCLUSIONS/RECOMMENDATIONS
APRIL 1986
-	Cleanup criteria and guidelines
(Highest priority)
-	Small facilities
-	Field programs
-	Treatment & Disposal
-	Groundwater cleanup
-	Long term monitoring
-	Role of aov't and oublic

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STEERING COMMITTEE
RECOMMENDATIONS
JUNE 1986
-	Letter to Federal/Provincial ADM's
and Industry Associated Presidents
-	Workshop Recommendations
-Highest priority
-Criteria
-Inventory
-Cooperative effort
-To follow up
-Funding
-	Response
-Recognized need
-Prepared to participate
-Funding
-Planning
ONTARIO & QUEBEC
INITIATIVES
 Development of policies
and guidelines
 Quebec action level
- A, B, C
 Ontario decommissioning
guideline
B-38

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INVENTORY OF CLEANUP CRITERIA
AND METHODS TO SELECT CRITERIA
REPORT COMPLETED
APRIL 1987
-Canada, U.S., Europe
-Site specific examples
REPORT TO mSTE COMMITTEE
MAY 1987
REVIEW BY MARK RICHARDSON
U.S. OFFICE OF TECHNOLOGY ASSESSMENT
Analysis of approaches to set cleanup goals
Unacceptable
Technically and Economically
Impractical
- ad hoc
-restore to background/pristine
-best available technology
Potentially Feasible
Preferred
-national standards
-risk assessment
-cost-benefit analysis
site classification based on
use combined with national
standards, risk assessment
and cost-benefit analysis
B-39

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U.S. OFFICE OF TECHNOLOGY ASSESSMENT
NATIONAL. CONSISTENT APPROACH REQUIRED.
No consistent approach	No consistent lewis of cleanup
Factors to be considered when selecting cleanup goals:
-Inherent hazard (potential to cause harm)
-site-specific considerations and exposure (pathways
analysis)
-assessment of risks (hazard and exposure, probability of
adverse effects)
-available technologies (detection, quantification,
remediation)
-resource limitations (money, trained personnel,
equipment)
-institutional constraints (laws & regulations,
Jurisdiction)
STEPS IN DECOMMISSIONING ON A SITE-SPECIFIC BASIS
I CONTAMINANTS IDENTIFIED/MEASU^Pl
B-40

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STATUS OF CURRENT
PROGRAM
	Project objective
	Components of project
	A.E.R.I.S.
(Aid in Evaluating the
Redevelopment of
Industrial Sites)
	National Guideline for
Decommissioning of
Industrial Sites
PROJECT OBJECTIVE
Development and validation
(critical components) of a
method for establishing site
specific cleanup criteria for
industrial sites.
B-41

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COMPONENTS FOR PROJECT
 REVIEW AND EVALUATION
OF METHODS
 DEVELOPING OPTIMUM
APPROACH AND METHOD
 VALIDATING CRITICAL
COMPONENTS
SPONSORS
-Federal Government50%
(Environment Canada
D.S.S.)
PROJECT
BUDGET
$1.1 MILLION
-U.S. EPA
35%
-Alberta
-Quebec
-Ontario
-CPA
15%
-PACE
-CCPA
Project initiation June 1987
completion feb. 1990
B-42

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PROJECT TEAM
CONSULTANTS
Monenco Consultants Ltd.
PROJECT ROLE
Management
Senes Consultants Ltd.
Cantox Inc.
Zenon Environmental Inc.
Pathways
Toxicology
Analytical
KRH Environmental Co. Ltd. Laboratory
PROJECT ORGANIZATION
CLIENT COORDINATING
COMMITTEE (I \ )
[TECHNICAL WORKING GROUP (7)
EXPERT REVIEW COMMITTEE
i
PROJECT MANAGEMENT
M.J. Riddle
D.M. Gorber
B-43

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METHOD REVIEW
REPORT
A) Methods and strategies currently
used to develop cleanup criteria
for contaminated sites.
(completed January 1969)
-Reviewed by Technical
and Steering Committees.
-Submitted to C.C.R.E.M.
Waste Committee 12/01/89.
-Comprehensive Review
-Inventory Criteria Report
Precursor.
METHOD REVIEW
A- 1) EVALUATION BASIS:
-Site specific data
-All environmental media
-All environmental contaminants
-Incorporate variety scientific
data
-Degrees of contaminants
exposure
-Routes of exposure
-Risk assessment
-Missing data
B-44
-Land use

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METHOD REVIEW
A-2) STRATEGIES:
-Site classification
-Environmental standards
-Risk assessment
-Cost benefit
-Technology
-Background
METHOD REVIEW
A-3) A combined approach
and methodology that
SYSTEMATICALLY considers
ALL of the strategies.
B-45

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A.E.R.I.S.
(Aid in Evaluating the Redevelopment
of Industrial Sites)
Links exposure assessment (multi-
media pathway models) with toxicity
assessment as part of an overall
risk evaluation procedure.
1.	Development of a risk assessment
method for selecting cleanup
criteria.
-user friendly computer model
-human exposure vs soil
concentration
2.	Selection of pollution transport
equations for model based on
evaluation in field study.
Model will aid in selection of
cleanup criteria for cases with
extensive contamination (conflict
between most economical and most
environmentally acceptable
approaches).
B-46

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MODEL DESCRIPTION
1. Input of site specific Information
-	user responds to questions
-	approve or change default
values
-	ask for help, background
information
-	examples: soil, climate, pollutants
land use - residential
commercial
recreational
agricultural
2. Calculation of soil concentration
that results in acceptable level
of risk.
Concentration in air, soil,
water, plants; resulting
human exposure
Comparison of exposure with
ADI
- Adjustment of soil concentration
and recalculation of exposure
B-47

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3. Graphic display of mode! output
Recommended cleanup criteria;
background
existing guidelines (Canadian
water quality)
Concentration in soil vs water
air
plants
Importance of each pathway to
total exposure
I 1 *sfai/sSk i * i	Ik If
IMU I If ilMMI 1 mmi III IM> I IIMIm
nni ivnnu
A)	GENERIC
-	not industry sector specific
B)	MAJOR COMPONENTS
-	appropriate steps, information
needs, practices and considerations
-	cleanup criteria and procedure
C)	PRIMARY BACKGROUND AND
REFERENCE DOCUMENTS
-	guide
-	draft Ont & Qu6 guidelines
-	inventory criteria report
-	workshop material
-	current methodology study
-	U.S. material
-	other (i.e. water quality
guidelines)
B-48

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PROPOSED DECOMMISSIONING
GUIDELINES
1 Introduction
2.	Legislation
3.	Planning
4.	Site assessment
5.	Reconnaissance testing program
6.	Plant phaaedown
7.	Development of cleanup criteria
8.	Detailed testing program
9.	Preparation of cleanup plan
10.	implementation of cleanup plan
11.	Confirmation testing
12.	Long term monitoring
13.	Approval
14.	Land use control
15.	Liability
16.	Preventative measures
B-49

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a
n/
. 1
M
THE DEVELOPMENT OF SOIL
CLEANUP CRITERIA
IN CANADA
'V.'
 1  s'
S- - 
S3w
y a..-  .:
i
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i
*j

B- 50
iiniiiiiiiniuiiiiiiil
tmm#
+TT 
IT#'
--'iVr-.;
- WVi?

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CONTAMINATED SOIL CLEANUP
IN CANADA
VOLUME I
METHODS AND STRATEGIES
CURRENTLY USED TO DEVELOP
CLEANUP CRITERIA FOR
CONTAMINATED SITES
prepared for the
Decommissioning Steering Committee
1988-09-16
B-51

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ABSTRACT
A potential threat to human and environmental health is posed by
the existence of toxic substances at closed industrial sites or inadequate
waste disposal sites. It is generally acknowledged that this potential
threat must be reduced to an "acceptable level" or eliminated completely.
To deal with this problem (i.e. how clean is clean?) various governments
and regulatory agencies in North America and Europe use a wide variety of
strategies and approaches. These strategies can be divided into the
absolute method, which is geared toward establishing a fixed concentration
for a given contaminant in a specific medium, or the relative method, which
derives a site-specific contaminant concentration to protect human health
and the environment.
The Canadian Council of Resource and Environment Ministers
(CCREM) have recognized the inconsistency of the various approaches used in
Canada to develop cleanup criteria. CCREM has identified the need to
establish a uniform approach for the development of cleanup criteria, which
incorporates site-specific characteristics and is protective of both human
health and the environment.
An evaluation of the various strategies used by governmental and
agency jurisdictions in North America and Europe to develop cleanup
criteria was made in terms of their capability to:
o	incorporate site-specific data;
o	address all environmental media;
o	address all environmental contaminants;
o	incorporate a wide variety of scientific data;
o	distinguish various degrees or periods of contaminant exposure;
o	deal with various routes of exposure;
o	deal with the effect of more than one contaminant exposure to a
biological receptor;
o	differentiate between non-carcinogenic and carcinogenic
contaminants;
o	incorporate risk assessment;
o	deal with missing data; and
o	incorporate the desired end land use.
Only the strategies adopted by the U.S. Environmental Protection Agency,
the U.S. Army and the State of California had the aforementioned
capabilities.
In view of the many strategies utilized for cleanup criteria
development and the requirements for the development of a scientifically
defensible, easily standardized, and "user-friendly" system, it is
recocmended that a combined approach be investigated. This combined
approach would incorporate elements from strategies in both the absolute
and relative methods categories for the purpose of providing Che most
cost-effective mechanisms to meet the diversity of sites requiring
cleanup. This strategy would be consistent with the need identified by
CCREM for a uniform approach to the development of cleanup criteria which
incorporates site-specific characteristics and which is protective of both
human health and the environment.
B-52

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EXECUTIVE SUMMARY
A potential threat to human and environmental health is posed
by the existence of toxic substances at closed industrial sites or ln-
adequate waste disposal sites. It is generally acknowledged that this
potential threat must be reduced to an "acceptable level" or eliminated
completely. While this concept is admirable, the actual determination of
what toxic substances should be eliminated and exactly how to define an
"acceptable level" of a toxic substance can become very Involved. To
deal with this problem (i.e. how clean is clean?) various governments and
regulatory agencies in North America and Europe use a wide variety of
strategies and approaches. These strategies can be divided into two
broad categories: absolute methods and relative methods.
The absolute methods generally focus on an established value
(or fixed concentration) of a given contaminant in a specific medium
(i.e. air, water or soil). Exactly how this established value was
derived is usually less important than the fact that a specific
regulatory agency or government use it to define:
o contaminated versus uncontamlnated;
o an acceptable level of contamination; and/or
o various levels of contamination requiring different responses.
The relative methods focus on the derivation of a site-specific
value which will protect human health and the surrounding environment
according to:
o the physical-chemical properties of the contaminant;
o the movement of the contaminant through environmental media at
the site; and
o the human interaction with those environmental media.
B-53

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The Canadian Council of Resource and Environment Ministers
(CCREM) have recognized Che inconsistency of the various approaches used
in Canada to develop cleanup criteria. CCREM has identified the need to
establish a uniform approach for the development of cleanup criteria,
which incorporates site-specific characteristics and is protective of
both human health and the environment.
Specific alternatives or strategies for the development of
cleanup criteria (as subsets of the general categories of absolute and
relative methods) can be described as:
o ad hoc practices;
o site-specific risk assessment;
o national goals for residual contamination;
o restoration to background or "pristine" levels;
o technology-based standards (best available technology or best
engineering judgement);
o cost-benefit approach; and
o site classification and restoration relative to present and
future land use.
After a review of these alternatives, the U.S. Office of Tech-
nology Assessment (1985) concluded that the ad hoc practices were no
longer acceptable and cleanup criteria based on background or pristine
levels did not make environmental, technical or economic sense. Although
attractive, technology based standards did not offer human health and
environmental protection comparable to the cost of implementation. The
strategies of setting national goals, the cost-benefit approach and site
specific risk assessment could be used, but each one poses considerable
problems and has substantial limitations. Of all the strategies, cleanup
criteria based on site classification (i.e. present and future use of a
site and surrounding area) seemed the most beneficial approach. An even
better approach might be obtained by utilizing a combination of some of
B-54

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Che strategies. Thus, a single strategy might include various conponents
of site classification, risk assessment, cost-benefit analysis and exist-
ing, relevant environmental standards, as well as consideration of the
available cleanup technologies.
Existing strategies used in North America and Europe according
to governmental or agency jurisdiction are described below.
o Alberta has no systematic approach to cleanup criteria selec-
tion. The province requires the responsible company or organi-
zation to identify site contaminants, contaminants of concern
and cleanup levels for governmental approval.
o Ontario is revising its guide for restoration and rehabilita-
tion of industrial sites. This document provides details of
the data and information required for governmental approval of
any cleanup plan. Numerical guidelines are provided for some,
mainly inorganic, contaminants.
o Quebec uses an approach based on both the Dutch and French
systems. This system uses specific numerical values (concen-
trations) of soil and groundwater contaminants to define back-
ground, moderate contamination and severe contamination, as a
basis for the management of contaminated material.
o The State of California utilizes a standardized, systematic and
integrated set of individual tasks (the Site Mitigation Deci-
sion Tree) to set site-specific cleanup criteria for any media
at any abandoned or uncontrolled waste site within the state.
o The State of New Jersey derives site-specific, acceptable soil
contaminant levels as the end-product of calculations describ-
ing human exposure to contaminated soil and groundwater (as a
result of contact with contaminated soil). The system also
B-55

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quantifies the exposure of aquatic organisms to contaminated
surface water (as a result of contact with contaminated soil).
The State of Washington has a standardized, systematic,
priorized set of procedures for initial and long-term cleanup
of contaminated sites. The system is based on the potential
for contaminant migration through all environmental media to
cause acute and chronic adverse human health effects.
The U.S. Army Preliminary Pollutant Limit Value approach was
developed to predict the probable environmental limits for a
soil contaminant to affect human health through a variety of
pathways. Each pathway is described by a specific mathematical
equation derived from the physical and chemical properties of
the contaminant and the transporting media. Single pathways
are combined to a total daily dose to a receptor organism. The
contaminant concentration at the source would then be reduced
until the total daily dose reaching the receptor is at an
acceptable level.
The U.S. Environmental Protection Agency has a specific set of
procedures (the Superfund Public Health Evaluation Manual) for
the derivation of cleanup criteria to prevent adverse health
effects in the exposed human population. The main features of
this system are the quantification of the migration of contami-
nants among environmental media and a detailed human exposure
assessment.
The Netherlands has established a list of contaminants (approx-
imately 50 organic and inorganic chemicals and chemical mix-
tures) and associated concentrations in soil and groundwater.
Three levels or categories of contamination defined by these
concentrations are: 1) normal or background; 2) moderate
B-56

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contamination; and 3) severe contamination. These concentra-
tion levels then form the basis for recommendations on the
management of contaminated materials.
o The United Kingdom has published a list of soil contaminant
values ("trigger concentrations") below which a site could be
regarded as uncontaminated. The trigger concentrations vary
with the proposed future use of the site and have been adapted
from existing guidelines developed for other purposes or were
based on professional judgement.
o France has published a list of values for four levels of con-
tamination (i.e. threshold values) which once attained require
a response. These four levels (responses) are: 1) background
maximum (i.e. no response); 2) investigation threshold (i.e.
further investigation required before disposition of contami-
nant is determined); 3) treatment threshold (i.e. soil must be
treated to reduce contamination) and 4) emergency threshold
(i.e. immediate and decisive action must be taken to remove
contamination).
An evaluation of the various strategies used by governmental
and agency jurisdictions in North America and Europe to develop cleanup
criteria was made in terms of their capability to:
o	Incorporate site-specific data;
o	address all environmental media;
o	address all environmental contaminants;
o	Incorporate a wide variety of scientific data;
o	distinguish various degrees or periods of contaminant exposure;
o	deal with various routes of exposure;
o	deal with the effect of more than one contaminant exposure to a
biological receptor;
B-57

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o differentiate between non-carcinogenic and carcinogenic con-
taminants;
o Incorporate risk assessment;
o deal with missing data; and
o incorporate the desired end land use.
Only the strategies adopted by the U.S. EPA, the U.S. Army and
the State of California had the aforementioned capabilities. In view of
the many strategies utilized for cleanup criteria development and the
requirements for the development of a scientifically defensible, easily
standardized, and "user-friendly" system, it is recommended that a com-
bined approach be investigated. This combined approach would incorporate
elements from strategies in both the absolute and relative methods cate-
gories for the purpose of providing the most cost-effective mechanisms to
meet the diversity of sites requiring cleanup. This strategy would be
consistent with the need identified by CCREM for a uniform approach to
the development of cleanup criteria which Incorporates site-specific
characteristics and which is protective of both human health and the
environment.
B-58

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rsum
Les substances toxiques se crouvanc dans des emplaeemencs
induscriels desaffectes ou lieux d'eiimination de dechets mal aaenages
constituent une menace potentielle pour la qualice de 1'environnement et
la sante humaine. II esc generalement adrais que cecte menace potentielle
doit e tre supprioee ou reduice k un niveau acceptable. Heme si
1'intention est louable, il peut etre, de fait, tres complique de
determiner quelles substances toxiques doivent etre e liminees et de
definir des concentrations acceptables pour chacune d'elles. Pour
resoudre ce probl&me, les divers tats et organismes responsables nord-
americains et europeens ont adopte une grande variete de strategies et
d'approches. Ces strategies se repartissent dans deux grandes
categories: les methodes absolues et les methodes relatives.
Les methodes absolues font generalement appel k des crit&res
preetablis (ou concentration fixe) pur un contaminant donne dans un
milieu particulier (l'air, l'eau ou le sol). La fa^on dont le critere a
ete elabore importe habituellement moins que l'usage qu'un organisme de
reglementation ou un etat en fait, soit:
distinguer ce qui est containing de ce qui ne l'est pas;
etablir un degre acceptable de contamination; et/ou
decider du type d'intervention en fonction du degre de
contamination.
Les methodes relatives s'appuient sur une grandeur qui est
particuli6re 4 1'emplacement et qui dans ces fonctions particuliferes
assurera la protection de la sante et du milieu environnant. Ce critere
tiendra compte:
des proprietes physico-chimiques du contaminant;
du deplacement du contaminant k travers les divers milieux
environnementaux;
de 1'interaction de 1'Homme avec ces milieux.
Les Conseil Canadian des ministres des ressources et de
1'environnement (CCMRE) a constate 1'incoherence des diverses methodes
adoptees au Canada pour ^laborer des critferes de decontamination. Le
CCMRE s'est sensibilise k la necessite d'adopter une approche uniforme
pour la mise en place des crit&res de decontamination, qui tient compte
des caracteristiques propres aux emplacements et qui vise la protection
de la sante ainsi que de 1'environnement.
Four 1'elaboration des critferes de decontamination, les
solutions de rechange ou strategies (sous-ensemble des crit&res generaux
des methodes absolues et relatives) peuvent etre decrites comme suit:
les pratiques ad hoc;
1'evaluation du risque propre k un lieu;
les objectlfs nationaux de contamination residuelle;
la restauration au niveau du bruit de fond;
les normes basees sur les meilleures techniques disponibles ou
sur les meilleures regies de l'art;
B-59

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l'approche couts/benefices;
le classeemnt ec la rescauracion des lieux en foriction de
leur utilisation actuelle ou future.
A la suite d'une evaluation de ces strategies en 1985, le U.S.
Office of Technology Assessment a conclu que les pratiques dites ad hoc
n'etaient plus acceptables et que la restauration au niveau du bruit de
fond etait ecologiquenent, techniquement et economiquement inconcevable.
Bien qu'attrayante, la decontamination basee sur les meilleures
techniques disponsible n'offrait pas une protection de la sante et de
1'environneoent proportionnelle aux couts de la mise en oeuvre.
L'e tablissement d'objectifs nationaux, l'approche couts/benefices et
devaluation du risque specifique 4 une lieu posent, malgre leurs
qualites, des probl6mes importants et ils sont considerablement limites.
Seuls les critferes de decontamination fondes sur le classement du lieu et
de ses abords selon leur utilisation actuelle et eventuelle ont semble le
plus avantageux. Le mieux encore serait de combiner certaines de ces
strategies en une seule qui pourrait ainsi employer le classement du
lieu, 1'evaluation du risque, 1'analyse du rapport couts/benefices, les
nornes environneaentales pertinentes, de meme que la prise en
consideration des techniques de decontamination disponibles.
Les strategies utilisees actuellement en Amerique du Nord et
en Europe par les Etats et les organismes competents sont dcrites ci-
dessous.
o L'Alberta n'a pas de strategie systematique lui permettant de
selectionner des crit&res de decontamination. Elle demande A
la compagnie ou A l'organisme responsable d' identifier les
contaminants se trouvant sur le lieu et ceux qui sont
prgoccupants et de proposer, pour approbation, les niveaux de
decontamination sugger^s.
o L'Ontario revise actuellement son guide de restauration et de
rehabilitation des lieux industriels. Ce document precise
quels sont les donnees et les renseignements requis pour
obtenir 1'approbation de plans de decontamination. Des
criteres sont indiquds pour certains contaminants,
inorganiques pour la plupart.
o Le Queebec s'inspire des modules neerlandais et fratals,
c'est-A-dire qu'A partir de grandeurs particuliires
(concentrations affectant les contaminants des sols et des eaux
souterraines) il definit trois niveaux de contamination (de
base, moderee et grave) en vue de la gestion de la matifere
contaminee.
o La Californie fait appel A un ensemble uniformise ,
systematique et integre de tAches unitaires (l'arbre di
decisions pour la decontamination des decharges) afin
d'etablir des critAres de decontamination propres k chaque
lieu desaffecte ou sauvage dans l'tat.
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Le New Jersey obcient les concencracions aecepcables de
contaminants du sol en se basant sur des calculs tenant compte
de 1'exposition de l'Honme aux sols contamines et aux eaux
souterraines contaminees. Pour chaque site le systfcme permet
aussi de quantifier 1'exposition des organismes aquatiques aux
eaux de surface contaminees (par un sol contamine).
L'Etat de Washington a mis sur pied un systeme uniforme
systematique permettant un nettoyage preliminaire et A long
terme des lieux contanines. Le systeme est fonction de la
probability que la migration eventuelle des contaminants dans
les divers milieux exerce des effets nocifs, tant aigus que
chroniques, sur la sante.	'
Le systAme "Preliminary Pollutant Limit Value" de l'Armee
americaine a 6t labore pour determiner les limites de
probability qu'un contaminant se trouvant dans un sol affecte
la sante par differents cheminements. Chaque cheminement est
decrit A l'aide d'une equation mathematique decoulant des
proprietes physico-chimiques du contaminant et des milieux
traverses. Les differents cheminements sont combines pour
obtenir une dose journaliAre cumulie pour un organisme
recepteur. La concentration du contaminant A la source est
alors reduite jusqu'A ce que la dose cumulee se retrouve A un
niveau acceptable.
L'EPA recourt A un ensemble specifique de modalites (Superfund
Public Health Evaluation Manual) afin d'etablir des niveaux de
decontamination empechant les contaminants d'avoir un effet
nocif sur la santg de la population exposee. Les principales
caracteristiques de ce systeme sont que la migration des
contaminants dans les divers milieux est quantifiee et que
1'exposition de l'fitre humain est evaluee dans le detail.
Les Pays-Bas ont dressA une liste des contaminants (environ 50
composes et melanges organiques et inorganiques) et de leur
concentration dans les sols et les eaux souterraines. Ces
concentrations dAfinissent trois degres de contamination: (1)
normale ou de base; (2) modAreAe; (3) grave, dont dAcouleront
les recommendations sur la gestion des matiAres contaminees.
Le Royaume-Uni a publiA une Usee des seuils sous lesquels on
peut prAsuaer la non-contamination du sol pour un contaminant
donne. Ces seuils, qui varient selon 1'utilisation projetAe
du lieu, ont AtA adaptss A partir de critAres utilises A
d'autres fins ou se fondent sur une appreciation technique.
La France a publiA une liste de critAres, correspondent A
quatre niveaux de contamination distincts, soit: (1) le seuil
d'anomalie (aucune intervention); (2) le seuil d'investigation
(enquAte approfondie nAcessaire avant de se prononcer sur la
necessity d'Aliminer le contaminant); (3) le seuil de
traitemenc (c'est-A-dire traitement du sol afin d'en rAduire
la contamination); (4) le suell d'urgence (c'est-A-dire
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intervention immediate et decisive pour supprimer la
contamination).
L'evaluation de chacune des strategies utilisees pur elaborer
des critferes de decontamination s'est faite en tenant compte
de leur capacite k:
inelure des donnees propres k chaque lieu;
tenir compte de tous les milieux;
tenir compte de tous les contaminants;
amalgamer une grande variete de donnees scientifiques;
distinguer entre les divers niveaux ou periodes d'exposition;
tenir compte de diverses voies d'exposition;
tenir compte de l'effet sur un recepteur biologique d'une
exposition k plus d'un contaminant;
distinguer entre les contaminants cancerogenes et non
cancerogenes;
evaluer le risque;
tirer le meilleur parti possible de donnees fragmentaires;
tenir compte de 1'utilisation finale souhaitee du sol.
Seules les strategies de l'EPA, de l'Araee americaine et de la
Califomie possedaient ces caracteristiques. En raison des
nombreuses strategies utilisees pur 1'elaboration de crit&res
de decontamination et de la necessite d'elaborer un systeme
scientifiquement defendable, facile k uniformiser et k
utiliser, il est recommande d'etudier la possibility de
developper un systeme combinant les methodes absolues et
relatives. Ce systeme combine permettra un meilleur rendement
couts/benefices, tenant compte de la grande diversity des
lieux pour lesquesl un nettoyage est envisage. Cette faqon de
proceder repondra au besoin, constate par le CCMRE,
d'uniformiser les critferes de decontamination en tenant compte
des caracteristiques particuli&res aux differents lieux et k
la necessite de proteger la sant6 et l'environnement.
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THE DEVELOPMENT OF SOIL
CLEANUP CRITERIA
IN CANADA
CONTAMINATED 80IL CLZANUF
IN CANADA
VOLUME 2
INTERIM RX70RT ON THE
"DEMONSTRATION" VERSION OF
THE AERIS MODEL
(AN AID FOR EVALUATING THE
REDEVELOPMENT OF INDUSTRIAL SITES)
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CONTAMINATED SOIL CLEANUP
IN CANADA
VOLUME 2
INTERIM REPORT ON TBS
"DEMONSTRATION" VERSION 07
THE AERIS MODEL
(AN AID FOR EVALUATING THE
REDEVELOPMENT 07 INDUSTRIAL SITES)
prepared for the
Decommissioning Steering Committee
1988-12-15
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NOTICE OF WARRANTY
The organizations and individuals associated with the creation or development
of AERIS make no representations or warranties of any kind with respect to its
contents and disclaim any implied warranties of suitability for any particular
purpose. Neither are they liable for any errors in the software or any damages
resulting from its performance or use.
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SUMMARY
Wherever industrial activities have caused on-site soils or ground water to
become contaminated and redevelopment to another use is being considered,
there is the potential for future site users or those located down gradient to
be exposed to chemicals present in site soil through various pathways such as
the inhalation of vapours, direct ingestion of soil, or the ingestion of local
ground water.
At the present time, few jurisdictions have established acceptable soil
concentrations. In June 1987, Environment Canada awarded a contract to a
consortium of consultants headed by Monenco Consultants Limited. One of the
goals of the consortium was to produce a computer model that can be used to
derive clean-up guidelines for industrial sites where redevelopment is being
considered or planned. The result is the "demonstration" version of the AERXS
model. The acronym AERXS (Aid for Evaluating the Redevelopment of Industrial
Sites) was chosen to help users remember its intended use, that of being an
aid for evaluating industrial sites. As an aid, AERIS is suited to identifying
the factors that are likely to be major contributors to potential exposures
and concerns at sites, those aspects of a site redevelopment scenario with the
greatest need for better information, or as an indicator of the extent to
which remedial action may be needed at a site.
The AERIS model consists of four basic elements - an "intelligent"
preprocessor, component modules, a postprocessor, and supporting data bases.
The preprocessor takes the form of a series of questions that AERXS asks the
user about the redevelopment scenario to be evaluated. The preprocessor is
referred to as "intelligent" due to the utilisation of "expert system"
technology. Xt uses a set of rules (collectively referred to as a "knowledge
base") to establish a structure to the decision support offered; to aid the
user in estimating unknown input parameters, and to control the flow of
information among the other program modules.
The preprocessor passes the information generated by the user's answers to the
component modules which calculate environmental concentrations, doses
experienced by the selected site user, and the resulting "acceptable"
concentrations in soil. There are seven component modules in the
"demonstration" version of AERXS.
The Correlation Module is used to predict mass transfer coefficients. The
predictions subsequently are used in the Air Module which calculates the flux
of chemical from the soil into the air and basements of buildings where it can
be inhaled by a site user or visitor. The rate at which a chemical will be
transported from soil into the outdoor air is influenced by properties of the
soil, properties of the chemical, and environmental conditions.
The Unsaturated Zone Module predicts concentrations in soil-water and soil-air
in the soil above the water table. Xt assumes that there is a contaminated
layer that starts at the surface and that the user can define the layer in
terms of its average or typical depth and contaminant concentration. Xf
appropriate, there can be an underlying non-contaminated soil layer.
The Saturated Zone Module predicts concentrations in ground water. Key factors
it considers include the depth of contamination with respect to the depth to
the local water table, and the location of a well used for drinking water, if
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appropriate.
The Produce Module is used to estimate concentrations in produce grown on the
site. The uptake of chemicals is assumed to be contributed by root uptake and
foliar deposition. The extent of uptake is influenced by the type of produce,
length of growing season, chemical properties of the chemicals, and soil
characteristics.
Zn the Ingestion Module, the intakes of water, soil, and garden produce are
estimated. The concentrations in the water, soil, and produce are determined
in the Saturated Zone Module, Unsaturated Zone Module, and Produce Module,
respectively.
In the Inhalation Module, the amounts of chemical inhaled by the receptor
while outdoors and indoors are calculated. Both the inhalation of vapours and
particulate matter are taken into account.
In the Total Dose Module, the doses via all pathways are combined. The total
is then compared to the "acceptable" dose level. The user can decide whether
all or some fraction of the "acceptable" level is to be used.
The calculations of the component modules are passed to the postprocessor,
which offers various tabular'and graphical ways of displaying the results.
Each run of the model concludes with tables that display dose estimates for
each route, total dose estimates, and identification of an "acceptable" soil
concentration. At the user's discretion, three types of graphical summaries
can be displayed: a plot of soil concentrations versus dose; pie charts of the
relative contributions of each route to total exposure; and diagrams that
compare the calculated "acceptable" concentrations to guidelines or criteria
issued by regulatory agencies.
AERIS data bases can provide much of the information needed for the
calculations. Information is retrieved in response to the user's answers
concerning the scenario to be evaluated. The types of information that can be
retrieved include physico-chemical data, "acceptable" dose levels,
bioavailability factors, concentrations associated with other types of adverse
effects, and guidelines or criteria from various jurisdictions. The user has
the opportunity to edit any of the information retrieved from the data bases
so that the redevelopment scenario can be made to resemble actual situations
of interest. AERIS also includes default values and various aids to help users
select appropriate values. The data bases in the "demonstration" version of
AERIS have information for:
-	two types of site users: an adult and a young child
-	four future land uses: residential, commercial, recreational (park land),
and agricultural
-	four organic compounds: benzene, methyl ethyl ketone, phenanthrene, and
pyrene
three inorganic substances: lead, selenium, and zinc
-	the meteorology of six Canadian cities: St. Johns, NFLD, Montreal, PQ,
Toronto, ON, Winnipeg, MN, Edmonton, AL, and Vancouver, BC
-	physical characteristics of nine soil types and 14 underlying formations.
AERIS is structured so that each run evaluates one chemical for one receptor,
one land use, and one environment. The user is encouraged to run the model
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several times and base deeiaiona en the collective outcomes of those suns.
Accordingly, adjustments to input parameters can be made relatively easily.
ARZS is designed to evaluate situations where the soil had been contaminated
sufficiently long ago to establish equilibrium or near-equilibrium conditions
between the various compartments of the environment. These conditions should
apply to moat industrial sites that are being considered for redevelopment. As
such, AERXS is not suitable for evaluating recent spill sites or locations
being considered as candidates for receiving wastes. Nor is it suitable for
calculating changes in environmental concentrations or exposures over time due
to ongoing contaminant contributions from a constant or sporadic source.
To illustrate various aspects of the AERXS model and its response to different
sets of input parameters, two hypothetical redevelopment scenarios were
created. Scenario "A" was assigned characteristics typical of those that might
be encountered at a site in southern Ontario, while Scenario "B" is more
representative of a site in central Alberta.
The AERXS model was used to identify "acceptable" soil guidelines for each
acenario by conaidering three soil contaminanta (benzene, phenanthrene, and
lead), for all four of the land uaea addressed in the data base, and using the
young child aa the receptor.
For benzene, the "acceptable" soil concentrations for Scenario "A" (0.08 to
0.6 ag/kg) are slightly higher than for Scenario "B" (0.04 to 0.6 mg/kg). The
only guidelines in Canada include a value of 0.5 mg/kg recommended by the
Province of Quebec as the threshold at which detailed site investigations may
be needed, and a concentration of 5 mg/kg which is recosmended as the
threshold at which inmediate corrective actions may be necessary.
The lower concentrations in Scenario "B" stem from the lower organic carbon
content in that site's soil and the subsequently higher concentrations of
vapours in air (and higher receptor doses via inhalation). The inhalation of
vapours is a dominant pathway (50 to 84%) for total exposure to benzene in all
land uses except recreational (in which all time on-site is spent outdoors).
Associated with the "acceptable" soil concentrations are outdoor air
concentrations well below the air quality criterion from Ontario but ground
water concentrations (at the site boundary) above the guideline from Quebec.
The values also are less than those reported to cause odours or
phytotoxicological effects.
For phenanthrene, the concentrations for Scenario "A" (3300 to 20400 mg/kg)
are slightly lower than for Scenario "B" (3500 to 23300 mg/kg) . Site soil
conditions in Scenario "A" result in slightly higher ground water
concentrationa of phenanthrene, an important pathway that accounts for 24 to
64% of the total dose estimates. The only guidelines in Canada include a
value of 5 ppm recomended by Quebec as the threshold at which detailed site
investigations may be needed, and a concentration of 50 ppm which is
recommended as the threshold at which immediate corrective actions may be
necessary.
For lead, concentrations for Scenario "A" (8 to 500 mg/kg) are slightly higher T
than for Scenario "B" (5 to 15 mg/kg) . Soil guidelines in Canada lie in the
range of 200 to 1000 mg/kg. The dominating influence of produce ingestion in
Scenario "A" stems from a relatively high plant uptake factor. The
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"demonstration" version of AERXS makes no allowance for reductions of
concentrations in produce that result during food preparation such as washing,
peeling, or boiling. As a result, the estimated doses from eating produce are
likely to exceed actual doses. This becomes an important consideration in
interpreting the output for scenarios in which the consumption of produce is a
major pathway.
The sandy soil in Scenario "B" results in higher concentrations of lead in
ground water and therefore doses via that route are significantly greater than
in Scenario "A". The dominating influence of ground water ingestion in
Scenario "B" results in "acceptable" soil concentrations considerably lower
than those being used or considered by some regulatory agencies. The inclusion
of site ground water as a source of exposure is an unlikely condition
especially in urban areas. Zf ground water had not been included as a pathway,
the "acceptable" soil value for Scenario "B" would have been approximately 100
to 450 mg/kg. For both scenarios, the use of lead-specific bioavailability
factors (rather than the default values) likely would significantly increase
the "acceptable" soil concentrations.
Associated with the "acceptable" soil concentrations for lead are ground water
concentrations (at the site boundary) below the drinking and ground water
guidelines of several Canadian agencies. The values also are well below those
reported to cause phytotoxicological effects.
The investigations of Scenarios "A" and "B" suggest that various aspects of
AERZS are performing as intended. For example, the "acceptable" soil
concentrations are inversely proportional to the relative level of
toxicologieal concern posed by chemicals. As anticipated, future site use is
an important consideration in setting "acceptable" concentrations. Residential
and agricultural uses consistently generate lower "acceptable" concentrations
than recreational and coiranercial uses. Comparisons of output for a compound in
Scenario "A" with that for Scenario "B" show that site soil and meteorological
conditions also can be important influences in determining "acceptable" soil
concentrations.
Based on a review of the results for the two scenarios, it is apparent that
"acceptable" soil concentrations for inorganic substances are strongly
influenced by soil pH and the value of the distribution coefficient (Kg^) 
Since default values for Kdi are not provided by the model, a user who must
"guestimate" at values for	may want to run the model several times to
evaluate the overall sensitivity of the results to this parameter. For organic
compounds that have physico-chemical characteristics in the data base, there
is not a key parameter analogous to the Kdi< but for compounds not in the data
base, the veracity of the values used for aqueous solubility, vapour pressure
and octanol-water partition coefficient should be key considerations in
determining the level of confidence that can be placed in the results.
Because the development of the AERXS model has only reached the
"demonstration" stage, the results that it produces always must be interpreted
in the context of several cautionary notes:
- The "acceptable" soil concentrations that are identified are based solely
* on human health concerns. The conservative, risk-based philosophy and
default values that appear throughout the model (examples include
receptor behaviour characteristics, the bioavailability factors, the one-
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in-a-million level of risk for VSD values, the general availability of
contaminated site soil for exposure) aake it possible to generate
"acceptable" soil concentrations lower than those that regulatory
agencies may be using or considering. Likely causes include the use of
risk as a basis for setting concentrations and the inclusion in the model
of pathways usually not considered. Conversely, relatively high
"acceptable" soil concentrations can be identified when using AERZS,
particularly if the scenario being evaluated generates very small dose
estimates or the important exposure pathways are relevant for chemicals
with certain physico-chemical properties or environmental behaviours. For
example, this could occur in the evaluation of a non-volatile chemical
that has a low level of toxicological concern in a consnercial setting.
-	The algorithms used to estimate environmental fate and concentrations in
environmental compartments as a function of the concentration in soil
have been verified but not calibrated (that is, the predictions of the
algorithms have not been compared to concentrations measured at actual
industrial sites in various environments).
-	There likely are inadequacies in the algorithms in the "demonstration"
version of AERZS. During model development, it was recognized that some
aspects of the algorithms may be poorly suited to evaluating conditions
where soil is extremely alkaline or acidic, plant uptake is not well
understood, and the overall approach may require site complexities to be
replaced with generalizations.
-	The "acceptable" soil concentration values that are determined by AERZS
should not be taken as absolutes but rather as being generally indicative
of appropriate concentrations. To establish soil guidelines with greater
confidence, it may be necessary to evaluate a scenario by running the
model many times so that output variability and sensitivity can be
assessed. It also may be necessary to examine each of the conservative
assumptions used from a chemical-specific perspective and/or other non-
health related issues may need to be considered.
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AERIS - AN EXPERT SYSTEM TO AID IN
THE ESTABLISHMENT OF CLEAN-UP GUIDELINES
by
B:G. Ibbotson1 and B.P. Powers2
1.0 INTRODUCTION
Wherever soil has become contaminated and the contamination poses a threat to people or the
environment, a series of questions inevitably emerges: Does the site need to be cleaned? What
types of remedial measures or actions should be taken? When will the site be safe to use? What
level of residual contamination is acceptable? These and other concerns often are expressed by
the simple phrase "how clean is clean?". Unfortunately, the answer is not so simply stated and at
the present time few jurisdictions have established acceptable soil concentrations or clean-up
guidelines.
The process of deciding whether to reduce or remove soil contaminants and render a site suitable
for use is a complex issue. Many factors need to be considered including the type of industry
that used the site, the contaminants that are present, the age of the plant, site-specific
characteristics such as its geography, geology, hydrogeology, and climate, past waste
management practices, and the proposed future use of the site. The extent and costs of clean-up
activities are largely determined by the level of contamination which, from environmental and
human health standpoints, can safely be left on-site.
To provide direction and guidance to decommissioning efforts across Canada, the Canadian
Council of Environment and Resource Ministers (CCREM; subsequendy renamed the Canadian
Council of Ministers of the Environment or CCME) established the Decommissioning Steering
Committee (DSC). Members of the DSC include Environment Canada, the environment
ministries of Alberta, Ontario, and Quebec, and several industrial associations. In 1987, the DSC
awarded a contract to a consortium of companies to investigate various aspects of
decommissioning. SENES Consultants Limited took on the task of creating a computer program
capable of deriving clean-up guidelines for industrial sites where redevelopment is being
considered. The result of this effort is the AERIS program, an Aid for Evaluating the
Redevelopment of Industrial Sites. The version of AERIS described in this paper currendy is
being reviewed by the Technical Working Group of the DSC and is expected to be finalized in
1989.
Presented at the Fourth Conference on Petroleum Contaminated Soils: Analysis, Fate,
Environmental Effects, Remediation and Regulation, University of Massachusetts, 25 to
28 September 1989, Amherst, MA
1	- Senior Environmental Engineer, SENES Consultants Limited, 52 West Beaver
Creek Road. Richmond Hill. Ontario L4B 1P9
2	- Environmental Scientist, SENES Consultants Limited
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2.0 BASIC PROGRAM STRUCTURE
2.1 Underlying Premises and Constraints
While the broad objective of this study was to develop a model for establishing site-specific
clean-up guidelines, the process of establishing guidelines is far more complex than can be
represented by a mere computer model. As such, it was recognized from the beginning of the
modelling effort that whatever program was developed, it should not be perceived or used as a
sole arbiter in setting criteria. Accordingly, the acronym AERIS was chosen to help users
remember its intended use, that of being an aid for evaluating the redevelopment of industrial
sites. As an aid. AERIS can be used to identify the factors that are likely to be major contributors
to potential exposures and concerns at sites and those aspects of a redevelopment scenario with
the greatest need for better site-specific information.
The typical user originally was assumed to be an environmental scientist, but not necessarily an
expert in understanding environmental fate, toxicology, computer programming, or the other
disciplines that are represented in the model. It was also assumed that some users probably
would use AERIS to study generic situations while others would be interested in specific
scenarios. Those interested in specific scenarios might have some site-specific data but likely
would be uncertain about some of the many factors that can be considered in such an evaluation.
The assumptions about the intended uses and users, together with the objectives and constraints
noted above, influenced a series of decisions made at the outset of model development about
basic model characteristics:
AERIS would be structured so that each run evaluates one chemical for one receptor,
one land use, and one environmental setting. This may require a user to run the model
several rimes and base decisions on the collective outcomes of those runs. Accordingly,
AERIS would be designed so that adjustments to input parameters could be made
relatively easily.
The user should be given the opportunity to select default values for various parameters
or provide site-specific inputs so that the redevelopment scenario in the program can be
made to resemble actual situations of interest. As a result, AERIS would include default
values and various aids to help users select appropriate values.
AERIS would consider only those exposures that are experienced on-site. Off-site
exposures such as those that might be experienced by people whose drinking water
supply is down gradient of a site or who consume commercially-sold produce raised at a
former industrial site would not be calculated. Off-site populations would be considered
indirectly by comparing concentrations in air, water, and produce with existing
environmental criteria such as point-of-impingement criteria for air quality and drinking
water objectives.
AERIS would be designed to evaluate situations where the soil had been contaminated
sufficiently long ago to establish equilibrium or near- equilibrium conditions between the
various compartments of the environment. These conditions should apply to most sites
that are being considered for redevelopment.
It would be assumed that the concentration of the contaminant in soil is constant across
the site and over the depth of soil that is contaminated. Furthermore, the concentration is
assumed to remain constant over time (although there is the option to correct model
results for degradation).
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As such, AERIS is not suitable for evaluating recent spill sites or locations being considered as
candidates for receiving wastes. Nor is it suitable for calculating changes in environmental
concentrations or exposures over time due to ongoing contaminant contributions from a constant
or sporadic source.
Based on many of these considerations, it was decided to design AERIS to run within an "expert
system" programming environment. This facilitated the creation of a model in which the user has
the option of entering either site-specific data or relying on default values. At each point where
the user is asked for information, on-screen assistance can be invoked to help a user make
decisions and understand how the choices can affect the outcome. The entire process has a
relatively high degree of "friendliness" and provides some automatic error checking.
Because it runs within an "expert system" programming environment, AERIS consists of four
basic elements - an "intelligent" preprocessor, a supporting data base, component modules, and a
postprocessor.
2.2 The Preprocessor
The preprocessor takes the form of a series of questions that AERIS asks the user about the
redevelopment scenario to be evaluated. These questions and answers collectively are referred to
as the "Input Session". The answers are used to create a "context" file that describes the scenario
of interest. Context files can be saved and recalled at the user's discretion.
The preprocessor is referred to as "intelligent" due to the utilization of expert system technology.
The preprocessor uses a set of rules (collectively referred to as a "knowledge base") to establish
a structure to the decision support offered; to aid the user in estimating unknown input
parameters, and to control the flow of information between other program components. The
preprocessor contains the "control modules" which are responsible for the user interface during
the input and output sessions, the inference flow mechanism, the retrieval of information from
the data base, and the management of information flow among the component modules.
The preprocessor uses rules to determine if and when goals are met. Many of the rules are in the
form of If... Then... Else statements which represent the decision making that an expert would
consider when evaluating this type of scenario. A rule may be predicated upon one or more
subrules. The resulting branched arrangement formed by the rules is similar to that of a decision
tree. If sufficient information is gathered during the Input Session, the preprocessor passes the
data to the component modules. Only those modules deemed appropriate by the preprocessor are
activated.
2 J The Component Modules
The component modules contain algorithms that estimate contaminant concentrations in various
compartments of the environment. The estimated concentrations serve as the basis for estimating
exposures via various routes of exposure. Figure 1 indicates the sequence that the modules are
used in AERIS and shows how they are interrelated by the information that flows between them.
If concentrations of a contaminant have been measured in one or more compartments of a site, a
user has the option to override the estimated concentrations with the site measurements.
The Correlation Module is used to predict mass transfer coefficients. The predictions
subsequently are used in the Air Module which calculates the flux of chemical from the soil into
outdoor air and into basements of buildings where it can be inhaled by a site user or visitor. The
rate at which a chemical will be transported from soil into the outdoor air is influenced by
B-73

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FIGURE I
COMPONENT MODULES
AND INFORMATION FLOW
B-74

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properties of ihe soil, properties of the contaminant, and environmental conditions.
The Unsaturated Zone Module predicts concentrations in soil-water &nd soil-air in the soil above
the water table. It assumes that there is a contaminated layer that starts at the surface and that
the user can define the layer in terms of its typical or average depth and concentration of
contaminant over that depth. If appropriate, there can be an underlying non-contaminated soil
layer. The Saturated Zone Module predicts concentrations in ground water. Key factors it
considers include the depth of contamination with respect to the depth to the local water table,
and soil characteristics.
The Produce Module is used to estimate concentrations in produce grown on the site. The uptake
of chemicals is assumed to be contributed by root uptake and foliar deposition of local soil
panicles. The extent of uptake is influenced by the type of produce, length of growing season,
chemical properties of the chemicals, and soil characteristics.
In the Ingestion Module, the intakes of water, soil, and garden produce are estimated. The
concentrations in the water, soil, and produce are determined in the Saturated Zone Module,
Unsaturated Zone Module, and Produce Module, respectively. In the Inhalation Module, the
amount of chemical inhaled by the receptor while outdoors and indoors are calculated. Both the
inhalation of vapours and paniculate matter are taken into account.
In the Total Dose Module, the doses via all pathways are combined. The total is then compared
to the "acceptable" dose level. The user can decide whether all or some fraction of the
"acceptable" level is to be used. While human health often will be often be the most stringent
basis for setting clean-up guidelines, a user has the option of specifying a concentration in any
one of several environmental compartments as the basis for calculating an "acceptable" soil
concentration.
2.4 The Post Processor
The results calculated by the component modules are passed to the postprocessor, which offers
the user various ways of displaying the results during the "Output Session". Each run of the
model concludes with tables that display dose estimates for each route and the identification of
an "acceptable" soil concentration. Three types of graphical summaries can be displayed: a plot
of soil concentration versus dose: pie charts that show the relative contributions of each route to
total exposure; and diagrams that compare the calculated "acceptable" concentrations to
guidelines or criteria issued by regulatory agencies.
2.5 The Data Base
The AERIS data base can provide much of the information needed for the calculations. Informa-
tion is retrieved as the user answers questions concerning the scenario to be evaluated. The types
of information that can be retrieved include physico-chemical data, "acceptable" dose levels,
bioavailability factors, concentrations associated with other types of adverse effects, guidelines
or criteria from various jurisdictions, receptor characteristics, meteorological data, and physical
characteristics of soils and underlying formations. The data base in AERIS has information for:
two types of site users: an adult and a young child
four future land uses: residential, commercial, recreational (park land), and agricultural
more than 30 organic compounds and three inorganic substances
the meteorology of six Canadian cities: St. John's, NFLD, Montreal, PQ, Toronto, ON,
Winnipeg, MN, Edmonton, AL, and Vancouver, BC
physical characteristics of nine soil types and 14 underlying formations.
B-75

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The user has the opportunity to edit all of the information retrieved from the data base so that the
redevelopment scenario can be made to resemble the actual situation of interest. AERIS also
includes default values and various aids to help users select appropriate values.
2.6 Pathways Considered
Site users can be exposed to substances present in site soil through various pathways (routes of
exposure). AERIS allows all or any of the following pathways to be considered: inhalation of
vapours and paniculate matter when indoors and outdoors; direct ingestion of local soil and
indoor dust; ingestion of plants grown on-site; and ingestion of ground water (see Figure 2).
The extent to which a person is exposed to a substance by any of these pathways is influenced
largely by the physical characteristics of the person and the way(s) that they use the site. The
AERIS data base contains information for two types of individuals (an adult and a young child)
and four types of future land use (residential, commercial, recreational, and agricultural). A
program user has the option to use any or all of the default values or can replace default values
with specific values at their discretion.
The characteristics associated with residential land use is directed towards estimating doses that
result from the full-time use of the site. The receptor is assumed to live in a single-story house
with a full basement located in the middle of the site. A garden on the property supplies fruits
and vegetables.
Commercial land use is intended to estimate doses that result from spending a substantial
portion of most days on a site inside a building. As such it is analogous to portraying an office
worker or a child at a day-care centre. The building is assumed to have one story and no
basement.
Recreational land use is intended to generate doses received by frequent visitors to a park or
playground. While on-site, visitors are assumed to be engaged in vigorous activities.
The characteristics of agricultural land use are similar to those of residential except that larger
amounts of time are spent outdoors and paniculate matter levels at elevated for a portion of the
year as they would be during plowing.
4.0 SAMPLE RESULTS
To illustrate various aspects of the AERIS program and its response to different sets of input
parameters, two hypothetical redevelopment scenarios have been created. Scenario "A" has
characteristics typical of those that might be encountered at a site in southern Ontario, while
Scenario "8" is more representative of a site in central Alberta. Table 1 displays the information
used to portray the two scenarios.
The AERIS program was used to identify "acceptable" soil guidelines for each scenario by
considering two soil contaminants (benzene and lead), for all four of the land uses addressed in
the data base, and using the young child as the receptor. Table 2 presents the results for both
scenarios.
For benzene, the "acceptable" soil concentrations for Scenario "A" (0.08 to 0.6 mg/kg) are
slightly higher than for Scenario "8" (0.04 to 0.6 mg/kg). The only guidelines in Canada include
a value of 0.5 mg/kg recommended by the Province of Quebec as the threshold at which detailed
site investigations may be needed. The lower concentrations in Scenario "B" stem from the
B-76

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FIGURE 2
PATHWAYS CONSIDERED IN AERIS
POTENTIAL PATHWAYS:
DIRECT INGESTION OF SOU.
INHALATION OF PARTICULATE MATTER
(T) INGESTION OF GARDEN PROOUCS
OIRECT INGESTION OF OUST
INHALATION OF PARTICULATE MATTER
Q INHALATION OF VAPOURS (BOTH OUTOOORS AND INOOORS )
(5} INGESTION OF GROUNOWATE*
B-77

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lower organic carbon content in that site's soil and the subsequently higher concentrations of
vapours in air (and higher doses via inhalation). The inhalation of vapours is a dominant
pathway (50 to 84% of total exposure) for benzene in all land uses except recreational (in which
all time on-site is spent outdoors). Associated with the "acceptable" soil concentrations are
outdoor air concentrations well below the air quality criterion from Ontario but ground water
concentrations above the guideline from Quebec. The associated soil values also are less than
those reported to cause odours in air or phytotoxicological effects.
For lead, concentrations for Scenario "A" (8 to 500 mg/kg) are slightly higher than for Scenario
"B" (5 to 15 mg/kg). Soil guidelines from several Canada provinces lie in the range of 200 to
1000 mg/kg. Ingestion of produce dominates the exposure in Scenario "A". AERIS makes no
allowance for reductions of concentrations in produce that result during food preparation such as
washing, peeling, or boiling. As a result, the estimated doses for eating produce likely exceed
actual doses. This becomes an important consideration in interpreting the output for scenarios in
which the consumption of produce is a major pathway.
The sandy soil in Scenario "B" results in higher concentrations of lead in ground water and
therefore doses via that route are significantly greater than in Scenario "A". The dominating
influence of ground water ingestion in Scenario "B" results in "acceptable" soil concentrations
considerably lower than those being used or considered by some regulatory agencies. The
inclusion of site ground water as a source of exposure is an unlikely condition especially in
urban areas. If ground water had not been included as a pathway, the "acceptable" soil value for
Scenario "B" would have been approximately 100 to 450 mg/kg. For both scenarios, the use of
lead-specific bioavailability factors (rather than the default values) likely would significantly
increase the "acceptable" soil concentrations.
5.0 CONCLUSIONS
AERIS has achieved many of the original objectives set for this project: it is highly user-
friendly; it can be used even if various pieces of site data are missing; it is highly flexible in the
types of contaminants and scenarios it can evaluate; and it generates site-specific clean-up
guidelines. During the development of the model, it also was realized that with increasing ease
of use also came the increasing possibility of misuse. While the original goal was to create a
product that even a novice could use to develop guidelines, the developers have come to regard
the model as being better suited to assisting expens to evaluate situations expeditiously and
consistently. Rather than being used as a surrogate for expertise, its preferred role is as a tool to
assist expens. That AERIS should not be perceived to be a substitute for expertise is evident in
the cautionary notes that the developers suggest be applied to the interpretation of model results:
The conservative, risk-based philosophy and default values that are used when health
concerns are the basis for evaluating a site make it possible to generate "acceptable" soil
concentrations lower than those that regulatory agencies may be using or considering.
Conversely, relatively high "acceptable" soil concentrations can be identified when using
AERIS if the scenario being evaluated generates very small dose estimates or the
important exposure pathways are relevant for chemicals with certain physico-chemical
properties or environmental behaviours.
The algorithms used to estimate environmental fate and concentrations in environmental
compartments as a function of the concentration in soil have been verified but not
calibrated (that is, the predictions of the algorithms have not been compared to
concentrations measured at actual industrial sites in various environments). An
assessment of the model's worth may only be possible once it has been used to evaluate
several real situations.
B-78

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Some of the algorithms represent processes that are not well understood (such as plant
uptake) and the overall approach may require site complexities to be replaced with
generalizations.
"Acceptable" soil concentrations determined by AERIS should not be taken as absolutes
but rather as being indicative of appropriate concentrations. Scenarios should be
evaluated by running AERIS several times with key parameters adjusted between runs to
develop an appreciation of the sensitivity of the output to input data or assumptions.
B-79

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Table 1
PARAMETER INPUTS FOR CHARACTERISTICS OF SCENARIOS "A" AMD
meteorology
site length
soil type
underlying formation
ground water table
soil pH
aauifer thickness
K^- for lead
depth of contamination
organic carbon content
hydraulic gradient
Scenario "A"
Toronto
1000 m
stiff, glacial clay
unweathered
marine clay
1.5 m
7.4
5 m
0.04 is^/kg
1 m
2.5	%
0.01
Scenario "B"
Edmonton
1000 m
uniform, dense sand
silty sand
3	m
6.0
5	m
3.5	m^/kg
1	m
1	%
0.01
Other Assumptions for Both Scenarios
-	dissolution dominates over desorption for lead
-	all bioavailability factors set to default values
Table 2
"ACCEPTABLE" SOIL CONCENTRATIONS FOR SCENARIOS "A" AND
Chemical/
Land Use
benxene
residential
commercial
recreational
agricultural
lead
residential
commercial
recreational
agricultural
Scenario "A"
(mq/ka)
0.12
0.36
0.60
0.12
8
493
111
8
Scenario "B"
(mq/ko)
0.04
0.20
0.64
0.04
4.9
14.3
11.4
4.9
B-80

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Rene Kleijntjens
B-81

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Technological and kinetical
aspects of microbial soil
decontamination in slurry

reactors on mini plant scale.
R.H. Kleijntjens, A.J.J. Smolders, K.Ch.A.M. Luyben
Department of Biochemical Engineering,
Delft University of Technology,
Julianalaan 67, 2628 BC Delft, The Netherlands
B-83

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ABSTRACT
Technological and kinetical aspects of microbial soil decontamination in
slurry reactors on miniplant scale
R.H. Kleijntjens, A.J.J- Smolders, K.Ch.A.M. Luyben, M.C.M. Van Loosdrecht,
Department of Biochem. Eng., Delft University of Technology, Julianalaan 67,
2S28 EC Delft, The Netherlands
A new soil slurry bioprocess for the decontamination of polluted soils is
developed using an integral research approach. For this reason technological
and hydrodynamical research on soil slurries in three phase (S-L-G)
suspension reactors is combined with biological degradation experiments in
the same type of suspension reactors.
In the kinetical experiments aerobic microbial degradation activity is
studied in a slurry mini-plant. The slurry handling in the three stage mini-
plant, consisting of two bioreactors in series and a dewatering section, is
executed in line with the full scale process design. Also the process
conditions are chosen close to the expected full scale conditions. First
step in the process is the separation of entering soil into a coarse and
fine particle fraction. It is the fluidized coarse fraction which is, after
a relatively short residence time, withdrawn from the bottom of the first
reactor while the suspended fraction remains in the system. This mode of
operation makes the first reactor a bioreactor-separator unit, on which
further slurry handling is based.
Preliminary experimental results have shown that separation of polluted
soil, in the primal unit, into two different fractions can be achieved in a
semi-continuous mode. The average solid hold-up in the first experiment was
15 wt'o, in the entering soil diesel present as an oil-like pollutant with an
average concentration of 10 g/kg dry matter. In the withdrawn coarse
fraction, containing mainly the relatively clean sand particles, a diesel
concentration of about 1.5 g'r/kg dry matter was detected. The fine soil
fraction, containing mainly clay and silt particles which adsorb prefe-
rentially the pollutant, is transported from the first into the second
bioreactor. It is in the, fines containing, suspension that microbial
degradation activity is located. The average residence time for the
suspension of fines in the mini-plant is about one week. After remixing the
fine and coarse fractions in the third, dewatering, stage an overall diesel
conversion of 70 % could be measured.
For the given process conditions, chosen as pH 7, temperature 30 C, and a
nutrient medium of only Fe, Mg, P and N (fertilizer), the microbial system
was considered not to be functioning optimally. This conclusion was based on
the rather small degradation activity measured in the suspension of fines in
the second bioreactor.
A biokinetical model was developed to study the degradation process in more
detail. Four flows through the system were to be measured in order to test
the model: diesel, oxygen, carbon dioxide and the free proton flow. Pre-
liminary model results predict an overall yield of 0.4 Cmole biomass/Cmole
substrate, agreeing with literature values. Also a low rate of nitrification
in the system is predicted by the model.
Optimization of the process conditions related to slurry handling and futher
development of the model is on its way.
B-84

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Introduction
General elms:
The development of a continuous slurry bioprocess for
soil decontamination.
The set-up of a kinetica! description for aerobic diesel
breakdown in the slurry system.
Characteristics of the slurry system.
Soil:
Particles are agglomaroted
and packed;
Pollutants are encapsulated
in large soil particles;
Impeded transport of 0, 
CO, and nutrients.
Slurry:
Particles are freely suspended;
Improved availability of pollutants
due to surface enlargement:
- Increased transport rates.
Set-up of research:
Construction and development of a continuously operated mini plant;
Technological description of the three phase slurry (SLG);
Development of a bioki.ieticol model for the aerobic diesel degradation;
Experimental determination of the diesel breakdown in the mini plant;
Validation of the model with data from mini plant experiments.
Impeded
transport
Improved
transport
Pollutant 
Soil	Slurry
Slurry characteristics in the mini plant
Two important, technological design parameters
are investigated:
	the solid holdup, particle loading of the system;
-	the particle size distribution in the slurry.
Classification of soil particles
fine froction:
cloy and silt, large
specific surface
dps 150 m
high adsorbing power
for oil pollutants
coarse fraction:
	sand, small specific
surface
	dps 1001000 Mm
	low adsorbing power
for oil pollutants
As shown in the figure, the Influent soil is split into
a fine and coarse fraction, which are recombined
after the second stage. An average solid holdup
of 15 % (w/v) is reached.
Particle size distribution in mini plant
B-85

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HaO
Analysis
Modelling of continuous, aerobic diesel degradation
The soil slurry is on ecosystem in which, besides diesel degrodotion, several
other microbiological processes, like nitrification, humification etc. occur.
Diesel, a mixture containing compounds ranging from olkanas to polyaromatic
hydrocarbons, is degraded by a mixed population of microorganisms.
In the model, only three processes are considered relevant: diesel degradation
with ammonium (1) and nitrote (2) as N-source respectively and nitrification (3).
Stoichiometric relations
DIESEL + aNH
DIESEL ~ aNO
3 *
~ 14.550.
B10MASS ~ 7.8N0. + 15.BH (3)
+ 7.211-0	J
with DIESEL: CH.
Nitrlfi
cotion
Diesol
degrodotion
CO, I CO,
Biomass Biomass
From these three stoichiometric relations. 7 overall rote equations, for each of the
7 participating compounds, containing 11 variables, can be derived. Thus, 4 variables
(conversion rates) have to be determined to solve the system. These rate values are
calculated from balance equations in which experimental data ore used.
Simplified steady state balance equations	

~-C

H+
*V,NaOirwOH ** v.aed' ll.nad
V_
rCOj "  V3 ' c~ - - - c
'02,9,111 ~ C0j,q,out '
co2,g.in " cco2,,oue '
Svmbola:
C	:	concentration
r	:	conversion rate
V	:	voluae
c	:	volume traction of coil
p	:	soil density
~s	:	mm flow of soil
~"	i	voluaetrie liquid flow
~v	i voluaetric ;ai flow
e'	: residence tine
indisfiai
d
diesel
(b ;
fluidized bed
9 *
gas
H :
protons
ad
aedium
OH :
OH-lons
 i
soil suspension
6-86

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Mini plant performance:
Experimental conditions: - Residence time: 2 x 100 hours
- T-30 C. pH=7.0
The miniplant was operated for 60 days, giving the following average
fl/kg
g/kg
g/kg
g/kg
g/kg
diesel concentrations:
	influent soil
	reactor 1  suspension
 fluidized bed
	reactor 2  suspension
	effluent soil
10
10.S
1.5
B
3
-	The influent soil can be split into a relatively clean coarse
froction and a more polluted fine fraction (see figure).
-	An overall diesel conversion of 70 percent was reached in this
system.
Experimental verification of the model:
Opwatlan tlm (dart)
In reactor 1, the following 4 conversion rates were
measured in the " steady state ":
-	Diesel
-	Oxygen
-	Carbon dioxide
-	Protons
1.94 C-mmol/l.h
1.50 mmol/l.h
1.20 mmol/l.h
0.25 mmol/l.h
O 0 10 1SR0 86a0M40 4MMM(
operation tlm (doy)
By putting these values in the biokinetical model, other
model parameters can be determined. Some prelimenary
conclusions can be drawn:
-	The bruto yield of biomass on diesel is about 0.4, which
is in accordance with literature data.
	The nitrification rate is relatively low.
Future research will concentrate on improving the diesel
degradation in the second reactor, and making a nitrogen
balance over the system for a more profound evaluation
of the biokinetical model.
B-87

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Colin Mayfield
B-89

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Anaerobic biodegradation
Aromatics - reviewed by Berry et al. (1987)  Microbiol. Rev. 51:43-59.
Overview
Two basic pathways for ring reduction- hydrogenation and hydration
Hydration can occur using oxygen from water forming phenol from benzene and p'
cresol from toluene (Vogel and Grbic-Galic, 1986 and 1987).
Five anaerobic processes that can degrade aromatics -
1.	Photnmetabolism
2.	Fermentation
3.	Nitrate respiration (dcnitrification)
4.	Sulfate reduction
5.	Mcthanogencsis
1	Bveen*
2	Cydofttia*
3.	Ctfdoheient
4.	HydroscycJohtaOA*
5 Cyclohtianon#
6. 1,2 - Dh/droiycyclofteiar*
? 2 - Hydro*yhe*cnoie
8.	CyclOhioft'l,2-Dionc
9.	*Hydroiyhionoi*
10 Adipott Samioidtftyd*
H. AOCOIt
12	Cap root*
13	Phenol
14.	Btfuooze
15.	2-0*ocyCtahtaoniCflrboyat
16	MinyteyeiehBon-2-on
17	Hcptonoote
18	Toluene
19	Memy
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Microorganisms in groundwater
1.	Numbers - range from 1 to 10,000,00 per gram/dry weight using modern techni-
ques.
2.	Activity - turnover times of naturally occurring compounds (amino acids and
sugars) range from 50 to 2000 hours (Canadian sites at slower end of values!)
3.	Specific activity per cell varies less than numbers - probably the major dif-
ference between sites was in terms of percentage of active cells, not specific ac-
tivity per cell.
4.	Bacteria tend to be adapted to low nutrient conditions  they are oligotrophia
5.	The microorganisms in groundwater do not seem to be inhibited by "normal"
(i.e. commonly found) levels of contaminants such as
inonoaromatics,PAHs,creosote and creosote by-products, phenols, halogcnated
nromatics and methanes, and heavy metals.
B-92

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Calculations of free energy changes:
Electron Donor Electron Acceptor	kcal/electron j
equivalent I
acetate	O2
acetate	NO3"
acetate	SO42*
acetate	CO2
glucose	O2	-28.70
glucose	NO3"	-19.45
glucose	SO42'	-4.94
glucose	CO2	-4.26
glucose	glucose	-2.43
(fermentation to
ethanol)
-25.28
-16.03
-1.52
-0.85
B-93

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Metastable intermediates:
Glucose fermentation to methane:
Stages in fermenation -
1.	Glucose + HCO3" 	 acetate + propionate +
butyrate + hydrogen
(kcal = -2.74 = 64.3% of overall total)
2.	Acetate + H2O 	 methane + HCOv
(kcal = -602 = 14.1% of overall total)
3.	Butyrate + H2O 	 methane + HCO3"
(kcal = -0.075 = 1.8% of overall total)
4.	Propionate + H2O 	 methane + HCO3"
(kcal = 0.093 = 2.2% of overall total)
5. H2 + CO2 	 methane + H2O
(kcal = .75 = 17.6% of overall total)
B-94

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L.
O
c
o
75
c
O
L
P
U
LJ
fornate
glucose
glycerol
methanol
pyruvate
glycine
lactate
ethanol
succinate
benzoate
acetate
nethane
-i	1	1	1	T
-5 -10 -15 -20 -25
kcal /electron mole
-30
-35

9"


Zero-Orde^r

8"

Monod,
no Growm .


7"
Firit  Order


1
0
n
E
3
Z
6-
5"
/
Monod,
With Growth
Logarithmic

o
o
jz
4"
Logistic


'
o
3"



O.OOI 001 0.1 I 10 100 1000
Initial Substrate Concentration (ug/ml)
FIGURE-3a
Kinetic Models as a Function of Substrate
Concentration and Bacterial Cell Density (From
Alexander,1985)
B-95

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Fermentation
pyrogallol, gallic acid
2,4,6-hydroxybenzoate
phlorglucinol
syringic acid
CO2 & acetate
1982 (Schink & Pfennig)
o-methyl groups of
aromatic acids
acetate & bydroxylated
derivative of acid
1985 (Frazer & Young)

Denitrification
Compound metabolized
Product(s)
Date
p-hydroxybenzoate
liydroxybenzoate
1970 (Taylor)
benzoate
benzoate
3 and 4 hydroxybenzoate
1-cycloliexenecarboxylate
cyclohexanecarboxylate
adipate
1975 (Williams & Evans)
1984 (Braun & Gibson)
ecu
brominated halometlianes
chloroform *
1983 (Bouwer & McCarty)
3-fluorophthalate
2 and 3-fluorobenzoate
1981 (Aftring et al.)
liydroxybenzoate
phenol
1989 (Kuhn et al.)
* may be chemical reaction (reduced iron ?)

B-96

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Sulfate Reduction
benzyl alcohol, p-cresol
nntliranilic acid
-
(1981) Balba
benzonte
C02
(1983) Widdel et a!.
isomers of cresol
-
(1979) Sniolenski &
Suflita
Methanogenesis
plienylacetate, hydrocinnamnte,
cinnnniatc, tyrosine, benzoate
-
1934 (Tarvin & Buswell)
benzoate
methane
1976.(Ferry & Wolf)
lignin ferulic acid
methane
1979 (Healey et al.)
3-chlorobenzoate

1984 (Shelton & Tiedje)
halogenated aromatics
(ninny)
dehalogenated
products
1982	(Suflita et al.)
1983	(Horowitz)
1985	(Suflita &MiIler)
1986	(Wilson et al.)
and others.
N.B. Most results involve "mctlmnogenic consortia" of bacteria, not pure cultures.
B-97

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5. Intermittent, controlled, alternating injections of low levels of oxygen and
electron acceptors to modify groundwater in a localized area. Could set up al-
ternating aerobic and anaerobic environments without excess biomass produc-
tion. Could set up process leading to eventual methanogenic conditions (and
consequent bioremediation activity), subsequent addition of oxygen could lead
to methane-oxidizing activity. Addition of nutrients would then start process
again.
In all cases need to apply stochiometry of reactions to calculate additions of
nutrients, electron acceptors and oxygen.
B-98
Factors affecting bioremediation in groundwater
1.	Contaminants - are they amenable to aerobic and/or anaerobic biodegradation ?
2.	Concentration - are the concentrations present likely to support growth or be
metabolized by co-metabolism or secondary substrate metabolism ?
3.	Concentration of nutrients, electron acceptors, dissolved oxygen, etc., in the
groundwater.
4.	Ilydrogeological conditions (site specific)
-	porosity, flow pattern and velocity
-	DOC and TOC and their effects on adsorption and retardation
-	mixing zones, heterogeneity of porous media
-	historical data on contamination events
-	other sources of contamination or nutrients

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Summary
1.	Aerobic biodegradation and remediation is well-established in groundwater
systems.
2.	Anaerobic bioremediation theory and technology is less well-understood; there
are few well-documented Held examples.
3.	Some non-aromatic organic compounds are obviously more amenable to
anaerobic bioremediation.
4.	The hydrogeology of the site must be understood before using bioremediation
technology. Even aerobic groundwaters can be "driven" anaerobic by
biodegradation of contaminants.
5.	Anaerobic bioremediation has some advantages when it is applicable;
The electron acceptors (NO3", SO42", CO2) are soluble and move rapidly in
groundwater since they are not adsorbed.
The contaminant plume can be "overtaken" by the treatment.
Final contaminant concentrations could be very low.
Can be cheaper and less obtrusive than other methods.
Can be used in conjunction with other methods.
B-99

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Appendix C
Papers by
NATO/CCMS Fellows

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HEAVY METAL REMOVAL PROM CONTAMINATED GROUNDWATER BY THE
USE OF METALLURGICAL SOLID WASTES AKD UJf CONVENTIONAL MATERIALS
Interim Report submitted to the NATO/CCMS Pilot Study
on "Demonstration of Remedial Action Technologies for
Contaminated Land and Groundwater",3rd.International Conference,
6-9 Nov.1989,Montreal, CANADA
Dr.Re'?at APAK,istanbul University,Faculty ef Engineering,
Department of Chemistry and Institute for Environmental Research,
Vezneciler 34459,Istanbul,TURKEY
In the research proposal submitted to the 2nd.Int.Meeting,
1988,Bilthoven,The Netherlands,the purification of heavy
metal -(and possibly pesticide-)contaminated groundwater was
aimed by adsorption/flocculation treatment with metallurgical
solid sorbents,i.e.,red-muds,blast fnmflce, slags, fly ashes
and sludges,and possibly with other unconventional materials
utilizing either an in situ or pump-and-treat technique.
A literature survey of the unconventional coagulants and sorbents
as well as the pollutant removal mechanisms of red muds and
slags were presented.The removal efficiencies (jig metal per
g adsorbent) of the heavy metals Fb(II) ,Cu(II) ,Cd(II) and
U02(II) with acid-treated red muds and untreated granulated
slags were given.Although the proposed activity does not
introduce an innovated technology,it may present a novel
approach in respect to the cost-effective materials suggested
for groundwater treatment.
For advective-dispersive transport of unreactive dissolved
pollutants in groundwater .through a homogeneous adsorbent
soil layer,a single dimensional kinetic equation of the form
dC/dt = D(d2C/dl2) - v^dC/dl)	...(1)
can be given,where D is the hydrodynamic dispersion coefficient
in the direction of flow,^ is the mean linear flow velocity
of groundwater, (dC/dl) and (dC/dt) are the concentration
gradients of the dissolved pollutant wrt. distance and time,
respectively.
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For relatively slow movements of groundwater,mechanical
dispersion is neglectable in comparison to molecular diffusion,
and eqn.(1) reduces to the one-dimensional form of Pick's
2nd. law:
(dC/dt) = D (d2C/dl2)
Given sufficient time,pollutants may he transported to
considerable distances even through media of low permeability.
Let us suppose that a series of wells are drilled into an
aquifer, in the path of an advancing front of water which
contains the heavy metal and/or pesticide contaminants,the
wells being disposed along a line approximately parallel to
the advancing front.^Then we may prepare a dispersion of the
proposed industrial waste adsorbents (preferably pretreated
with acid) in water together with a phase separation - inhibi-
ting agent,and we may introduce this dispersion into the
aquifer through the wells.Alternareiy red mu^js,slags and
sludges may "be buried in the contaminated groundwater flow
path and placed on the surface of groundwater seeps.This adsor-
bent may then act as an in situ adsorption-filtration bed,
removing the indicated contaminants as groundwater passes
through.The latter may be visualized as a fixed-bed reactor
(FBR) from the engineering viewpoint .Increasingly sophisticated
models capable of predicting breakthrough curves for a variety
f applications for single solute adsorption in(FBR)s have
been developed over the past twenty years.
The technique of modeling has the capability of providing
accurate and efficient prediction of the operational system
dynamics most critical to scale-up,e.g.,the optimal adsorbent
(2)
bed thickness.Since the film model v 'alone cannot interpret
the adsorptive removal of large molecules such as chlorinated
(*3}
pesticides,the alternate film-particle diffusion modelv ,
which assumes that mass transport is controlled by a combination
of the film resistance of the hydrodynamic boundary layer and
macroporous intraparticle resistance,may effectively define
the overall rate of adsorption.In this model,an external film
of the uniform liquid phase surrounds the adsorbent particle,
but the particle has a radial macropore-based concentration
distribution.The basic differential equation of the model
comprises,in addition to the terms of eqn(l) which predicts
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the transport of pollutants in groundwater,a third term involving
macropore concentration distribution (q_).
SI
(dC/dt) = Dd(d2C/dl2) - v1(dC/dl) -jop(lzI (dqaTe/dt) ..(2)
p
where D,=liquid phase dispersion coefficient e.g.,cm /sec),
3
apparent particle density (g/cm ) ,e=liquid phase volume
fraction (dimensionless) and q =volumetric average of q
 Yc	a.
over the macropore of radius Rfl.
_3_
R,
w-jKfa v>2ir> *-(3)
a  Id
and (dqa/dt) = Ds g 	2	(rfl2.(dqa/dra)) ...(4)
' ra dra
2
D0 =specific surface diffusivity of the solute (e.g.,cm /sec)
Sf 8
in the macropore.
The boundary conditions for the liquid phase are:
C = c0 + (Dd/v1)(dC/dl) at 1=0	(5)
CQ=initial aqueous phase concentration of pollutant (e.g. ,mol/L)
and (dC/dl)=0 at 1=L	...(6) (L=adsorbent bed thickness)
The corresponding macropore solid boundary conditions are:
kf(C-Ca) = ES)g/>p (dqs/dra) at ra-Ha ...(7)
kf=specific column-based film transfer coefficient(e.g., cm/sec)
and (dq&/dra)=0 at rfi=0	...(8)
In this model,Cgaequilibrium aqueous concn.of the pollutant
species,is provided by the particular isotherm model at the
macropore concentration corresponding to the surface of the
particle.The FBR initial condition for the liquid phase states
C = 0 at t=0	...(9)
while the initial condition for the macropore is given by .
qg =0 at t  0	...(10)
By integrating eqn.(2) using the succeeding boundary condi-
tions, it is possible to predict the breakthrough curves for
various adsorbents,solutes and hydrodynamic conditions
representing contaminant mass transport,controlled by the
combination of film and macropore intraparticle resistance
over the adsorbent layers by means of suitable computer
(< t;)
programs. J'
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The performance ox an adsorption or ion-exchange system
used far groundwater decontamination would depend on a number
of factors,i.e.,the chemical character of influent stream
and pollutant concentration,physical and chemical form of the
adsorbent (grain size,surface characteristics,chemisorption
possibilities etc.),the nature of the prevailing equilibrium
and rate-limiting mass transfer pro cesses, groundwater velocity
and- sorber bed thickness.An efficient design of such a process
is based on laboratory and pilot-plant experiments.
Laboratory scale Freundlich or Langmuir isotherms of an
adsorptive process combined with the breakthrough curve
(i.e.,effluent concentration profile as a function of throughput
of column) make one aware of the specific equilibrium and rate
factors controlling process performance and save a great deal
of time and expense associated with the design of the process
facility. ^The S-shaped breakthrough profile is dependent on
the physical-chemical characteristics of the sorbate and sorbent,
speciation and concentration of sorbate in the influent stream
at a particular pH,the equilibrium reaction and rate-limiting
conditions, flow velocity and bed thickness.The combination of
these factors is specific for a certain application,constituting
the inherent difficulty in the design of these processes.(Pig.1)
Contrary to ion-exchange, the breakthrough curve for an
adsorption process is typically more elongated and the use of
a single-stage fixed bed may result in an inefficient operation.
A series f fixed-beds (FBRs),on the other hand,allows the
breakthrough point of anyjprior bed(s) to be neglected until
breakthrough takes place from the final bed. ^
An economic analysis of the fixed-bed adsorption process
can be carried out by the "operating line" approach of Erskine
and Schulinger.^For this purpose the throughputs (volume of
treated water) until breakthrough are experimentally determined
for different bed depths.If the "exhaustion rate" is defined
as the volume of consumed adsorbent bed at the throughput
prior to breakpoint,and the "superficial liquid retention time"
is defined as the ratio ef the net contactor volume to the
superficial water flow rate ,then exhaustion rates may be
plotted as a function of retention times.(Pig.2) The exhaustion
rate decreases hyperbolically with retention time because the
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initial portions of longer "beds are allowed to reach higher
levels of saturation ,thereby reducing the pollutant loading
on the final portions and extending the throughput prior to
breakpoint.The operating lines of minimum retention time and
minimum exhaustion rate are the two asymptotes of this hyperbola.
The minimum exhaustion rate corresponds to the retention time
that provides saturation levels corresponding to equilibrium
with the influent concentration.The minimum retention time is
the contact period required to achieve only the treatment level
specified by the desired effluent concentration.Capital and
operating costs may then be estimated as a function of super-
ficial retention time and total cost be minimi zed. Since the
regeneration of the proposed industrial waste adsorbents could
not be economically undertaken,the transport of these cheap
wastes to the remedial action site and their installation
would contribute to the capital costs.
Metal speciation and hydrolytic precipitation
Of the heavy metals,all except iron usually have a concen-
tration of c 1 mg/L in groundwater.Their low concentrations
are due to the low solubility ef their minerals and to their
adsorbability on clay minerals and the hydrated oxides of iron
and manganese .However groundwater sources near abandoned mines
and landfills or places where metal finishing and electroplating
effluents are dumped may exhibit anomalous concentrations of
the heavy metals.
Metals occur in groundwater in the following three chemical
forms (dissolved phase):
(i)	free hydrated ions
(ii)	ions forming weak complexes less stable than the adsorbent-
adsorbate interaction (the mono- or poly-nuclear hydrolytic
metal complexes or relatively weak inorganic anion complexes
with C032"/HC03",HPO^"/H2P0+",S042~,Cl",P~and SOf fall in
this category)
(iii)ions	strongly complexed by natural or pollution-originated
soluble organic substances (e.g.,metal humates and fulvates,
metal complexes with pesticides and detergent constituents,etc.) .
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Soft metal ions like Cd(II) and Hg(II) are frequently
present in groundwater in their colloidal species which can
be adsorbed on hydrophobic surfaces. '
Once the total concentration of the concerned heavy metal
in groundwater is measured,one erucial question is how the
pollutant metal will behave in a completing environment of a
specific pH and pE.To answer this question,we need to build
a model which shows the pH where hydrolytic precipitation of
the metal initiates.
. If the total concn.of metal in water is CT,all serts of
polynuclear(hydrolytic and ligand-bound) complexes of the metal
coexist in aqueous phase,and
ct=[mJ+2 ifjl^COH)./] +2if>iL;j] +!1 Z[MiLjJ + '	(11)
i=l 3=1	i=l 0=1	i=l 5=1
M.(OH). representing the polynuclear hydroxo-,and M.L.,
1	J	X J
MiLj e,fcc# ^ein* the L,L* etc. polynuclear ligand-bound
complexes of the metal, [m] stands for the free hydrate a metal
concentration.
By substituting equivalent terms from the relevant
cemplexing equilibria for the concn.of complexes in eqn.(ll)
we get ^ or	 ^ L
CT= [M J +4.^2.2^. [M]1 [OH]3 +^i X	[l]3 + ...
[m]1	<12)
OH -riL	Lf
where , B^.. and B^ ftre cuaniia-fcive formation (stability)
constants of the complexes M^(OH)^,M^L^ and ,respectively
(given in tables).
For the particular pH of the aqueous phase, [oh] =10p^~^Kw
and free ligand concentrations may be measured by chromatographic
techniques.Then eqn.(12) would assume the polynomial form of the
t.th degree in terms of M,the free metal concentration.
CT= ]L	... (14)
1 k=l x
where t is the greatest of numbers (n, q,s,..).
[M]can be solved for in eqn.(1-4-) and the ion product may be
tested whether
[m"J[ohT2^Ksp ...(15) is valid.
Ksp? slu1:)ility product of the metal hydroxide,e.g.,M(0H)2 .
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Thus the upper limit for the total metal concentration
in the aqueous phase of the particular pH may be set by testing
the validity of eqn.(15) so as to permit laboratory-scale
adsorption experiments in a simulated medium without having
to take the precipitation of the metal hydroxide into account.
Conversely far lab-scale sorption experiments,we may not
exceed a maximum pH (found by eqn.15) for a given total concn.
of metal.in order to ensure that metal removal oecurs via
sorption of the metal species on the adsorbent surface and not
by hydrolytic precipitation.
For example,uranyl hydroxide precipitation starts at pH=4.00
for a total uranium(VI) concn.of Um=0.1 M,and pH .. =7.22
5 (11)	PP^*
for Um=10 ^ M. 'By considering the relevant polynuclear
(12 13)
hydrolytic species of uranyl, * 'we may write, in accord v/ith
eqn.(11) :
Ut=[u22+] +[u020H+]+ 2f(U02)2(0H)22+]+ 3[(U02)3(0H)5+] ...(16)
Substituting from the corresponding equilibria yields
UT=[uo22+j+ [uo22+>2x^p^V22f -3* 6f^K2+]3 "(17)
Use of eqn.(17) reasonably explains the experimental pH
values^^ of the indicated uranyl solutions v/here the hydrolytic
precipitation of U02(0H)2 initiates.
In general,most heavy metals,e.g.,lead and copper,would
have been removed down to a concn.of <1 mg/L excluding Mn
in conventional lime-treated wastewaters of pH 7.0-7.5
However the formed heavy metal hydroxides andhydrated oxides
may contribute to the suspended solids content of wastewater
which may settle quite slowly.By seepage to groundv/ater, the
suspended solids-associated heavy metals may be resolubilized
in complexing environments containing organic and inorganic
ligands.To monitor the quality of water near potential heavy
metal pollution sources,the transport of metals in groundwater
should be studied by drilling of several wells around the
source,and the levels of indicator metals in well water should
be continuously determined and compared with background levels.
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Sorption efficiency vs. influent concentration (Rj vs. CL)
*	a	o
and Freundlich isotherms of adsorption (m vs. C) concerning
heavy metal removal with red muds,blast furnace slags and
hydrated oxides
Definition of terms:
R^ is a measure of metal sorption efficiency of the adsorbent
(i.e.,metal distribution coefficient)
 _ metal(bound) M* metal removed/*-adsorbent
iii  	 = 
metal(free) jig metal remaining /mL-3olution
in aq. phase
C = initial concn.of influent solution
o
Preundlich adsorption isotherm:
m = k.C_^^n^ or Log m = Log k + (1/n) Log C_
S	9
whe re
m=equil. amount of solute in the solid phase per unit weight
of adsorbent (jug/g)
k and (1/n) = characteristic Preunril irJupa.nazgg.tgr a rrhich
relate to the specific equilibrium capacity and intensity,resp.
(These parameters should be calibrated by lab-scale batch
evaluations).
Cg= solution concn. of pollutant remaining at equil. (;ig/mL)
Red muds were mineral acid-activated (with HC1) .washed with
water and dried prior to use;blast furnace slags were only
water washed. (Mesh size of all adsorbents:-SO mesh).
The details of the acid treatment as well as the primary
mechanisms of sorptive removal processes on these adsorbents
were given in the previous report.Activated red muds (r.m)
remove metals basically by hydrous oxide gel adsorption/pptn.
and flocculation by adsorption of hydrolytic products,while
blast furnace slags (b.f.s.)of a calcium aluminosilicate
structure preferably tend to sorb metals by ion-exchange and
physical adsorption.
Lead
Pig.3 shows R^ vs. CQ graphs of 90 mL Pb(NO^) influent
solution contacted with (A):l g r.m. (B):2 g r.m. (C):2 g b.f.s.
at pH: 4 for 6 hr (room temp.) .Adsorption isotherms obtained
in each case are:
(A):	Log a = 2.923 + 0.125 Leg Cg
(B):	Log m * 2.894 + 0.093 Log Cg
(C):	Log m = 2.677 + 0.320 Log Cfl
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Sorption of lead with synthetically prepared hydrous MnC^:
Adsorption isatherm (Langrauir type): 1/m = 1.514.10~^(1/CS)
for 106C6310
s
Removal is complete over pH 4,>50>% removal observed even at pH 2.
The adsorption is not a simple counter-ion adsorption,but
specific adsorption on the hydrous oxide gel surface (in accord
with the gel-layer model of hydrous oxidesv " ) since the
oxide adsorbs lead considerably even at the oH of its point of
(18)
zero charge.
Considering the extremely high removal efficiency ef lead
with hydrous MnOg.xHgO over a wide pH interval,it would be
rational to aerate a side stream of Mn-containing groundwater
(contaminated with Pb)so as to coprecipitate and selectively
adsorb lead on the hydrous MnOg surface.Since natural ground-
waters frequently contain iron and manganese salts,such a
technology, i.e., side stream aeration through several recharge
(19)
wells, 'would also enable the sorptive removal of ks on the
Fe(OH) .5.XH0O precipitate, the latter of which being expected to
"(20)
form in that medium; 'The active MnOg ceuld also be retained
on a matrix material such as sawdust by (KMnO ,+oxalic acid)
to synthesize a sorbent efficient in heavy metal removal. J
Conner
Fig.4 shows Rd vs. CQgraphs of 100 mL of Cu(II) solution
contacted with (A): 1 g r.m. (B):l g b.f.s. at pH 4.5 for 5 hr.
The corresponding isotherms are:
(A):	Log m = 3.694 + 0.116 Log Cs
(B):	Log a = 3.383 + 0.154- Log C_
s
Activated r.m. is generally more effective for Cu(II) removal
than b.f.s.
For Cu(II) adsorption with a synthetic Fe(OH)^ suspension
in 1 M solution, the adsorption isotherm is:
Log m = 4.135 + 0.130 Log C (for 250*C *6000 ug/mL)
s	s
This also shows that iron,relatively abundant in groundwaters,
could form the ferric hydroxide suspension under suitable
aeration conditians (as described for Mn) at natural pH values
which would subsequently scavenge Cu contamination.
Cadmium
Fig. 5 shows the Rd-C0 variation of Cd(II) contacted with
1 g r.m. at pH 4.5.The corresponding isotherm is
Log m a 3.508 + 0.101 Log C_
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Uranium stJeciatien and removal
"	O
Basaltic groundwater,having a higher pH and (CO^ +HC0^ )
content than granitic groundwater,has the ability to leach
uranium possibly as the tricarbonato uranyl(II) complex out of
uranium mill and mine dumps and vitrified fission products of
nuclear reactors.Aquifers surrounding the U-ore zone and related
groundwaters have been reported to show uranium contamination
(22)
incidents at"in situ leach mining"sites. '
In neutral ana weakly acidic waters,polynuclear hydroxo-
complexes f uranium(VI),namely U020H+, (U02) 2COH) 22+ and
(U02)^(0H)^+ exist in the bulk phase with U02(II). Therefore
flocculation by adsorption of hydrelytic products,along with
uranyl adsorption on hydrated oxide surface (i.e.,A120^,Pe20^
and Ti02.3H20) may play an important role.ffaturally in a
complexing environment,i.e.,C0^2~/HC0-j~,the threshold adsorption
is expected to shift to alkaline pH values.
Rd vs. CQ graphs of U02(II) with r.m. and b.f.s. are given
in figures 6 and 7,resp.,100 mL of uranyl nitrate solution
of a particular pH being equilibrated with 1 g of adsorbent
in each case.The corresponding isotherms with r.m. are:
Log m = 1.864 + 0.899 Log Cg (pH=3.0)
Log m = 3.605 + 0.217 Log Cg (pH=4.5)
Log m = 3.265 + 0.383 Lag C	(pH-7.0)
3
The isotherms with b.f.s. are:
Log m = 3.722 + 0.051 Log Cg (pH=4.5)
Leg m = 1.098 + 1.326 Log c	(pH7.0)
Red mud is a much better adsorbent for uranyl than b.f.s.
The higher sorption of uranyl on r.m. at pH 4.5 (in comparison
to that of pH 7.0) may be attributed to specific adsorption
on the hydrous oxide surface, since the former pH is much lo\ver
than the point of zero charge of most oxides constituting
the r.m.On the other hand, the basic mechanism of removal near
hyarolytic precipitation pH values seems to be gel precipitation
(sweep flocculation).
At pH 4.5,an uranium loading of 10 000 pg/g on treated
(20
red muds ha3 been observed in batch equilibration tests. '
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Phosphate
Extensive use of synthetic fertilizers and domestic effluents
enriched with phosphate-builder detergents cause P transport
to groundwater.Some pesticides and detergents,resistant tc
biodegradation,may elude treatment plants and reach groundwater.
For many parts of Turkey where the central sewer system has not
been constructed,seepage through septic trenches may contaminate
groundwater with domestic effluents and detergents.Especially
pesticides and fertilizers in agricultural runoff may easily
reach shallow aquifers posing serious problems.
In batch tests,phosphorus removal by activated red mud
was observed to proceed rapidly at first,then relatively slower,
about 7055 of the total P being removed in the initial stage.
Keat treatment of red mud prior to phosphate removal resulted
in dehydration and loss of hydroxyl group components which
occurred to the detriment of phosphate adsorption.The P removal
mechanism comprises adsorptive flocculatitan end partly ion
exchange resulting	in the adsorption of A1(0H) oHoP0. on the
(20 d d 
r.m. surface.
In conventional	treatment techniques,phosphate removal is
maximal at a pH ef 4- with Fe(III) and at a pH of 6 with Al(III)
(25')
salts as coagulants.^ J' For waters of higher alkalinitiy,
economics usually dictate the use of additional metal salt
rather than pH adjustment.Theoretically the minimum solubility
of AlPO^ occurs at pH 6.3,and that of FePO^ occurs at pH 53.^^
Column experiments were carried out for observing the removal
of KaHgPO^ with red mud and calcined pyrite ash; b.f.s. was not
a satisfactory adsorbent.Fig.8 shows the experimental set-up
for obtaining the breakthrough and elution curves.In the r.m.
column,the rate of influent percolation through the adsorbent
was 15 raL/8 hr,with the purpose of simulating groundwater
movement at a hydraulic loading rate of 1 ft/day.Fig. 9 shows
the breakthrough curve.
In groundwater,hydrogen ions are produced in equilibrium
reactions involving bioexidation of organic matter and ammonia,
and through oxidative hydrolysis of Fe(II) and Mn(II) .These
H+-ions react with HCO^"" in natural waters to produce carbonic
acid which lowers the pH.Thus elution possibilities of the
retained phosphate (and some heavy metals) with COg-saturated
water (HgCO^) were investigated so as to assess the recontami-
nation risks of the aquifer with the released species.
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A relatively low proportion of retained ph.03ph.ate could
be eluted from the red mud column with COg-saturated water,(Pig.10)
Calcined pyrite (ash) from Bandirms Etibank Sulphuric Acid
Plant %vas tested for the adsorptive removal of phosphate,prepared
from Kal^PO^.Sineve the mineral acid pre treatment of the ash
was inefficient,only water washed,ground and sieved (-200 mesh)
material was used.The major components of the ash were
Fe2Q3~75%,Si02~15$,and AlgO^S#,mainly consisting of hematite
and magnetite.An optimal proportion of 5 g ash per 100 mL of
solution was used in column tests.Since the phosphate removal
decreased over pH 4.5,a NaHgPO^ solution (approx.of this pH)
was used as influent.The breakthrough curve obtained with an
influent of 5 nig P/L and a flow rate of 2 mL/min is given in
Pig.11.The Freundlich adsorption isotherm for 2Cg105 ^igP/mL is:
Log m = 2.323 + 0.304 Lag C
'	3
The P-adsorption capacity of pyrite ash was about two orders
of magnitude less than that of activated -alumina.
Arsenic
Arsenic in an oxidative environment dissolves in groundwater
3-	2-
as arsenate and its protonated forms; i.e. ,AsO^ ,HAsO^ and
f^AsO^.In weakly reducing environments,the predominant species
are H^AsO^HgAsO^"" and HAsO^^~.At lew pEjASgS^ is stable and
As is 7/ell beyond the limits set for drinking water.Since its
main species are chargeless or negatively charged,As would
not be expected to be retained by adsorption or ion-exchange
during groundwater flow.As removal may be enhanced in the
presence of sulfide in weakly acidic medium due to the low
solubility of its sulfide.
Arsenate (As0^~) removal by coprecipitation was maximal
between pH 6-7 on Fe(OH)^ (FeClyf-NaOH) and between pH 5-8 on
ai(oh)3 (aici3+nh3).
Equilibrated beaker tests showed that 1 g activated red mud
almost completely removed the 20 ppm As in 100 mL of solution
between pH 5-6.Arsenate taken up by red mud could be leached
with alkaline solutions.
Column tests with 15 g f actvd.r.m. did not show a break-
point for a sodium arsenite solution (contg. 30 ppm "As" )
up to 250 mL of throughput.(The initial fractions showed the
presence of As possibly due to non-equilibrium conditions).
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Arsenate removal mechanism,like that of phosphate,is thought
to proceed mainly through adsorptive flocculation of the ferric-
hydroxo arsenate species,and partly through anion exchange
resulting in the adsorption of A1(0H)2*.I^AsO^ on the r.m.
surface.
Pesticides
Som.e persistant pesticides from agricultural runoff may
elude treatment plants and contaminate groundwater .Though
these pesticides have limited aqueous solubility,their concen-
trations nevertheless may exceed threshold values.Processes
that modify convective transport of pesticides through soil
and into groundwater include adsorption/desorptian,degradation,
(
volatilization,runoff and plant uptake. 'Pesticides are nor-
mally leached out of sandy soils and retarded by soils of
high organics content.
It is well-known that filler or carried materials such as
clays or silicas have been used as sorptive materials for the
impregnation of pesticides in commercial formulations/^)
p,p*-DDT,being a persistant pesticide in environmental
waters,has been used as a standard compound for sorption studies.
Alternate procedure for groundwater treatment: Pump-and-treat
technolopy with a calcined sorbent
The desirable contents of constituents in a calcined mate-
rial suitable for water treatment are indicated in literature as:
CaO: 20-40%,AlgO-j: 15-35%, and SiOg: 20-40%. In batch experiments
both treated and untreated adsorbents were used.By acid pre-
treatment,the problem of microcontaminant leach-out from the
sorbents was minimized.
The b.f.s. and r.m. of identical grain size (-80 mesh) were
mixed in 2:1 ratio and calcined at 1100C for 1/2 hr.The
calcined material was denser than water and gave definite
alkaline reaction in aqueous suspension.A maximum amount of
0.5% sulfur compounds as "S" was tolerated in the resulting
material(S coming from b.f.s.).
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This material successfully removed the divalent metal cations
of Pb,Cd,Cu and UOgClI) from their 10 ppm solutions in lab.
experiments with a dosage of 1 g per 100 mL.The adsorbent/floc-
culant may be used for the treatment of pumped groundwater,
which might have been contaminated, e.g.,by seepage containing
metal plating and metal finishing wastewater.After the relati-
vely easy separation of sludge with or rrithout the use of
diatamaceous earth or perlite as filtering aid,the treated
groundwater may be used for irrigation or dilution of contami-
nated groundwater.The rate of settling of sludge,as observed in
preliminary experiments,is higher than that obtained with
conventional coagulants used in conjunction with polyelectrolytes.
For most natural waters of neutral pH,the main sorption mecha-
nism may be adsorption/flocculation.In qualitative tests,the
metals taken up by the calcined adsorbent did not leach out
at a pH of 5.4 (E.P.A. test) .As the pH was lowered, the silicate
structure of the calcined material would, be affected by acidity
and desorption of metals would start to occur.
For designing a pump-and-treat technique for contaminated
groundwater by the use of a calcined adsorbent/flocculant, an
ingenious combination of air stripping, flocculation,sedimenta-
tion and filtration should be developed.Cases have been reported
where the application of polymeric flocculation aids caused an
early clogging of the sand filters,which may be attributed to
the mechanical filtration of voluminous polymer coils in the
(29}
pores of the filter cake formed by residual suspended solids.
As for the density and settling characteristics of the floes,
sodium silicate as a flocculation aid had an improving effect,
in accord with reported data
The sulfide problem
"Tien using the blast furnace slags as adsorbent/flocculant,
sulfide,a precipitating agent for Cu,As and most heavy metals,
may be leached out at acidic pH from the b.fjs. adsorbents."/hen
2
red muds and bfs.s are used together,oxidation of sulfide(S )
by Fe^+ and polyhydroxo-species of ferric iron to(FeS+S) is
feasible ^, the latter capable of being flocculated by alumized
red mud solids.
Furthermore sulfide may precipitate most metals,immobilizing
them in less soluble compounds than their hydroxides.
C16

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The metal sulfides are not amphoteric and hexavalent chromium
may also be precipitated in the process without a separate
reduction step.The probable reactions are:
p-u	2-*-
M + PeS * MS + Fe
Cr2072~+ 2?eS + 1^0 *-2Fe(OH)3+ 2Cr(0H)3+2S + 20H"
Thus the removal of chromium(VI),if present,is automatically
accomplished through reduction and precipitation of chromium
as 'Cr(III)hydroxide in a single step.However sulfide,being
toxic itself,should be carefully controlled in water by the
use of ion-selective electrodes.
Technology selection and EPA's recommendation
(32)
EPA's Technology Screening Guide 'recommends in situ
chemical remediation for heavy metal contaminated soils and
sludges,the potential applications of which include treatment
of metals and radionuclides (mining mill tailings) by neutra-
lization, precipitation,and solidification/stabilization;and
treatment of hydrocarbons,metals ana radionuclides by oxidation/
reduction.The methods worked out up to this point for simulated
purification of heavy-metal -contaminated groundwaters mainly
focus on the volume reduction technologies of neutralization/
precipitation and adsorption/flocculation with industrial waste
sorbents.
Possible future developments of the study
As an essential database for the design of a treatment
facility,breakthrough curves of heavy metals and pesticides
(and their probable combinations) on unconventional sorbents
and the elution possibilities of the retained pollutants in
changing environments will be more extensively studied as
functions of various parameters,i.e.,conc'n.,pH,metal speciation,
sorbent dosage,etc,Additionally in situ stabilization/solidi-
fication of chroraate containing wastes in lagoons of leather
tanning effluents by the use of red muds and fly ashes in cement
formulations may be investigated.Uptill now,the project has been
carried out totally in the dept. laboratories and no external
funds could have been used.
C-17

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Assuming that the present situation continues (meaning
weak university resources,inavailability of funds and lack
of cooperation with the government sector(e.g.,the Turkish
State Planning Organization which could have sponsored such
projects with KATO's recommendations)it will be hard for the
project worker(s) to generate new and useful results.For the
same reasons,an on-site demonstration of the proposed remedial
action does not seem probable in the near future.The suggestions
af the Pilot Study Director and the representatives of the mem-
ber countries '.rill be welcome in this regard.
1'

l''
>
i-

C<
1

i
.v.

\   * * 



ZONE
L "R J












T a -

Z01IE




c

C

1
**,* 



rr 1

Z01IE




D J


c'l



^3
t
K
Fig.l-Idealized breakthrough curves for different depths
in a fixed bed reactor (PBR) (After 7/eber^ ^ ^
C-18

-------
4)
E
0
SUPERFICIAL LIQUID RETENTION TIME
Fig.2-The operating line approach of Erakine and Schulinger^
Pig.3- Rd va.C0 curves ot lead(II) with U):l g r.m.(B):2 g r.a
(C):2 g b.f.s.
C-19

-------
1000-
<)
I
I
500 -
t
R 
\
\
\ (B)
XL.
50
100
150
Cu(II) ,C0(/ig/mL)-
Pig.4- Rd vs. CQ graph far Cu(TI) with (A): 1 g rm.(B):l g bfs.
C-20

-------
1000-
t
500-
0	50	K
Pig.5- Rd ,vo.C0 curve far Cd(II) with 1 g r.
Cd(II)tC0(ji6/mL)-
1000-
500
(B)
V(c>


U02(II)tCe(pg/nL)(A)

-e 	o	-
50
100
150
Pig.6-R^va.C#curves for U02(II) with 1 g r.a.(A)pH 3.0 (B)pH4.5 (C)pH7.0
C-21

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100-
50
50	00
U02(II),Co(Mg/niI.)-
150
Pig.-T-Rd vs.Ce- for U02(II) with bfs. U)pH:4.5 (B)pH:?.0
f	
Contaminant solution feed
reservoir-(to maintain constant
3 hydrostatic pressure over column)
I
Adsorbent-perlite(2:l mass ratio)
'homogeneous mixture
Perlite layer(to aid percolation)
'Porous glass plate or glass \700l plug
r
Tap
Graduated .cylinder for fraction
collection
Fig.8-Experimental set-up for obtaining breakthrough and
elution curves
C-22

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Fig.9-Breakthrough curves for phosphorus adsorption on r.m.
20 AO 60 80 100 120 ai_.ffiu.nt
Fig.lO-Elution of phosphorus from r.m. by (^saturated water
C-23

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Fig.ll- P breakthrough curve on calcined pyrite ash
(5 g pyrite ash, 5 Jug/mL influent concn., 2mL/min flow rate)
RESULTS OP INCOMPLETE COLUMN EXPERIMENTS (adsorbent washed
but not acid-treated)
120 mL of 250 ppm U soln. (prepd.from uranyl nitrate at pH4.5)
did not show a breakpoint on (3 g r.m.+1.5 g perlite)adsorbent
of coarse,medium and fine sizes.(An uranium loading of 10 mg/g
on r.m.could be exceeded)
Percolating 200 ppm Cd(II) soln. (prepd. from CdClg) through
a -144 mesh(3 g r.m+1.5 g perlite) column with a rate of 40mL/8hr
showed the breakthrough at 120 mL of throughput,and practical
saturation was achieved with 260 mL,
Percolating 200 ppm Cu(II) so In. (prepd.from CuSO^) through
the r.m#column(same as that of Cd)with a rate of 20mL/8hr did
not show a breakpoint at 160 mL of throughput,meaning that Cu
loading of r.m.would exceed 10600 /ig/g.
In similar tests,Pb(II) loading was observed to exceed
3550 )ig Pb/g r.a.(pH 5)
Batch equilibration tests and column experiments showed
that the p,pf-DDT loading on r.m.would exceed 500 ;*g/g r.m.
(Influenttl ppm DDT solution in 1:100 acetone-water)
C-24

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REFERENCES
(1)	D. F. Pent on, L.W.Holm and D.L.Saunders,U.S.Patent 4,664,809
May 12,1987.
(2)	A.S.Michaels,Ind.end Eng.Chem.,44(1952) 1922.
(3)	J.E.Rosen,J.Cheni.Phys.,20(1952)387.
(4)	J.C.Crittenden and '7.J.'Veber, j.Envir.Eng.Div. ,Am.Soc.
Civil Engrs.,104(1978)185 and 433.
(5)	'KiT.Liu and 'V. j.'tfeber, j.'Vater Poll.Control Fed., 53(1981)1541.
(6)	"'.J. Weber and J.0,.Thaler in "Scale-up of Water and
Wastewater Treatment Processes'^ ed.N.'.v. Schmidtke and D.W.
Smith) Proceedings lst.Int.'Vorkshop on Scale-up of Water
and 7/astewater Treatment Processes,Alberta, 1983,Butterworth.
11
(7)	"*/.J.V/eber,Phsicochemical Processes for ;"ater Quality Control"
'Viley-Intersci. , John V/iley and Sons,Ne'.vYork,NY(1972) .
(8)	D.G.Erskine and W.C-.Schuliger,Chem.Engr.Progr.,67(1971)11.
(9)	R.Thompson,"Trace Metal Removal From Aquequs Solution",
The Royal Soc.of Chemistry,special publ.No.6lfLondon,1986.
(10)R.Apak	and V.Apak,Chemistry-89 Chaaistry. and jChemi.cal
Engineering Symp.,Ege University,Ku?adasx, Oct .1989.
(11)S.A.Brusilovskii,Trudy	Inst,C-ed.Rudnykh Mest.,Petrog.,
I/Tineral.i Geokhim. ,42(1960)58 (Chem.Abstr.54(1960)24069e).
(12)M.P.Y>'hittaker,E.M.Eyring	and E.Dibble, J.Phys.Chem. ,69(1965) 2319.
(13)i.I.Mavrodin-Tarabic,Rev.Roum.Chim.,19(1974)	1461 (C.A.82:103868m) .
(14)H.W.Gehm	and j.I.Bregman,"'Handbook of V/ater Resources and
Pollution Control",Van Nostrand Reinhold Co.,New York,1976.
(15)R.J.Ring,D.M.Levins	and AlB.Cooper,Austr.Chem.Eng.Conf. 13th.
(1985)151.
(16)	J.Kudla,Tech.Poszukiwan Geol.,25(1986) 18(C.A. 107:64389u).
(17)	J. vV.PerrsmtR. J.Hunter and K. j.L.Wright,Austr. J. Chem.,
27(1974)461.
(18)	J.j.Morgan and W.Stunnn, J.Colloid Sci. ,19(1964) 347.
(19)	D.F.Edson,Proc.-Int.Water Conf.,Eng.Soc."rest Pa., 46(1985) 518.
(20)	E.Isic,Vodoprivreda,19(1987)141 (C.A.107:I6l269n) .
(21)L.Berak,Czech.CS	203,307 1 5LIay 1983(C.A.99:165614k).
(22)T.D.Vandell,Interfacing	Technol.Solution Min.,Proc.
SME-SPE Int.Solution ISin.Syrap. ,2nd. 1981 (Publ. 1982) 299.
(23)H.Mikami,M.Sasaki,K.Hachiya	and T.Yasunaga, J.Phys. Chem.,
87(1983)5478.
(24)V.Apak	and E.Unseren,in"Flocculation in Biotechnology and
Separation Systems"(Ed.Y.A.Attia),Elsevier Publ.,Amsterdam,
1987.
C-25

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(25)H.L.Recht	and M.Ghassemi,EPA Report 17010 EKI(1970).
(26)C.S.Helling	and T.
-------
Robert Bell
C-27

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PLANT UPTAKE OF NON-IONIC ORGANIC CHEMICALS FROM SOILS
J.A. Ryan1*, R.M. Bell2, J.M. Davidson3, and G.A. O'Connor4
1.RREL, USEPA, Cincinnati, Ohio, 45268.
2.Environmental Advisory Unit, University of Liverpool, U.K.
3.University of Florida, Gainesville, Florida.
4.New Mexico State University, Las Cruces, New Mexico.
ABSTRACT
Methodologies utilizing simple properties of chemicals - half-life	log octanol-water partition coefficient (log Kgu) and
Henery's Law constant (He) - are developed to screen organic chemicals for potential plant uptake.
INTRODUCTION
Early in 1983, the American Chemical Society's Chemical Abstract Service
registered its 6,000,000th chemical. The Toxic Substance Control Act Inventory
list 63,000 chemical substances whose manufacture, .processing and ultimate use
for commercial purposes has occurred in the United States since January, 1975
(TSCA Inventory, USEPA, 1985). Additionally, the number of synthetic organic
chemicals used and disposed of by society is increasing at a rate of about 1000
new chemicals per year, (Loehr and Halina, 1986) . This endless supply of compounds
together with the variety of reactions they can undergo in the environment makes
describing their environmental impact exceptionally challenging.
Of the possible locations for the disposal of wastes - surface waters,
atmosphere or land the latter represents a common location for waste disposal as
well as an opportunity to manage wastes with minimal environmental impact. The
object of the land disposal practice is to degrade, immobilize, and/or transform
the wastes into beneficial, or at least non detrimental constituents. There are
over 200 industrial waste Jand treatment sites in the United States, and a larger
number of land treatment sites for municipal wastewater and sludge (Loehr and
Halina, 1986). Land disposal of wastes has increased during the past decade and
is projected to continue to increase in the future (Loehr and Halina, 1986).
The study of organic chemicals in the soil environment has been dominated by
agricultural chemicals (e.g., insecticides, nematicides and herbicides) and
specific compounds that persist in the soil (e.g., PCB's, PBB's etc.). This
narrow perspective probably occurred because of the prevalence of agricultural
chemicals in soil, complexity of reactions, large number of compounds, and cost
associated with organic analysis. Specific compound attention has been propagated
by the formation of lists of specific compounds, such as the organic priority
pollutant list of 1976. Even with this narrowing of focus, the cost associated
with a chemical by chemical investigation is prohibitive. The approach therefore
C-29

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has been to utilize physicochemical parameters, or to group compounds on the basis
of their chemical or physical properties and study selected compounds from each
group. Clearly, we must insure that the grouping of compounds is correct and that
the factors used in the groupings predict the behavior and impact of compounds
hot studied.
The following attempts to provide a framework which uses physicochemical
parameters to evaluate potential plant uptake of neutral or weakly ionized organic
chemicals from soil. The procedure does not predict plant concentration of
organics in a field situation, but provides a procedure for grouping chemicals
by their relative potential for plant uptake. As such, it should allow compound
screening for their likelihood for plant uptake and, therefore, justify
experimental evaluation as well as identify chemicals of low concern where testing
may be counterproductive. It should also reveal where information is needed to
confirm the screening model.
BEHAVIOR OF ORGANIC CHEMICALS.
Many processes impact organic chemicals in the soil environment. The sum of
these actions determine the compounds environmental impact (Figure 1). Factors
such as pH, CEC, OM content, clay content and soil water content all impact the
rate and extent of these processes (Goring and Hamaker, 1972). In a given
situation (soil and environmental conditions) however, the processes are dependant
upon the physical and chemical properties of the chemical. The characteristics
of a chemical that determine its distribution between vapor, solid, liquid and
adsorbed phases in the soil, and its degradation rate become the characteristics
that determine its environmental fate and impact upon plants. These processes
determine not only the form of the compound that is present, but also the speed
at which the compound moves or spreads through the soil and atmosphere to achieve
its impact. The importance of each of these processes will be discussed
separately.
FIGURE 1 SOIL TRANSFORMATIONS
C-30

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Degradation
Plant uptake of most chemicals is concentration dependent, therefore a
compound's persistence can alter its ultimate fate and environmental impact.
An assessment of the half-life of a particular compound is a relatively simple
way of limiting the number of soil borne organic compounds that need to be
considered as likely to' impact a plant grown in contaminated soil. The
concentration of synthetic organic compounds in the soil decrease with time,
providing no further additions occur. Processes contributing to the decrease with
time are biological and/or chemical degradation. These processes have been shown
to be dependent on soil and environmental factors (ie., temperature, water
content, soil pH, and organic C) , (Hamaker, 1972). Without the quantitative
information necessary to describe the functional dependence of degradation on
these factors, it has been shown that degradation of a specific organic chemical
can be described by a first order rate constant, y., (Nash, 1980; Rao and Davidson,
1980; Jury et al., 1983; Gillett,1983) . This parameter is usually measured by
determining the fraction of an applied chemical remaining.aftar.,a time t according
to Equation 1 :
where M(t) is the quantity of the compound remaining in the soil at time t. The
half-life, T1/2, cf a compound is defined as the time required for one half of the
concentration of the chemical at any point in time to be lost from the soil. This
is related to the rate constant (/z) by :
Half-lives of many chemicals have been published (USEPA, 1979; Jury et al.,
1983; Smith and Dragun, 1984). Unfortunately, reported values of n may vary
enormously because measured half-lives of compounds in the soil do not always
reflect degradation. Often losses include other pathways (i.e., volatilization,
leaching, etc.). Additionally, water content, microbial population, and
temperature can significantly influence the rate of loss thus, a chemicals life
may vary from soil to soil. Half-lives are reported in Table 1 from data in USEPA,
1979. Compounds are distinguish from one another on the basis of half-life in the
soil: less than 10 days, (Class A); between 10 and 50 days, (Class B) ; and greater
than 50 days, (Class C). Gillett considered compounds of T1/2 greater than 14 days
of sufficient stability to be of concern (Gillett, 1983). The impact of chemical
half-lives on concentration of a pollutant in the soil over time is shown in
Figure 2. Pollutants with half-lives of less than 10 days, for example, are
reduced to less than 0.10% of their original concentration after 100 days in the
soil, in contrast, pollutants with half-lives of greater than 50 days are still
present at >25% of their original concentrations after 100 days. Their impact,
and relative potential for plant uptake, are much more pronounced than that for
M(t) - M(O) exp
[1]
[2]
C-31

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compounds with half lives of less than 10 days.
1 -

a 0.9 -
 0.8-
HALF-TIME (days)
 0.7-
V\ 	-^100
5 0.6-
05 0.5-
\ 			
s= 0.4-
\ \j0
 rt o
" 0.3-

E-
u 0.2-
V^IQ ~ 
<

 o.i -

n

u *

0 20 40 60 80 100

TIME (days)
FIGURE
2 EFFECT OF CHEMICAL HALF LIFE AND TIME ON

FRACTION REMAINING
The average concentration present during the plant growing period can be
calculated by integration of Equation 1 between the limits 0 and t (growth period)
and dividing by t. Assuming a growth period (i.e. 50 or 100 days) the effect of
half-life on the average soil concentration as a fraction of the amount originally
applied illustrates that the limits for classification of compounds based on half-
lives are arbitrary (Figure 3). The length of exposure (i.e. plant growth period)
and relative average exposure must be specified before compounds can be classified
by their half-lives. For example, our use of 10 and 50 day half lives as
classification end points was based on a 100 day growth period and relative
average exposures of 0.15 and 0.5. Using the same half-life end points but a 50
day growth period means relative average exposures of 0.3 and 0.7.

0. 9
1





o
GO
-




/~s.
o
w
n
-"s.
>
(0
x:
0. 7
0. 6
0. 5
0. 4
0. 3
-

50 days ^		 	
100 days


0. 2
-





0. 1
-





n






U
C

20
40 60 80
HALF-LIFE (DAYS)
100

FIGURE 3
AVERAGE
SOIL CONCENTRATION VS HALF
LIFE




FOR 50
AND 100 DAYS OF GROWTH

C-32

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TABLE 1. Log K^, Half-life and He for the Priority Pollutants
Conpound log Kw
T1/2
He
Coopomd log
T1/2
He
PESTICIDES







20.Acrolein
-0.09
8
2.8E-03
21.Aldrin
4.62
C
4.9E-04
22.Chlordane
4.3
C
3.9E-03
23.000
5.99
C
0.5E+00
24 .DOE
5.69
B
9.0E-O4
25.0DT
5.98
C
2.0E-03
26.0ieldrin
2.9
C
3.0E-04
27.Endoaulfan
3.55
C
nd
28.Endrin
4.5
C
1.7E-05
29.Heptachlor
3.9
A
6.2E-02
30.Heptachlor epoxide
3.9
c
3.2E-05
31.Hexachloroeyclohexane
3.8
B
3.0E-04
32.Lindane
3.72
c
6.0E-04
33.Isophorone
1.70
nd
nd
34.TCDD
6.14
c
nd
35.Toxaphene
3.85
C
2.1E-01
raLTCHLCBIHATED BIPHENYLS







36a.Arochlor 1016
4.38
c
8.6E-01
36b.Arochlor 1221
4.09
c
1.3E-02
36c.Arochlor 1232
4.54
c
2.1E*00
36d.Arochlor 1242
4.11
c
5.5E-02
36e.Arochlor 1248
5.6
c
1.1E-01
36f.Arochlor 1254
6.04
c
1.1E-01
36g.Arochlor 1260
6.11
c
2.9E-01
37.2-ehloronaphthalene
4.12
c
1.3E-02
HALOGENATED ALIPHATIC HYDROCARBONS






38.Chloraaethane
0.91
c
1.6E+01
39.0ieh Ioromethane
1.25
B
8.5E-02
40.TriehIoroaethane
1.9
B
1.2E-01
41.Tetrachlorcnethane
2.64
nd
9.6E-01
42.Chloroethane
1.54
8
6.1E-01
43.1,1-dichIoroethane
1.7?
B
1.7E-01
44.1,2-di chI oroethane
1.48
B
3.8E-02
45.1,1,1-trichIoroethane
2.17
nd
1.3E+O0
46.1,1,2-triehloroethane
2.17
nd
3.1E-01
47.1,1,2,2-tetrachloroethane
2.56
A
1.6E-02
48.HexachIoroethane
4.62
nd
4.1E-01
49.Chloroethene
0.60
A
6.2E-01
SO.1,1-dichloroethene
1.48
A
1.8E-01
51.1,2-trans-dichloroethene
1.48
A
2.7E-01
52.TrichIoroethene
2.29
A
3.8E-01
53.Tetrachloroethene
2.88
A
6.4E-01
54.1,2-di ch I oropropane
2.28
nd
1.2E-01
55.1 .Benzo(a]pyrene
6.04
c
4.9E-01
98c.0 (benzo[a]anthracene
5.97
C
nd
98d.Indeno(123-cdlpyrene
7.66
c
nd
MISCELLANEOUS COMPOUNDS







99.0iaethyl nitrosaaine
0.06
nd
nd
lOO.Oiphenyl nitrosaaine
2.57
nd
nd
101.0i-n-propyl nitrosaaine
1.31
nd
nd
102.Benzidine
1.81
A
nd
103.3,3-dichlorobenzidine
3.02
A
nd
104.1,2-diphenylhydrazine
3.03
nd
nd
105.Acrylonitrile
0.25
A
3.8E-03




uhere log K and half-live* (ataetsed aa A  < 10 days, B  10-50 daya.C   50 da/*) are baaed on the principal fata process in the
anvironaentll)SEPA,79); where Henry1* Constant ( dioansionleas) haa been obtained froai the UERL Treatability Oatabaae
C-33

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Adsorbed-Llauid Partition
Considerable research data exists on the equilibrium between an organic sorbed
to the soil and that in the soil-water phase. For simplicity, this is often
expressed as a linear sorption isotherm (Karickoff, 1981):
Cs= Kd Cu	[3]
where Cs is the sorbed concentration (g/kg soil), CL is the solution concentration
(g/m3 soil solution) and Kd (m3/kg) is the slope of the sorption isotherm or
distribution coefficient (Kay and Elrick, 1967). Equation 3 assumes complete
reversibility and equilibrium between the two phases, which may not strictly occur
for some chemicals. Di Toro and Horzempa (1982) , reported that the sorptive
process of 2,4,5,2',4',5'- hexachlorobiphenyl consisted of both reversible and
strongly bound components. Such bound residues could not be extracted by normal
analytical techniques, but could be detected by radiolabelling. Similar findings
have been reported by others working with herbicides and chlorobenzenes (Khan,
1982; and Scheunert, et al., 1985) and may require the above mathematical approach
for sorption be modified to account for bound residuals.
In soils and sediments, where the clay content is relatively low, pollutant
sorption occurs primarily on the organic fraction of the soil, (Hamaker and
Thompson, 1972; Rao and Davidson, 1980). The degree of sorption of the non ionic
organic pollutant is then dependant upon the organic carbon content in the soil,
or sediment. Variation between materials, which otherwise exhibit a wide range
of physicochemical properties, can then be reduced by defining an organic carbon
distribution coefficient (K^):
- J*	[4]
' OC
where Kd is the slope of the sorption isotherm in m3/kg, and is the organic
carbon fraction in the soil or sediment, (Means, et al., 1982). This assumes that
all organic matter has the same chemical structure.
Km is defined as the ratio of the organic chemical concentration in octanol
to that in water, when an aqueous solution of the organic chemical is mixed with
n-octanol and then the organic chemical allowed to partition between the two
phases (Dawson, et al., 1980). There have been many investigations into the
relationship between and KM. Briggs (1973) for example reported:
logK^ = 0.524 logK^ + 0.62	[5]
from his work with 4 agricultural soils and 30 chemicals chosen for their wide
range of properties. Similar relationships, see Equation's 6, 7, 8, 9, and 10,
have been reported ( Means, et al., 1982; Schwarzenbach and Westall, 1981; Rao,
et al., 1982; Karickhoff, 1981; and Brown and Flagg, 1981 respectively).
logK^ - logK^ - 0.317	[6]
logK^ = 0.721 logK^ +0.49	[7]
C-34

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logR^ = 1.029 logK^ - 0.18	[8]
logK^ = 0.989 logK^ - 0.346	[9]
logK^ = 0.937 logK^ - 0.006	[10]
The relationships are surprisingly similar to one another considering they cover
over 100 chemicals, as well as a large number of soils and sediments (Figure 4).
Thus when the sorption value of a particular pollutant in a particular soil is
not available, advantage can be taken of the relationship between the organic
carbon distribution coefficient (K^) and the octanol water partition coefficient
(KoJ the chemical. Recently, a nonempirical measurement (first-order molecular
connective indexes) calculated from the non-hydrogen part of the molecule has been
shown to predict the of organic compounds with great success (Sabljlc, 1987).
As these calculated values for various organic compounds become available it will
allow for their use in place of or
To have greatest impact upon plant uptake, the organic compound must stay
within the vicinity of the plant root, and not be quickly leached away by mass
flow. For example most residual soil-acting herbicides have Kd values in the range
of 1-20 with values up to 40 being satisfactory for most soil applications
(Graham-Bryce, 1984). Compounds with Kd's of greater than 1000 become inactivated
by soil sorption (Graham-Bryce, 1984). Based on Equation 4 and Equation 9 for a
soil with f^ = 0.0125 (OM  2%) Kd's of 1, 20, 40, and 1000 would represent log
Km's of 2.3, 3.6, 3.9, and 5.3, respectively.
Liguid-Vapor Partition
Vapor phase partitioning of a compound in the soil influences the spread of
the compound through the soil. Even for chemicals with relatively low vapor
pressure, this transport route has been shown to be significant (Mayer,et al.,
1974). Those chemicals that have a high vapor pressure may easily move from the
soil solution into the soil air phase, where they can move throughout the soil
C-35

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and across the soil surface. The vapor-phase may be taken up by the plant either
through roots or by above ground portions of the plant.
The compartmentalization of the compound between the soil solution and the air
spaces in the soil is frequently described by Henry's Law (Jury et al., 1983) with
the extent of partitioning described by Henry's Constant (He). This can be
calculated as:
Henry's Constant (He) = ^6,J,0gP- ^	[11]
where P = vapor pressure of pure solute in mm/Hg,
M = molecular weight of solute,
T - absolute temperature, and
S = solubility in water mg/L
(Thibodeaux, 1979) . Henry's Constant may be expressed in different units and vary
by several orders of magnitude depending upon the source of the original data.
For example, estimated values for vinyl chloride of 2.3 X 10"2 to 6.39 atm m3/mol
are reported by Mackay and Shiu (1981) and .Goldstein (1982), respectively.
Experimentally determined He values are considered more reliable than calculated
values. Henry's Constant, dimensionless, for the priority pollutants is provided
in Table 1.
Comprehensive studies have not been conducted to determine the He above which
volatilization plays an important role in the transport of a chemical in the
atmosphere. Thus, it is not possible to select a He above which transport in the
soil will occur primarily in the vapor phase. However, a partition between the
vapor and aqueous phases of greater than 10"* is normally sufficient for a
chemical to be a good preemergence herbicide (Graham-Bryce, 1984). Jury et
al., (1984) utilized three volatility categories with He values of 2.5 x 10'3, 2.5
x 10"5 and 2.5 x 10"7. Gillett (1983) utilized values of 10"3 and 6 x 10"5 in his
classification. Thus, the value of 10'4 may be a reasonable transition point for
determining when vapor diffusion becomes important. This would mean that vapor
diffusion would be important for all PCB's and halogenated aliphatics and
unimportant for some of the monocyclic and polycyclic aromatics and many
pesticides. Soil sorption can significantly reduce chemical volatilization
(Fairbanks et al., 1987) thus, the arbitrary value of 10'* may overestimate the
importance of volatilization in high organic carbon soils. Jury et al., (1983)
used He and KM to calculate volatilization flux from soil.
PLANT UPTAKE 07 ORGANIC CHEMICALS
Chemical uptake by plants is a complex process that may involve a compound
specific active processes, and/or a passive process in which the chemical
accompanies the transpiration water through the plant. If the former case
dominates, a rigorous relationship between plant uptake and the chemicals
C-36

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physicochemical parameters may not exist, although some general guidelines may
be expected. If uptake into the plant is a passive process, rigorous relationships
should exist.
It is generally accepted that there are four main pathways by which a chemical
in the soil can enter a plant (Topp et al., 1986). These are:
1.	root uptake and subsequent translocation by the transpiration stream,
2.	vegetative uptake of vapor from the surrounding air,
3.	uptake by external contamination of shoots by soil and dust, followed
by retention in the cuticle or penetration through it, and
4.	uptake and transport in oil cells which are found in oil containing
plants like carrots and cress.
The amount of an organic chemical found in a plant will be the sum total of
each of these transport routes minus metabolic losses. Their respective importance
will depend upon the nature of the organic chemical, the nature of the soil, and
the environmental conditions under which plant exposure occurs. Pathways 3 & 4
are significant only in specific situations. Thus, for the purpose of describing
the general case of plant uptake, they can be discounted as major routes of plant
contamination. Host reported instances of plant uptake of soil-borne organic
compounds make no attempt to discriminate between pathways 1 & 2. Therefore, the
relative importance of each pathway, Under different environmental conditions,
has not been assessed at present.
Root Uptake And Translocation
Shone and Wood (1972) investigated the absorption and translocation of the
herbicide simazine by 6-day-old barley plants in solution cultures. The
experiments were either 24- or 48-hour experiments conducted under different
conditions of humidity, light intensity, temperature, and levels of metabolic
inhibitors. The relationship between simazine transport and water uptake was
described by a transpiration stream concentration factor (TSCF), defined as:
Tscp = ua simazine in shoots per mL water transpired
Hq simazine per mL of external solution
They found that water was taken up preferentially to simazine, because the TSCF
was always less than unity, i.e., the concentration of simazine in the plant
shoots per mL of water transpired never reached that in the external solution.
There was no evidence of loss of or breakdown of the parent compound during the
experiment. The concentration of simazine in the plant roots, on a fresh weight
basis, however, reached a value greater than unity as a result of physical
sorption of the herbicide to the root tissue.
Evaluation of other triazines led to the conclusion that plant uptake was, in
general, a passive process because TSCF was less than unity, (Shone et al.,1973).
C-37

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Plant uptake of 6 herbicides and a fungicide showed that TSCF was independent of
concentration and less than unity for all except 2,4-D at pH 4.0 (Shone and Wood,
1974). In the case of 2,4-D at pH 4.0, plant uptake was metabolically influenced.
Briggs et al.,(1982) evaluated plant uptake of 18 chemicals and found that the
TSCF was less than unity for all chemicals studied. They related the TSCF to the
octanol/water partition coefficient (K^) for the chemicals and found a bell
shaped relationship between TSCF and K^, with a broad maximum around a of 1.8.
A Gaussin curve (Figure 5) was fitted to the data such that:
TSCF = 0.784e-^19K0U " 1-78) /2.44]	[12]
The authors suggested that at KM values below 1.8, translocation is limited by
the lipid membranes in the root. At KM values above 1.8, translocation is limited
by the rate of transport of the lipophilic chemical from the plant root to the
top of the plant. All the TSCF values were below unity, suggesting passive
chemical movement into the shoot with the transpiration stream. There was no
evidence that chemicals were taken up against a concentration gradient.
l.o-

0.8 -

fa 0.6-
u
U3
4 -
/* 
 "V
0. 2 -
 \
0 -
			 "a

1 0 1 2 3 4 5
log Kov
FIGURE
5 RELATIONSHIP BETWEEN log Kow AND TRANSPIRATION
STREAK CONCENTRATION FACTOR
Aaaoteo from Br loos et ai ^902
Shone and Wood (1974) proposed that the uptake of a chemical into a plant root
could be described by a root concentration factor (RCF), defined as:
= concentration in root.(ua/a fresh wt.l
concentration in external solution,(ng/mL)
Using radiolabeled herbicides in solution culture with barley seedlings, they
showed that the quantity of the herbicide transported to the plant stems (TSCF)
could not be inferred from the concentration in the plant roots (RCF). In
addition, although the RCF of some of the tested herbicides exceeded unity, uptake
was not affected by temperature. This, suggests the compounds were retained by
physical sorption rather than biochemically.
When barley seedlings were transferred from the herbicide amended solution
culture to a herbicide free solution, RCF decreased before TSCF was affected by
C-38

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the change (Shone et al., 1974). Thus lipophilic herbicides appear to penetrate
the cortical cells of the root whereas the lipophobic herbicides are largely
confined to the free cell space in the root.
Briggs et al.,(1982) found that RCF was related to K^. Starting with a value
of less than unity for polar compounds, RCF increased with increasing K^.
Sorption of chemicals by macerated roots was very closely related to the RCF of
living roots, for the more lipophilic chemicals. In contrast, the RCF of macerated
roots continued to decrease as the lipophilicity decreased (Figure 6). There was
a linear relationship between the log concentration factor of the macerated roots
and log K^:
log Kov
FIGURE 6 EFFECT OF TISSUE STATUS ON THE RELATIONSHIP
BETVEEN log Kov AND ROOT CONCENTRATION FACTOR
Aoaptea from a-iggs et al. 1982
Assuming that RCF of living roots could be explained by two processes: (1) a
partitioning of the organic chemical between the lipophilic root tissue and
external solution culture and (2) a fraction of root that is aqueous and equal
in concentration to external solution phase (constant for all compounds, 0.82).
Briggs et al., (1983) suggested that sorption of chemicals by the root is a
partitioning described by:
log(RCF - 0.82)  0.77 logK^ - 1.52	[14]
They proposed an analogous stem concentration factor (SCF):
SCF = concentration in stem (ua/a fresh wt.l
concentration in external solution (/xg/mL)
Macerated stems sorption of organic compounds was also related to the KM of the
compound:
logSCF(lt(11cratBd ,t) = 0.95 logK^ - 2.05	[15]
Assuming that the contribution of the aqueous phase in the stem was similar to
that in roots (0.82), the partition between the stem and xylem stream is:
^^(^(WiytM i^) " 0*2)  0.95 logKM  2.05	[16]
1 C- 39

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The SCF is then given by the K(steni/J(yletl partition coefficient multiplied by the
partition of the external solution present in the xylem sap (TSCF):
SCF = [io(0*951ogK< ~ 2.05) + 0>82]*	1?j
[ (0.784) io_0*434^^^o" ~ 1-78) /2.44] ^
For 15 chemicals (logK^ from -0.57 to 3.7), the experimental points fit the
predicted line quite well (Figure 7). The shift in log where TSCF reaches a
maximum (1.8) to where SCF reaches a maximum (4.5) arises because sorption of
the more lipophilic compounds by the stem tissue increases faster than the TSCF
decreases. The predicted decline in SCF for compounds of log KM > 4.5 was not
tested.
There have been other attempts to relate plant uptake and translocation of an
organic chemical to either the physical or chemical properties of the chemical.
Topp et al., (1986) reported the relationship:
logRCF =0.63 logK^ - 0.959	[18]
following their exposure of barley seedlings for 7-days to various chemicals in
water culture.
The concentration factor (CF) concept is a useful way of describing the
relative concentration of an organic chemical in a particular plant part. It has
many limitations, however. These arise because the concentration of organic
chemicals, both within the soil or nutrient solution and within the plant part
do not remain constant with time. Chemicals in the soil, or in nutrient solution,
may be depleted by plant uptake or degradation; chemicals in a plant may also be
reduced with time by degradation within the plant, or by increases in plant mass
effectively diluting the chemical. Changes in uptake as measured by the CF, have
been reported, Figure 8 (Topp et al., 1986). Different CF's arise depending upon
the timing of the actual sampling. Further it seems logical that the CF would
depend upon soil concentration, initial vs soil concentration at time of plant
C-40

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sampling. Further research on this topic is needed to define the effect of time
of sampling (both plant and soil) on CF's sc different experiments can be
compared.
o 					
0	50	100
TIME (days)
FIGURE 0 EFFECT OF PLANT TYPE AND LENGTH OF GROVTH
PEROID ON THE PLANT CONCENTRATION FACTOR
Adaoteo from Topp et ai. 1986
The work of Shone, Briggs, and their co-worKere reported above was carried out
in nutrient solution cultures where sorption and desorption effects of soil
organic matter were absent. The application of their results to plant uptake from
field soils requires that soil sorption be considered. The effect of soil sorption
on soil solution concentration can be mathematically described using the following
relationship:
SCT = SCs + 0CL [19]
where CT is the total organic chemical concentration in the soil (ng/g), S is the
soil bulk density (g/cm3), Cs is the adsorbed chemical concentration (ng/g), 6 is
the soil-water content by volume (mL/cm3) , and CL is the chemical concentration
in the soil-water phase (/ig/mL). Using the linear equilibrium relationship in
Equation 3 and 4 allows Equation 19 to be rewritten in terms of CL such that:
C,	S 	
CT
[20]
It is now possible to combine equations relating soil sorption and soil
solution concentration and calculate RCF, TSCF, and SCF for different chemicals
on a total soil concentration basis. Substituting Equation 20 into Equation 17
where CL is the external solution and:
SCF = concentration in stem
(sou)	concentration in soil
gives:
SCF(S0,L) - 6K	e	{[1 (0-951gKo- " 2-05)+ 0.82]*	[21]
0w' oc
[(0.784)10--434^1OK0- " 1-78> ^2-44l ]}
For nutrient solutions this equation reduces to Eq [17] when  0, 6 = 1,
and S = l. Inclusion of soil sorption into the SCF from Briggs et al.,(1983)
C-41

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alters the relationship between SCF and log Kw such that the log where plant
adsorption is a maximum decreases from 4.5 for nutrient solution to 1 for soils.
(Figure 9) . The decrease in SCF for chemicals with log greater than 1 is
supported by the published literature on plant uptake in soil systems (Travis and
Arms, 1988).
7 "

6 -

5 -
/ \ SCF(solution)
4 "
/ \
CJ
/""N. / \
tn 3 .
/ N. / \
2 -
/ \
1 -
n
y/ ^^/\SCF(soil) \
U ^


10123456789

log Kov
FIGURE 9 EFFECT OF SOIL ON THE RELATIONSHIP BETVEEN

log Kov AND STEM CONCENTRATION FACTOR
Equation 21 implies that plant uptake is related to soil organic matter content
(Figure 10).Differences in the plant uptake of an organic chemical in soils with
different organic carbon contents has been shown experimentally. Lichtenstein et
al., (1967) for example, showed higher concentrations of the pesticide aldrin in
roots of peas when grown in aldrin- polluted quartz sand compared to a loam soil
containing approximately the same total concentration of the pollutant.
log Kov
FIGURE 10 EFFECT OF SOIL ORGANIC MATTER OH THE
RELATIONSHIP BETVEEN log Kov AND
	STEM CONCENTRATION FACTOR	
It is also apparent from Equation 21 that increases in soil water content
reduce SCF (Figure 11). However, for a soil with a of 0.0075 (1.25% organic
matter), changes in soil water content over the range 0.1 to 0.5 mL/cm3 altered
SCF less than 10% for chemicals with a greater than 2.5. The fraction in
solution, (eq/C^ increases as soil water content increases even though the
organic chemical concentration (CL) in the soil solution-phase decreases.
C-42

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Therefore, if plant transpiration were increased by increasing soil water content,
plant concentration could be increased. Walker, (1971) found that the
phytotoxicities of the pesticides atrazine, simazine, linuron, lenacil, and
aziprotryne were increased as the moisture content of the soil increased. He
related the effect to differences in the quantities of the pesticides that were
accumulated by the plants, with the degree of accumulation being directly
proportional to water uptake.
log Kov
' FIGURE 11 EFFECT OF SOIL VATER CONTENT ON THE RELATIONSHIP
	BETVEEN log Kov AND STEH CONCENTRATION FACTOR	
In conclusion, assuming degradation of the organic chemical does not occur
within the plant, and plant root uptake and translocation of organic chemicals
from the soil is passive, plant uptake can be described as a series of consecutive
partitions reactions. Partitioning occurs between soil solids and soil water, soil
water and plant roots, plant roots and transpiration stream, and transpiration
stream and plant stem. This partitioning can be related to the KM of organic
compounds such that pollutants with high log KM values, (eg. TCDD (6.14), PCB's
(4.12-6.11), some of the phthalate esters (above 5.2) and the polycyclic aromatic
hydrocarbons (4.07-7.66)) are most likely to be sorbed by the soil and/or plant
root. Chemicals with lower values are likely to be translocated within the
plant and may reach significant concentrations within the above ground portions
of the plant.
Vapor Phase Uptake
For volatile compounds, diffusion in the vapor phase and subsequent uptake by
the root and/or shoot may be an important route of chemical entry into piants
(Parker, 1966, and Prendeville, 1968). Two processes precede the penetration of
chemicals in the soil into plant tissue via the air: 1) volatilization of the
chemical from the soil and 2) deposition from the air onto the plant surface. Soil
volatilization depends upon the vapor pressure of the compound which varies
according to ambient temperatures, water solubility of the compound, and sorption
capacity and physical properties of the soil.
C-43

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Increasing the soil-water content of a soil will increase the potential for
volatilization loss of a chemical (Guenzi and Beard, 1970). Harris and
Lichtenstein (1961) shoved that the rate of volatilization of aldrin from soil
increased with aldrin concentration, soil moisture, relative humidity, temperature
and the rate of air movement. Chemical concentration effects cease when the
concentration reaches that required to give a maximum saturation vapor density
equivalent to that of the pure compound. For dieldrin in a Gila silt loam soil
this concentration was 25 ppm (Farmer et al., 1972). These authors also report
that under similar environmental conditions the rate of volatilization was lindane
> dieldrin > DDT, which is the same order for increasing vapor pressures. Jury
et al., (1983 and 1984) developed a behavior assessment model that separates
compounds into volatilization categories based on Henry's constants.
There have been few investigations aimed at separating root uptake and
translocation of a chemical from vapor phase uptake into plant shoots. In an
experiment designed to discriminate these effects, Beall and Nash (1971) found
soybean shoots were contaminated by soilapptied "di^lttrxTt;-' midrln- and heptachlor
largely via root uptake and subsequent translocation. Vapor phase foliar sorption
however dominated for DDT and was nearly 7 times greater than root sorption and
translocation. Foliar contamination from vapor sorption of residues from all four
insecticides was similar (about 6.5 ppm plant dry weight), whereas contamination
from root sorption and translocation varied from 38 ppm to 1 ppm depending upon
the compound.
Using similar experimental techniques, Fries and Harrow (1981) found that PCBs
reached the shoots of plants via the vapor phase rather than from root uptake,
although the importance of this route for PCB contamination of plants remains
inconclusive.
Topp et al., (1986) investigated the uptake of 16 organic chemicals by barley
seedlings. Foliar uptake was related to the amount of chemical volatilized from
the soil surface. The relationship (Figure 12) after 7 days exposure was:
FU = 46.11 + 28.95 log VOL	[22]
where FU was foliar uptake as percent of total UC uptake, and VOL was the organic
UC trapped from the air plus that sublimated on the walls of the exposure chamber
as percent of the total UC applied (Note that in the original publication the
sign in front of log VOL is negative, this is assumed to be a typographical
error). Four compounds (benzene, pentachlorophenol, diethylhexylphthalate, and
the phenylenediamine pigment) did not fit the calculated line because they were
nonpersistent and taken up after mineralization to UC02.
There are many difficulties in extrapolating vapor phase uptake in the
C-44

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laboratory to that in the field. Overall, volatilization rates are likely to be
higher in the laboratory than in the field. This is because laboratory soils are
normally kept moist to encourage plant growth, and this encourages
volatilization. In addition, the actual deposition of volatilized chemicals onto
a plant in the field is likely to be lower as atmospheric turbulence may be
higher.
UPTAKE
100 


X"
 
m

X FOLIAR
50 -
B
m
\


0

-1 0 1
log VOLATILIZATION
2

FIGURE
12
RELATIONSHIP BETVEEN VQLJLTILIZATTOJI
FOLIAR UPTAKE Aoaptea from Topp et ai.
.AND.
1986
The importance of plant uptake of organic chemicals via volatilization under
field conditions, remains to be determined. However, it appears potentially
significant for compounds with He greater than 10'*. The impact could be estimated
by calculating cumulative volatilization losses over the growing period and
assuming that all of it ends up in the plant. The model of Jury et al., 1983 could
be utilized for this purpose.
Plant Type
The final variable affecting plant uptake of soil-borne organic pollutants is
the plant species itself. There has been no systematic examination of plant
responses to organic chemicals in soil, although it does appear that, as with
plant uptake of soil-borne heavy metals, there is variation in uptake both between
species and within the same species on an individual level (Chaney, 1985; and
McNeilly, 1978) . For example; Harris and Sans (1967) found that sugar beet roots
accumulated more dieldrin from a clay soil that contained dieldrin, than did
carrots, potatoes, sugar beet tops, corn, oats, and alfalfa. Lichtenstein and
Shulz (1965) on the other hand, report that carrots usually take up more
organochlorine insecticides than do other root crops such as potatoes, radish,
turnip, and beet. This apparent contradiction can be resolved by consideration
of varietal differences which can be as much as 400% when different carrot
varieties are grown in soil containing endrin (Hermanson et al., 1970).
CONCLUSIONS
In solution culture, the movement of nonionic organic compounds into roots is
a passive process, equivalent to a partitioning between the liquid and solid
C-45

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phase, and can be related to the octanol water partition coefficient of the
compound. Subsequent translocation of the chemical from roots to shoots depends
on the K0l( of the compound and the transpiration rate of the plant. Based on
available data, compounds with a log Kw of approximately 4.5 are most likely to
accumulate in the stem and leaf tissue of plants.
In soil systems, there is competition between the plant and soil solids
(organic fraction) for the partitioning of organics from solution. As the sorption
of the compound by the soil organic phase increases, the quantity available for
plant uptake decreases. Based upon these considerations compounds with log
of 1 -2 are most likely to have significant transport of the chemical to above
ground plant tissue produced in soil systems. If metabolism of the compound in
the roots is significant, even compounds with low log K^'s may not be
translocated (McFarlen et al., 1987). Compounds with high log > 5.0 would not
be expected to be present in above ground plant tissue if plant uptake is limited
by soil solution.
The potential for root or plant sorption of organic compounds from vapor is
dependent upon the vapor pressure of the compound. Very few experiments on this
route of plant contamination have been conducted. Based upon the movement of
herbicides in the soil, a Henry's constant of 10'4 may be used as a transition
point between primary movement in solution and vapor phases. If it can be assumed
that vapor movement in the soil will result in vapor uptake by the plant, then
those compounds with He >10'4 are potential candidates for vapor phase uptake.
Superimposed upon both of these processes is the half-life of the compound.
If it is short, i.e., less than 10 days, the chemical is likely lost from the
system before it can be taken up by the plant. Those compounds with long half
lives, i.e., greater than 6 months or greater than the growing season of the
plant, presist long enough to impact plants.
Applying these screening processes to the priority pollutants, listed in Table
1, reduces the number of chemicals likely taken up by plants. For example, if
plant uptake and translocation without vaporization is the pathway of concern,
the list of 107 chemicals is reduced to 50 on the basis of half-life and Kw,
(Table 2). If vaporization is of concern the list is reduced from 107 to 64 on
the basis of half-life and He, (Table 3).
C-46

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TABLE 2 Log K0I(, Half-life and He for Priority Pollutants which are subject to
plant uptake from soil
Compound
log
T1/2
He
Conpomd
108 
-------
TABLE 3. Log K^, Half-life and He for the Priority Pollutants which are subject
to plant uptake via volatilization
Compoind
100 "ow
T1/2
He
Compound
ia
T1/2
He
PESTICIDES







20.Acrolein
-0.09
B
2.8E-03
22.Chlordane
4.3
C
3.9E-03
23.D0D
5.99
C
0.5E+00
25.DDT
5.98
C
2.0E-03
27.Endosulfan
3.55
C
nd
31.Hexachlorocyclohexane
3.8
B
3.0E-04
33.Isophorone
1.70
nd
nd
34.TCDO
6.14
C
nd
35.Toxaphene
3.85
C
2.1E-01




POLYCHLORI MATED BI PHENYLS







36a.Arochlor 1016
4.38
C
8.6E-01
36b.Arochlor 1221
4.09
C
1.3E-02
36c.Arochlor 1232
4.54
C
2.1E+00
36d.Arochlor 1242
4.11
c
5.5E-02
36e.Arochlor 1248
5.6
C
1.1E-01
36f.Aroch(or 1254
6.04
c
1.1E-01
36g.Arochtor 1260
6.11
C
2.9E-01
37.2-ch(oronaphthaIene
4.12
c
1.3E-02
HALOGEHATED ALIPHATIC HYDROCARBONS






38.Chlorcmethane
0.91
C
1.6E+01
39.DIchIoromethane
1.25
B
8.5E-02
40.TrichIoromethane
1.9
B
1.2E-01
41.Tetrachloromethane
2.64
nd
9.6E-01
42.ChIoroethane
1.54
B
6.1E-01
43.1,1-dichloroethane
1.7?
B
1.7E-01
44.1,2-dichloroethane
1.48
B
3.8E-02
45.1,1,1trichIoroethane
2.17
nd
1.3E+00
46.1,1,2-trichloroethane
2.17
nd
3.1E-01
48. Hexach t oroethane
4.62
nd
4.1E-01
54.1,2-dichloropropane
2.28
nd
1.2E-01
56.HexachIorobutadiene
3.74
c
4.3E-01
SS.Bromomethane
1.10
B
4.4E+00
59.Brogadichloromethane
1.88
nd
nd
60.0ibromochIorcmethane
2.09
nd
nd
61. Tribmoqettiane
2.30
nd
2.4E-02
62.0ichlorodifluoronethane
2.16
C
6.3E+01
63.TrichIorofIuoromethane
2.53
nd
2.4E+00
HALOGEHATED ETHERS







66.Bis<2-chloroisopropyl)ether
2.58
nd
4.7E-02
68.4-chlorophenyt phenyl ether 4.08
nd
1.0E-02
69.4-branophenyl phenyl ether
4.28
nd
nd




MONOCYCLIC ASOUTICS







72.Chlarobenzene
2.84
nd
1.5E-01
73.1,2-dichlorobenzene
3.38
nd
1.5E-01
74.1,3-dichlorobenzene
3.55
nd
1.1E-01
75.1,4-dichlorobenzene
3.55
nd
9.9E-02
77.Hexach1orobenzene
6.18
C
7.0E-02
81.2,4-dini trotoluene
2.01
nd
1.3E-02
82.2,6-dini trotoluene
2.05
nd
1.3E-Q2
93.4,6-dinitro-o-eresol
2.85
nd
nd
PHTHALATE EST ESS







^4b.Diethyl
3.22
B
1.9E-03




POLTCTCLIC AROMATIC HYDROCARBONS






95a.Acenaphthene
4.13
C
1.0E-02
95b.Acenaph thyI ene
4.07
c
4.8E-03
95c.Fluorene
4.18
C
4.8E-03
95d.Naphthalene
3.37
c
2.0E-02
96a.Anthracene
4.45
C
1.1E-02
96c.Phenanthrene
4.46
c
1.6E-03
97b.Benzolb] fluoranthene
6.57
nd
nd
97c.BenzoIk]fluoranthene
6.84
c
nd
97d.Chrysene
5.61
C
8.8E-02
97e.Pyrene
5.32
c
2.8E-01
98a.8enzo(ghi1pery lene
7.23
C
nd
98b.Benzo(a]pyrene
6.04
c
4.9E-01
98c.0i benzo[a]anthracene
5.97
C
nd
98d.lndeno(123-cd]pyrene
7.66
c
nd
MISCELLANEOUS COMPOUNDS







99.Dinethyl nitrosamine
0.06
nd
nd
lOO.Oiphenyl nitrosanine
2.57
nd
nd
101.Di-n-propyl nitrosanine
1.31
nd
nd
104.1,2*dfphenyIhydrazine
3.03
nd
nd
Clearly, plant uptake of soil borne organic pollutants is a complex phenomena.
More work is needed before the potential environmental impact of organic
pollutants can be adequately assessed and actions designed to limit such impacts.
C-48

-------
REFERENCES
Beall, H.L.,and R.G. Nash. 1971. Organochlorine insecticide residues in soybean
plant tops: Root uptake vs. vapor sorption. Agron. J. 63: 460-464.
Bowen, H.J.M. 1977. Residence times of heavy metals in the environment. In Proc.
Int. Conf. Heavy Metals in the Environment. Eds. T.C.Hutchinson, et al. Institute
for Environmental Studies. University of Toronto. Ontario. Canada. October, 1975.
Briggs, G.G. 1973. A simple relationship between soil adsorption of organic
chemicals and their octanol water partition coefficients. Proc. 7 Brit.
Insecticide and Fungicide Conf. Nottingham U.K. pp83-86.
Briggs, G.G., R.H. Bromilow, and A.A. Evans. 1982. Relationship between
lipophilicity and root uptake and translocation of non-ionized chemicals by
barley. Pestic. Sci. 13: 495-504.
Briggs, G.G., R.H. Bromilow, A.A. Evans, and M. Williams. 1983. Relationships
between lipophilicity and the distribution of non- ionized chemicals in barley
shoots following uptake by the roots. Pestic. Sci. 14: 492-500.
Briggs, G.G., R.H. Bromilow, R. Edmondson, and M. Johnston. 1976. Distribution
coefficients and systemic activity. Chem. Soc. Spec. Publ. No. 29: 129-134.
Brown, D.S. and E.W. Flagg. 1981. Empirical prediction of organic pollutant
sorption in natural sediments. J. Environ. Qual. 10: 382-386.
Chaney, R.L., 1985. Potential effects of sludge borne heavy metals and toxic
organics on soils, plants, and animals, and related regulatory guidelines. Annex
3, Workshop 9, pp 1-56. In Final Report of the Workshop on the International
Transportation, Utilization or Disposal of Sewage Sludge Including
Recommendations. PNSP/85-01.
Dawson, G.W., C.J. English, and S.E. Petty. 1980. Physical and chemical properties
of hazardous waste constituents. Attachment 1. Appendix B. Identification and
listing of hazardous wastes. EPA Office of Solid Waste.
Dejonckheere, W., W. Steurbaut, G. Helkebeke and R.H. Kips. 1982. Leaching of
aldicarb and thiofanox and their uptake in soils by sugarbeet plants. Pestic.
Sci. 14: 99-107.
Di Toro, D.M. and L.M. Horzempa. 1982. Reversible and resistant components of
PCb adsorption-desorption isotherms. Environ. Sci. Technol. 16: 594-602.
C-49

-------
Fairbanks, B.C., G.A. O'Connor, and S.E. Smith. 1987. Mineralization and
volatilization of polychlorinated biphenyls in sludge-amended soils. J. Environ.
Qual. 16: 18-25.
Farmer, W.J., K. Igue, W.F. Spencer, and J.P. Martin. 1972. Volatility of
organochlorine residues from soil; Effect of concentration, temperature, air flow
rate and vapor pressure. Soil Sci. Soc. Amer. Proc. 36: 443-447.
Fries, G.F., and G.S. Marrow. 1981. Chlorobiphenyl movement from soil to soybean
plants. J.Agric. Food Che. 29: 757-759.
Gillett, J.W. 1983. A comprehensive prebiological screen for ecotoxicologic
effects. Environ. Toxic. Chem. 2: 463-476.
Goldstein, D.J., 1982. Air and steam stripping of toxic pollutants: Vol. II,
USEPA, Report No. 68-03-002.
Graham-Bryce, I.J. 1984. Optimization of physicochemical and biophysical
properties of pesticides. In Pesticide synthesis through rational approaches.
Eds. Magee, P.S., G.K. Kohn, J.J. Menn. American Chemical Society.
Goring, C.A.I.and J.W. Hamaker. 1972. Organic chemicals in the soil environment.
Marcel Dekker Inc., New York.
Guenzi, W.D.,and W.E. Beard. 1970. Volatilization of lindane and DDT from soils.
Soil Sci. Soc. Amer. Proc. 34 : 443-447.
Harris, C.R. and E.P. Lichtenstein. 1961. Factors affecting the volatilization
of insecticidal residues from soil. J.Econ. Entomol. 54 : 1038-1045.
Harris, C.R., and W.W. Sans. 1967. Absorption of organochlorine insecticide
residues from agricultural soils by root crops. J. Agr. Food Chem. 15: 861-863.
Hermanson, H.P., L.D. Anderson, and F.A. Gunther. 1970. Effect of variety and
maturity of carrots upon uptake of endrin residues from soil. J. Econ. Entomol.
63: 1651-1654.
Jury, W.A., W.F. Spencer, and W.J. Farmer. 1983. Behavior assessment model for
trace organics in soil. I. Model description. J. Environ. Qual. 12: 558-564.
C-50

-------
Jury, W.A., W.J. Farmer, and W.F. Spencer. 1984. Behavior assessment model for
trace organics in soil. II. Chemical classification and parameter sensitivity.
J. Environ. Qual. 13: 567-572.
Jury, W.A., W.F. Spencer, and W.J. Farmer. 1984. Behavior assessment model for
trace organics in soil. III. Application of screening model. J. Environ. Qual.
13: 573-579.
Kay, B.D., and D.E. Ekrick. 1967. Adsorption and movement of lindane in soils.
Soil Sci.104: 314-322.
Karichkoff, S.W. 1981. Semi epirical estimation of sorption of hydrophobic
pollutants on natural sediments and soils. Chemosphere 10: 833-846.
Kenaga, E.E. 1972. Guidelines for environmental study of pesticides; Determination
of bioconcentration potential. Resid. Revs. 44: 73-113.
Khan, S.U. 1982. Studies on bound 14C-prometryn residues in soil and plants.
Chemosphere. 11: 171-195.
Lichtenstein, E.P. and K.R. Schulz. 1965. Residues of aldrin and heptachlor in
soils and their translocation into various crops. J. Agr. Food Chem. 13: 57-63.
Lichtenstein, E.P., T.W. Fuhremann, N.E.A. Scopes, and R.F. Skrent. 1967.
Translocation of insecticides from soils into pea plants; Effects of the detergent
LAS on translocation and plant growth. J. Agric. Food Chem. 15: 864-869.
Loehr, R.C., and J.F. Malina. 1986. Land treatment: A Hazardous Waste Management
Alternative. Water Resources Symp. 13.
Mackay, 0. and W.Y .Shiu. 1981. Critical review of Henery's Law constants for
chemicals of environmental interest. J. Phys. Chem. Ref. Data,10(4):1175.
Mayer, R., J. Letey, and W.J. Farmer. 1974. Models for predicting volatilization
of soil incorporated pesticides. Soil Sci. Soc. Amer. Proc. 38: 563-568.
McFarlane, C., C. Nolt, C. Wickliff, T. Pfleeger, R. Shimabuku, and M. McDowell.
1987. The uptake, distribution and metabolism of four organic chemicals by soybean
plants and barley roots. Environ. Toxic. Chem. 6: 847-856.
McNeilly, T. 1982. A rapid method for screening barley plants for aluminum
tolerance. Euphytica 31: 237-239.
C-51

-------
Means, J.C., S.G. Wood, J.J. Haslett, and W.L. Banwart. 1982. Sorption of amino
and carboxy-substituted polynuclear aromatic hydrocarbons by sediments and soils.
Environ. Sci. Technol. 16: 93-98.
Parker, C. 1966. The importance of shoot entry in the action of herbicides applied
to the soil. Weeds. 14 : 117-121.
Prendeville, G.N. 1968. Shoot zone uptake of soil applied herbicides. Weed Res.
8: 104-114.
Rao, P.S.C., J.M. Davidson, V.E. Berkheiser, L.T. Ou, et al.1982. Retention and
transformation of selected pesticides and phosphorus in soil water systems. A
critical review. EPA 660/3- 82-060.
Ryan, J.A. 1976. Factors affecting plant uptake of heavy metals from land
application of residuals. Proc. Conf. Disposal of residues on land. St. Louis.
Sabljlc, A. 1987. On the prediction of soil sorption coefficients of organic
pollutants from molecular structure: Application of molecular topology model.
Environ. Sci. Technol. 21:358-366.
Scheunert, I., E. Topp, J. Schmitzer, W. Klein, F. Korte. 1985. Formation and
fate of bound residues of 14C benzene and 14C chlorobenzenes in soils and plants.
Ecotoxicol. Environ. Safety 9, 159-170.
Schwarzenbach, R.P., and J. Westall. 1981. Transport of non polar organic
compounds from surface water to groundwater. Environ. Sci. Technol. 15: 1360-1367.
Shone, M.G.T., and A.V. Wood. 1976. Uptake and translocation of some pesticides
by hypocotyls of radish seedlings. Weed Res. 16: 229-238.
Shone, H.G.T., and A.V. Wood. 1974. A comparison of the uptake and translocation
of some organic herbicides and a systemic fungicide by barley : I Absorption in
relation to physico-chemical properties. J. Exp. Bot. 25: 390-400.
Shone, H.G.T., B.O. Barlett, and A.V. Wood. 1974. A comparison of the uptake and
translocation of some organic herbicides and a systemic fungicide by barley; ii
Relationship between uptake by roots and translocation to shoots. J.Exp. Bot. 2:
401-409.
C-52

-------
Shone, M.G.T., D.T. Clarkson, J. Sanderson and A.V. Wood. 1973. A comparison of
the uptake and translocation of some organic molecules and ions in higher
plants.Ton Transport in Plants. Academic Press, chapter 8, 571-582.
Smith, L.R,.J. Dragun. 1984. Degradation of volatile chlorinated aliphatic
priority pollutants in groundwater. Environ. Int. 10,291-298.
Thibodeaux, L.J. 1979. Chemodvnamics - Environmental movement of chemicals in
air, water and soil. Wiley Interscience. p501.
Topp, E., I. Scheunert, A. Attar, and F. Korte. 1986. Factors affecting the uptake
of 14C labelled organic chemicals by plants from soil. Ecotoxicol. Environ. Safety
11: 219-228.
Travis, C.C. and A.D. Arms. 1988. Bioconcentration of organics in beef, milk,
and vegetation. Environ. Sci. Technol. 22: 271-274.
USEPA. 1979. Water related environmental fate of 129 priority pollutants. Volumes
1 and 2. EPA-440/4-79-029b.
USEPA, 1985. Toxic Substance Control Act, Chemical substance inventory.
EPA-560/7-85-002a.
Walker, A. 1971. Effects of soil moisture content on the availability of soil
applied herbicides to plants. Pestic. Sci. 2: 56-59.
(Received in Germany 11 September 1988; accepted 4 October 1988)
C-53

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Thomas Dahl
C-55

-------
STRIN GFELLOW SITE
Remedial Investigation/Feasibility Study
Glen Avon, California
Tom Dahl
Environmental Protection Agency
National Enforcement Investigations Center
November 1989
	vEPA	
C-57

-------
SUPERFUND REMEDY SELECTION PROCESS
SUPERFUND REMEDY SELECTION
EVALUATION CRITERIA
	Overall Protection of Human Health and
the Environment
	Compliance with ARARs
	Long-Term Effectiveness and Permanence
	Reduction of Toxicity, Mobility, or Volume
	Short-Term Effectiveness
C-58

-------
SUPERFUND REMEDY SELECTION
EVALUATION CRITERIA (cont'd)
	Implementability
	Cost
	State Acceptance
	Community Acceptance
Location of ttw StringMlow Wasta Disposal Sit*
C-59

-------
y
OPERATIONAL
1956
PERIOD
l
-------
SCALE IN FEET
CONCRETE DAM
COLLECTION SUMP
LEGEND
DISPOSAL
PONDS
AREAS CONSIDERED
TO BE CONTAMINATED
FROM POND SPRAY
General Site Configuration by 1972 for Disposal Operations
(From JMM. 1982)
C-61

-------
AIR EMISSION
SURFACE
WATER
DOWNGRADIENT
GROUNDWATER
FLOW
Pathways for Contaminsrit Transport at the Stringfeilow Sits
C-62

-------
STRINGFELLOW SITE STUDIES
	Environmental (Soil, Air, Water) Sampling
	Geology/Hydrology
	Fault/Fracture Survey
	Geophysical
-	Electromagnetic Conductivity
-	Resistivity
-	Seismic
STRINGFELLOW SITE
STUDIES (cont'd)
	Soil Gas Sampling
	Hydraulic Testing
	Groundwater Modeling
	Air Modeling
	Risk Assessments
C-63

-------
STRINGFELLOW SITE
TREATABILITY STUDIES
Reverse Osmosis
	Carbon Adsorption Optimization
	Carbon Regeneration
Incineration
	Metals Precipitation
	Air Stripping
Ultraviolet Oxidation
STRINGFELLOW SITE
TREATABILITY STUDIES (cont'd)
	Dewatering Tunnel (Conceptual Study)
	Ion Exchange
	Stabilization/Solidification
Rotating Biological Contactor
Ultrafiltration
Freeze Technology (Ongoing)
	Additional Treatability Studies (Ongoing)
C-64

-------
SUMMARY OF PRINCIPAL FINDINGS
Stringfellow Site Remedial Investigation Report
June 1, 1987
The studies conducted during the remedial investigation
involved-a number of engineering and scientific disciplines and
generated information related to the definition of the String-
fellow site and the spread of contamination from the site. The
principal findings of these studies include:
ON-SITE CONDITIONS
Approximately 22 million gallons of contaminated
ground water are presently contained in unconsolidated soil
and rock material onsite. An undetermined total volume of
contaminated ground water is in the fractured bedrock
underlying the site. Contaminated ground water was found
as deep as 200 feet below land surface in bedrock sampling
wells.
The majority of contaminants onsite were found in the
ground water; the onsite soil (alluvium/fill) is not a pri-
mary source of mobile contaminants (solvents, metals,
etc.). Mobile contaminants were found almost exclusively
in the ground water.
Contaminated ground water is migrating downgradient
from the site, leaving the site almost entirely through the
fractured bedrock beneath the subsurface barrier wall.
The site contains over 800,000 cubic yards of uncon-
solidated soil and rock (alluvium, DG and metamorphic rock)
that contains contamination and can be excavated with con-
ventional equipment.
C-65

-------
The barrier/extraction system intercepts and recovers
a significant portion of the potential ground-water leakage
from the site. The fraction of potential leakage inter-
cepted is calculated at over 80 percent. Virtually all
offsite leakage is through the bedrock beneath the site's
subsurface barrier. A direct indication of the effective-
ness of the barrier/extraction system are the presently
declining water levels in onsite monitor wells.
The compositions and distributions of onsite contami-
nated soils, rocks, and ground water are extremely hetero-
geneous .
Soils beneath the site cover and above the water table
are principally contaminated with pesticides, polychlori-
nated biphenyls (PCBs), para-chlorobenzene sulfonic acid
(p-CBSA), and traces of slightly water soluble organic
compounds. These soils are also acidic and contain several
heavy metals at levels above natural background.
The pesticides and PCBs in the unsaturated soil/fill
onsite are immobile. The remaining low levels of soluble
organics and metals can be mobilized by leaching from
ground-water infiltration.
The onsite soil/fill below the water table contains
many of the same insoluble organic compounds as in the
unsaturated zone; however, levels of water soluble organics
and heavy metals are much higher and appear to largely be
associated with the ground water. The contaminants in the
onsite ground water are able to readily migrate offsite
unless mitigated.
C-66

-------
DQWNGRADIENT CONDITIONS
Ground-water flow downgradient of the Stringfellow
Site is controlled by both stratigraphic and hydraulic
features in Pyrite Canyon. But beyond the mouth of the
canyon it is controlled primarily by the regional hydraulic
gradient and a north-south subsurface bedrock high which
appears to extend from the canyon, forming a western
boundary for the Glen Avon Basin.
A plume of contaminated ground water extends over 2
miles downgradient from the site and ranges frpm 200 feet
to about 900 feet in width.
The Stringfellow-related contaminants found in this
plume in the aquifer under the community of Glen Avon in-
clude several organic solvents (trichloroethylene, chloro-
form, chlorobenzene, dichlorobenzene), sulfate, and p-CBSA.
Of these contaminants only two, trichloroethylene (TCE) and
chloroform, presently occur at levels in excess of regula-
tory standards.
- Even though the Glen Avon Basin is hydrologically con-
nected to the Chino Basin to the west and the general
ground-water flow is in that direction, the subsurface bed-
rock high separating the two basins appears to be restrict-
ing the westward migration of the contaminant plume.
Ground-water contaminated with dissolved heavy metals
presently extends about 2,000 feet downgradient from the
site. However, contaminant metals associated with offsite
soils in Pyrite Canyon may be remobilized and migrate fur-
ther downgradient in the future unless mitigated.
C-67

-------
Under 1985/86 water level conditions, which are
affected by significant mid-canyon extraction, ground-water
flux past canyon cross-sections is estimated to increase
from about 12 to 15 gallons per minute (gpm) in the upper
portion of Pyrite Canyon below the site, to about 28 gpm
just north of Highway 60 (5,000 feet downgradient of the
site).
The two mid-canyon extraction wells existing in 1985
are estimated to have been extracting about 50 to 60 per-
cent of the total ground-water flow through the mid-canyon.
The addition of five (5) additional interception wells in
the mid-canyon in late 1986 has increased this fraction.
Apparent decreases in ground-water contaminant concen-
trations between the site and the mid-canyon during 1984
and 1985 may reflect a decrease in contaminant leakage from
the site as a result of onsite ground-water extraction.
Contaminated surface runoff can discharge from the
site during sustained rainfall; however, the levels of con-
taminants in the surface water appear to be diluted below
regulatory standards before being discharged from the mouth
of Pyrite Canyon.
Surface soils within 1,000 feet south of the site have
been contaminated at levels above environmental standards;
no contaminated surface soils were found outside of Pyrite
Canyon.
Within the zone extending approximately 1,000 feet
downgradient of the barrier, measurable contamination was
also found in sub-surface soils. These observable levels
of site-related contaminants reflect the remnants of past
C-68

-------
site operations and materials left by surface water and
ground-water contaminants from the site.
Air emissions modeling indicates that, even if the
onsite cap/cover were removed to excavate the underlying
contaminated materials, minimum threat would be posed to
the residents of Glen Avon.
PUBLIC HEALTH EVALUATION
Prior to initiation of interim abatement actions in
1980, the pathways for exposure to the contaminants in-
cluded air, surface water, soils, and ground water; at
present, the primary exposure pathway of concern is
migrating contaminated ground water.
The combined maximum lifetime risk from exposure to
ground water contaminated with TCE and chloroform in the
community area, if used for drinking water, exceeds the
U.S. Environmental Protection Agency's risk guidelines.
Without site remediation and ground-water cleanup,
the contaminants which have already migrated below the mid-
canyon extraction system will continue to migrate downgra-
dient in the Glen Avon aquifers, adding to the risk of
exposure for the local community.
Contaminated surface soils exist in the first 1,000
feet downgradient from the site's subsurface barrier sys-
tem, posing a potential risk to individuals in Pyrite
Canyon via inhalation of air suspended dust under severe
wind conditions. Continual airborne dust from this zone
will not reach the community area, and the levels of soil
C-69

-------
contamination in this zone do not pose an ingestion or skin
contact health risk.
Subsurface soils within 2,000 feet downgradient of the
site are accumulating precipitated and adsorbed contami-
nants from migrating ground water. While presently posing
no human health threat, this zone must be considered a
secondary contamination source during remediation planning.
Surface water runoff which passes through the site
during rains picks up measurable amounts of contaminants
and carries them off site. Under present conditions no
measurable amounts of surface water contamination have been
found further than 2,000 feet downgradient of the site.
C-70

-------
UGB-74
-80
UGB-6
,^6*'
"UGB102
O
ta
4
UCB I
,y
tf BARRIER 0AM
UGB 114
LEGENO
UGI  Upgradiant Infiltromatar TauSita
OCI  OivSIn Inflltromatar TaitSita
OA - On-Slta Auger Boring
BA  Bilsw Barriar Down Auger
Boring
OC  On-SlteWallCluiterv
OW - On-S It* Monitoring WaU
UGB  Upgradtani Badrock Wall
UDG  Uogradlani Oacomooiad
OGB  Oowmqradiant Badrock Wall
  Not Completed A Wall*
~  Approximate Location
90'+48,<- Atlmuth and Inciination o<
Directional Wall
200
400
SCALE IN FEET
On-Sits and Upg radiant Sampling and Infiltrometar Sites
C-71

-------
APPROXIMATE CANYON FLOOR BOUNDARY
R.I. MONITORING WELL
O PRIOR MONITORING WELL
~ PRIVATE MONITORING WELL
 Canyon
PC* i
40TH8249-
40TH8259-
FC5A3
 FC3
 MW18B
 FC1
-PYR4037
. PYR4075
PYR4105
			
40TH8320 *
k SCH4091
I VER4118 it FC102A2

Community
Zona
Downgradiant Groundwater Monitoring Wall Locations
C-72

-------
	7	
/ LC3
I 
/ *
PYR3851
~
AGA4111
N PC4 FC2
\ 	 
*AGA410&
*AGA4142
\
\
J
40TH8249
40TH8259 ~ * *s|
*40TH8320
VER4118* SCH4091

PYR4105
FC102A2#
PYR4037
 PYR4076
/FC111A2
^ FC113A2
LCI
LC2
 
o
MW17B
FC1
o
MW16B
\
\
I
/
U LC-4B
FC3
 O 
MW18B
FCSA3
\
^  FC115A2 / FC10JA2
'MISSION BLVO.
MIS8684
44TH8660
FC204A2'
FC258A2 v
FC264A2  
FC211  FC229A2
~ MIS7890
FC249A3
FC252A2
1/
FC558A2
FCS64
FC570A2

FC552A2
V
 FC2S7A2
 FC2S1
#FC311A2
~	PYR4352
 FC467A2
	FC551A2
*TYR43B6
.FCS32A2
>FC678A2
D0NW8443*
FC726A2
FC738A2
* TYR4419
^FC720 a
FC712A2
FC706A2*
 FC702A2
FC752A2
*GAL8041
GAL 7838
FC836A2
GAL8216 *
FC848A2
PYR4665,
FC896A2
FC948A2
FC862A2#
.FC924A2
GALENA ST.
* TYR4695
PC932A2
FC936A2
 FC940A2
AGA4875	* STN4800
AGA491S
AGA4930
~	ACA5040
~	AGA5070
it JUR8250
-N -
 Rl MONITORING WELL
0 PRIOR MONITORING WELL
~ PRIVATE WELL
500
500 1000
SCALE IN FEET
Community Zone Groundwater Monitoring and Private
Well Locations
C-73

-------
SUBSURFACE
CLAY BARRIER WITH
GE I INJECTION BENE A TH
ON SITE AREA
A MONITORING WELLS PLACED DURING
NOVEMBER - OECEMBER 1986
EXTENT OF TRICHLOROETHYLENE
ITCE) PLUME OF CONTAMINATED
* GROUNDWATER*
	MONITORING WELLS INSTALLED
PRIOR TO Rl INVESTIGATION
 Rl INTERCEPTOR WELLS
A Rl MONITORING WELLS
~	Rl MONITORING WELL CLUSTERS* 
O	COMMUNITY AND PRIVATE WELLS
Approximate Location of TCE Contaminated Groundwater That Extends From The Stringfellow Site into Glen Avon.

-------
A
r\_/J
GALENAST
Groundwater TCE Concentrations (l/^g/l and above), 1985-1866.
(ND indicates below detection limit of 0.03 ji g/i)
C-75

-------
<-J' -I
8tt?
5 o-
(3) * W3B
<5
m
o=
o
o
Oh
Ld^
O

ma FCI11A2
FC252A2
FC211A2
o
5
8
FC93SA3
I I I I I I I I I I I I I I I I I I I | I I I I I I I I I | I I 1 I I I I I I | I I I I I I I I I [ I I I I I I I I I |
0 2000 4000 6000 8000 10000 12000
DISTANCE BELOW THE SITE (ft)
Example of Contaminant Concentration vs. Distance Curve Contained in Appendix B.
C-76

-------
{/
Si
/
s
rv

1
X
I	
\

\

\
13*# * *

111

*

. *

IU* * '

1JJ*
GALENA ST
Groundwater SO4 Conrantrationi (200 mg/J and above), B85-1986,
C-77

-------
(r^\\
UPPER
MID-CANYON
ZONE
ZONE :S:S,	
SP-Jr--
	r\\y&
2.77 (MW7B)j 1 ' -T // 0.51
74.6
28.1 (MW38)
26.B
14.1 (MW4B)
38.4
26.7	IMWBB)
MID-CANYON
ZONE
0.46 (MMSBI
NO
NO (MW9BI
| ^	-*NO
e
\
l
r'

V
LOWER
CANYON
ZONE NM
NO
NO (MW10B)
NO
NO (MW11B)
v NO
- NO (MW16B)
NO (MW12BI
NO (LC1A2)
NM
NO ILC3A2)

KEY
xxxx
1984 Cr (mo^ll
xxxx
1985 Cr (mg/l)
NM -
wall not Initailad
NO 
not datactad
\
\
NM
/NO (LC2A2)

COMMUNITY
ZONE
i (FC1A2)
NM
NO IFC101 A1)\
I
/
NM
.NO (FC211A2)
500	0
500
1000
scale in feet
l nm
NO (FC291A2)
Soluble Groundwater Chromium Concentration Contours for Existing
Wells Downgradient of the Stringfellow Clan I Site (1984,1985)
C-78

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Average Percentage of Dissolved Solids Components
(Well OW-1, 2, 4, OC3D, Data from EPA/NEIC, 1985).
VOA
<1%
Percentage of DOC Components
(Well OW-1, Data from EPA/NEIC, 1985).
C-79

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Other Heavy Metals
<1%
Average Percentage of Inorganic Components in Groundwater
(Weil OW-1, -2, and -4; Data from EPA/NEIC 1985)
C-80

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/
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-------
METALS REMOVAL

ORGANICS REMOVAL

LIME POLYMER FLOCCULATION
/ CLARIFIER
0
1
00
rv>
EQUALIZATION
TANKS
SLUDGE
HOLDING
TANK
STREAM B
DEWATERED
SLUDGE TO

I
<2~*\
SAND
FILTRATION
DIRTY FILTER
BACKWASH
STORAGE
O CLASS I
I
DISPOSAL
FILTER
PRESS
EQUALIZATION
TANKS
-oocr
CARBON
ADSORPTION
CONTACT
VESSELS
~a
3
CLEAN
BACKWASH
ft EFFLUENT
STORAGE
DISCHARGE
TO TRUCK.
HAUL TO
SARI LINE
o
CARBON
TRANSFER
VESSEL
NOTES:
1.	STREAM A IS FROM WELLS OW1, OW 2. 0W 4, IW 1 AND THE FRENCH DRAIN.
DESIGN FLOW IS50GPM.
2.	STREAM B IS FROM MID-CANYON WELLS IW 2. IW 3. IW B. IW C, MA-1, MB-1, MA-4.
DESIGN FLOW IS 80 GPM.
3.	TREATED GROUNDWATER IS HAULED AND DISCHARGED TO THE SARI LINE.
Treatment Schematic for Existing Mid-Canyon Pretreatment Plant

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SELECTION OF PREFERRED
REMEDIAL ALTERNATIVE
	86 Technologies Examined
	30 Technologies Retained for Remedial Alternatives
Selection
	7 Remedial Alternatives Subjected to Detailed
Analysis
	Preferred Alternative Selected
C-83

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SUMMARY OF REMEDIAL ALTERNATIVES RESULTING
FROM THE STRINGFELLOW SITE FEASIBILITY STUDY
REMEDIAL ALTERNATIVE 1
The no action alternative, would involve discontinuing on-site
(Stream A) and mid-canyon (Stream b) groundwater extraction and
treatment that is presently performed. Also, there would be no
effort to: minimize the generation of contaminated leachate
from the on-site area; or to clean up or stop the further migra-
tion of the downgradient plume.
REMEDIAL ALTERNATIVE 2
Natural flushing of the on-site area and downgradient plume
cleanup.
REMEDIAL ALTERNATIVE 3
On-site dewatering, extraction and treatment of on-site
leachate, and downgradient plume cleanup.
REMEDIAL ALTERNATIVE 4A
On-site dewatering, extraction and treatment of on-site
leachate, in-situ soil-gas extraction, in-situ soil flushing,
and downgradient plume cleanup.
REMEDIAL ALTERNATIVE 4B
On-site dewatering, extraction and treatment of on-site
leachate, in-situ soil-gas extraction, selective soil excavation
of higher contamination areas, soil treatment and redisposal on-
site, in-situ soil flushing, and downgradient plume cleanup.
REMEDIAL ALTERNATIVE 5
On-site dewatering, extraction and treatment of on-site
leachate, full excavation of all diggable soil, soil treatment
followed by redisposal on-site into the excavation, and downgra-
dient plume cleanup.
REMEDIAL ALTERNATIVE 6
On-site dewatering with extraction and treatment of on-site
leachate, in-situ soil-gas extraction, treatability studies,
and downgradient plume cleanup.
C-84

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REVISED REMEDIAL ALTERNATIVES ESTIMATED COST
COMPARISON - OVERALL SITE REMEDY
RA RA RA RA RA RA*
No. 2 No. 3 No. 4A No. 4B No. 5 No. 6
Zone 1
448
Never
65
60
63
Zone 2
162
162
46
46

Zone 3
40
40
40
40

Zone 4
25
25
25
25

Approximate
Time Until
Groundwater
Cleanup is
Achieved
(Years)
Estimated	40.7 44.2 55.5 253.3 630.9 64.7
Capital Costs
(million $)
f
Estimated	131.2 156.2 197.8 392.3 741.7 186.0
Present
Worth Costs
7% Discount
Rate
(million $)
* RA is the DHS/EPA Preferred Alternative.
C-85

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James Gossett
C-87

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BIOTRANSFORMATION OF DICHLOROMETHANE
IN METHANOGENIC SYSTEMS
by
James M. Gossett and David L. Freedman
School of Civil & Environmental Engineering
Hollister Hall
Cornell University
Ithaca, New York 14853
Presented at the Third International Meeting,
NATO/CCMS Pilot Study on Demonstration of
Remedial Action Technologies for Contaminated Land and Groundwater
November 6-9,1989
Montreal, Canada
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I. INTRODUCTION
The research reported herein is part of a larger, USAF-sponsored effort to investigate the
potential for biodegradation of four chlorinated solvents under methanogenic conditions:
tetrachloroethylene (PCE), trichloroethylene (TCE), chloroform (CF), and dichloromethane
(DCM). In this present paper, we focus on our investigations with DCM.
A. Objectives and Scope of Work
The broad goal of our research effort is to investigate the fundamental factors
influencing the biodegradation of dichloromethane (DCM) by enrichment cultures grown under
methanogenic conditions. Gaining a deeper understanding of how DCM is degraded under such
conditions will markedly improve the chances of successfully employing bioremediation
technologies.
More specifically, our research objectives are:
1.	To determine if DCM can serve as a growth substrate.
2.	To elucidate the pathways by which DCM is degraded under methanogenic
conditions, including the construction of an oxidation/reduction balance.
3.	To determine which class of organisms  methanogens or nonmethanogens
 is responsible for mediating DCM degradation.
4.	To develop a kinetic model of DCM degradation in mixed cultures.
5.	To develop continuous-flow biological reactor systems for treatment of DCM-
contaminated waters.
Surprisingly little information is available in the literature concerning the
degradation of DCM under methanogenic conditions. The progress we have made thus far
includes: development of a DCM-degrading enrichment culture; correlation of DCM degradation
to methanogenesis; demonstration of the pivotal role played by acetogenic bacteria in DCM
degradation; delineation of degradative pathways; determination that DCM can serve as a growth
substrate; and successful operation of a fixed-film, continuous-flow reactor which degrades DCM
to CH4 and CO2 at 20"C.
II. SUMMARY OF PROGRESS TO DATE
A. Experimental Strategy
The starting point for this research was the development of a mixed culture capable
of degrading DCM under methanogenic conditions. This was accomplished using the mixed liquor
from a laboratory digester. The digester had been started with sewage sludge from the Ithaca, NY
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Wastewater Treatment Plant, then operated in a semicontinuous mode with a 10 g COD/L synthetic
substrate, designed to maintain a diverse population of anaerobes. DCM degradation was achieved
in a culture derived directly from the lab digester.
The DCM degrading mixed liquor was then used to inoculate a series of enrichment
cultures. The purpose of the enrichments was to eliminate as many of the organisms as possible
which weren't involved in DCM degradation, as well as to remove significant amounts of
extraneous, undefined organic matter. Developing enrichment cultures has enabled progress in
correlating DCM degradation to methanogenesis, and in analysis of the pathway(s) by which DCM
has been degraded (Gossett and Freedman, 1988).
B. Materials and Methods
Chemicals and Radioisotopes. DCM was obtained in neat form (99 mol %
pure; Fisher Scientific); Chloromethane (CM) was purchased dissolved in methanol (200 Hg/mL,
1 mL ampule; Supelco, Inc.). [I4C]DCM (Sigma Radiochemical) was diluted in ISO mL distilled
deionized water and stored in a 160 mL serum bottle, capped with a Teflon lined rubber septum.
The [14C]DCM stock solution contained 2.93 x 107 dpm/mL (4.68 jimoles DCM/mL); GC
analysis of the [14C]DCM stock bottle headspace indicated the presence of an unidentified
contaminant, which was shown not to be radiolabeled. There was also no indication that this
contaminant interfered (e.g., as an inhibitor) with the DCM degradation studies. ScintiVerse-E
(Fisher Scientific) liquid-scintillation cocktail (LSC) was employed for [14C] assays.
Cultures and Enrichment Procedures. With the exception of some
continuous-flow, fixed-film reactor studies, all experiments were conducted at 35*C, under
quiescent conditions, in 160-mL serum bottles to which 100 mL of liquid was added. The bottles
were sealed with slotted grey butyl rubber septa and aluminum crimp caps (Wheaton Scientific).
Virtually no loss of DCM was observed from water controls (WC) which used these septa; they
were less permeable to oxygen than Teflon-lined rubber septa, were easier to puncture, and
maintained better flexibility following autoclaving. [They were not used in PCE/TCE studies
because significant losses of these compounds (and their reductive dechlorination products) were
noted in water controls.]
Autoclaved seed controls (ASC) were used to evaluate the degree of sorption and
abiotic transformations of DCM. When these phenomena were consistently shown to be
negligible, use of the ASCs was discontinued.
Semicontinuous operation of the enrichment cultures was often practiced with
bottles which were actively degrading DCM. This entailed removal of a volume (usually 4.0 mL)
of well-mixed liquid and its subsequent replacement by some combination of basal medium and
DCM-saturated water to yield the desired DCM concentration. When semicontinuous operation
was not practiced, the disappearance of DCM was followed by addition of only DCM-saturated
water.
Analytical Methods. Analysis of volatile organics was performed by gas
chromatographic (GC) analysis of a 0.5-mL headspace sample, using a flame-ionization detector
C-91

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(FID) in conjunction with a 3.2-mm x 2.44-m stainless-steel column packed with 1% SP-1000 on
60/80 Carbopack-B, as previously described (Gossett, 1987; Freedman and Gossett, 1989).
Degradative pathways were examined through semi-continuous addition of
radiolabeled [14C]DCM to sixth-generation enrichment cultures. Following various periods of
operation, distribution of 14C among suspected DCM degradation products was determined as
previously described (Gossett and Freedman, 1988; Freedman and Gossett, 1989).
HPLC analysis was employed to determine the concentrations of soluble,
nonvolatile fermentation products, similar to the method described by Zinder and Koch. (1984). A
Hewlett Packard 1090 HPLC was used to pump 250-jiL samples through a 300-mm HP X-87H
ion exchange column (Bio-Rad Laboratories) and into an LC-25 refractive index detector (Perkin-
Elmer). The mobile phase (13mM H2SO4) was delivered at 0.7 mL/min. By operating the ion
exchange column at two temperatures (30 and 65C) it was possible to resolve formate,
formaldehyde, acetate, propionate, methanol, isobutyrate, butyrate, and ethanol. For example,
although methanol and propionate coeluted at 30C, they were well resolved at 65C
C. Results and Discussion
Pathways of DCM Metabolism. Figure 1 summarizes the pathways
involved in biotransformation of DCM by a methanogenic mixed culture. The radiotracer studies
which led us to this model were presented earlier (Gossett and Freedman, 1988) and will not be
detailed here. In essence, the model is the result of studies with [14CJDCM in which various levels
of bromoethanesulfonate (BES), a selective inhibitor of methanogenesis, were employed to inhibit
either acetoclastic methanogens (at low levels of BES) or all methanogens (at high levels of BES).
Subsequent monitoring of [14C] species and H2 allowed deductive development of the model.
H20
_v
DCM Oxidizers
>
HC1
H2

CO-) Reducing Methanogens1
H20

CO,
CH,
Acetoclastic Methanogens S *CH4 + C02
Figure 1. Proposed Model for Biodegradation of DCM by a Methanogenic Mixed
Culture.
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The accumulated evidence suggests that acetogenic bacteria mediate the degradation
of DCM, not methanogens. This evidence includes the degradation of DCM in the complete
absence of any methane formation (due to BES inhibition), and the formation of both acetic acid
and hydrogen as products of DCM degradation.
Additional indirect evidence which implicates non-methanogens was obtained by
examining DCM degradation in the presence of a potent antibiotic. Four bottles were set-up
identically, continuously shaken, and incubated at 35C. Over the first 29 days of operation, the
ability of each bottle to repetitively degrade increasing levels of initial DCM doses was established.
On day 29, two of the bottles received 10 mg of vancomycin (an inhibitor of cell wall synthesis in
eubacteria), while the other two bottles continued to receive only DCM. As shown in Figure 2, the
two bottles which did not receive vancomycin were able to repetitively degrade increasing levels of
DCM (no effort was made to increase the initial DCM dose above approximately 120 ^moles/100
mL, though it certainly would have been possible). In the other bottles, DCM degradation was
sustained for at least one spike after adding the vancomycin, but then DCM degradation began to
fall off considerably. Assuming that the vancomycin dose used affected eubacteria and not
methanogens (demonstrated by other investigators), these results add to the evidence indicating the
central role played by non-methanogens in DCM degradation. Though we cannot be absolutely
sure, we believe acetogens are the principal DCM oxidizers, as well as responsible for acetate
production from DCM.
Figure 3 shows the pathways we have observed to be affected by vancomycin and
BES additions.
C-93

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o
o
03
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120
100
80 H
Bottle #1:
No Vancomycin Added
o 60-
40"

10
20
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o
E
=i
O
Q
Bottle #2:
Vancomycin Added (10 mg, t=29)
20 30
Time (days)
Figure 2.
Effect of Vancomycin on DCM Degradation.
C-94

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h2o
\ /
ch2ci2 i ..
NlK Vancomycin
DCM Oxidizers
\> "co2
HC1
/
C02<
J
HC1
I
\
h2
V.
yBES^
CO? H"" CO-> Reducing Methanoeens
		y\l/
h2o
CR,
*ch3cooh
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\ /\ .
Acetoclastic Methanoeens	CH4 + COj

Figure 3. Pathways in the Proposed Model Which are Affected by BES and/or
Vancomycin.
Kinetics of DCM Degradation. The rate of DCM degradation at 35*C
was measured using batch-fed DCM enrichments to which an initial DCM concentration of 2 mM
was added (170 mg/L). At such a high concentration, methanogenesis was inhibited and hydrogen
accumulated (Figure 4); when DCM concentration was sufficiently reduced, methane production
resumed. DCM degradation followed an apparently zero-order kinetic model (constant rate = 7.6
|imol DCM/hr). The quantity of methane which resulted (about 8 pmol) was far lower than the
100 ixmol expected from degradation of 200 jimol of DCM. This suggests that most of the
methane formed resulted from C02-reducing methanogens, not from acetoclastic methanogens.
The latter organisms were likely more severely inhibited by the high initial levels of DCM
employed.
DCM as Growth Substrate. Significant progress has been made in
determining whether or not DCM can serve as a growth substrate, using the following
experimental design. Four serum bottles were set-up. Each received 90 mL of basal medium
(with 50 mg/L yeast extract as the only non-DCM carbon source) plus 10 mL of inoculum from
cultures which were actively degrading DCM, and incubated in an orbital shaker bath maintained at
35*C. Two of the bottles ("with-DCM") received repetitive additions of DCM. Initially, these
additions were approximately 10 |imoles/100 mL; over time they were increased to as high as 2.4
mM (204 mg/L). Two other bottles ("without-DCM")  serving as controls  were set-up
identically but received no DCM.
C-95

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Time (hrs)
Figure 4. Kinetic Experiment, 35C.
C-96

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Suspended organic carbon (SOC) was used as the measure of growth. At approx-
imately 14-day intervals, 5 mL was removed from each of the bottles, and replaced with 5 mL of
basal medium containing yeast extract (50 mg/L). 2.3 mL of the sample was used to measure total
organic carbon (TOC); 2.7 mL was filtered (0.45 pm) and used to measure dissolved organic car-
bon (DOC). The difference between TOC and DOC was SOC. Net growth on DCM was calcu-
lated by subtracting SOC in the "without-DCM" bottles from SOC in the "with-DCM" botdes.
Results after 133 days of operation are shown in Figure 5. SOC in the "with-
DCM" bottles began to rise definitively above SOC in the "without-DCM" bottles on day 49, just
as cumulative DCM consumption began to rise significandy. Concern still remained, however,
that this growth may have been attributable  at least in part  to methanogens (through the use
of DCM degradation products) and not to the organisms responsible for DCM degradation.
Nevertheless, even though BES was not added to these botdes, methane output was well below the
stoichiometric level expected (Figure 6), due to inhibition by high levels of DCM. This inhibition
was evident initially, when methane output in the "with-DCM" bottles was slighdy below that of
the "without-DCM" bottles. Methane output in the "with-DCM" botdes did eventually surpass that
in the "without-DCM" bottles, but it slowed and nearly stopped when DCM additions exceeded
approximately 1.8 mM (around day 63). By day 77, average cumulative DCM degradation was
2565 |imoles; had methanogenesis not been inhibited, cumulative methane output would have been
1401 n.moles (1283 as a consequence of DCM degradation plus 118 from the yeast extract).
Instead, only 357 (imoles were produced, indicating severe inhibition of methanogenesis.
Another, initially unexpected form of inhibition was encountered in these
experiments  that due to low pH resulting from HQ production in biological dechlorination of
DCM! Around day 75, DCM consumption stalled. Measurements on day 91 indicated that pH had
dropped to 5.1 and 5.4 in the two bottles receiving DCM, whereas the two without DCM had pHs
of 7.4 and 7.6. Addition of bicarbonate buffer, along with a 5% reinoculation from an active
DCM-degrading enrichment, revived the culture, allowing renewed DCM consumption, followed
by renewed biomass formation (as defined by SOC). Note, however, that after this period of
upset, biomass formation lagged considerably behind DCM consumption.
Day-91 samples were also analyzed for HAc and MeOH concentration, using a
HPLC with a refractive index detector. HAc concentrations were 6.77 mM and 6.94 mM in the
two "with-DCM" botdes. MeOH was not detected in either of the samples. The bottles receiving
no DCM had no detectable levels of HAc or MeOH.
The correlation between SOC formed and DCM degraded is quite good (Figure 7).
SOC formation was calculated by subtracting average SOC in "without-DCM" bottles from the
SOC in "with-DCM" botdes. These data indicate that approximately 8.5% of the DCM carbon
degraded was convened to cell carbon, a yield within the range expected for anaerobic micro-
organisms. The accumulation of SOC in the "with-DCM" bottles was likely due to organisms
other than methanogens  i.e., from degradation of DCM, rather than from acetate or H2. To
explain the observed synthesis as resulting solely from methanogenic activity on H2 or acetate
requires that unrealistically high yield coefficients be assumed. Thus, we conclude that DCM does
indeed serve as a growth substrate.
C-97

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400
i	1
120 140
T3_l
O e
E
32
0) o
C2^
O t
Ofl)
^ e
O I
D E
40 60 80 100 120 140
Time (days)
Figure 5. Growth on DCM.
C-98

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o
o
75

o
E
E
0)
c
CO
Q)
Potential Methane (based on DCM consumed)
Observed Methane
Control (no DCM added)
QgpODOOLUUJUL> I  H I >
-A-A- - A" A"" A"A" * A' - A- - - A
20
40 60 .80 100
Time (days)
120 140
Figure 6. Methane Formation During the "Growth" Experiment Depicted in
Figure 5.
Fixed'Film Reactor Studies. A fixed-film reactor is currently in operation
to study biodegradation of DCM under continuous-flow conditions. Figure 8 is a schematic of the
system, which consists of two glass columns, each 91-cm (3-ft) long x 5-cm (2-inch) diameter,
filled with 6-mm glass beads (added as a medium for bacterial attachment). The columns are
connected in series.
The first column contains a mixed culture of facultative and strict anaerobes and is
intended solely to maintain anaerobiosis for the second column. A refrigerated basal salts medium
containing acetate (100 mg/L) is provided by a peristaltic pump to the bottom of this "pre-column".
Numerous HPLC analyses consistendy indicate that all of the acetate is consumed in the pre-
column. Since resazurin is included in the feed, it is evident that the culture in the pre-column is
maintaining low redox conditions; the resazuiin in the column remains clear even though the feed is
blue (indicating high redox) or pink (indicating redox potential of > -50 mV). Effluent from the
pre-column enters the "DCM column" at its bottom. DCM-saturated water is injected into the flow
(using a syringe pump) prior to entering the DCM column.
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DCM Consumed (mmoles/100 mL)
Figure 7. Biomass Formation from DCM Degradation  Day 26
through Day 77.
Sample ports are spaced at 15.24-cm (6-inch) intervals along the length of the DCM
column. Sample ports are constructed of a hollow stainless-steel cylinder, machined to extend
from the exterior of the sample port to near the column center. The steel is held firmly in place by a
Teflon O-ring and bushing assembly. The exterior of the steel is covered with a Teflon-lined
rubber septum. The septum is held in place by an aluminum crimp cap.
The DCM column was inoculated with 2 liters of an active, DCM-degrading
enrichment culture. The DCM column was first operated in recycle mode for 22 days (at 35*C) to
facilitate microbial attachment. During this period, 0.1 mM DCM (8.5 mg/L) was added to the
column, allowed to degrade (in 2-3 days), then added again. Following this recirculation period,
the pre-column was connected in series and the system was operated in continuous-flow mode.
The DCM column was initially operated at a 2-day hydraulic retention time (HRT) based on void
volume, with a nominal DCM influent concentration of 0.1 mM. Eight days after commencing
continuous operation, only traces of DCM (<1.2 pM) were detected at the first sample port within
the column, and none at any higher location. Significant CH4 levels were noted at higher points
within the column, indicating biotransformation.
Samples are taken from the column routinely as follows: a 5-mL gas-tight syringe
(Supelco, Inc.) fitted with a custom-made, 4-inch side-port needle (Dynatech Precision
Instruments) is purged with 30%C02/70%N2 and inserted in the effluent (top) sample port. A 4-
mL liquid sample is drawn from the column and injected into a 14-mL vial sealed with a Teflon-
lined septum and aluminum crimp cap. The volume of sample delivered to the vial is determined
C-100

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gravimetrically. Samples are taken in this manner from each sample port from top to bottom.
Following equilibration at 35C, a 0.5-mL headspace sample is analyzed by GC.
PRE-COLUMN

A'Aj
) Q A 4 i
Wi
 O 1
gas
collection

peristaltic
pump
refrigerated
basal salts
medium +
acetate
sampling
vent
ft*
i

effluent
collection
DCM COLUMN
sampling
ports
syringe pump:
DCM-saturated water
Figure 8. Schematic of fixed-film columns.
After one month of operation, we began lowering the column temperature 
ultimately to 20*C, where it is now operating. Noting successful degradation at 20*C, we stepped
up the influent concentration of DCM to 0.4 mM (34 mg/L). Figure 9 shows the column profile
for such conditions. At such a high influent DCM concentration, inhibition of methanogenesis is
expected; the displacement of methane production to higher points within the column suggests that
C-101

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inhibition is-indeed occurring. Due to the relative lack of sensitivity associated with our acetate
method, we had not attempted measurements of acetate within the column. However, as influent
DCM is increased, we expect to be able to detect acetate and H2 at intermediate points of the
column (positions "12" through "24").
Sampling Port
Figure 9. Profile of Fixed-Film, Continuous-Flow Column Receiving DCM at 400
HM Concentration. Conditions: T = 20C; hydraulic retention time =
2 days; 0.5 mg/L yeast extract in feed.
III. FUTURE PLANS
In order to advance the prospect of using methanogenic systems for treatment of DCM
contaminated water, further research is being carried out in both suspended-growth and
immobilized-cell reactors. The suspended-growth studies will allow examination of more
fundamental issues:
Isolation of the microorganisms responsible for DCM degradation;
Characterization of the isolates (including the ability to grow on a variety of non-
chlorinated substrates, a property of significant practical importance in systems
where the level of DCM may be too low to alone support growth);
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l* Delineation of degradation pathways (i.e., a more fundamental approach that
previously employed; cell-free extracts from isolates will be purified with reversed-
phase HPLC);
Determination of the ability of enrichments to degrade chlorinated compounds other
than DCM.
The fixed-film reactor studies are oriented more towards the practical issues of how best to
accomplish treatment Foremost in this regard is the capability of the DCM degrading organisms to
attach to fixed-film media. Assuming this is possible, the reactors will be used to evaluate a variety
of treatment conditions, including DCM concentration, variation in hydraulic residence time, and
the effect of other chlorinated aliphatics  particularly CF  on the efficiency of DCM removal.
This research was supported by the U.S. Air Force Engineering and Services Center (AFESC),
Tyndall AFB, FL, under contract no. F08635-86-C-0161.
REFERENCES
Freedman, D. L.; and Gossett, J. M. 1989. Biological Reductive Dechlorination of
Tetrachloroethylene and Trichloroethylene to Ethylene under Methanogeic Conditions. Applied
and Environmental Microbiology 55. 2144-2151.
Gossett, J. M. 1987. Measurement of Henry's Law Constants for Ci and C2 Chlorinated
Hydrocarbons. Environmental Science & Technology 21(2): 202-208.
Gossett, J. M.; and Freedman, D. L. 1988. Biodegradation of Dichloromethane Under
Methanogenic Conditions. Presented at the Second International Meeting, NATO/CCMS Pilot
Study on Demonstration of Remedial Action Technologies for Contaminated Land and
Groundwater, November 7-11,1988, at the National Institute of Public Health and Environmental
Protection, Bilthoven, the Netherlands.
Zinder, S. H. and Koch, M. 1984. Non-Aceticlastic Methanogenesis from Acetate: Acetate
Oxidation by a Thermophilic Syntrophic Coculture. Archives of Microbiology 138: 263-272.
C-103

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Robert Olfenbuttel

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STATUS OF
FINAL NATO/CCMS PILOT STUDY REPORT
MONTREAL
6 - 9 NOVEMBER 1989
ROBERT OLFENBUTTEL
FELLOW
INTENT OF FINAL REPORT
> Reference Document Identifying Important Factors in Technology
Evaluation and Selection
	Focus on Technology Strengths And Limitations: Lessons Learned
	Will Not be a Design Manual
	Readers will be National Authorities and Users of Technology
OUTLINE OF FINAL REPORT
	Introduction/Background of Pilot Study
	Chapters Organized by Technology Type
	Technical and Economics Conclusions
	Recommendations - To NATO Council
	Appendices
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SUMMARY REPORT
	In Addition to Final Report
	10 to 12 Page Summary
	Conclusions and Recommendations
- NATO Council will Consider for Making Policy
FINAL REPORT CHAPTERS
1.
Thermal Treatment

2.
Physical/Chemical:
Stabilization/Solidification
3.
Physical/Chemical:
Chemical
4.
Physical/Chemical:
Volatilization (In Situ)
5.
Physical/Chemical:
Soil Treatment by Extraction
FINAL REPORT CHAPTERS
6.	Physical/Chemical: Pump and Treat
7.	Microbial Treatment:
In Situ
Above Ground
8.	Process of Selecting a Technology for a Site
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FINAL REPORT CHAPTERS
Conclusions (Technical/Economics)
Recommendations (to NATO Council)
Appendices
-	Case Study Reports
-	Fellowship Reports
-	Governmental Agencies/Offices Involved with Remediation
and/or Technology Development/Assistance
CHAPTER OUTLINE
. Scientific & Engineering Principles of the Technology
-	Potential Applications
-	Laboratory and Field Testing Needs
-	Choosing the Technology: Lessons Learned
 Case Studies
-	Why Chosen
-	Technical Approaches
-	Status of the Technology (Commercial, Developmental)
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CHAPTER OUTLINE
< Summary of Site Characteristics/Pollutants Studied
-	Typical/Unique
-	Lessons Learned Re: Data Needs
 Technology Effectiveness
-	Generally and Uniquely
-	Lessons Learned for Improving Effectiveness
-	Lessons Learned in Set Up, Testing, Decommissioning
CHAPTER OUTLINE
 Limitations of the Technology
-	Pollutants, Soil/Groundwater Conditions
-	Costs
-	Technology Status
-	Materials Handling (Key factor)
-	Other?
CHAPTER OUTLINE
 Costs
-	Capital
 Operations and Maintenance
-	Demonstration Costs
-	Other?
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CHAPTER OUTLINE
. Acceptance by Public and Government Regulators
-	Permittability
-	Lessons Learned (if anything)
. Future Status of the Technology
-	Compared to Other Technologies
-	R&D Recommendations
 When it will be Commercialized (if appropriate)
. Contacts for Additional Information
FINAL REPORT PREPARATION
. Planning Subcommittee	. Reviewers
R. Olfenbuttel (U.S.) - Chairman	M. Helle
R. Bell (U.K.)	E. Scozo
S. James (U.S.)
J. Schmidt (Canada)
M. Smith (U.K.)
V. Hathaway (U.K.)
FINAL REPORT PREPARATION
 Concerns
-	Adequate Data and Information In Case Studies?
-	National Representatives to Obtain
-	Discussions will Include Material from Fellows
-	Sufficient Lessons Learned?
-	Commercials Versus Objectiveness
-	Need for Chapter Writers
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PREPARATION OF CHAPTERS
CHAPTER
Introduction
1.	Thermal Treatment
2.	Stabilization/Solidification
3.	Chemical
4.	Volatilization (In Situ)
5.	Soil Treatment by Extraction
WRITER
R. Olfenbuttel
S. James (1st draft in)
M. Hinsenfeld (?)
9
9
HOW DO WE OBTAIN THE WRITERS?
	National Representatives?
	New Fellows?
	Current Fellows?
.	Other?
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WRITERS NEEDED
2.
3.
4.
5.
7.
PUBLISHING OF REPORT
. Through U.S. EPA with Logos of NATO, W. Germany and Netherlands
and EPA
. Distribution:
NATO (125 copies), OECD (40 copies)
Libraries Associated with NATO and Infaterra (U.N.)
Others (to be determined)
 Available in Spring 1992
C-113
CHAPTER	WRITER
Stabilization/Solidification	M. Hinsenfeld (?)
Chemical	?
Volatilization (In Situ)	?
Soil Treatment by Extraction	?
Microbial Treatment	?
in Situ	?
Above Ground	?

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Wayne Pettyjohn
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INTERIM REPORT
CAUSE AND EFFECT OF RAPID CHANGES IN SHALLOW GROUND-
WATER QUALITY
Wayne A. Pettyjohn
School of Geology
Oklahoma State University
Stillwater, Oklahoma 74078
PRESENTED TO
NATO/CCMS PILOT STUDY OF REMEDIAL ACTION AND
TECHNOLOGIES FOR CONTAMINATED LAND AND GROUND WATER
October 1989
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INTRODUCTION
General Overview
Shallow or surficial aquifer systems pose a challenge to
hydrogeologists because they are located so close to the land surface,
and are highly susceptible to contamination from a diverse range of
sources. Some of the mechanisms that control contaminant
migration, however, are poorly understood. Comprehension of these
controls is further complicated by the fact that shallow and surficial
aquifers may be subject to rapid changes in chemical and biological
quality. A better understanding of the controls could aid in the
development of aquifer protection plans, in reducing the degree of
contamination, and in restoring contaminated systems. Moreover, it
would aid regulatory agencies to develop more accurate
methodologies for establishing background concentrations that better
represent the dynamics of aquifer systems.
This research was based on a multi-phase program of data
collection at two controlled field sites located in north- central
Oklahoma. Site 1, where research has been most intensive, is located
in a residential neighborhood on the flood plain of a small stream.
Nitrate fertilizer is applied to the lawn three times per year. Site 2
lies near the shore of a lake and is far removed from human
activities.
Research Objectives
The objectives of this research were first, to document and
attempt to explain why shallow ground-water quality can change
significantly within a matter of hours or days. Second, to gain a
greater understanding of the processes that allow contaminants to
move at a rapid rate through unconsolidated fine-grained material.
Third, to document and account for the wide range of values in the
chemical quality of shallow aquifer water, and finally, to discern the
processes by which ground-water recharge occurs during periods of
soil-moisture deficiency.
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SITE DESCRIPTION
Geography
Both study areas are located in Payne County, Oklahoma. They
lie in the Central Redbed Plains physiographic province, which is
characterized by rolling plains and broad valleys formed by the
weathering of non-resistant red shales. A slope of less than 1% allows
for little surface runoff from Site 1. The topography at Site 2 ranges
from 942 to 1079 feet above sea level.
Climate
Mean daily temperatures in Payne County range from 39
degrees F in the winter months to 80 degrees F in the summer.
Annual precipitation and evapotranspiration average 34 and 30
inches, respectively. Precipitation generally occurs as localized
showers of short duration and high intensity during the spring and
summer, and as regional storms of longer duration during the fall
and winter. The months of greatest precipitation, based on 93 years
of record, occur in May and September. Effective regional ground-
water recharge rates average 1 inch per year (Pettyjohn and others,
1983).
Site 1 Location
Site 1, which contains about 14,000 square feet, is located in a
residential neighborhood in Stillwater, Payne County, OK (NE 1/4 sec.
11, T 19 N, R 2 E). The site, situated on the Boomer Creek flood plain,
lies about 350 feet east of a small unnamed tributary (fig. 1).
Site 1 Geology
This investigation focused on a surficial aquifer system that
consists of Quaternary alluvial deposits that fill a steep- walled valley
cut into the Doyle Shale, which is Late Pennsylvanian in age (fig. 2).
Outcrops of the Doyle Shale, which consists of interbedded layers of
thick, red shale and thin, lenticular sandstone units, lie about 300
feet east of the site. The alluvium, composed of a nonbedded mixture
of very fine-grained sand (50%), silt (25%), and clay (25%), terminates
against the Doyle outcrop.
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Bit
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Figure 1. Site Location and General Geology of Payne County,
Oklahoma.
950
900
850
800
750
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Horizontal Seal*: 1 Inch  1000 Imi
Vertical Scala: 1 Inch  100 taal
Vartlcal Exaggeration: 10s

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Figure 2. Geologic Cross-Section at Site 1.
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Site 1 Soil Description
The surficial material at Site 1 is classified as an Ashport soil
that originated from alluvial deposits on a narrow, nearly flat flood
plain. Ashport soils are characteristically moderately permeable, well
drained, have a silt-loam texture, and are classified as Fluventic
Haplustolls (Soil Conservation Service, Payne County Survey, 1985).
The unconsolidated, fine-grained alluvial material, which
contains soil structures throughout, has a maximum thickness at the
site of 43 feet, and it lies unconformably on the Doyle Shale (fig. 3).
Analysis of a 45-foot long composite core by Ross (1987) revealed
three soil profiles; surface, upper, and lower. The dark gray upper
and lower profiles, beginning at depths of 4 and 27.5 feet,
respectively, have been radiocarbon dated at 1300 +/-70 and
10,600 +/-170 years B.P.
The profiles are composed of loam, silt loam, silty clay loam,
and clay loam horizons. Dominant structures include weak to
moderate subangular blocky, parting to either coarse to moderate
medium platy or moderate, medium prismatic structure. Root casts
are present throughout the profile, as are slickensides and fractures.
Iron/manganese nodules decrease in abundance downward from 5.3
to 5.3 to 25.5 feet. Calcite nodules occur from 6.5 to 9 feet below
land surface. Soil mineralogy is dominated by quartz grains, with
feldspar comprising three to five percent of the grains present. Iron-
stained clay and silt make up the matrix.
Site 1 Surface water Hydrology
Site 1 is located about 350 feet east of an unnamed tributary to
Boomer Creek. Boomer Creek flows southeastward and is the major
drainage in the area. A slope of less than 1% allows for little surface
runoff from the site resulting in ponding after significant
precipitation events.
Site 1 Ground-water Hydrology
Transmissivity, hydraulic conductivity, and storativity
coefficients average about 2225 gpd/ft, 57 gpd/ft2 and .01,
respectively. Water levels fluctuate from about 3 feet in the spring to
about 12.5 feet below land surface in the late summer. Rapid rises of
a foot or two may occur during recharge events. Ground- water
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SOIL PROFILE
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velocities fluctuate seasonally from less than 0.4 to greater than 1
foot per day.
The water-level gradient varies between .003 and .008. Flow
direction, generally southward toward Boomer Creek, varies in
direction from 145 to 225 degrees. Hoyle (1987) and Hagen (1986)
suggest that flow direction may be controlled by evapotranspiration
by the large trees that grow along the site's southern boundary.
Site 2 Location
Site 2 is located on the western most bank of Lake Carl
Blackwell, Payne County, OK (SW 1/4, NE1/4, sec. 10, T19N, R1W).
Site 2 Geology
The area is located on Quaternary alluvium that is underlain by
sandstone, mudstone, and conglomerate of the Wellington Formation,
which is Permian in age.
Site 2 Soil Description
The soils at Site 2 belong to the Port Silt Loam Series and are
characterized as fine, silty, mixed, thermic Cumulic Haplustolls. The
dominate clays in the soil are montmorillonite and kaolinite (Soil
Conservation Service, Payne County Survey, 1985). Observable
fractures at the soil surface indicate the presence of desiccation
cracks (macropores).
Site 2 Surface Water Hydrology
Lake Carl Blackwell, an artificial lake, covers about 500 acres
and has an average depth of 16 feet. The lake is fed by Stillwater
Creek, which is the major drainage, for the area.
Site 2 Ground-Water Hydrology
The water-bearing zone beneath Site 2 is composed of clay
loam and sandy clay loam that has a transmissivity value in the
range of 100 gpd/ft. Depth to the water table averages about 5 feet
below land surface.
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SITE INSTRUMENTATION
Laboratory
Site 1 contains an on-site laboratory equipped with a digital
thermometer and pH meter sensitive to .1 degrees C and .01 pH
units, respectively, a temperature-compensating conductivity meter,
and a digital titrator. A tipping bucket rain gauge, barograph,
photometer, and thermometer continuously monitor and record
meteorologic conditions.
Ground-Water Monitoring Wells
Site 1 is monitored by 43 wells (fig. 4) that are distributed
among 10 sites; the wells range from 8.5 to 43 feet in depth. Holes
for most of the monitoring wells were excavated by hand auger. In
each of the wells the PVC pipe is screened, and sand packed; the
annular space is filled bentonite. The wells were developed by
backwashing and surging. Twentyfive of the wells are located in
clusters of 5 wells, each of which is designed to sample a discrete
part of the aquifer. Four sets consist of wells that are 8.5, 9.5, 10.5,
and 14 (2 wells) feet deep. Four of the wells have the lower 4 inches
slotted. The fifth well is slotted along the lowermost 6 feet (fig. 5).
Horizontal distance between wells in a cluster varies from less than
.5 to 3 feet. Clusters are located at sites A, B, C, D, and E. In two wells
pressure transducers coupled to recorders continuously monitor
ground-water levels at 15 and 30 minute intervals.
The well at Site 2,10 feet deep, is constructed of 1-inch
diameter PVC pipe. The lower 5 feet are slotted and gravel packed
with pea-sized gravel. Above the gravel pack, the annular space is
filled with bentonite.
Test Wells
In order to allow high yield aquifer tests to be conducted at
Site 1, a test well, four inches in diameter and 43 feet deep, was
installed by hollow-stem auger at the B site. At the F site, a four-
inch diameter, 40-foot deep production well with 30 feet of screen
was installed. Ah attached 2-inch diameter well of similar length and
construction is used to measure well loss during tests.
Soil-water Suction Lysimeters
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Figure 4 Location of Monitoring Wells at
Site 1.
Screen
Grout
Sand Pack
4
Wall Numbar

m ' 8.8
8.8
tot
13.8
13.8
Figure 5 Typical details of a Well
Cluster at Site 1.
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Water in the unsaturated zone is held at less than atmospheric
pressure and, therefore, must be removed by suction. Eight suction
lysimeters are located between the A and B clusters at Site 1. Each
lysimeter consists of one bar, high flow, porous ceramic sampling
cups bonded to PVC tubing. Compressional O-rings located at the top
of the chamber and around the stainless steel access tubing form air
tight seals.
Holes for the lysimeters were excavated with a Giddings truck-
mounted soil probe. The lysimeters are installed at depths that
correspond with major soil horizons (fig. 6). The ceramic cups are in
contact with 200 mesh silica flour; bentonite pellets and native soil
fill the annulus.
Soil-Moisture Neutron Probe
Data on soil moisture were obtained by inserting a Troxler
model 330 depth moisture gauge into neutron probe access tubes (7
feet deep) adjacent to each well cluster. The 1.7 inch diameter
aluminum access tubes are open at the bottom. The tubes were
installed by pounding the pipe into the soil and augering out the
inside until the desired depth was reached. Site 2 contains 8 access
tubes placed in a grid pattern around the observation wells (fig. 7).
METHODOLOGY
Ground-Water Geochemistry
Nalgene plastic sample bottles (500 ml) were cleansed before
each use, following EPA approved procedures. Bottles were washed
with detergent in hot water, rinsed 3 times with tap water, rinsed 3
times with deionized distilled water, rinsed once with either dilute
hydrochloric or nitric acid, and rinsed 3 times again with deionized
distilled water.
Prior to each sampling event, data on static water levels in each
of the monitoring wells, air temperature, barometric pressure, and
rainfall amounts were collected.
To ensure that fresh formation water was obtained, three well
volumes were purged from each well by peristaltic pump prior to
sampling. The evacuated water was discharged about 10 feet from
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set at Site 1.
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Figure 7. Neutron access tube locations
at Site 2.
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the well to avoid immediate recharge. Samples were withdrawn by
peristaltic pump through Tygon tubing and discharged into the
sample bottles. The bottles were rinsed with water from the well
before being filled. Since approximately 200 milliliters of formation
water passed through the tubing before samples were collected, cross
contamination of water samples collected at different wells was
prevented. Ground -water samples were collected weekly, and
before, during, and after several rain events.
Variations in the quality of water in the unsaturated zone were
monitored by analyzing water samples collected from the suction
lysimeters. A vacuum of -24 inches of mercury was placed on each
lysimeter using a 42 liter displacement capacity vacuum pump.
Vacuum pressure was maintained by sealing the Tygon tubing with a
clamp. Samples, collected by peristaltic pump through Tygon tubing
attached to the lysimeter's stainless steel discharge tube, were
discharged into Nalgene bottles. The peristaltic pump discharge line
was cleaned after each use by flushing with deionized distilled water.
Information on the downward movement of chemical species in
the unsaturated zone was acquired by monitoring tracers applied at
the land surface. The tests, designed to simulate precipitation events,
were performed under both wet and dry initial soil- moisture
conditions. A 6 x 8 foot plot surrounding the lysimeters was
inundated with 500 mg/1 KBr solution (wet conditions) and 500 mg/1
CaCl solution (dry conditions) in amounts equivalent to 3 inches of
rain. Samples were taken from the 10 suction lysimeters and
analyzed for bromide and chloride.
Field parameters were determined in an on-site laboratory
immediately after collection. Prior to each sampling event, calibration
of the pH and conductivity meters was completed. A digital titrator
was used to measure bicarbonate concentrations. The sample was
titrated to a 4.5 pH color endpoint with 2N HC1. A simple equation
allows the number of digits required to reach the endpoint to be
converted into mg/1 of HCO3.
Immediately after the determination of field parameters,
samples were refrigerated and stored at 4 degrees Celsius. Samples
were filtered through .2 micrometer Gelman acetate filters and split
into two parts. One part was acidized with IN HC1 to a pH of <2 and
stored for cation analyses. The remaining portion was stored for
anion analyses.
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A Dionex 2000i ion chromatograph was used to measure
chloride (CI), nitrate (N03), sulfate (SO4) and bicarbonate (HCO3)
concentrations. Prior to the start of sample analyses, calibration of
the chromatograph, using standard solutions prepared by the
dilution of 1000 mg/1 CI, NO3, and SO4 stock solutions, was
completed. Recalibration was done following the analyses of 20
samples.
Samples were analyzed for calcium (Ca), magnesium (Mg),
sodium (Na), potassium (K), total iron (Fe). manganese (Mn),
aluminum (Al), and silica (Si) using inductively coupled plasma
atomic emission spectroscopy (ICP). Decade standards for each
element were prepared by the dilution of stock solutions made by
the dilution of standard reagent solutions. Each sample was analyzed
four times and reported as an average concentration.
Cleanliness of a batch of precleaned sample bottles was verified
by filling test bottles with deionized distilled water and subjecting
the water to the same analysis as the ground-water samples.
Duplicate samples were taken in the field to test the accuracy of field
and analytical methods. During anion analyses, duplicate samples
and calibration standards were analyzed approximately every fifth
sample to measure the chromatography performance. Samples of
known cation concentrations were analyzed on a regular basis to
ensure that the ICP was functioning properly. Performance was
further documented by the analyses of E.P.A. water along with the
samples.
Aquifer Performance
The validity of various methods for estimating the hydrologic
parameters of unconsolidated, fine-grained alluvial aquifers was
evaluated using data obtained from pumping tests, slug tests, and
laboratory analysis of aquifer material. Several tests were conducted
by pumping water from the fifth well of a cluster with a peristaltic
pump at a rate of .32 to .72 gpm and recording drawdown in the
other wells of a cluster by pressure transducer and steel tape. Other
methods involved removing water from a 4-inch diameter test well
by a submersible pump at rates ranging from 2.7 to nearly 10 gpm
and recording drawdown at other wells at the site. Slug tests were
performed by removing a known volume of water from a well with a
bailer and recording water-level recovery with a pressure
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transducer. Aquifer test data were interpreted using techniques
developed by Theis, Jacob, Franke, Prickett, and Neuman. Slug-test
data were evaluated using a variety of analytical techniques. A
constant head permeameter was used to obtain laboratory values of
hydraulic conductivity
Ground-Water Hydraulics
Information on horizontal and vertical gradients was obtained
by the measurement of water levels in each of the 43 monitoring
wells. Depth from the top of the well casing to the top of the water
table was measured by chalked steel tape or by pressure
transducers. Top of casing elevation was surveyed for each well to
permit accurate measurement of the water-table elevation. To
maintain consistency, water levels were taken from a marked point
at the top of each well casing. Hydrographs and water-level maps
were constructed from the measured data.
Infiltration
In order to gain a greater understanding of the roles that
macropores play in the movement of water through the unsaturated
zone, infiltration experiments were conducted at Site 2. A known
volume of water was applied to the surface, and changes in soil-
moisture were monitored by inserting a Troxler Depth Moisture
Gauge into neutron probe access tubes. Data collection began IS
minutes after water was applied to the surface. Readings were taken
at half foot intervals to a total depth of four feet. Monitoring
continued until stabilization of soil moisture occurred. The resulting
data were plotted using a variety of computer graphing techniques.
Photographs of soil surface cracks were taken during wetting and
drying cycles to document macropore development.
Soil Analyses
Physical and chemical characteristics of earth materials were
determined by detailed analysis of cores. A composite core, 45 feet
long, was obtained by combining cores taken from six 8-inch
diameter holes drilled by a continuous flight hollow-stem auger at
the B and F sites. The core was logged and photographed in the field.
Textural classification involved particle-size analyses and the
determination of clay fraction by pipet method. Bulk density was
determined by wrapping samples in preweighed foil, oven drying for
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48 hours at 105 degrees C, and comparing "wet" and "dry" weights.
In order to examine soil mineralogy, selected soil samples were
impregnated with epoxy resin, slabbed, thin sections prepared and
polished to a thickness of 30 micrometers. Thin sections were viewed
in plane-polarized, cross-polarized, and reflected light. Clay
mineralogy was examined using x-ray diffraction analysis.
PRINCIPLE FINDINGS AND SIGNIFICANCE
Evaluation of the data collected during the course of this study
revealed the following:
1.	There is considerable variation in inorganic chemical
concentrations with respect to both time and space. Electrical
conductivity, for example, commonly ranges between about 250 and
2200 umhos and nitrate from about .1 to more than 60 mg/1. In 4
years of data collection, no two wells have ever had the same
concentration of any constituent. Stratification of anions at any given
sampling point is present, but cannot be correlated from point to
point. At a single sample point, the concentration of one anion may
increase and another may decrease with depth (Froneberger, in
prep). The most significant changes in water quality (NO3), resulting
in at least fourfold increases, were observed within hours after a
rainfall event, and this was followed over the next two days by a
fivefold decrease (figs. 8 and 9 ).
2.	Urban features can exert a strong influence on shallow water
quality. Dilution of ground water was observed after rainfall events
in wells located adjacent to a downspout. The presence of a large
covered area (about 4000 square feet covered by a building) was
seen to have an effect on nitrate concentrations since wells located
within the covered area were significantly higher than those in other
wells, perhaps owing to a lack of direct recharge from above.
Elevated chloride concentrations were present at times of low water
table in wells located in the vicinity of a sewer line.
3.	Vegetation, particularly deep rooted trees, was found to have a
significant effect on water quality, fluctuation of the water table, and
the direction and velocity of ground-water flow. The C and D well
clusters, located near a number of large trees (fig. 4), consistently
had the highest bicarbonate concentrations. Maps of the
potentiometric surface reveal that the direction of ground-water
flow, generally southward toward Boomer Creek, varies in direction
C131

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Figure 8. Change in nitrate following
1.3 inches of rain on September
13 1985 in a well 14 feet deep.
Figure 9* Nitrate Concentration, Cluster A,
March 27-April 15, 1986.
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HORIZONTAL
HYDRAULIC GRADIENT
Figure 10. Horizontal Hydraulic Gradient,
Direction and Magnitude,
April 1985 to June 1987
Figure 11. Water-level map on
July 26, 1986.
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WATER LEVEL ELEVATIONS
2 APRIL 1906
Iiri i I
 m rici  
OnAOItMII 9.003
Figure 12. Water-level map on
April 2, 1986.
-9M-T
.
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79lWell A4, Depth 14 ft.
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00
Figure 14* Water table fluctuation in a well, 14 feet
deep, and precipitation, July, 1985 to
October, 1986.
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from 145 to 225 degrees from summer to late spring (fig. 10), and
during the same interval the hydraulic gradient is reduced by half,
from .006 in July to .003 in April (figs. 11 and 12).
Additionally, the water table fluctuates daily in response to
ground-water removal by transpiration (fig. 13). The decline or
drawdown during daylight hours is directly related to sunlight
intensity, temperature, and precipitation, the latter of which, to some
extent, controls relative humidity. The drawdown varies from one
location to another, indicating differences in water use and/or
porosity, but it commonly averages about .3 feet in the vicinity of the
D wells during the summer. During the growing season, April
through September, transpiration causes the water table to decline
about .1 foot per day in the absence of recharge (fig. 14). The slope
of the water-level recovery during hours of darkness, as indicated by
Figure 13, indicates that ground water flows into the "cone of
depression" at a velocity of nearly 1 foot per day.
During the four years of record, the water table has not
declined below about 12.5 feet below land surface, regardless of the
lack of precipitation. This may indicate that 12.5 feet is the
maximum depth at which trees at Site 1 are capable of removing
water directly from the saturated zone. That is, the trees may be
forced to obtain their water requirements largely from the
unsaturated zone.
4. Fertilizer application, coupled with rain, has a short lived but
significant effect on the concentration of nitrogen in ground water,
regardless of the soil-moisture content. Nitrogen concentrations tend
to rapidly increase after a recharge event following application, but
then decline below the pre-event concentration within three or four
days (figs. 8 and 9). The change in nitrate concentration over a five
day interval following a recharge event appears to suggest the
infiltration of a relatively small volume of highly concentrated water
(a leveling off of the water-level decline and a fourfold nitrate
increase) that is followed about two days later with a large volume of
diluted water (a water-table rise and a fivefold decrease in
concentration) . Flow through the unsaturated zone, even when it is
very dry, is in the range of 5 feet per day or more. Following an
intense rain in July, 1989, water began to pass through the
unsaturated zone at a rate of about 14 feet per hour. This suggests
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early flow through macropores, subsequently followed by piston
flow.
5.	Ground-water recharge occurs during periods of soil -moisture
deficiency. This is evidenced by the fact that significant changes in
water level and water quality were observed within minutes to a
few hours following a rain event, even when soil-moisture was well
below field capacity. The- graph in Figure 15 represents the rapid
infiltration of water following a period of precipitation on July 14,
1989. In this case, the water table, about 7 feet below land surface,
began to rise within 30 minutes of the beginning of an intense (3.34
inches) rain. The lack of correlation between water level and
barometric pressure indicates that the aquifer is unconfined and not
sensitive to pressure loading.
6.	Macropores play a significant role in the movement of water
through the unsaturated zone. At Site 2, rapid infiltration to depths
of 3 feet was detected by neutron probe readings in places where
macropores were well developed. In contrast, infiltration in areas
with poorly developed macropores was only observed to a maximum
depth of 1.5 feet. The rapid response of the water table to rain at
Site 1, as described above, only could have occurred by flow through
macropores.
7.	Macropore development is not completely random.
Observation of photos taken before and during wetting and drying
cycles indicate that well -developed macropores, in this case
desiccation cracks, tend to reform in the same pattern, shape, and
location.
8.	Field determination of aquifer hydraulic characteristics, such as
transmissivity and hydraulic conductivity, of unconsolidated fine-
grained sediments, such as those present at Sites 1 and 2, are far
more realistic than those determined by laboratory methods.
Constant rate discharge tests allow the entire aquifer to be stressed
and thus provide hydraulic data that apply to the entire system.
Slug tests also have proven to be of substantial value and provide
estimates of hydraulic conductivity that are in relatively close
agreement with constant rate tests. The average hydraulic
conductivity of the aquifer, as determined by time-drawdown and
distance drawdown evaluations, averaged 57 and 39 gpd/ft2,
respectively, while the average value obtained from slug tests
averaged 48 gpd/ft2.
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877 8
12 2 4 6
July 14. 1989
10 12 2 4 6
| July 16. 1989
Time, in hour*
Figure 15 Barometric pressure and response of water
table in two wells, 14 feet deep, to
3.3 inches on July 11, 1989*
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Samples of cores taken from several .depths in the aquifer were
taken to the laboratory for hydraulic testing. The horizontal and
vertical hydraulic conductivity -averaged 5.6xl0*4 and 2.4x10"3
gpd/ft2, respectively. These values are more than 4 orders of
magnitude smaller than those determined by field methods. That
the former are far too small is proven by the yields that the wells
actually provide. The difference in results are probably due to core
compaction, smearing, and collapse of macropores when the samples
were prepared for permeameter analyses.
CONCLUSIONS
The observations made during the course of this study indicate
the need for the re-evaluation of several widely held beliefs and
practices. The general assumption that ground-water recharge cannot
occur during periods of soil- moisture deficiency is challenged by the
fact that changes in both water level and water quality were
observed shortly after a rain event, even though soil moisture was
well below field capacity.
Photos of macropores reforming in the same shape, pattern,
and location after wet periods invalidates the belief that macropore
formation is completely random.
The wide range in the concentration of constituents with
respect to both time and space calls into question the practice of
assuming that ground-water quality is rather uniform (it probably is
relatively constant in deeper, confined, and unstressed aquifers), and
therefore, samples collected at regular intervals will adequately
describe the quality that exists. Since it was found in this study that
electrical conductivity ranges over one order of magnitude and a
minor constituent, nitrate, over more than two orders of magnitude
throughout a very small vertical and areal extent, what is the
background concentration? Would it not be more appropriate to
consider background to be a range, in fact rather a broad range,
rather than a finite concentration?
When should water samples be collected from a shallow or
surficial aquifer. The concentration determined a few hours or a day
or two after a rain might well be very high as compared to that
present two to five days later, which, in turn, might be significantly
lower that that determined during a dry period.
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Throughout the glaciated regions of North America, the upper
20 to 40 feet of the glacial till is commonly oxidized and the water is
thousands of years younger than that present at greater depths. In
nonglaciated regions, such as Oklahoma, consolidated sedimentary
rocks, such as sandstone, siltstone, shale, and mudstone, are
commonly fractured to depths of SO to 70 feet, contain water
substantially younger than deeper zones, and transmit nearly all of
the water that infiltrates. Sediments such as these contain a mass of
pervasive fractures or macropores that may permit a rapid transfer
of water and, potentially, contaminants. Consequently, many rocks
that are assumed to be "impermeable" indeed are not.
If flow through many soils, unconsolidated fine-grained
sediments, and many consolidated or crystalline rocks is strongly
influenced by macropores, what is the effect on mass transport?
How valid are retardation coefficients? How valid are many of the
assumptions on which saturated and unsaturated flow models are
based?
Perhaps ground-water quality monitoring and aquifer
restoration techniques should take into account the wide range in
the quality of shallow ground water, gradient shifts that may be
caused by vegetation, and possible macropore participation in the
migration of constituents to the water table.
ACKNOWLEDGMENTS
Much of the data on which this report is based was obtained
through the arduous, time consuming, frustrating, and seemingly
thankless work accomplished by graduate students, past and present,
namely, David Hagen, Blythe Hoyle, Randall Ross, Jeff Melby, Tom
Acre, Mike Nelson, Dale Froneberger, and pattie Zietlow. Neither rain
nor snow, heat or cold could reduce their enthusiastic
participation...at least not very much.
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REFERENCES CTIED
Acre, TJ., 1989, The Influence of Macropores on Water Movement in
the Unsaturated Zone: Unpublished M.S. Theses, Oklahoma State
University, 129p.
Froneberger, D.F., in prep, Influence of Prevailing Hydrologic
Conditions on Variation in Shallow Ground- water Quality:
Unpublished M.S. Thesis, Oklahoma State University.
Hagen, D.J., 1986. Spatial and Temporal Variability of Ground
Water Quality in a Shallow Aquifer in North-Central Oklahoma: M.S.
Thesis, Oklahoma State University, 191p.
Hoyle, B.L., 1987. Suburban Hydrogeology and Ground-Water
Geochemistry of the Ashport Silt Loam, Payne County, Oklahoma:
M.S. Thesis, Oklahoma State University, 277p.
Melby, J.T., 1989, A Comparative Study of Hydraulic Conductivity
Determinations for a Fine Grained Alluvium Aquifer: Unpublished
M.S. Thesis, Oklahoma State University, 148p.
Nelson, M.J., in prep, Cause and Effect of Water-Table Fluctuations in
a Shallow Unconfined Aquifer: Unpublished M.S. Thesis, Oklahoma
State University.
Pettyjohn, W.A., White, H. and Dunn, S., 1983. Water Atlas of
Oklahoma: University Center for Water Research, Oklahoma State
University, Stillwater, 72p.
Ross, R.R., 1988. Temporal and Vertical Variability of the Soil and
Ground-water Geochemistry of the Ashport Silt Loam, Payne County,
Oklahoma: M.S. Thesis, Oklahoma State University, 116p.
Soil Conservation Service, 1987. Soil Survey of Payne County,
Oklahoma: U.S. Department of Agriculture, 268p.
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Sjef Staps
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INTERNATIONAL EVALUATION OF IN-SITU BIORESTORATION
OF CONTAMINATED SOIL AND GROUNDWATER.
J.J.M. Staps
National Institute of Public Health
and Environmental Protection (RIVM)
P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
Final Fellowship report for the Third International Meeting
of the NATO/CCMS pilot study on "Demonstration of Remedial
Action Technologies for Contaminated Land and Groundwater".
Montreal, Canada, November 6-9, 1989.
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ABSTRACT
ThiSjpaper is the result of the RIVM-project "International evaluation of in-
situ biorestoration of contaminated soil and groundwater". As a fellowship
project, it was associated with the international NATO/CCMS pilot project on
"Demonstration of Remedial Action Technologies for Contaminated Land and
Groundwater".
The philosophy of in-situ biorestoration is to stimulate the indigenous soil
microorganisms to degrade contaminants by improving the environmental
conditions in the soil using a water recirculation system.
The objective of the project is to show the possibilities for application of
the technique in relation with contaminants, soil conditions and other site-
specific circumstances by means of integration and evaluation of results of
in-situ biorestoration projects.
The project is limited to the Netherlands, Vest Germany and the USA. It was
implemented by visiting 23 relevant projects in these three countries, which
play a leading role in the development of remediation techniques for
contaminated soil and groundwater.
In-situ biorestoration is a relatively young, developing technology. It has
been used at several locations, mainly in the USA. It can be used especially
for locations at which both the unsaturated zone and the groundwater are
contaminated with hydrocarbons. A precondition is a good permeability of the
soil.
Experience has especially been gained with in-situ biorestoration at
hydrocarbon-contaminated petrol stations and industrial sites. The system
generally consists of a water recirculation system, aboveground water
treatment and conditioning of the infiltrating water with nutrients and an
oxygen source. However, there is no one-and-only application method for in-
situ biorestoration. The remediation, which can last from approximately six
months to several years, can reach residual concentrations below the B-value
of the Netherlands examination framework (see table 4). If applicable, in-situ
biorestoration is generally more cost-effective thgn other remediation
techniques; costs are approximately between 40-80 US $/m .
Recommendations from this evaluation include a further stimulation of the
development of this technology, improvement of the preliminary research,
expansion of the applicability to more recalcitrant contaminants, research on
bio-availability and research into oxygen supply and distribution in the
subsoil.
INTRODUCTION.
In behalf of the Dutch clean-up operation for contaminated soil, development
of adequate clean-up methods is considered to be of prime importance. Besides
thermal and extraction techniques, which still account for the greater part of
the clean-up operation, biological techniques have been developed in the
Netherlands. Landfarming, a biological treatment technology for excavated
contaminated soil, is now being used on a practical scale (Socz6 and Staps,
1988). However, in many cases it is impossible or too expensive to excavate
1 in (its original) place
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the soil. In-situ techniques are then the most appropriate methods, and can be
employed for treating both the soil and the groundwater.
In the Netherlands, application of in-situ techniques by companies nowadays
focusses on washing, circulating and cleaning of the groundwater (the former
pump-and-treat method). Especially in recent years, increasing interest is
also being shown in actual biorestoration in the soil. The environmental
conditions in the subsoil are optimized by supplying oxygen and nutrients and
circulating the water.
The first Dutch research into in-situ biorestoration was a feasibility study,
carried out by Delft Geotechnics, to evaluate the scope of an in-situ soil-
venting technique (van Eyk and Vreeken, 1988). The RIVM and the TNO
(Netherlands Organization for Applied Scientific Research) are preparing a
full-scale clean-up by means of a literature study and extensive experiments
on laboratory-scale since 1985 (Verheul et.al., 1988). However, a clear need
for information from full-scale clean-up projects and from foreign experience
was still felt. From literature and international contacts is was known, that
especially in the USA experience with this technology had been gained.
Besides, developments were also under way in West Germany (Nagel et.al., 1982
and others).
While the problem of soil and water contamination also became evident in other
countries, interest in remediation techniques, and especially in-situ
technologies, increased. This emerged at the first international workshop of
the NATO/CCMS pilot project on "Demonstration of Remedial Action Technologies
for Contaminated Land and Groundwater" in spring 1987. Several western
countries, including the Netherlands and the USA are participating in this
pilot project.
This was sufficient reason for the RIVM to start this evaluation in late 1987.
The author was awarded a fellowship of the NATO/CCMS project. Because of its
relevance to the development of remediation techniques in the Netherlands, the
study is partly financed by The Netherlands Integrated Soil Research program.
The project is limited to the Netherlands, West Germany and the USA. The
fellowship project was implemented by visiting 23 projects in this field in
these three countries, which play a leading role in the development of
remediation techniques for contaminated soil and groundwater. An overview of
the projects is given in the appendix.
Information, results and data are directly obtained from the experts involved.
Total information is arranged, and conclusions are drawn in this final paper.
A more comprehensive report, including detailed information from the visited
projects, is in print (Staps, 1989 ). Information concerning analytical
procedures is also included in this report.
EVALUATION OF IN-SITU BIORESTORATION PROJECTS
Introduction
Although not all organizations dealing with in-situ biorestoration are
included, the 23 projects chosen do provide a good idea of the feasibility of
this technology. The concerning group of 23 organizations consisted of fifteen
private companies, three institutes, two universities, one co-operation of an
institute, a university and a coast guard, and one air force.
A schematical overview of the projects, including several characteristics, is
given in the appendix. Projects U8 and U9 cannot really be regarded as in-situ
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biorestoration projects, because in both cases biorestoration does not take
place in the original location. The clean-up site in project U8 is a lagoon,
and in the case of U9, the clean-up consists of on-site landfarming. These two
projects are not included in this chapter, but, because of the direct
relationship to the other projects, they are included in the general overview.
Other divergent projects are N5 and U5; both are research projects, where the
contamination has been caused deliberately. Moreover, project N5 is deviating
because the biostimulation is performed only by venting of the soil, and thus
is limited to the unsaturated zone.
Projects D5 and D6 differ from the other ones in that they are still in the
conceptual phase, and data from demonstration scale test are as yet not
available.
A substantial proportion of the remaining group of "real" in-situ
biorestoration projects is characterized by research aspects, with the
majority having been set-up as a research project (Nl, D2, U3, U5, U6).
Background of the sites at which in-situ biorestoration has been or is being
applied
The locations at which in-situ biorestoration has been or is being applied can
be divided into two main groups:
-	filling stations (service stations, airforce bases, marshaling yards, bus
stations) with leaking pipelines or storage tanks,
-	chemical industry sites, mainly (former) refineries.
All locations were contaminated with hydrocarbons, for the most part defined
as petrol and/or diesel. At airforce bases, also kerosene or JP-4
contaminations occur. One-fifth of the projects concerned chlorinated
hydrocarbons. The smallest group of locations was contaminated with PAHs or a
mixture of chlorinated hydrocarbons, mineral oil and PAHs. The latter has not
yet been demonstrated.
Preliminary site characterization
The surface area of the sites at which2 in-situ biorestoration was applied,
varies largely; from 20 to 75,000 m . Vithin this variety, two clear groups
can be distinguished. The first group is3 formed by filling stations; the
surface area is mainly 400 - 1,000 m . The second group consists of large
chemical industry and (former) yefinery sites, and here, the area is varying
between 20,000 and 75,000 m . The depth upto which the contamination is
dispersed is generally between 3 and 10 meters below surface level.
It was striking that the discovery of a second contamination during the
cleanup-process occurred at several projects.
In relation with soil structure and geology, nearly all locations can be
defined as sandy. At several places, clay layers are present. Only in an
exceptional case, in-situ biorestoration is applied at a site with overburden
clay and fractured bedrock.
Concerning geology, permeability is a very important parameter for in-sity
biorestoration. For the projectssrevigwed, the K^-value varied between 10"
and 10" m/sj mainly having 10* -10* as order of magnitude. Generally, a Re-
value of 10" is regarded as being the minimum permeability for successful
application of in-situ biorestoration.
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Preliminary biodegradation research
In order to decide whether in-situ biorestoration can be applied at a
contaminated site, microbiological, hydrogeological and chemical aspects must
be regarded. Hydrogeological conditions include permeability, dispersion of
contaminants, groundwater level and flow. The parameters which might be
considered before chosing or designing in-situ biorestoration are:
-	Microbial parameters (total cell count, nitrifiers, denitrifiers,
hydrocarbon degraders)
-	Oxygen demand
-	Nutrient demand
-	Contaminant degradation rate
-	Bio-availability.
Total cell count forms the base for research on populations of microorganisms.
Parameters in relation with biological activity are an important part of
microbial research. For in-situ biorestoration, the number of metabolic active
organisms and enzyme samples are important as an indicator for biodegradation
in the subsurface. As regards hydrocarbon contamination, determination of the
percentage of hydrocarbon degraders is an important monitoring aspect too.
Besides, there is a large group of relevant physical and chemical parameters,
including permeability, pH, oxygen, redox conditions, temperature, TOC, DOC,
BOD, Fe-concentration, Mn-concentration, concentration of (heavy) metals,
Nt t ,, ammonium-concentration, nitrate-concentration, nitrite-concentration
anB phosphate-concentration.
A high permeability is one of the conditions for a successful in-situ
biorestoration.
Soil gH may affect sorption of ionizable compounds in addition to limiting the
types of microorganisms in the subsurface. Methanogenes, which have been
implicated in mineralization of some aromatic hydrocarbons, are inhibited at
pH values below 6 (Lee et.al., 1988).
Biodegradation of many organic pollutants in the subsurface may be limited by
insufficient concentrations of oxygen or unfavourable redox conditions.
Also temperature influences microbial metabolism of subsurface pollutants. The
temperature of the upper 10 m of the subsurface may vary seasonably. However,
in the Netherlands, it will not deviate-much from 10C. Also below 10 m,
temperature will be about this value. It is important to keep this in mind
when comparing results from projects in for example Florida (U6) or California
(U5) where much higher temperatures (20-25 C) are measured with projects from
other regions.
Total organic carbon (TOC), dissolved organic carbon (E2) chemical oxygen
demand (COD) and biological oxygen demand (BOD) are sum parameters. TOC and
DOC are direct parameters for the carbon concentration of organic compounds.
Decreasing concentrations of TOC and BOD values indicate mineralization of the
organic contaminants.
Determination of Fe and Mn concentrations is important because high
concentrations of these metals can cause precipitation under aerobic
conditions, caused by the infiltration of oxygen during the biorestoration
process.
Other heavy metals can be important, especially at contaminated sites, because
at toxic levels, they can inhibit the activity of microorganisms.
Inorpanic nutrients like nitrogen and phosphorus may be limiting when the
carbon/nitrogen/phosphorus (C:N:P) ratio is unfavourable. Determination of
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ammonium, nitrate and nitrite gives insight in the stage of the conditions in
the subsoil.
After the characterization of the site regarding microbiological,
hydrogeological and chemical/physical parameters, a first decision can be
taken whether in-situ biorestoration is applicable at a specific site.
However, there is no one-and-only application method for in-situ
biorestoration. If the option of in-situ biorestoration is chosen, nearly all
visited organizations perform preliminary biotreatment studies on laboratory
scale to get insight in the optimal stimulatory actions for a biodegradation
process at the site and to choose the right combination of microbial,
hydrogeological and physical/chemical actions. Only organizations with very
broad experience in the field of pump-and-treat and in-situ biorestoration
design a site-specific in-situ biorestoration system almost directly based on
the site characteristics (Ul, U7). A large majority of the projects included
preliminary laboratory research, both small-scale tests and percolation
studies in columns. In a few cases, field experiments in a small area
representative of the contaminated site have also been performed.
System design
Description of the installation
In-situ biorestoration involves the stimulation of the biodegradation of
contaminants at contaminated sites without excavation of the soil. In this
process, the soil of the contaminated location is used as a bioreactor (see
figure 1).
The specifications of the "bioreactor" in the subsoil are based on the
characteristics of the contaminated site, and the objectives and requirements
of the clean-up. They include for example the type and distribution of the
contaminants in the subsoil, the soil geology and hydrology and the need for
isolation of the location.
In most cases a semi-closed configuration is used in such a way, that the
contaminated location is isolated and controlled; uncontaminated groundwater
can enter the contaminated site, but contaminated groundwater cannot move to
uncontaminated areas.
The site can be isolated using hydrological intervention technologies or civil
engineering operations. In general, a hydrological system is designed, in
which the groundwater is centrally withdrawn, and after above-ground
treatment, reinfiltrated at several points on the periphery of the location.
The groundwater is withdrawn at a higher rate than it is infiltrated, the
surplus generally being discharged into a sewer.
To support degradation in the subsurface, an above-ground treatment system is
used to degrade the contaminants in the withdrawn groundwater, and to
condition the water before re-infiltration.
Biodegradation relies entirely on the contact between the contaminants (in the
water phase) and the microorganisms. In the case of highly volatile compounds
as contaminants, clean-up can partly be achieved by vaporization of the
unsaturated zone using a soil venting system, as is shown in project N4. The
contaminated exhaust air can be treated above ground by adsorbtion (e.g.
activated carbon) or oxidation in a biological, thermal or catalytic manner.
Research project N5 describes the design of an in-situ soil venting system,
used both as a physical (evaporation) and a biological process
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(biodegradations). This system can be used for contaminations in the
unsaturated zone.
Figure 1. General scheme of in-situ biorestoration.
There are several options for reinfiltration:
-	injection wells
-	infiltration galleries
-	surface application.
Infiltration into the saturated zone through injection wells is the most
direct method, but also has disadvantages: oxygen and nutrients are only
poorly delivered to the unsaturated zone and the wells have small surface
areas. Therefore, they can prone to clogging. The installation cost decreases
in the order: injection wells, infiltration galleries and surface application.
When visiting the projects, it appeared that Infiltration galleries were used
nearly twice as often as injection wells. Surface application is only rarely
used.
At one research project (U6, Downey 1988), the three options were used
simultaneously in order to gain insight in their applicability.
As regards the above-ground treatment, the first part is generally a sandbox.
Undissolved contaminants are removed in an oil/water separator. An air
stripper is used to remove volatile contaminants. In a few projects,
biological systems, such as a trickling filter, were used for degrading
dissolved compounds.
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When required by the legislator, the contaminated air from the air stripper is
oxidized in order to bring about degradation of the contamination instead of
moving the contaminants from one compartment (groundwater) to another (air).
In the Netherlands, this is performed using a biological compost filter, in
which adapted microorganisms degrade the contaminants. In the USA, catalytic
oxidation systems are employed.
Hydrological aspects
In general, in-situ biorestoration is performed by means of saturating the
subsoil. The main hydrological steps taken consist of central withdrawal of
the groundwater and reinfiltration at several injection points on the
periphery of the location. Groundwater is withdrawn at a higher rate than it
is infiltrated. This occurred at about 95% of the locations.
At two projects, in-situ biorestoration was performed without water saturation
(D2 and D4). However, saturating the soil makes it easier to optimize the
environmental conditions in the soil with respect to other parameters like pH,
oxygen content, nutrients, etc. It depends on the site-specific situation
whether saturation and other optimizations will be chosen, or no saturation
and fewer other optimizations. However, in most cases, saturation is the
preferred method.
Oxygen supply
As far as is known, in-situ biorestoration has only been applied to
hydrocarbon-contaminated sites. In order to initiate hydrocarbon oxidation,
microbial populations utilize oxygen:
C6H6 + 7H02 -~ 6C02 + 3H20 (for benzene).
As a result of the contamination, the subsoil of contaminated sites is
anaerobic, or contains very low concentrations of oxygen. Therefore, oxygen
has to be supplied for in-situ biorestoration. Sources of oxygen include air,
pure oxygen and hydrogen peroxide. Subsequent oxidation can also be sustained
by alternative electron acceptors, for example nitrate.
Lack of oxygen or necessary redox conditions will limit in-situ biorestoration
of contaminated soil and groundwater. When applying in-situ biorestoration in
practice, oxygen is usually the limiting factor.
The alternatives to oxygen supply used in the projects visited were:
-	air
-	pure oxygen
-	hydrogen peroxide
-	nitrate
-	nitrate / ozone
-	methane / oxygen
Oxygen sources
The simplest method of supplying oxygen is aeration. However, the amount of
oxygen that can be added with air is strongly limited: only 8 mg/1 under
normal groundwater conditions (table 1). As a result, very large volumes of
oxygenated water may have to be infiltrated at the contaminated site, and
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because of permeability constraints, the remediation time is then relatively
long.
Table 1. Available quantities of oxygen from different sources.

air-saturated
02-saturated
H202
N0g

water
water
200 mp/1
200 me/1
available oxygen
10
40
94
168
(me/1 at 10C)




As shown in table 1, this problem can be overcome in part by using pure
oxygen (40 mg 02/l) or hydrogen peroxide (100 mg 02/l from 200 ppm H202):
H202 - H20 + h03
Hydrogen peroxide is toxic at higher concentrations and can therefore only
be used up to a limited concentration. In the case of H202, the
bioremediation is usually started with low concentrations (40-50 mg
H202/1), or even with pure oxygen. The objective of this measure is to let
the indigenous population of microorganisms acclimate to the oxygenated
environment. Once the population is acclimated, the peroxide concentrations
can be increased in increments of approximately 50 to 250 ppm in intervals
increasing from approximately one week to one month (U3), to achieve an
increased infiltration of oxygen. Such a gradual increase of peroxide
concentrations can be continued up to a concentration of about 1000 ppm
H202.
In the initial phase of biorestoration, the oxygen supplied is utilized by
the microorganisms in the vicinity of the infiltration point. When
contaminants in this area have been degraded, the oxygen can be transported
over larger distances, and biodegradation will then occur in an area,
further away from the infiltration point. This process continues until
oxygen breakthrough at the withdrawal wells.
An important aspect with respect to peroxide is its stability. As
remediation of the site progresses, the H202 must be carried increasingly
longer distances. This means that H202 must be stable in order to deliver
the oxygen to the area where it is needed. The decomposition of peroxide is
catalyzed by metals, such as iron and manganese. H202 can also be degraded
by the bacterial cell, with the enzyme catalase serving as the catalyst. On
the other hand, phosphate can stabilize hydrogen peroxide (Britton, 1985).
This is actually performed at demonstration projects. The form of phosphate
is mostly monophosphate. To reduce phosphate adsorbtion to the soil, a
combination of simple and complex polyphosphate salts can be used (Brown
et.al., 1986). The use of phosphate solutions is twofold: as a nutrient, it
also has a positive influence on the biodegradation when the original
concentration of phosphate is too low.
Nitrate as electron acceptor
Nitrate can serve as an electron acceptor. Comprehensive fundamental
research regarding the use of nitrate has been performed in Vest Germany
(Riss et.al., 1987). Here, laboratory research showed that nitrate can only
be utilized when a first phase with elementary oxygen has passed, and when
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the nitrate is present under anaerobic conditions. There has not always
been given satisfaction to these preconditions when applying nitrate for
in-situ biorestoration (see e.g. projects N1 and N4).
As is shown in table 1, one part of nitrate is equivalent to 0.84 parts of
oxygen. Take, for example, the oxidation of methanol:
1.5 02 + CHjOH - C02 + 2 H20
NOj + 1.08 CH3OH + H+ - 0.065 C6H7N02 + 0.47 N2 + 0.76 C02 + 2.44 H20
(Brown, 1989).
Until now, application of nitrate has only occurred in a few German states
and only incidentally in other countries. Application might encounter
licensing problems. In project N4, nitrate is added to the oxygenated
infiltrating water. Nitrate will also be used at project U3 as part of a
research program. Utilization of nitrate could not be determined in
research project N1 (Verheul et.al., 1988).
In project D9, a combination of ozone*and nitrate has been used: ozone
above ground, to treat the water and oxygenate the organic contaminants;
nitrate in-situ, in the subsoil, to serve as an electron acceptor for
subsequent biodegradation by the microorganisms.
Co-metabolism
At one research project (U5), biodegradation of chlorinated compounds by
methane-oxidizing bacteria (methanotrophs) involves stimulating the
population with methane- and oxygen-containing water. Methanotrophs obtain
energy from the oxidation of methane. They synthesize the enzyme methane
monooxygenase, which catalyzes the first step in the oxidation of methane,
which they use for energy and growth. Monooxygenase oxidizes a range of
hydrocarbons, and appears to bring about the epoxidation of chlorinated
alkenes (co-metabolism):
CHC1-CHC1 + H20 -~ CHC10CHC1 + 2H+ + 2e"
These epoxides are unstable in water and hydrolyze to a variety of products
which can be oxidized readily by other heterotrophic bacteria to inorganic
end products (McCarty et.al., 1989, Janssen et.al., 1987).
Comparison of oxygen sources
Table 2 shows a comparison for various oxygen systems for a severely
contaminated site.
It can be concluded, that there is a wide range in both cost effectiveness
and in treatment effectiveness. For example, venting can only be applied in
the vadose zone. In terms of cost effectiveness, the order is:
venting  peroxide > nitrate > air sparger > water injection
while in order of treatment effectiveness, the order is
peroxide - nitrate > water injection > venting > air sparging.
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Table 2. Cost/performance comparison for various oxygen systems; high
degree of contamination.
	Costs ($)			Performance		
System Capital Operation Maintenance kg/Day % Site Utilization Time of S/kg oxygen
Oxygen Treated Efficiency S Treatment Used
Air Sparging
35.000
800/nonth
1200/month
3
41
70
858 days
57.-
Mater Injection
77,000
1200/month
1000/month
4
75
50
1580 days
62.-
Venting System
88,500
1500/month
1000/month
1810
60
5
132 days
8.-
Peroxide System
60,000
10,000/month
1500/month
86
100
15
330 days
41.-
Nitrate System
120,000
6500/month
1000/month
96
100
12.5
335 days
49.-
(Brown, 1989)
The choice of an oxygen supply is most dependent on the contaminant load,
the mass transfer and the ease of transport and utilization. At low
concentrations, simple systems, such as air sparging, become more cost
effective.
Nutrient supply
The biodegradation rate will be limited when inorganic nutrients, such as
nitrogen and phosphorus, are present in limiting concentrations or mutual
ratio's. Regarding contaminated sites, the presence of nitrogen and
phosphorus should be viewed in relation with the carbon concentration from
the contaminants. In soil, a C:N:P ratio of 250:10:3 is considered to be
optimal for biodegradation. Also other C:N:P-ratios, e.g. of 100:10:2 have
been chosen.
The need for nutrients is dependent on the site characteristics. At certain
sites, nutrient addition can be unnecessary. In other cases, increasing the
inorganic concentrations at one time can be sufficient. If nutrient supply
is needed during the clean-up, nearly always batch-mode addition has been
chosen.
In order to satisfy nutrient requirements, a vide range of components can
be added. This includes compounds like NH4N0s,-Na- and K-orthophosphate and
trace elements.
In a few projects, such as Nl, addition of an easy degradable carbon source
(NaAc) enhanced the initial degradation of hydrocarbons during laboratory
experiments. However, the significance for demonstration scale seems to be
limited.
Addition of microbial populations
Besides stimulating the indigenous microbial population to degrade organic
compounds in the subsurface, another option is to add microorganisms with
specific metabolic capabilities to the subsurface. This is demonstrated - in
projects D3, D4 and D7. Soil samples are taken from the contaminated site
at spots where microorganisms occur, for example at the edge of the
contamination. The microorganisms which are present at those spots, will be
adapted to the contamination in the soil, and will be able to degrade the
contaminants. The samples are taken to the laboratory, where selection
occurs by enrichment culturing, until a suspension is obtained which
contains the selected microorganisms in high density. This suspension of
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microorganisms is then injected with the infiltrating water at the
contaminated site. The objective of this inoculation is to increase the
number of adapted microorganisms at the site, in order to accelerate
biodegradation.
Another method to add microorganisms to the subsoil is applied when a
biological groundwater treatment plant is applied above ground (N2 and N4).
The effluent of such an installation will contain large amounts of adapted
hydrocarbon degrading microorganisms which are injected in the soil. In a
research project, also inoculation by effluent water of a wastewater
treatment plant was used (project N5).
However, there is much uncertainty about the efficacy of the addition of
microorganisms to the subsoil and the possibilities of transporting
bacteria through the soil, in order to get them at the spots where they are
needed. Generally, 95% of the soil population tends to adsorb on soil
particles, whereas only 5% can be transported.
Results of the in-situ biorestoration projects
The projects visited differ widely in the clean-up results to be obtained.
For example, some projects do not aim to achieve a given concentration; on
the basis of the clean-up progress, it is decided what the residual
concentrations of contaminants should be.
There are much differences; in the Netherlands, the objectives set by the
legislator are generally 50 /zg mineral oil per liter (groundwater) and 50
mg/kg in the soil. In a few cases, this level can be 200 fig/1 and 1000
mg/kg d.w. in the soil.
In relation with the residual concentrations, it is important to notice
that different objectives have been used; in several projects, the goal was
to reach low concentrations in the groundwater, whereas in other projects
low concentrations in the soil were decisive.
In the USA and Vest Germany, the reported objectives varied between
undetectable levels (mineral oil) in the groundwater and less than 5000
mg/kg in the soil.
As regards results of in-situ biorestoration, the visited projects can be
divided into three groups:
a)	demonstration projects that have been finished (N3, N5, D4, D7, D8, D9,
Ul, U6)
b)	demonstration projects that are tinder way (N2, N4, Dl, D2, U2, U3, U4,
U5, U7)
c)	projects which are in the stage of preparation of a field demonstration
(HI, D5, D6).
This paragraph is limited to projects of groups a) and b). Table 3 shows
the results of the finished projects.
About half of the in-situ biorestoration projects reviewed in this study
have been finished.
The significance of the results appears from relating the residual
concentrations, which have been reached in the projects finished, to the
C-156

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corresponding concentrations of the Netherlands examination framework for
soil pollutants.
Table 4 shows the relevant values of this framework.
Table 3. Residual concentrations and remediation time for a few in-situ
biorestoration projects finished.
Code
Contaminant
Residual
concentration
Compartment
Remediation time
(months)
N3
aromatics
< 30 pg/1
water
6

mineral oil
< 200 Mg/1
water

N5
BTX
< 5 mg/kg
soil
12

diesel oil
150 mg/kg
soil
18
D4
diesel oil
4600 mg/kg
soil
12
D7
fuel oil
< 100 mg/kg
soil
9
D8
diesel/arom.
30 mg/kg
soil
10 ;
D9
aromatics
oil
non-detectable
levels
water
U1
gasoline
< 10 mg/kg
soil
48
U2
4-chloro-2-
methylphenol
> 80% of area
cleaned-up
water
24
U6
JP 4
550 kg he removed
 
12
1) non-detectable levels reached for part of the contaminated area; clean
up was continued for gaining complete clean-up of the site.
Table 4. Relevant part of the Netherlands examination framework for soil
pollutants.
Indicative values: A - reference value
B - indicative value for further investigation
C - indicative value for cleaning-up
Presence in:	soiKmg/kg dry weight) groundwater (fig/1)
	A	B	g	ABC
mtic unjimiiirtii
benzene
0.05(d)
0.5
5
0.2(d)
1
5
ethylfcensene
0.05(d)
5
50
0.2(d)
20
60
toluene
0.05(d)
3
30
0.2(d)
15
SO
xylene
0.05(d)
5
SO
0.2(d)
20
60
phenols
0.05(d)
1
10
0.2(d)
15
SO
aromatics (total)
-
7
70

30
100
poly eye lie tnastie hydrocarbon
s (PAH*)




total PAHs
1
20
200
-
10
40
organic c






aliphatic chlor.
-
7
70
-
15
70
coop, (total)






chlorophenols
-
1
10
-
0.5
2
(total)






mineral oil	 1000 5000	50(d) 200 600
* " reference value soil quality
d " detection limit
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As regards the Netherlands examination framework for soil pollutants,
residual concentrations below B-level, or even undetectable levels of
contaminants have been reached in the finished projects. Five out of nine
projects reach the A-level, thus meeting the standards used in the
Netherlands. Venting (N5) was successful as regards volatile components
(petrol), but not for PAHs.
The results of the projects which are underway are generally promising.
Comparison of the results of the different in-situ biorestoration projects
is very tricky. This is mainly caused by the application of different
methods, used in the course of the in-situ biorestoration projects:
-	methods of soil and groundwater sampling and analysis,
-	determination of physical and chemical site parameters.
Occasionally, there are also gaps in the total overview of the restoration
course.
The total overview of the in-situ biorestoration projects, as presented in
the appendix, also shows the results in relation with other aspects, such
as soil structure, oxygen source, applied system and nutrients used.
The remediation time varied between 90 days and 4 years, and is largely
dependent on the site characterization (soil structure) and the kind of
contaminants.
Costs for in-situ biorestoration
A wide range of site- and system characteristics and objectives influences
total costs for in-situ biorestoration projects. These include:
-	geology and soil structure
-	type and concentrations of contamination
-	distribution of contaminants in the subsoil
-	total surface and volume of the contaminated area
-	system characteristics: recirculation, water and gas treatment a.o.
Because these aspects can vary significantly, the costs for completing the
projects can vary considerably.
It must be stressed that these figures should always be seen in relation to
other treatment techniques for a certain contaminated location, including
cost for excavation and transport.
The projects can be divided into two main groups:	s
-	petrol stations (approximately 400 - 1,000 m ; 1,000 - 5,000 m I
-	refinery- a$d industrial sites (approximately 20,000 - 75,000 m ; 30,000
- 400,000 m ).
Petrol stations
Costs for in-situ biorestoration at contaminated petrol stations varied
between 62,000 and 750,000 US $ (40- 250 ys $/m ). Included are relatively
cheap projects of approximately 60 US $/m which could be performed without
abovegroundwater treatment (Ul) or without water recirculation (D4).
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A comprehensive itemization of the different costs for using in-situ
biorestoration to treat a specific petrol station is shown in table 5
(Fournier, 1988).
It should be noted that, dependent on the situation, the contribution of
hydrogen peroxide to the total cost of the operation can be substantially
higher; contributions of 90% have occurred.
Table 5. Estimated costs for in-situ biorestoration of a petrol station
(Fournier, 1988).
Capital costs
Groundwater monitoring wells	5,000
Reinjection well	. 2,300
Nutrient and peroxide addition equipment	3,000
Recirculation equipment	5.000
Equipnant	17,300 12
Preliminary site assessment costs
Laboratory tests	16,300
Field tests	5,000
Reports	2.000
Total preliminary tasting	23,300 16
Total initial expenditures	40,600
Annual operating and maintenance costs
Groundwater monitoring	6,200
Reinjection well maintenance	14,200
Chemical costs	^^gjJIOO
Total imrmal costs	34,400 72
Present worth factor for 3 years	i 2.402
Present worth of O&M costs	82,630
Present worth of ISB option	123,230
Total costs over 3 Tears	S143.800	100
Refinery- and industrial sites
Cost for in-situ biorestoration at refinery- and industrial sites varied
between 330,000 and 16 milliog US $. Again, especially system design
determines total cost: 7.- US $/m if a relatively simple in-siu type of
landfarming is used (D2) up to approximately 150.- US $/m for a more
complex system design.
From the information from the projects it can be concluded that operating
and maintenance costs account for about 2/3 of the total costs. Generally,
1/3 of the costs is due to preliminary research and installation costs, in
about equal amounts.
In many cases in-situ biorestoration will be more cost-effective than other
techniques, such as incineration and soil washing of the excavated soil,
possibly combined with groundwater treatment (approximately 70-170 $/m
excluding excavation and transport costs (Staps, 1989a)).
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CONCLUSIONS
Application
 The locations at which in-situ biorestoration has been used can be
divided into two main groups:
*	filling stations (service stations, airforce bases, marshalling yars,
bus stations) with leaking pipelines or storage tanks (400 - 1,000 m2),
*	chemical industry sites, mainly (former) refineries (20,000-75,000 m ).
-	With respect to soil structure and geology, nearly all locations can be
defined as sandy. Clay layers are present in several areas. Only in an
exceptional case in-situ biorestoration is used at a site with overburden
clay and fractured bedrock.
-	Regarding hydrology, permeability is a very important parameter for in-
situ bioretorationB In the projects reviewed, the K_-yalue6varied
between 10 and 10 m/s, but was $ostly of the order of 10" -10* m/s.
In general, a K^-value of 10 m/s is regarded as being the minimum
permeability required for successful application of in-situ
biorestoration.
-	All locations were contaminated with hydrocarbons. Most contaminations
are defined as petrol and/or diesel. A few locations were contaminated
with PAHs or a mixture of chlorinated hydrocarbons, mineral oil and PAHs.
The frequent discovery of secondary sources of contamination points out
that the characterization is not always sufficiently carried out.
Design
-	The approach of in-situ biorestoration at the visited projects could be
characterized by either a hydrological or a microbiological background.
Only rarely, a good integration of both disciplines could be seen.
-	The decision for application of in-situ biorestoration can only be taken
after a comprehensive site-characterization. The specific
characterization of the contaminated site and preliminary biotreatment
laboratory studies (if possible followed by field studies) should be
performed to determine optimal stimulation actions and thus the
different forms in which the technology can be applied.
-	As regards hvdroloeLcal measures. generally a system is designed, in
which the groundwater is centrally withdrawn and, after aboveground
treatment, is reinfiltrated at several spots at the outer border of the
location. In order to support the degradation in the subsurface, an
aboveground treatment system is used to degrade the contaminants in the
groundwater which is pumped-up, and to condition the water before
reinfiltration.
-	As regards the aboveground treatment, the first part is generally a
sandbox. Undissolved contaminants are removed in an oil/water separator.
An air stripper is applied for removal of volatile contaminants. At a few
projects, biological systems, such as a trickling filter, were used for
degradation of dissolved compounds.
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-	Recirculation of the pumped-up groundwater has positive effects on the
biodegradation in the soil. This may be due to the infiltration of
degradation products, which are relatively easy to break down and which
stimulate the activity of the microorganisms in the subsoil.
-	The contaminating vapours in the air from the air stripper can be
oxidated by means of a biological compost filter or a catalytic oxidizing
system in order to acquire degradation of the contamination instead of
moving the contaminants from one compartment (groundwater) to another
(air).
-	On demonstration scale, most of the time the limiting factor is lack of
oxygen or necessary redox conditions. Hydrogen peroxide is most popular
as oxygen source. However, for certain applications it can be relatively
expensive. Other sources are air, pure oxygen and nitrate (as electron
acceptor). The choice for a system is based on cost-efficiency,
contaminant load and the ease of transport and utilization.
-	Necessary nutrient addition is fully dependent on the original available
nutrients in the soil and the uptake by the microorganisms. Usually,
addition of nitrogen and phosphorus is necessary. In a few cases, also
trace elements have been supplied. Other projects could be biorestorated
without any artificial supply of nutrients.
-	The effect of the adding detergents is still questionable. Fundamental
research and most practical experience indicate that the effect on
degradation is negative. Clogging of the soil can occur when detergents
are supplied, probably due to an interaction between the oil, water,
detergent and solid phase.
-	Addition of microorganisms to the subsoil, with the aim of enhancing the
biodegradation, is being used by a few companies. Although such supply
will always have some beneficial effect, until now, this has not been
proved. Cost-benefit calculations are also lacking. A major objection
here is, that soil microorganisms tend to adsorb onto (soil) particles,
and consequently cannot be transported over long distances in the
subsoil. This implies that the effect of the inoculation is very limited.
White spots
-	Bottle-necks in relation with in-situ biorestoration can be:
*	insufficient infiltration rates, mostly caused by clogging,
*	insufficient hydrological isolation,
*	relatively long remediation period, needed for reaching low
concentrations of contaminants,
-	When using in-situ biorestoration, the precise fate of degraded
hydrocarbons. such as gasoline, is not yet known. A proportion, is
transformed to leachable DOC, another part to DIC, but a large part is
still unaccounted for.
-	With the exception of project Nl, research on in-situ biorestoration has
not provided knowledge about mass balances. When degradation occurred in
project Nl, the percentages of leached and degraded aromatics were about
C-161

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the sane. The aliphatics were removed by degradation only, and then
almost completely.
Results and significance
-	As regards feasibility, in-situ biorestoration can technologically
compete with other technologies when it is applied at a suitable
location, and the process is well run. As regards the Netherlands
examination framework for soil pollutants, residual concentrations below
B-level, or even undetectable levels of contaminants have been reached in
most of the finished projects. Contaminants are mainly hydrocarbons
(gasoline, diesel, mineral oil).
The remediation time varies roughly between 3 months and 4 years, largely
depending on the initial concentrations, the kind of contaminants, the
soil structure and the requirements which are set. Concerning practical
projects 3without research aspects, costs can vary between approximately
40-80 $/m . This means that in many cases in-situ biorestoration will
alsg be more cost-effective than other techniques (approximately 70-170
$/m excluding excavation and transport costs (Staps, 1989a)).
RECOMMENDATIONS
General policy
-	This evaluation included the visit of 17 contaminated sites, and
concludes that in-situ biorestoration is a promising technology for a
selection of contaminated sites. However, it is important to notice that
most spills, and thus damage to the environment and the spending of large
amounts of money for remediation, could have been prevented by good
house-keeping. Therefore, at locations where spills might occur,
prevention is recommended in the first place.
-	The most fundamental recommendation that can be made from this study, is
to stimulate the development of in-situ biorestoration. This study shows
that the technology has a large potential. At present, it is important to
collect reliable (demonstration) data, which can be used in the following
areas:
*	optimization of the technology, mainly regarding oxygen transport and
utilization, peroxide transport and stability and removal of
contaminant residuals from soils (bio-availability).
*	extending the technology's range of applications, especially to more
recalcitrant contaminants.
*	development of models of (in-situ) biorestoration.
-	In-situ biorestoration is expected, to be a promising technology,
especially for application at contaminated industrial sites. This is
mainly because of the minimal physical impact on the environment, caused
by the process; industrial activities can be continued during the clean-
up.
-	When demanding certain residual concentration levels, regulators should
not only consider concentrations in the groundwater, but also in the
soil. It should be prevented that an in-situ biorestoration project is
finished because the contamination levels in the groundwater are
C-162

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sufficiently low, while significant concentrations are still present in
the unsaturated zone of the soil. Percolating water from precipitation
will transport (a part of) residual contaminants and contaminate the
clean groundwater again, making a second clean-up operation necessary.
-	The approach taken by the experts involved in several of the projects
visited can be characterized by either a hydrological or a
microbiological background. However, in-situ biorestoration is not only
pure biotechnology, but is indeed an integration of biotechnology and
hydrology. Integration of a number of disciplines is indispensable.
-	Because of the general complexity of soils, the course of the degradation
process can never be predicted completely. Therefore, preliminary
research, both in the laboratory and in field tests will always be
necessary. The field tests should include oxygen utilization rates,
possible in-situ peroxide stability and potential clogging problems.
Laboratory methods for predicting the course of the in-situ
biodegradation should all be improved.
-	There is a need for more sharing of meaningful site data by those
experiencing in this technology. This is especially needed as regards
data on peroxide stability and transport, oxygen utilization and the
removal of fuel residuals from soils. Therefore, projects like Nl, U3 and
U6 are very useful. An open policy of organizations with experience of
the technology can expose bottlenecks concerning both practice and
demonstration, thereby directing the research of universities and
institutes and making this research more valuable.
-	Knowledge about modelling of transport behavior in the soil seems to be
sufficient. Modelling of biodegradation processes in the soil however, is
still a difficult problem and requires further attention. A precondition
for further development however is the availability of representative
data, which should be published by the experts involved in in-situ
biorestoration projects.
System design
-	Venting of volatile contaminating compounds in the unsaturated zone and
treatment of these components above ground (possibly combined with
recirculation and biorestoration in the saturated zone) seems to be a
promising and cost-effective method calling for further attention.
-	A combination of chemical treatment above ground and biological treatment
in the subsoil can possibly expand the application of in-situ
biorestoration, especially to compounds which are more difficult to break
down biologically (such as PAHs) and more readily biodegraded once a
first oxidation step has taken place. Further research in this field can
be recommended.
-	Stimulation of the biological activity by heating the infiltrating
groundwater was used at one project only (D5). Here, it was not
conclusively shown that this was a cost-effective method. Measurements in
test plots should be conducted to demonstrate whether and when the
heating effect is economical.
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-	There is much uncertainty about the efficacy of the supply and
distribution of oxygen (-sources) in the subsoil. Research on alternative
oxygen sources (02, H202) and electron acceptors (NOj) is useful.
Hydrogen peroxide is a relatively expensive oxygen source, the more so
because only a very limited part of it can actively be used for the
biodegradation of the contaminants; this is estimated to be approximately
15% (Brown, 1989).
-	In-situ peroxide stability must be greatly improved to provide adequate
oxygen downgradient of injection points.
-	As regards inoculation, the selection by enrichment culturing is
especially performed by compounds of the contamination. A very
interesting possibility would be to expand this technique to a selection
for the tendency of microorganisms to adsorb onto soil particles. The
small percentage of the population that does not tend to sorb, could thus
be selected, possibly resulting in improved biodegradation in situ
because these organisms can be carried a longer distance in the subsoil.
This aspect needs further attention.
-	Co-metabolism, such as the biodegradation by methanotrophes, deserves
more attention because it may broaden the applicability of
biorestoration.
-	Determents could be useful with respect to the following aspects:
*	limitations caused by the low availability of contaminants to the
microorganisms,
*	extension of the applicability of in-situ biorestoration for compounds
with a low solubility.
In order to open up possibilities for these aspects, fundamental research
into the use of detergents in this field is necessary. Not only
artificial supply of detergents in the in-situ biorestoration system
should be considered, but also the possible use of surfactants produced
by microorganisms in the soil.
Mass balances
-	There is a strong need for mass balances on both laboratory and pilot
plant scale. Mass balances will improve the insight in the contribution
of different processes in the total biodegradation process.
-	The limited possibilities to monitor biological activities in the soil is
partly responsible for the lack of knowledge about the process of in-situ
biorestoration. The development of methods, which can be used for
monitoring the biological processes in the soil, would greatly contribute
to a better understanding of the processes, and thereby, to a more
selective and economical supply of for example oxygen and nutrients.
-	In order to gain a better insight into the contribution of biodegradation
to the total degradation process in the laboratory, a satisfactory method
for sterile experiments should be developed. The methods currently
available are insufficient.
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-	The precise fate of degradation products is not yet known. A proportion
is converted to leachable DOC, another part to DIC, but a large part is
still unaccounted for. Insight into the quantity, quality and
significance of degraded hydrocarbons, such as gasoline, is needed,
especially as regards the question of "how clean is clean?".
Specific problems
-	More attention should be paid to the problem of closing in the subsoil,
resulting in disappointing infiltration rates. This problem can be
related to different factors, such as geology (permeability), excessive
growth of microorganisms, or high concentrations of iron or manganese.
-	Once relatively low residual (threshold) concentrations with in-situ
biorestoration have been reached, the limiting factor usually becomes the
availability of contaminants to the microorganisms. This is in the region
of, for example, less than 250 mg/kg of dry soil in the case of mineral
oil. When cleaning up soil contaminated by mineral oil in the
Netherlands, residual concentrations must always be less than 50 mg/kg.
This makes the limiting factor in this case, principally availability,
even more important. Further fundamental research in this area is
recommended.
Overview
An overview of the most important recommendations is given in table 6.
Table 6. General overview of recommendations.
iPolicy |System deeign
|Rs&rch I
1 '
1*
stimulation of experience |* combination of bioresto-
|*
oxygen: 1
1
and sharing of information | ration and venting
i
- supply and diatribution |
1*
integration of microbiology,|* problem of clogging
I
- alternative oxygen |
1
hydrology and (aoll-) I
i
aourees 1
1
cbamlatry I
i
- peroxide atability |
|*
preliminary raaaarch |
1*
monitoring poaaibilitiea |
1
including heeting and |
|
extension to broadar 1
1
naas balances |
i
application 1
|*
conalderation of both |
1*
threshold concentrationa |
1
aoil and groundwater |
I*
co^eteboliem |
1
1
|
addition of micro-organisms |
1
1
1*
addition of detergents |
1
1
1*
aterile experiments |
1

I*
modelling of bieraatoration |
1
1
1*
combination of chemical |
1
1
1
1
I
i
and biological traatawnt |
i
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ACKNOWLEDGEMENTS
The author wishes to acknowledge the experts visited who are involved in
in-situ biorestoration projects. Without their contribution, this
evaluation could never have been made. The open discussions with many of
these experts gave considerable support to this report.
The author wishes to thank Mr. Donald Sanning of US-EPA Cincinnati,
director of the above mentioned NATO/CCMS Pilot study, who has played an
important role in contacting key experts in in-situ biorestoration in the
USA.
LITERATURE
Brown, R.A. Oxygen sources for biotechnological application. Paper
presented at Biotechnology Work Group. Feb. 21-23, 1989, Monterey,
California.
Brown, R.A., Norris, R.D. and Westray, M.S. In situ treatment of
groundwater. Presented at HAZPRO '86, The Professional Certification
Symp. and Exp., Baltimore, Md., April 1986.
McCarty, P.L., Semprini, L. and Roberts, P.V. Methodologies for evaluating
the feasibility of in-situ biodegradation of halogenated aliphatic
groundwater contaminants by methanotrophs. Proceedings, AWMA/EPA
Symposium on biosystems for pollution control, Cincinnati, Ohio, Feb.
21-23, 1989.
Downey, D.C. Enhanced Biodegradation of jet fuels. Eglin AFB, USA. A Case
Study for the NATO/CCMS Pilot Study on Remedial Action Technologies for
Contaminated Land and Groundwater - November 1988.
Eyk, J. van and Vreeken, C. Venting-mediated removal of hydrocarbons from
subsurface soilstrata as a result of stimulated evaporation and enhanced
biodegradation. Proceedings of Forum for Applied Biotechnology. The
Faculty of Agricultural Sciences. State University of Gent, Belgium.
Gent, September 29, 1988.
Fournier, L.B. An effective treatment for contaminated sites. Hydrocarbon
Technology International, 1988, p. 207-210. Sterling Publishers, London.
Janssen, D.B., Grobben, G. and Witholt, B.H. Toxicity of chlorinated
aliphatic hydrocarbons and degradation by methanotrophic consortia. In:
Neijssel, O.M., Meer, R.R. van der and Luyben, K.C.A.M. (Eds.)
Proceedings of the fourth European Congress on Biotechnology, Vol. 3.
Elsevier Science Publishers, Amsterdam. 1987.
Lee, M.D., Thomas, J.M., Borden, R.C., Bedient, P.B., Wilson, J.T. and
Ward, C.H. Biorestoration of aquifers contaminated with organic
compounds. CRC Critical Reviews in Environmental Control, Volume 18,
Issue 1 (1988), p. 29-89.
Nagel, G., Kuehn, W., Werner, P. and Sontheimer, H. Sanitation of
groundwater by infiltration of ozone treated water. GWF-
wassser/abwasser, 123 (8): 399-407, 1982.
Riss, Gerber and Schweisfurth. Mikrobiologische Untersuchungen fiber
wesentliche Faktoren bei der unterirdischen Beseitigung organischer
Altlasten unter anaeroben Bedingungen mit Nitratdosierung. Universit&t
des Saarlandes, Homburg/Saar. 1987.
Socz6, E.R. and Staps, J.J.M. Review of biological soil treatment
techniques in the Netherlands. In: Wolf, K. , van den Brink, W.J. and
C-166

-------
Colon, F.J. (Eds.), Contaminated Soil '88, p. 663-670. Kluwer Academic
Publishers, 1988.
Staps, J.J.M. European experience in hydrocarbon contaminated groundwater
and soil remediation. RIVM-report no. 738708002. 1989a.
Staps, J.J.M. International evaluation of in-situ biorestoratipn of
contaminated soil and groundwater. RIVM-report no. 73708006. 1989 (in
press).
Verheul, J.H.A.M., van den Berg, R. and Eikelboom, D.H. In situ
biorestoration of a subsoil, contaminated with gasoline. In: Wolf, K.,
van den Brink, W.J. and Colon, F.J. (Eds.), Contaminated Soil '88, p.
705-716. Kluwer Academic Publishers, 1988.
C-167

-------
Cod*IOrgan!z at1on
1 Location
(Soil structure
1Contamination
(Oxygen source
1 System
INutrlents
ICosts
IResults |Remediation time
IProblems
Nl
RXVM /
Pilling station
sand
petrol
hydrogen
recirculation
MH4K03
S 325.000
Exp: 6*12 months


TWO



peroxide

RH2P04/Ra2HP04
5 125/ton


N2
HTTS
Filling station
sandy
petrol /
air
recirculation
COD:M:P-100:5:2

46-99.6%
-infiltration




diesel




removed in
-control









6 months
system
M3
CRM
Contaminated
sand and loamy
domestic fuel
air
recirculation
RR03

B-value for half year
Infiltration


oil beneath
sand layers
oil


C:W:P-100:10:1

allphatlcs and
in loamy


building
lOe-S / 6xl0e-4





mineral oil
layers
114
urn
Cat exploration
sandy with
condensate;
air
recirculation
ROS
$ 350,000

pumped up


alta
clayy layers
volatile arom.
nitrate

R20


conc.>than










expected
N5
Delft
Field test
sand
petrol and
air
venting
C:R:P-100:10:2

p:96% removed 12 months


Geoteehnlcs

4Rl0e-460 mg/1


Mlkroblologle
alto

hydrocarbons


fertilizer
- $/3
in 14 months

03
AnaRat
Bus station

hydrocarbons
hydrogen
Inoculation









peroxide





D4
Argus
Filling station
coarse sand
diesel oil
air
unaaturated t
phosphate
2 $/m3
<4600 mg/kg 12 months







inoculation
anreonlun










manganese



DS
TGU
Refinery
aand / gravel
PAH'S
nitrate
recirculation /
|NH)3P04

Exp: S years







heating




DC
Bauqrund
Former refinery
clay layers
chlorinated
nitrate
will result
id




Institut

and gravel
hydrocarbons f

from research







sands
Mineral oil -










PAH's







-------
07
IMA GmbH
industry site
sandy
10e-2 / 10e-3.S
fuel oil
hydrogen
peroxide
unsaturated /
inoculation
(NH4)3P04 ~
trace elementa
41-10
/n3
6000-X100 mg/kg 9 months

Dt
Rloeckner
Oecotec
Refinery

diesel
petrol
aromatiea

saturated /
recirculation
not specified

175->2S mg/kg
IS weeks

D9
Enqler-Bunte
Znstitut
yard
coarse sand
and gravel
2.lxl0e-3
oil
aromatles
nitrate / oeonc
> saturated /
recirculation /
heating


undetectable
levels
300 days

U1
DuPont
Bioiyiteni
PlUinf atatlon

gaaoline
hydrogen
peroxide
saturated /
recirculation
C:tf:P-:l:l
$ ISO.000
99/kg he
<10 mg/kg
4 years

U2
ecova
Peatlclde
production
aandy till
4-chloro-2-
isethylphenol
air
saturated /
recirculation
no addition
$300,000

S years
(planned)

U3
US Kerr Bnv. Ub Air station,
US coast Guard leaking
Rice University atorage tank
aand and gravel
highly
permeable
BTEX
hydrogen
peroxide
no
recirculation
RH4C1
KH2P04
ffa2HP04

7.2xl0e-4 mg/1
In 250 days
>  months

U4
John Nithts 4
Asa., Inc.
Leaking pipeline
assembling plant
foverburden clay
10e-3 m/e
gaaoline
hydrogen
peroxide
recirculation
and venting
Restore 375R

undetectable
(0% of area)
2 yeara
*03 formation
05
Stanford
University
Research
project
sand / gravel
10t-3 si/s
DCBp TCB
methane /
oxygen
recirculation


30% TCB. 90%
t-1,2-DCB and VC
removed
 days

UC
USAP Bng. and
Serv. Canter
Alrforce Base
Leaking pipeline
7xl0e-4 m/a
JP 4
hydrogen
peroxide
lnflltr. gallery Reatore 375R
Injection wells
apray irrigation
> $ 1.4 mln
550 kg he
removed
12 montha
peroxide
deatablll-
tatlon
07
Groundwater
Technology
Industrial
facility
glacial till
BTEX
C4-C12
hydrogen
peroxide
recirculation
Restore

undetectable
levels (10%)
72 daya

ui
EflSR
ftatardoua
waste lagoon
lagoon
BTE, naphtalene air aparglng
chloroform a.o.
aerating /
mixing
no addition
Exp:$90 mln
90% in 112 days


U9
LSU
Abandoned refi-
nery (research)
river ellt /
sandy clay
(polyeyclic)
aromatles. oil

landfarmlng

$  mln
In 25 days



-------
Aysen Turkman

-------
CYANIDE REMOVAL FROM CONTAMINATED GROUNDWATER
Assoc. Prof. Dr Ay^en TURKMAN, Turkey
INTRODUCTION
Total water consumption in Turkey is about 11.8 billion
m3/year, o-f which 4.03 billion m3/year is supplied from
groundwater <34 %) (Abidoglu, 1981). When only domestic water
supply is considered (drinking + household use) 0.3 billion
m3 /year of water is supplied by dams and the remaining 1
billion m3/year is supplied -from groundwater and springs
1981). Thus,the contribution o-f groundwater to the
domestic water consumption is about 67 V. . As this high value
indicates groundwater pollution control is very important for
Turkey.
Although the history of environmental pollution control
studies do not go back very far in Turkey, the environmental
problems are not yet at an unsolyable stage. At present,
because of the infrastructure inadequacy problems in many
pi aces,there are heavy local water, sea and soil pollution
problems. In some cases, groundwater pollution is detected
only qualitatively and water source is rejected. Detailed
water pollution detection and research studies are done
mainly in big cities and by Universities.
The causes of groundwater pollution in Turkey may be grouped
as follows:
a.	Pollution due to the domestic wastesi A big percentage of
inhabited areas is unsewered and septic pools are used for
wastewater disposal. The high incidence of waterborne infec-
tion indicates evidence of wastewater irtfiltration into the
groundwater. Also fecal coliform and total coliform analysis
show the same result. In some areas sewerage system is very
old and leaking sewers result in groundwater contamination.
b.	Fertilizer and pestiside application! Although indust-
rialisation is taking place at a rapid rate in Turkey, she
still keeps her main characteristic of being an agri-
cultural country. Because chlorinated hydrocarbons (including
DDT), organophosphates, carbamates and many other types of
pestisides were in use in Turkey, some studies reveal that
groundwater contains some amounts of these chemicals,
especially non biodegredable ones (Temizer, 1979).
c.	Industrial pollution! Due to the chaos we had related to
environmental pollution control, some industries have their
treatment plants, others do not, some of them are planning to
pretreat their wastes, others are moving to organized
districts and there are many industrial wastewater treatment
plants that do not function properly. Thus, it is inevitable
C-173

-------
to have groundwater pollution of industrial origin. Although
there are a -few case studies related groundwater pollution,
it is like an iceberg, many of the cases are not revealed
yet.
SITE DESCRIPTION
Kemalpa^a, one of the provinces that belong to Izmir, is
established at the South East corner of the Kemalpa?a plain.
Its surface area is 30 km2 and height 200 m from the sea
level (Figure 1). The settlement is 29 km away -from Izmir and
takes place between the mountains and the Kemalpa?a plain
which is valuable and fertile. The plain is -famous for its
cherry trees. Transportation is easy with a main asphalt
road which was built on 1957. The history of Kemalpa$a goes
back to antique times. Kemalpa^a (Nymphoian) was between many
important settlements like Ephesus, Smyrna, Magnesia and
Sardis. The old reliefs about which Heredot also wrote are
there, but their meaning is still being discussed. There are
also ruins from Hitits, Byzans, Sel^uks, and Ottomans.
Kemalpa?a has a relatively mild climate with cool tempera-
tures and fairly heavy rainfall in winter and hot and dry
summers. This climate allows different kinds of crops to be
grown. The deficiency of water in summer is compensated by
water resources in the area. Because the settlement is at the
foot of the mountain, the summers are relatively cool and
growing different kinds of crops are possible (Kalaycioglu,
197S).
The surface distribution of the geologic formation that
underlie Kemalpa?a Plain area are shown on the hydrogeologic
map (Figure 2). The area may be studied under two separate
headings: metamorphic mountainous mass and alluvial plain
that formed lately. The plain remains between Kuijk Menderes
River basin and Izmir basins.
The sides of the Nif mountain is moderately consolidated by
pieces of rocks that broke from higher parts of the moun-
tain. The area under the road is composed of alluvial
deposits and debris falling from the mountain. The area
generally consists of limestone, gravel and Bandy clay. Of
the two faults in the area, one lies in North - South direc-
tion and the second one lies in East - West direction. The
area is along the first degree earthquake band.
Water resources in the area may be divided into two groups.
The most important water source, Nif River is born -from
Ulucak village, extends along the plain in East  West
direction and turns to the North where it unites with Gediz.
It is feed by many small creeks flowing from the Nif
mountain. Some of these small creeks dries completely during
the summer.
C-174

-------
Figure 1: Project arm location np
Flguir 2: hyoicgeologlcal up or tr	aica
C-175

-------
No sewerage system is present in the town. The cesspools are
rather primitive and unhealthy. The immediate need for infra-
structure is pointed out in reports. In 1948, water is
brought from 1500 m away by a network. Because it is
insufficient groundwater and spring water are also used in
the area. Some springs are abandoned due to the pollution.
The springs in the area issue through the layers of flysh (at
the bottom), limestone (in between) and gravel and debris (at
top). Rainfall infiltrates to the bottom along the cracks of
limestone until the impermeable flysh layer is reached. Then
it moves upward along the fault to the surface at two sides
of the valley where the springs are located (KalayciOglu,
1957).
Hydrogeological survey in the area reveals the following:
1.	The aquifer formation in the area are; limestone, alluvial
deposits that consist of sand and gravel, and Neogen series
which consist of sand, gravel and conglomerates.
2.	Safe perennial yield of groundwater in the area is 25 x
106 m3.
3.	The wells in the area which is indicated as "Area approp-
riate for groundwater abstraction " in Figure 2, gives water
from about 75-100 m deep, and the yield will be more than 20
1 /s (DSI,1979).
SITE HISTORY
More than 100 industrial organizations are located in
Kemalpa^a. Some of then are shown in Figure 3.
Kemalpa?a Municipality asks the industries to analyse their
effluents in order to determine industrial wastewater
pollution load in the area. The samples were brought to the
Dokus Eylul University laboratory and many environmental
parameters were tested including cyanide. 0.16 mg CN /I was
found at the effluent of a chemical industry (situated near
no.14 in Figure 3) which mainly processes natural resin. The
industry objected to the analytical result on the ground that
they do not use any cyanide compound. When wastewater analyse
was repeated, the same result was obtained after which
groundwater was suspected to contain the cyanide. In fact,
when groundwater sample was analyzed, it was found to
contain 0.074 mg of CN per liter. The water was stopped to
drink. Now it is only used in the process.
When groundwater of the chemical industry was found to
contain cyanide, other nearby industries using groundwater
were also curious about their water quality. The analysis of
groundwater samples in the area revealed that a cyanide
contamination of about 0.04 mg/1 of CN existed (Table 1).
C-176

-------
1 (Ictitcil -tltrUle piccictlo*
I	IM'j prOiCtlo^
J U.llU ItVftry
( Mspn NiVietvr*
VCrca colt
4 Prq.t Prediction
I.0l5*t*t
0 Optical* Kitfty
f.fsctf
10.f rJio-fnk>Ppi|
II.Potr	(ntfwidy
frtustry
U.'grlculturtl viCN production
Hfirali Pmiiilf
lS "raU Prvmli
O
^J
Tte area uhere groundwater pollution la detected
Figure 3: Lccatlon of Industries In the project area
ll.liilNr PfociuUt
11.1 total Ion Nalry
10.f*tll	|r0gftlf
M OtM HtlUt*
}0 OigiMud District	rd Mr.ltr Dipt.
11.fiptr	Niilry
2?. Hrtvf Outfit	t"Attry
2) Put frdittry
Zk CK*tc Huitiy
2).PtlftAfle kdiitiy
7&.llKuti Ncvrietuit
27.(r*ff| Indbtlry
20 Olo "#* HiiXi'aclur
2f Ollv* Oil Ic\try
10.Food PkU^
Hif a-
R'Ut

-------
Table 1: Cyanide concentrations of groundwater samples in the
study area
Location o-f the	Depth of the	Date	Cyanide
e	WM	concentration
			 _ _	mg/1
Fruko Tamek Pepsi (10)
Zipper Manufacture (4) Artesian
Coca-Cola <5)	120 m
135 nt
Chemicals Industry II Artesian 60 m
(14)
Food industry (9) Artesian
27.1.1988
0.035
13.9.1988
0.015
20.1.1988
20.1.1988
0.040
0.040
14. 1.1988
13.9.1988
0.074
0.020
27". 1.1988
0. 030
CYANIDES IN WATER
Cyanide refers to all of the CM groups in cyanide compounds
that can be determined as the cyanide ion. The cyanide
compounds in which cyanide can be obtained as CN are classed
as simple and complex cyanides.
In aqueous solutions of the simple alkali cyanides, the CN
group is present as CN and molecular HCN, the ratio depen-
ding on pH. In most natural water HCN greatly predominates.
In solutions of simple metal cyanides; the CN group may occur
also in the form of complex metal-cyanide anions of varying
stability. Many of the simple metal cyanides are sparingly
soluble or almost insoluble, but they form a variety of
highly soluble, complex metal cyanides in the presence of
alkali cyanides.
The complex cyanides have a variety of formula, but the
alkali metalic cyanides normally can be represented by
AylKCNJx. In this formula, A represents, the alkali present y
times, M the heavy metal (ferrous and ferric ion, cadmium,
copper, nickel,si 1ver, zinc or others), and >i the number of
CN groups, >'. is equal to the valence of A taken y times plus
that of the heavy metal. The initial dissociation of each of
these soluble, alkali-metalic comglex cyanides yields an
anion that is the radical M(CN)x ' This may dissociate to
some extend depending on several factors, with the liberation
of CN ion and consequent formation of HCN (Standard Methods,
1981).
The great toxicity to aquatic life of molecular HCN, _formed
in solutions of cyanides by hydrolytic reaction of CN with
water is well known. The to>:icitiy of CN is less than that
C-178

-------
of molecular HCN and it usually is unimportant because most
o-f the -free cyanide 
-------
3> A model study is cunciuctc-d to determine the cyanicic.-
retention capacity of soi 1 -
4) N&turil de-gradation o-f cyanide nave been observed in
laboratory conditions to determine the time required for
ovariide concontration to drop to a ncnharmful level.
First series: In the area where cyanide pollution took place
there are many industries that may discharge cyanide con-
tjininq wastes. These are dye industries <3), leather
industries (3), enamel industries <2), zipper industry <1),
chemicals industries <3>, metal industries (B> and textile
industries .
In order to determine the industry or industries causing
groundwater and wastewater samples are analysed -for their
cyanide content and shown in Table 2.
Second series: In this part o-f the study the effect o-f
chlorination on cyanide content has been determined. When
groundwater is supplied by municipality, in general it is
chlorinated prior to entering the distribution system. Thus,
the cyanide is destroyed by chemical oxidation. Although the
theoretical amount o-f chlorine required for cyanide oxidation
can be -found with the help o-f stoichiometry, because o-f the
differences between the theoretical and practical values, a
laboratory study is conducted. Known amounts o-f cyanides are
added to distilled water and tap water and chlorination
results are shown in Figures 4 and 5.
Table 2: Cyanide concentrations in groundwater and wastewater
samples of some industries in the study area.
CN cone.
mq/1
1988
WW
19G8
GW
March 89 March 89
WW GW
May 89
WW
May 89
GW
Textile
Industry


0.012
0.002
o.oea
0.001
Cerami cs
Industry


0. 45
0.01S
O.OSO
0.0015
Metal 0. 1Q
Plating Ind.
0.026
0.017
0.0059
0. 194
0. 177
Zipper
Industry
0.44
0.015



-
Chemicals
Industry
0. 16
0.074
0. 16
0.027


Nif River
0.
0012
0.
04S
0.
027
I ,
WW: Wastewater sample, GW: Groundwater Sample.
C-180

-------
solution added, ml/1
Clj solution added , ml/1
Fiqura 4i Chemical oxidation o-f cyanide with crtorin*
distilled Mater
Clj solution added, ml/1
Clj solution added , ml/1
I mg CN in 1 liter of tap water
Cl2 solution added, ml/I
Fi gure St Chamical oxidation a* cyanide with chlorlna In tap
Matar

-------
Third series: The model shown in Figure b has been cons-
tructed to observe the cyanide retention capacity o-f soil.
Cyanide containing water has been percolated through the soil
and the amount o-f cyanide remaining in water has been
measured. Since the soil composition e-f-fects the amount o-f
cyanide retained by the soil, the experiment was repeated
s-fter the addition o-f iron salts to the soil. The experi-
mental results are given in Table 3 for Kemalpa^a soil and
Table 4 -for Bornova soil.
25 cm
Figure 6: The model used to determine cyanide retention
capacity o-f soil
C-182

-------
Table 3: Cyanide Retention by Kemalpa$a Soil

In-fluent
cyanide concentration

Chemicals added
1 mg/1
2 mg/1
5 mg/1
Average
removal
Kemalpa^a Soil
0.37 mg/1
<63 '/.)
0.78 mg/1
<61 '/.)
1.9 mg/1
<62 */.)
62 7.
Soi 1 + 3 dig
FeCi_/ mq CN
o
0.30 mg/1
<70 */.)
0.6S mg/1
<66 7.)
1.70 mg/1
<66 '/.)
67 V.
FSD4+>^9
0.52 mg/1
<48 */.)
1.1 mg/1
<45 '/.)
2.7 mg/1
<46 7.)
46 X
Soil + mixture o-f
Fe304 + FeCl_
2.S mg/mg CN*
0.67 mg/1
<33 */.)
1.38 mg/1
<31 '/. )
3.4 mg/1
<32 7.)
32 Vm
Table 4: Cyanide retention by Bornova Soil
Chemical= added
In-fluent
1 mg/1
cyanide concentration
2 mg/1 5 mg/1
Average
removal
Bornova Soil
0.5 mg/1
<50 */.)
1.04 mg/1
<4S 7.)
2.65 mg/1
<47 7.)
48 7.
Soi 1 + 3 mg
FeCU/mq/CN"
0.45 mg/1
<55 Z>
1.00 mg/1
<50 X)
2.5 mg/1
<50 */.)
52 */.
Soil + 2.5 mg
FeS04/mg CN
0.77 mg/1
<23 'A)
1.56 mg/1
<22 /.)
3.93 mg/1
<21 7.)
22 7.
Soil + mixture o-f
Fe3D4 + FeCU
2.3 mg/mg CN*
0.80 mg/1
<20 7.)
1.65 mg/1-

-------
with 5 mg/1 of CN . Experimental results are given in Table 5
and the data obtained are plotted in Figure 7.
Table 5: Decomposition o-f cyanide
Time,days	Cyanide Concentration
5 mg/1,aerated	5 mg/l+soil 10 mg/l+soil
1	2.35	0.80	1.60
2	.1.90	0.70	1.20
3	0. SO	0.50	0.65
4	0.44	0.25	0.52
5
6
7	0.21	0.06	0.20
S	0.13	0.04	0.10
9	0.08	0.01	0.03
10	0.0Q	0.005	0.025
DISCUSSION
Although the groundwater contamination by cyanides is not
very common, it may take place especially in areas where
cesspools are used for industrial wastewater disposal. In
Turkey, water pollution by cyanides is a very important
problem. For example it has been reported that about 5B kg of
cyanides are discharged to water bodies by industries in the
city o-f Izmir 
-------
That the groundwater contamination was caused by zipper
industry was -found as 'follows. Textile, metal plating and
zipper industries were discharging their wastes to cesspools
and the others to Nif river. Ceramics industry had its
treatment plant. Nif River analysis indicate that the river
receives same cyanide containing wastes. But it is diluted so
much that the order of cyanides in Ni-f River is the same as
in groundwater in the area. Thus, the idea that cyanide
containing wastes discharged to Ni-f River have percolated to
groundwater has been rejected. It is possible that cyanide
concentration in Nif River ay reach to very high
concentrations -from time to time but it is carried away so
rapidly that it is not very probable that it will cause a
groundwater pollution o-f about 2 km diameter. Although there
may be some contribution o-f cyanides from Ni-f River, it
cannot be the only source. Wastewater anal sis and discussion
with the industries who discharge to cesspools revealed that
the textile industry wastewaters did not contain more than
0.1 mg/1 o-f cyanide and metal planting industry was
collecting their cyanide wastes in metal containers. Zipper
industry had the complete manufacturing units until about one
year ago. Later on, they decided that the metal plating o-f
zippers would be made in another place. Informal information
cbtained from the personnel revealed that they used to
discharge zipper plating wastes to cesspools. After the
cyanide contamination was detected in groundwater within a
circle of about 2 kilometer including the zipper industry
they found it more suitabe to move the cyanide baths to
another branch they had in a small town where environmental
regulations are not so strictly applied.
Although chlorination of cyanide contaminated groundwater as
a drinking water treatment is not recomendable due to the
risks involved, the effect of chlorine on cyanide concent-
ration have been investigated in this research in connection
to the event occured in izmir. Zn some areas, it is possible
that the cyanide contamination may not be noticed if the
water is chlorinated and cyanide concentration is not very
high. As Figures 4 and 5 indicate the cyanide concentration
diminish very -fast with the application of chlorine. The
chlorine solution used is available in the market and
contains 20 '/. chlorine.
Chlori nation of water oxidizes the cyanide by the reaction
NaCN + Cl2	 CNC1 + NaCl
The rate of this reaction is pH dependent and slow below pH
8.5, but in the laboratory study conducted, water pH was not
increased since the aim was not the optimize the removal
conditions but to observe the change in cyanide concentration
under natural conditions. Comparison of Figure 4 and 5 reveal
that less cyanide was oxidized in the case of tap water.
C-185

-------
If cyanide contamination takes place as cyanide being the
single pollutant, chlorination may ha considered as a
solution. But when industrial wastewater percolates to the
groundwater cyanide may be accompanied by other pollutants
also.
When cyanide containing wastewater percolates thorough the
soil, some part of cyanide is retained in the soil and some
reaches to the groundwater. The part that reaches to the
groundwater is diluted and microbiologically degraded in the
course of time. Thus the original water is much more
concentrated than the contaminated groundwater.
The amount o-f cyanides that is retained by the ground depends
on the type of soil medium and its organic matter content.
Compar on o-f Tables 3 and 4 indicates the effect of
differences in soil type. Although both of the soil from
Bornova and Kemalpa^a contain clay, sand and gravel their
ratio of these substances and organic matter contents are
different.
ft 10 cm layer of soil can retain 55 7. of cyanide in soil.
Cyanides that are adsorbed on soil particules slowly
decompose with help of microorganisms. The part that form
complexes in water are much l*ss toxic than HCN but as
decomposition takes place HCN is produced in groundwater this
reation will be very slow because of the dark medium and it
is not very probable to reach toxic concentrations unless the
source is continuous.
Iron chloride addition causes a Blight increase on cyanide
retention capacity of Sibils. This may be e>:plained by the
strong interaction of "* ion with cyanide ions to for the
ferricyanide ion Fe
-------
Figure 7s Decomposition o-f cyanide
C-187

-------
REFERENCES
1.	Abidoglu,A. Lati+oglu,E. <1981)s Su ve Toprak Kaynaklannin
Geliiriimesinde Kurulu$1ararasi Koordinasyonun onemi , Su ve
Toprak Kaynaklarinin Gel i $tiri lmesi Kon-f eransi , DSt Genel
Mudurlugii, Ankara.
2.	DS1 (1979): Izmir Kemalpa^a Ovasi Yeraltisulari Hidrojeo-
lojik Etudu, Devlet Su t fieri Genel Md., II. Bolge MudiirlugU,
Izmir.
3.	Kalaycioglu, R. (1987)s Kemalpa?a (NYMPHAION) Tarihsel
Kent Dakusunun Incel enmesi , D.E.u.Fen Biliraleri Enstitusu,
Mimarlik BoIuiru Yiiksek Li sans Tezi, Izmir.
4.	Mckee and Wolf (1978): Water Quality Criteria, California
State Water Rescources Control Board, USA.
5.	Qzi>. u. (19S1) s Anadoluda Su Kaynaklarinin Dunti, Bugiinu,
Yarini , Su ve Toprak Kaynaklarinin Geli?tirilmesi Konferansi ,
DS1 Genel Mudurlugii, Ankara.
6.	Schippers, J.C. (1904): Summary of Standards and Goals for
Drinking Water, International Course for Hydraulics and Env.
Engineering, Delft, Holland.
7.	Standard Methods (1981): Standard Methods for the
Examination of water and wastewater, APHA, AWWA, WPCF, USA.
8. ^engiil , F. (1987) s Endiistriyel Siyaniir Kirliligi ve
Aritimi , Doga TU Miih. ve ?ev. D. 11,3.
9. Temizer,A.<1979)s Seyhan Baraji Sulama Biilgesi Yiiregin ve
Tarsus cvalari sulama, Drenaj ve kuyu sulari ile topraktaki
kalici insektrst Bakiyeleri Qzerine Ara^tirmalar, I. Ulusal
Zirai Mucadele II agl ari. Sempozyumu, Ankara.
C-188

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Peter Werner

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Report on activities in the frame of the
NATO/CCMS Fellowship Programne
Title:
Demonstration of Remedial Action Technologies
for Contaminated Land and Groundwater
Aspects of In Situ Remov
Contaminated Sites by
by Peter W
al of Hydrocarbons from
Biodegradation
erner
C-191

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Dr. Peter Werner
Report on activities in the frame of the NATO/CCMS Fellowship Programme
Title:	Demonstration of Remedial Action Technologies for Contaminated
Land and Groundwater
Activities: 1987: Participation in the SETAC-Conference in Pensicola
(Florida)
November, 9, 1987
Visit of the Eglin Airbase site
November, 10, 1987
Participation in the NATO/CCMS Meeting in Washington, DC
November, 11-13, 1987
1988: Participation in the TNO/BMFT Congress in Hamburg (Germany)
April, 14, 1988
1989: Visit of the institute of Erik Arvin (Department of
Environmental Engineering in Copenhagen, Denmark)
May, 11, 1989
Participation in an International Symposium on Processes
and Governing the Movement and Fate of Contaminants in' the
Subsurface Environment, Standford University
July, 24-26, 1989
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Contacted persons: Prof. Perry McCarty, Stanford University, Stanford,
California
Dr. Lewis Semprini, Stanford University, Stanford,
California
Prof. Paul Roberts, Stanford University, Stanford,
California
Prof. Herb Ward, Rice University, Houston, Texas
Prof. Erik Arvin, Technical University of Copenhagen,
Denmark
Prof. John Wilson, Robert S. Kerr Environmental Research
Laboratory, EPA, Ada, Oklahoma
Dr. S. Hutchins, Robert S. Kerr Environmental Research
Laboratory, EPA, Ada, Oklahoma
Dr. Doug Downey, U. S. Air Force, Tyndall, AFB, Florida
Prof. Dr. Muntzer, Institut de Mecanique des Fluids,
Universite Louis Pasteur, Strasbourg (France)
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Introduction
In the late 70's, the public interest in contaminated sites increased rapidly.
First aid measures consisted in replacing the polluted soil with non-polluted
material. The more people investigated soil and groundwater, the more
contaminated areas could be found. Gradually, the public became more and more
aware of the problems. Together with an increasing feeling of responsibility,
a large industry of remediation measures developed during the 80's.
Besides landfill, encapsulation, extraction, and incineration, which are just
mentioned here, there is a strong interest in biological methods to remediate
contaminated sites. The target of these methods using microbial activities is
a complete mineralisation of the pollutants [1, 2j.
The technical aspects of biological remediation using on-site and in-situ
methods are described in a great number of publications of which only a few
are refered to here [3, 4, 5, 6, 7].
The task of my fellowship programme is not to repeat things and facts which
have already been described in different journals or presented at different
congresses. Nor is it good to believe everything announced in advertising
brochures of firms which offer biological remediation already commercially.
As a microbiologist, I want to focus especially on problems still existing in
the field of biological processes used for remediation of contaminated sites.
This will help us to get a better understanding for the ongoing processes.
Moreover, it is necessary to regard biological processes on a realistic base.
It is not worth exaggerating these methods not knowing enough about the
background. The knowledge on biodegradation itself must be increased before
the methods can be applied realistically. We must be aware of the problems and
must admit that we do not know enough about them. Otherwise we might be blamed
later on for having dealt amateurishly with difficult question such as the
remediation of contaminated sites. Certainly, it is very useful to apply
biological methods where they really seem useful. But it is impossible to
solve all problems with microbiology. The aim must always be a combination of
C-194

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different methods.
The reputation of microbial processes in the frame of remediation methods
still is very good and we should take care that it remains like that.
In order to increase the possibilities to use microbial activities for the
elimination of contaminants, I put the main interest in the fellowship
programme on two problems which prohibit the biodegradation processes.
1)	Bioavailability of the contaminants
2)	Question of oxygen sources (air, oxygen, nitrate, hydrogenperoxide)
For a better understanding of the problem, I have to restrict my explanations
to the biodegradation of hydrocarbons.
1) Bioavailability of the contaminants
Contaminations of subsurface by oil products in general result from accidental
spills or leaking underground storages. Even when mobile oil has been removed
by pumping, residual trapped oil can be a long-lasting source of water
contamination by soluble hydrocarbons which therefore should be removed.
Enhanced biodegradation should be used with the support "of other means,
described elsewhere [7].
For the application of in-situ measures the following preconditions must be
guaranteed:
C-195

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Table 1: Requirements for biological in-situ treatment
MICROBIOLOGICAL POINTS OF VIEW:
Biodegradability of the contaminants
Concentration of the contaminants
Absence of toxic substances (e. g. heavy metals)
Solubility of the contaminants
HYDROGEOLOGICAL POINTS OF VIEW:
"4 ,
Hydraulic conductivity 5x10 m/s
Flushing circuit
Water treatment before infiltration
Homogenious distribution of the contaminants
Prevention of spreading of the contaminants
Homogenious flushing through the contaminated soil
A detailed description of the procedure is given in [2].
Among the different factors, which limit biodegradation, listed in Table 2, I
first want to focus on the bioavailability of the contaminants for the
bacteria.
Table 2: Limiting factors for the biodegradation in contaminated sites
1)	Physiological conditions (composition of inorganic nutrients, con
centration of the nutrients)
2)	toxic substances (e. g. heavy metals)
3)	biodegradability of the pollutants themselves (kinetic data)
4)	bioavailability (solubility, spatial separation)
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The problem of bioavailability is characterized in just four words, given in
Figure 1.
water
soil
c
bacteriaJ
V >
^ pollutants ^
Figure 1: Distribution-of pollutants and microorganisms in polluted soil
To enhance the biodegradation of contaminants, it is necessary to bring
microorganisms and pollutants into close contact. Normally, the contaminants
are very well attached to the soil or even integrated into the soil matrix -
as it is known in the case of clay. We have to consider that the pollution of
the soil normally takes a very long time (in the case of coal gasification
plants about 50 years) and so diffusion plays a predominant role. We cannot
expect that the organics are released within a short period of time. So it is
an urgent task to increase the concentration of the pollutants in the aqueous
phase to enable the bacteria to biodegrade them. In my opinion, it is not
worth increasing the number of bacteria artificially because they are not able
to penetrate the soil, at least in the case of clay.
The first step of remediation is to establish and maintain conditions which
allow biodegradation. The second step is done by the bacteria themselves: if
they find acceptable physiological conditions they will settle and proliferate
voluntarily.
In order to illustrate the problem, an example of a laboratory experiment is
described here. A column has been filled with sand that had been contaminated
artificially with a consortium of 10 different PAH's. The initial concentra-
te 197

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tions of the soil used in the experiment are given in the first row of the
next table.
Table 3: Concentrations of PAH's during biodegradation in a laboratory pilot
plant [8]

Concentration (mg/kg)
1
1


Operation Time (d)
1
Substance




1

1
35
56
87
137 |
1
Naphthalene (NAP)
265.11
1.21
0.64
nn
1
nn |
Acenaphthylene (ACY)
318.66
13.52
9.93
1.37
0.94 |
Acenaphthene (ACE)
356.45
43.42
16.78
3.03
2.30 |
Fluorene (FLO)
378.19
146.76
88.79
13.10
7.53 |
Phenanthrene (PHE)
379.42
226.13
171.80
23.52
12.55 |
Fluoranthene (FLA)
400.13
357.27
398.88
55.62
29.56 |
Pyrene (PYR)
397.68
385.36
339.42
58.27
30.47 |
Benzanthracene (B2A)
40.53
44.65
35.93
11.60
11.26 |
Chrysene (CHR)
41.74
36.15
37.82
T9.66
17.28 |
Benzo(a)pyrene (BZP)
40.99
38.52
36.65
24.39
22.95 |
1
Sum
2619
1293
1137
211
1
135 |
I
Some results of the experiment are shown in Figure 2 on which the number of
hydrocarbondegraders is plotted with respect to the operation time. As a proof
for the bacteria, the incubation was done with naphthalene as a single carbon
source. In the beginning, there is an increase in the population of 2 orders
of magnitude, followed by a plateauphase which is almost constant over a
period of 5 weeks. The concentration of the PAH's during this time is about 23
mg/1 in water and 2.6 g/kg in soil. After the plateauphase, there is a decline
of the number of bacteria combined with a decrease in the concentration of
PAH's in water to a minimum of 0.03 mg/1. The concentration of PAH's in the
soil, however, still is very high (1.0 mg/kg soil).
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In the experiment presented here, we added 0.5 % acetone to the system and
were thus able to increase the concentration of hydrocarbons in the water. The
result was another increase in the number of bacteria in the system. The
microorganisms where neither prohibited by acetone nor were they able to
biodegrade it. At the end of the experiment, a concentration of about 140
mg/kg soil could be detected. The value is given separately because there was
another step done at the end of the experiment which should be discussed in
another scope. In order to increase the biodegradability we used UV-radiation.
OPERATION TIME (d)
Figure 2: Hydrocarbondegraders with respect to the operation time in a
laboratory experiment, showing the mineralisation of PAH's
(In a parallel experiment, in which HgCl^ was used to kill the
bacteria, only a slight decrease of PAH's could be found due to
stipping effects [8]).
From these data we can conclude that the solubility of PAH's is the growth
limiting factor.
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The elution of pollutants from different soils is very unlike from the
geological point of view and can be shown in an experiment demonstrated in
Table 4.
In both soils (sand and clay) from different contaminated coalgasification
plants in Germany there is almost the same concentration of the consortium of
PAH's (about 2,1/kg soil dry weight). An aqueous elution of 100 g soil in 1 1
of water in the result is almost undetectable in the case of clay while it is
about 10 mg/1 in the case of sand. For that reason, we have to look for a
method to increase the release of pollutants from a clay material.
Table 4: Aqueous elution of PAH's out of sand and clay from contaminated sites


CLAY

1
SAND |

concentration
I concentration |

in the
I in the
I in the
I in the I

soil
I supernatant
j soi 1
j supernatant j

(mg/kg)
1 (mg/1)
1 (mg/kg)
1 (mg/1) |
1
Indene
3,0
1
I >0,01
1 2,5
1 1
1 0,10 |
Indan
6,2
I >0,01
1 4,0
1 0,20 |
Naphthalene
70
1 0,04
I 105
1 6,00 |
1-Methylnaphthalene
82
1 0,04
I 65
1 0,80 |
2-Methylnaphthalene
110
1 0,07
I 210
1 1,00 |
Acenaphthene
210
I >0,01
I 140
1 0,90 |
Acenaphthylene
20
I >0,01
I 60
1 0,10 |
1,1-Biphenyl
25
1 0,02
I 60
1 0,20 I
Fluorene
265
1 0,02
| 400
1 0,15 |
Anthracene
130
I >0,01
I 250
1 0,08 |
Penanthrene
240
I >0,01
I 310
1 0,15 |
Pyrene
285
I >0,01
I 220
1 0,09 |
Fluoranthene
400
I >0,01
I 160
1 0,05 |
Crysene
110
I >0,01
I 90
1 0,01 |
Benz(a)anthracene
165
I >0,01
I 110
1 0,02 |
1
Sum
~ 2100
1
1 - 0,2
I ~ 2200
1 1
1 ~io |
C-200

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Prof. Paul Roberts and Dr. Lewis Semprini from Stanford University deal with
similar problems concerning bioavailability of contaminants in the subsurface.
They measure the effect of sorption on the rate of biodegradation [3]. This
group puts the main focus on the biodegradation of chlorinated hydrocarbons.
Another research group at Rice University in Houston carries out special
experiments with the biodegradation of hydrocarbons in clay materials (Prof.
Dr. Herb Ward). Thanks to the NATO/CCMS fellowship programme granted to me, I
was able to contact both groups which deal with these problems. The close
exchange of information still continues and another visit to Stanford
University is planned with the support of the fellowships's financial remains.
The problem we have to tackle is the release of organics bound to the soil in
order to increase the solubility and therefore to enable biodegradability in
the first place.
The disadvantages of the use of organic surfactants are summarized in [1] and
[9] and are not explained in detail here. I just want to mention the increase
of biomass and gasproduction which decreases the hydraulic permeability to
zero. Moreover, toxic surfactants can principally not be used.
The requirements a surfactant has to meet are:
-	neither to prohibit nor to enhance biomass production
-	no prohibiting effect on the biodegradation of the pollutants themselves
-	no influence on the environment.
We were able to find out that pyrophosphates fulIfi1 the preconditions, at
least on a laboratory scale.
The example of the experiment shows the effect of Na-Pyrophosphate on the
release of PAH's attached to sand. The efficiency for the two consortia of
PAH's is given in the figure of Table 3. The experimental conditions are
described at the top of the figure. The best efficiency of pyrophosphates to
increase the PAH content in the supernatant is in the concentration range of
0.1 %. Using 0.5 a decrease can already be observed which can be explained
C-201

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by sedimentation processes. The sedimentation time in the case presented was
10 minutes.
AA Z ACY.ACE.FLO.PHEN
i	* I FLA.PYR.B2A.CHRY.B2P
Sand:
O 10
C
V
ACY	48,96 mg/kg
ACE	47,86 "mg/kg
FLO	48,12 mg/kg
PHEN	51,74 mg/kg
FLA	49,86 mg/kg
PYR	47,62 mg/kg
B2A	5,68 mg/kg
CHRY	4,86 mg/kg
B2P	5,60 mg/kg
C
o
o
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.B 0.9 1.0
concentration Na-Pyrophosphate in %
Figure 3: Effect of pyrophosphates on the release of PAH's attached to sand
The effect of pyrophoshates on the release of "contaminants is even higher but
on the other hand it results in a complete destruction of the soil structure
itself. So far, we were not able to find any toxic or enhancing effect on the
biodegradation of the pollutants themselves. In the frame of research
programmes we follow the target to increase the concentration of pollutants in
the aqueous phase by releasing them from the soil. Besides pyrophosphates, a
consortium of other surfactants with similar effects is applied. An intensive
exchange of information on this important question with the purpose to solve
environmental problems by biodegradation will be continued in future.
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2) Question of oxygen sources
Normally, the biodegradation of hydrocarbons optimally occurs under aerobic
conditions. The solubility of oxygen in water, however, is limited to
approximately 9-10 mg/1 water at 10-15C, which is the temperature of
groundwater in Central Europe. Because of the high amounts and concentrations
of pollutants normally found in the spill, the growth limiting factor is the
available oxygen. As a rule, approximately 3 mg oxygen are consumed for the
oxydation of 1 mg hydrocarbons. There are some indications that aromatic
hydrocarbons can be biodegraded under methanogenic conditions but the kinetics
of these processes are too slow to be used as a remediation method [10].
One way to increase the oxygen concentration is to use technical oxygen which
will help to raise the values by the factor of 4 to 5. Another way is to work
alternatively with other additional oxygen sources such as nitrates. For the
complete mineralization of 1 mg hydrocarbons about 3,5-4 mg nitrates are
consumed. Theoretically, the concentration of nitrates can be raised almost
without limit. From this point of view, nitrate would be an excellent
electronacceptor for the biodegradation of contaminants because the optimum
final products are carbondioxide, water, and free nitrogen.
But unfortunately not all contaminants can be biodegraded in the presence of
nitrates. It is evident that free oxygen must be available for the first
oxidation step [5]. This is the case at least with aliphatic hydrocarbons. On
the other hand, only very little is known about the mineralization of aromatic
hydrocarbons under denitrification conditions. It seems as if some of them are
inserted directly in denitrification processes [11, 12]. The problems
concerning the biochemical pathways in these biodegradation processes have
been discussed with M. Hutchins and J. Wilson from the Robert S. Kerr
Environmental Research Laboratory, Ada, Oklahoma. The exchange of information
will be continued because this research group is still focussing, like we do,
on these interesting phenomena. The knowledge on the beneficial use of nitrate
for the remediation of contaminated sites is still very poor. On the one hand,
a lot of fundamental work in the laboratory has to be done, as it is described
in [12]. On the other hand, it is already necessary to do practical field
C-203

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work. Our institute is involved in two field projects in which nitrates are
used as additional oxygen sources. The results will be published in 1990 and
are to be presented at the next TNO/BMFT Congress in Karlsruhe in 1990.
Problems with the usage of nitrates mainly occur, besides in the selectivity
of the substrate spectrum, in the production of the unwanted nitrite, which
develops under so far undefined conditions.
Another possibility to bring additional oxygen into biological systems
consists in using hydrogenperoxide. There are no problems with the disinfec-
ting properties of this agent, as has been expected by microbiologists. In our
own experiments concentrations up to 2000 mg/1 of H^0^ could be used without
killing the bacterial population. These results are confirmed by the experien-
ces of Doug Downey [13]. Intensive discussions on the problems and an exchange
of experiences have taken place and are also planned for the future. Own
experiences were made in a field experiment comparing the use of nitrate and
HO in two similar sites. The results will be presented at the Conference on
2 2
Subsurface Contamination by Immiscible Fluids in Calgary, Canada, in April
1990 [14].
The advantage of the usage of hydrogenperoxyde is that it works as
electronacceptor for oxygen and that it can be diluted in water in high
concentrations. The disadvantage lies in the fact that the agent disintegrates
very rapidly to water and free oxygen which forms bubbles in the water.
Therefore, it is difficult to transport hydrogenperoxyde in the subsurface
into areas where it is needed. The question of stabilizing this substances is
not yet answered. On the other side, due to the production of gas bubbles in
the aquifer, the hydraulic permeability decreases rapidly.
C-204

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Conclusions and future plans for the fellowship programme
The objective of the fellowship progranme was to elucidate problems in the
frame of remediation measures of contaminated sites using microbial activites.
Due to the financial support by NATO/CCMS I had the chance to exchange
informations with other research groups. The focus of my work lay on two main
topics concerning microbial remediation: the bioavailability of contaminants
on the one side and the question of additional oxygen sources on the other.
The first step for a successful biological degradation is to bring bacteria
and contaminants into close contact. Some methods to increase the
concentration of the pollutants in the aqueous phase are described above. It
is only in solution that optimum biodegradation conditions can be installed
and above all maintained. Only when this problem has been solved, the question
of additional and/or alternative oxygendonors can be taken into view. The
application of nitrates and hydrogenperoxide is discussed in the report.
The NATO/CCMS fellowship programme allowed me to get into contact with
different research groups treating similar topics as I deal with. All these
groups are still working in order to find solutions for the problems, to get a
better understanding of the limiting factors, and to overcome the
difficulties. This will enable a more successful application in future of
microbial methods for the remediation of contaminated sites.
In order to keep in good touch with these people, I plan to participate in the
above mentioned conference in Canada where I will, have the oportunity to
present results of our own experiences.
The expenses of these travel activities can certainly not be covered with the
second part of the NATO/CCMS grant alone. But nevertheless "l intend to
participate in the conference and to visit at least one university in order to
stay in close contact and to be able to exchange experiences personally, which
seems to be the best way. For that reason, I do not spare the rest of the
travel expenses to be covered privately.
C-205

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References
[ 1] Werner, P., Brauch, H.-J.: Der Abbau von Kohlenwasserstoffen in
kontaminierten Standorten durch in-situ und on-site MaBnahmen. In:
Altlastensanierung '88, K. Wolf, J. von den Brink, F. C. Colon
(Hrsg.), 707-720 (1988)
[ 2] Werner, P.: Experiences in the Use of Microorganisms in Soil and Aquifer
Decontamination. In: Contaminant Transport in Groundwater, Kobus
and Kinzelbach (eds.), (1989), 59-63, Balkema, Rotterdam
[ 3] Semprini, L., P. V. Roberts, G. D. Hopkins and D. M. Mackay. A field
evaluation of in-situ biodegradation for aquifer restoration.
EPA/600/S2-87/096, U. S. Environmental Protection Agency,
Washington, D. C. (1989)
[ 4] Kobus and Kinzelbach (eds.), Contaminant Transport in Groundwater
(1989), Balkema, Rotterdam
[ 5] Battermann, G., Werner, P.: Beseitigung einer Grundwasserkontamination
mit Kohlenwasserstoffen durch mikrobiellen Abbau. gwf-wasser/
abwasser 125 (1984), 366-372
[ 6] Nagel, G. Sontheimer, H., Kiihn, W. Werner, P.: Das "Karlsruher
Verfahren" zur aktivierten aeroben Grundwassersanierung, Heft 29
der Veroffentlichungen des Bereichs und des Lehrstuhls fur
Wasserchemie am Engler-Bunte-Insitut der Universitat Karlsruhe,
1986
[ 7] Franzius, V. Stegmann, R. und Wolf, K.: Handbuch der Altlastensanierung,
Grundwerke, R. v. Deckers Verlag, G. Schenk (1988)
[ 8] Stieber, M., Bockle, K., Werner, P.: Abbauverhalten von PAK in
Untergrund (in preparation)
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[ 9] Battermann, G. Werner, P.: Feldexperimente zur mikrobiellen
Dekontamination. FGU-Kongress im Rahmen der BIG-TECH, Berlin,
November 1987
[10]	Grbic-Galic, D.: Microbial Degradation of Homocyclic and Heterocyclic
Aromatic Hydrocarbons under Anaerobic Conditions. To be published
in "Developments in Industrial Microbiology", Vol. 30 (1989)
[11]	Hutchins, S. R. and Wilson, J. T.: Evaluation of Denitrification for
Biorestauration of an Aquifer Contaminated with JP-4 Jet Fuel.
Presented at the International Symposium on Processes Governing
the Movement and Fate of Contaminants in the Subsurface
Environment, Stanford University, July 23-26, 1989
[12]	RiB, A., Gerber, J., KeBler-Schmidt, M., Maisch, H. U., SchweiBfurth,
R.: Altlastensariierung mittels Nitratdosierung: Laborversuche zum
mikrobiellen Abbau von Heizol (EL), gwf-wasser/abwasser J29
(1988), 32-40
[13]	DowneySD. C.: Enhanced Bioreclamation of a JP 4 Contaminated Aquifer.
Presentation at the SETAC-Conference in Pensicola (Fl), November
9-12, 1987
[14]	Werner, P., Battermann, G.: In situ-remediation of hydrocarbon spills:
microbiological field tests with nitrate and peroxide. To be
presented at the Conference on Subsurface Contamination by
Inmiscible Fluids- in Calgary, Canada, in April 1990
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Appendix D
Final Paper on a Project
Presented at an Earlier Conference
D-l

-------
NATO/CCMS Cover Sheet
TREATMENT CHARACTERIZATION
General Type:
Specific Type:
Manufacturer/Researcher:
Status:
Treatable Contaminants:
Treatable Waste Matrices:
On-/Off-s1te Treatment Location:
Pre- and Post-treatment Requirements:
Soil treatment by extraction -
Ex-s1tu
High-pressure soil washing
Klockner Oecotec GMBH
Commercial
Halogenated and aromatic hydro-
carbons, insoluble heavy metals
Soil
On-site (mobile)
Excavation and transportation of
soil; water conditioning
SITE DEMONSTRATION
Site Location:
Contamination:
Site Characteristics:
Observed Treatment Limits:
Costs:
Scrap metal and copper refinery,
Berlin, Federal Republic of Germany
Variety of organic pollutants,
lead
Soil containing 5 to 25% clay,
100,000 tons treated
Over 95% removal
DM 130 to DM 200 per ton ($80-120
per ton)
CONTACTS
Dr. Heimhard
Klockner-Oecotec GMBH
Neudorfer Str. 3-5
D-4100 Duisburg 1
0203-182420
D1pl-Inc. Kaufmann
Der Senator fur Bau- und
Wohnungswesen- HC
Wurttemberglsche Str. 6-10
D-1000 Berlin 31
030-8677375
D-2
4/89
4-b-l

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FINAL REPORT ON THE AFU (ANWENDUNGSGESELLSCHAFT Ft)R
UMWELTTECHN1KEN), BERLIN, MOBILE PLANT FOR SOIL
DECONTAMINATION BY HIGH-PRESSURE SOIL WASHING
Contents
1.	Introduction
2.	The High-Pressure Soil Washing Process
3.	Chemical Analyses by the "Bundesanstalt fiir
Materialforschung und -prilfung (Referat
Umweltschutztechnologien)11
4.	Conclusion and Prospects
(Distributed at the Third International Meeting 6-9 November 1989,
Monteal, Canada)

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1. Introduction
Since 1986 AFU (Anwendungsgesellschaft ftir Umweltechniken mbH) is
running a mobile plant for the cleaning of contaminated soil by
use of high-pressure jets of water in Berlin. First located on a
former scrap yard on Treidelweg, the high-pressure soil washing
plant is now in its third location in Berlin.
During the pilot project on Treidelweg 1986 through 1988, 7,000
tons of contaminated soil from three different industrial sites
have been successfully cleaned. The soil had been polluted with
chlorinated hydrocarbons, polycyclic hydrocarbons, phenoles,
benzene, mineral oil, lindan, lead, and cyanides.
Permanent teste by order of AFU show that the limits which had
been set for the reduction of pollutants have been reached in
most cases. These results have been supported by expertises on
random samples ordered by the independent "Bundesanstalt ftir
Materialforschung und -prtifung" (Federal Agency for Material
Research and Material Testing).
2. The High-Pressure Boil Washing Process
The high-pressure soil washing process has been developed in the
Netherlands and adapted to German requirements by KlttcJcner
umwelttechnik, Duisburg, FRG. The process is aiming at the
complete separation of pollutants from contaminated soil by
by means of washing. The remaining fractions are clean soil and a
small amount of concentrated contaminants, the latter having to
be disposed in a toxic waste dump or incinerated.
Prior to the development of the high-pressure soil washing
process, pollutants adherent to soil could only be seperated with
the help of wash active additives, i.e. tensides, which created
new threats to the environment. In the high-pressure soil washing
process, the soil first gets broken up by high-pressure jets of
water, and then is cleaned from the adherent pollutantB. This
Beperation takes place within a high-pressure jet pipe.
Within the jet pipe, water is shooting from a ring of nozzles
with pressures of up to 350 bar. The jets conically focus,
creating suction by which the homogenized soil is sucked through
the jets' focal point. During the acceleration, the soil is
chrushed to grains and the pollutants are separated from it.
Easily volatile pollutants are exhausted and absorbed by
activated carbon filters. The other pollutants are dissolved in
the process water, dispersed and emulsified. The water gets
processed and recirculated into the washing process.
D-4

-------
First, the humoBe particles are separated from the process water.
Then the non-soluable pollutants together with the fine particles
(sand, clay with a diameter < 0.03 mm) are removed. The process
water is chemically and physically treated through several
stages, i.e. oxidation, reduction, cleavage, neutralisation,
solid material separation, and activated carbon filtering.
Thereby the soluable pollutants are transformed into a
non-soluable stage and removed.
3. Chemical Analyses by the "Bundesanstalt ftir Materialforschung
und -prdfung (Referat Umweltschutztechnologien)
By order of the "Bundesanstalt ftir	Materialforschung und
-priifung" (Federal Agency for Material	Research and Material
Testing) random samples of contaminated	and cleaned soil have
been chemically analyssed.
3.1 Preparation of the samples
Samples of about 30 kg were taken either from the running
conveyor belts prior to and after the washing process or from the
dump, and then automatically divided into portions of about 1.2
kg.
In order to prepare the required number of portions, each sample
was homogenized first. The homogenization was carried out in
minimal time so that the easily volatile substances would not
evaporate. Then the samples were dried and the content of water
was analysed. Finally the samples were extracted by extraction
solvent, and the solution was concentrated if necessary and
analysed.
3.2 Analytical results
Contaminated and cleaned soil are classified into three groups:
Class I - usable
Class II - polluted, to be disposed of
Class IV - heavily polluted, to be disposed of.
The analytical results (in mg/kg [ppm resp. ppb] of air-dried
soil) are as shown in the following tables.
D-5

-------
Sample 1
Three samples of contaminated (eon.) and three samples of cleaned
(cl.J soil were taken from the running conveyor belt on
Kanalstrafie on May 11, 1987 and analyzed.
1con.	*con.	3con^	lcl> 2cl> 3C^
Lead	18.3	18.1	4.0
Cadmium	0.2	0.1	<0.1
Phenole	3.1	2.7	1.5	<0.1
AHC	< 0.1	for all samples
MOHC	474	250	341	18 16 16
org. Cl	<1	2.1	< 1	<1<1 <1
PAHC:
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benso(a)anthracene
Chrysene
Benzo(b+k)fluo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
indeno(1,2,3-cd)-
pyrene
Benzo(ghi)perylen
Sum of all PAHCfi
1.6
1.7
2.1
0.4
0.3
0.4
8.6
7.0
14.5
0.3
0.1
0.2
6.0
6.2
12.2
0.2
0.2
0.2
2.5
6.3
14.8
0.7
0.5
1.3
5.9
7.9
12.8
0.4
0.3
0.5
31.3
24.6
37.5
1.9
1.8
2.3
25.7
21.0
27.8
1.4
1.5
1.9
9.7
11.2
16.0
0.8
0.7
0.7
8.0
8.2
9.9
0.6
0.6
0.8
17.0
17.9
20.1
1.1
1.1
1.2
8.9
9.4
12.0
0.6
0.5
0.6
11.5
11.8
13.9
0.7
0.6
0.7
2.0
2.2
3.1
0.1
0.1
0.1
5.4
5.4
6.7
0.2
0.2
0.2
6.2
5.2
7.4
0.2
0.3
0.4
150.3
140.8
210.8
9.6
8.5
11.5
PCB (in tig/kg  ppb)
No. 28
No. 52
No. 101
-

2.0

0.1
0.1
No. 153
1.0
0.1
8.0
1.0
O.X
1.0
No. 138
48.0
0.2
5.0
5.0
0.1
11.0
No. 180
62.0
0.1
1.0
4.0
0.1
4.0
Sum of all PCBs:
112.0
0.5
16.0
10.0
0.2
16.0
D-6

-------
For these samples, the cleaning results can only be assessed
referring to the polycyclic aromatic hydrocarbons (FAHC) because
the initial concentrations of other pollutants have already been
very low before the washing process. Referring to the PAHCs the
cleaning result is better than 99%. Also referring to the mineral
oil content a result better than 90% is achieved.
While the contaminated samples are 'Class II' soil (polluted, to
be disposed of), the samples of cleaned soil belong to 'Class I'
(usable). Thus the cleaning has been successful.
Sample 2
Three samples of contaminated (con.) and three samples of cleaned
(cl.) soil were taken from the running conveyor belt on
KanalstraJJe on May 27, 1987 and analysed.

lcon.
*con.
^con.
*01.
2cl.
3cl.
Lead

15,3


5,3

Cadmium

<0,1


<0,1

Phenole
1,8
2,1
1.8
0,1
0,1
0,1
AHC
<0,1
<0,1
<0,1
<0,1
<0,1
< 0,1
MOHC
414
420
346
16
15
11
org* Cl
<0,1
<0,1
<0,1
<0,1
<0,1
<0,1
pahci






Naphtaline
1,3
0,7
3,9
0,3
0,3
0,4
Acenaphtene
0,9
1,7
14,5
0,3
0,1
0,8
Fluorene
0,8
0,8
9,3
0,3
0,1
0,7
Fhenanthrene
6,0
6,0
20,5
1,0
1,0
1,6
Anthracene
1,2
0,9
7,8
0,3
0,2
1,0
Fluoranthene
11,9
10,4
38,4
1,8
1,3
3,7
Pyrene
27,1
14,8
31,8
1,4
1,1
2,7
Benzo(a)anthracene .
5,6
5,8
14,6
0,8
0,7
1,6
Chrysene
6,7
6,1
11,6
0,6
0,6
1,1
Benzo(b+k)fluo-






ranthene
28,6
30,7
25,0
1,9
1,9
2,3
Benzo(e)pyrene
13,5
14,5
10,9
0,9
0,9
1,1
Benzo(a jpyrene
18,0
19,5
15,8
1,2
1,2
1,4
Perylen
3,1
4,4
2,4
0,2
0,2
0,2
Indeno(1,2,3-cd)-






pyrene
10,0
9,3
7,0
0,6
0,6
0,7
Benzo(ghi)perylen
9,4
9,6
7,1
0,6
0,5
0,6
Bum of all PAHCsa
144.1
135.2
220.5
12.2
10.7
19.9
D-7

-------
PCB (in ng/kg - ppb)
No* 28
10
3
4
1
1
1
No. 52
15
4
4
1
1
1
No. 101
5
3
4
1
1
1
No. 153
7
4
5
1
1
2
No. 138
9
4
4
1
1
3
No. 180
5
3
2
1
1
2
Sum of all PCBss
51
21
23
6
6
10
While the contaminated soil belongs to 'Class II', the cleaned
soil is ranking 'Class I'. Thus the cleaning has been successful
with a ratio of more than 90% reduction of pollutants.
Sample 3
Three samples of contaminated (con.) and three samples of cleaned
(cl.) soil were taken from the running conveyor belt on
Kanalstrafle on June 05/ 1987 and analysed.
con,
con.
'con.
lcl.
*cl.
'cl.
Lead
Cadmium
Phenole
AHC
MOHC
org. Cl
PAHCt
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Beneo(a)anthracene
Chrysene
Benzo(b+k)fluo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
Indeno(1,2,3-cd)-
pyrene
Benzo(ghi)perylen
Sum of all PABCflt

11.0


5.0


< 0.1


< 0.1

1.5
2.2
2.3
0.1
0.1
0.1

< 0.1
for all samples

436
449
472
34
23
42

< 0.1
for all
samples

2.5
12.0
1.5
1.9
1.1
0.8
2.0
23.7
2.6
1.1
1.5
1.4
1.7
23.5
2.1
1.1
1.6
1.3
6.2
47.9
6.2
2.9
4.3
3.2
1.8
20.6
1.8
1.4
1.7
1.6
12.0
62.2
28.7
4.0
5.6
5.2
21.9
46.5
44.5
3.2
4.0
3.7
6.9
22.0
9.0
1.6
2.2
2.0
7.0
15.8
9.8
1.3
1.7
1.5
30.3
33.9
34.7
2.4
2.8
2.6
14.3
16.4
16.7
1.1
1.3
1.3
20.0
20.8
20.7
1.4
1.8
1.7
4.4
3.7
3.9
0.2
0.3
0.2
9.2
9.9
9.1
0.6
0.7
0.6
8.1
9.8
8.0
0.6
0.6
0.6
148.3
368.7
199.3
24.8
31.2
27.7
D-8

-------
PCB (in ng/kg - ppb)
No. 28
7
6
2
1 1
1
Mo. 52
5
2
4
1 1
1
No. 101
3
3
1
1 1
1
No. 153
4
5
2
1 1
1
No. 138
6
5
3
1 1
2
No. 180
3
3
2
1 1
1
Sum of all PCBst
28
24
14
6 6
7
The samples of cleaned soil rank 'ClaBB I', while the samples of
contaminated soil are 'Class II'. The cleaning ratio iB better
than 90%. Referring to the 15 different PAHC that were analyzed,
the average content in the contaminated soil is 230 mg/kg; in
cleaned samples it is 31 mg/kg. The cleaning ratio for PAHCs is
almost 90%. The desired results are achieved.
Sample 4
Three samples of flotation concentrate (flo.) in which the
pollutants should be concentrated and three samples of cleaned
(el. j soil were taken from the running conveyor belt on
KanalBtraAe on June 10, 1987 and analysed.
1cl. 2cl.	3cl.	1flo.	2flo. 3flo.
Lead	12.4	94.5
Cadmium	0.1	0.5
Phenole	0.1 0.3	0.1	6.0	4.7 7.4
AH C
Benzene	0.1	for all	sampleB
Toluene	0.1	for all	samples
Xylene	0.1 0.1	0.1	0.2	0.3 0.2
MOHC	17 24	46	2350	870 2110
org. CI	1.0 1.0	1.0	1.0	1.0 1.0
D-9

-------
xflo. 2flo. 31o. *01. 2cl. 3cl.
PAHCt
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benco(b+k) fluo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
lndeno(l,2,3-cd)-
pyrene
Benzo(ghi)perylen
Bub of all PAHCsi
PCB (in |*g/kg - ppb)
No.	28
Mo.	52
No.	101
No.	153
No.	138
No.	180
Sum	of all PCBsi
21
44
31
81
104
112
77
to
100
146
179
181
73
8*
ts
282
2*7
337
207
201
2*5
97
89
112
83
69
83
172
140
186
78
*0
81
112
90
112
29
15
17
38
34
35
40
32
37
1538
1500
1784
1
1
2
1
2
3
1
2
2
1
4
2
2
5
3
1
3
1
7
17
13
<0,1
o,t
0,1
< 0,1
0,1
0,1
< 0,1
0,1
0,1
1,0
1.4
1.
0,1
0,2
0.2
1,s
1.7
2.4
I.J
1.4
2,1
0,8
0.9
1.
0,7
0,6
1.0
1.9
2.2
M
o,t
1.0
1.*
1|5
1.5
2,3
0,2
0.2
o,
0,6
0.7
M
0,7
0.7
0,9
11.3
13.6
19.2
39
30
32
57
14
9
28
32
21
28
26
34
28
24
48
14
14
17
194
140
159
The separation of pollutants and their concentration in the
flotation concentrate have obviously been achieved. Referring to
the 15 PAHCs, there are on average 15 mg contained in each kg of
cleaned soil and 1200 mg contained in one kg of flotation
concentrate. These hardly volatile PAHCs have been concentrated
by flotation.
But not all of the pollutants do accumulate in the flotation
concentrate; otherwise their overall concentration would be much
higher. Therefore part of the contamination must have been
removed with the exhaust air and the waste water.
D-10

-------
Sasiple 5
Three samples of contaminated (con.) soil and three samples of
cleaned (cl.) soil from the running conveyor belt, and three
samples of flotation concentrate (flo..) were taken on KanalstraAe
on June 18/ 1987 and analyzed.
1con. *eon. ^con. ^-cl. 2cl. *cl.
Lead

26,0

9,7


Cadmium

0,1

<0,1


Phenole
<0,1
0,6 0,2
40,1
<0,1

*10,1
AHC

bei alien Proben 0,1



MOKC
60
63 225
9,5
7,5

10,5
org. Cl
0,1
<0,1 <0,1

"

"
PCB (in (ig/kg  ppb)






Mo. 28
1 #3
2,3 1,3
0,5
m

0,5
No. 52
5,5
1,7 3,5
0,9
0,5

0,8
No. 101
7,0
7,6 5,5
1,1
1,2

1,0
No. 153
9,0
16,0 9,3
1,3
2,7

1,8
No. 138
12,0
21,7 11,5
1,9
6,1

2,7
No. 180
5,5
12,1 6,3
0,8
1,9

1,4
Sum of all PCBss
40,3
61,4 37,4
6,5
12,4

8,2


^f lo.
2flo.
" 3flo.


Phenole

4,2
4,5
12,
2

Benzene

0,1
<0,1
0,
1

Toluene

 0,1
<0,1
o,
1

Xylene

<0,1
<0,1
0,
1

MOKC

398
486
694


org. Cl

< 1
<1
 #
6

PCB (in ug/kg  ppb)






No. 28

35
23
100


No. 52

50
40
us


No. 101

50
35
35


No. 153

55
60
55


No. 138

113
108
90


No. 180

43
38
30


Sum of all PCBsi

346
304
425




D-ll





-------
^con.^con.^con. lel.*el.3cl. lflo.2flo.3fio.
PAHCi
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chryaene
Benzo(b+k)fluo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
Indeno(1,2,3-cd)-
pyrene
Benzo(ghi)perylen
0,3	0,9
0,3	0,3
4.2	3,3
1,0	1,4
.1	'0,3
3.0	
3.3	<,4
3.4	3,7
7.1	#,0
3,3	3,9
1.3	1.2
1,0	2.2
2,3	2,t
<0,1 0,1 -- 17
0,1 1,2 0,4 32

-------
8asple 6
On August 04, 1987, three samples of contaminated soil and three
samples of cleaned soil were taken from the plant's input and
output (30 minutes after the washing process), respectively, and
analysed.
The following concentrations of heavy metals were analysed by
plasma spectrometry with inductive coupled plasma (XCP) (two
measurements! a and b)s
Lead Copper Chrome Cobalt Zinc Nickel Vanadium Cadmium
Lcon.  J
b)
Average
'con.
a)
b>
Average
'con.
a)
b)
Average
1cl.
a)
b)
Average
cl 
a)
b)
Average
cl 
a)
b)
Average
133
138
17
263
20
9
2
123
163
11
287
26
9
2
128
161
14
275
23
9
2
1*0
106
12
241
26
8
1.5
135
41
13
234
24
8
1,4
148
74
13
238
25
8
1.5
91
34
>,5
204
20
8
1
101
39
12
210
24
8
1
9*
37
11
207
22
8
1
<7
48
9
188
29
8
1
71
84
8
185
25
8
1
69
66
9
187
24
8
1
98
91
10
134
22
8
1
106
81
9
133
21
7
1
102
86
1
135
22
8
1
64
37
8
140
22
7
1
62
32
8
141
22
7
1
63
33
8
141
22
7
1
water content (%)
cyanide (mg/kg)
mixed sample of
contaminated soil
9.1
0.7
mixed sample of
cleaned soil
15.8
0.2
*con. ^con. ^con. 1
cl. 2cl. 3cl.
MOHC
110
63
85
33
26
31
D-13

-------
*con. ^con. ^con. *cl. *cl. ^el.
PAHCl
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrane
Benso(a)anthracene
Chrysene
Benso(b+k)fluo-
ranthene
Benso(e)pyrene
Benso(a)pyrene
Perylcn
lndeno(l/2f3-cd)-
pyrene
Benzo(ghi)perylen
Sum of all PAHCbi
0,1
nn
on
slit Probtn kltiner sis
0,7
0,8
1,4
0,4
0,2
0,1kl.
0,2
0,9
0,2
<0,1
0,1
0,2
2,1
4,5
1.3
0,7
1,2
1.2
0,5
M
0.3
0,1
0.2
0.4
3,
M
2,1
1.0
1.0
1.*
3,7
5,2
2.2
1.0
1,3
1.3
2,5
2,6
1,2
0,7
o,e
0,8
2,4
3,0
1,5
0,5
0,7
0,8
5,3
3,0
2,2
1.0
1.3
1.2
1,3
1,4
0,9
0,2
0,5
0,3
1,4
2,0
1,3
0,5
0,7
0,
0,4
0,3
0,3
<0,1
0,2 kl.
0,1
1,4
1,7
0,0
0,5
0,5
0,5
1,3
1.1
0,6
0,2
0,4
0,4
25.4
24.9
16.5
6.6
10.1
9.3
From the three samples of contaminated and the three samples of
cleaned soil, mixed samples were taken and analyzed for PCBe. The
following concentrations were founds
PCB (in mg/kg)	contaminated	cleaned
0,004 5
0,005 J
0,012 2
0,011 4
0,019 1
0,010 1
0,062 5
In general, the soil had not been very heavily polluted prior to
washing. Only referring to its content of mineral oil, lead, and
copper they belong to 'Class II'. The samples of cleaned soil are
ranking 'Class I'. Therefore the cleaning has been successful.
With respect to the soil's low initial contamination, the
calculation of a cleaning ratio would not be meaningful.
No.	28
No.	52
No.	101
No.	153
No.	138
No.	180
Sum	of all PCBsi
0,014 4
0,020 7
0,021 7
0,025 4
0,034 1
0,01* 6
0,133
D-14

-------
Sample 7
On August 26/ 1987, three
cleaned soil from the Probstha
Lead Copper Chrome Cobalt Zinc Nickel Vanadium
ample* each of contaminated and
n site were taken and analyzed.
249
88 14
7 207

291
77 14
7 214
1
290
79 14
7 211
1
m
78 18
8 204
1
189
88 14
8 209
1
189
72 19
8 209
1
201
88 19
8 211

201
71 19
8 213

201
79 19
8 212

80
28 7
9 108

81
25 8
3 108

81
28 7
9 108

(3
24 11
2 110

88
29 8
2 114

88
27 9
2 112

78
90 9
9 119

78
90 9
9 119

'con.
a)
b)
Average
con,
a)
b)
Average
'con.
*)
b)
Average
cl .
)
*>)
Average
'cl.
V
b)
Average
cl.
)
b)
Average
lcon. 2con.
'con.
140
210
214

4"2
31
31
n.n.
n.n.
n.n*
<
0,1
<0,1
<0,1
2,0
0,7
1,0
<
0,1
n.n.
0,4
2,0
0,2
0,8
<
0,1
0,1
0,1
1.1
1.7
2,7

0,8
1,2
1,0
0,7
0,9
0,7

.0,1
0,2
0,1
3,8
3,9
4,8

1.1
1,7
1,*
3,8
3,1
M

0,8
1.3
1,2
2,0
2,2
3,0

0,9
0,8
0,8
1.7
1,7
2,7

0,9
0,8
0,9
3,3
3,9


0,8
1,2
1,1
1,"
1,1
1.1

0,4
0,9
0,4
2,3
1,8
2,1

0,4
0,8
0,9
0.8
0,8
0,7

0,1
0,1
0,1
1,7
1,1
2,0

0,9
0,9
0,4
1,8
1,1
1.8

0,2
0,4
0,2
28.3
22.8
32.3

6.3
9.3
8.1
HOHC
PAHC
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b+k)luo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
Zndeno(1(2,3-cd)-
pyrene
Benzo(ghi)perylen
Bum of all PAHCbi
D-15

-------
Although the initial pollution of the contaminated soil is
relatively low, it has to be classified 'Class IX' referring to
its content of lead and MOHCs. The cleaned soil is of 'Class I'
quality. The target has been met with a cleaning ratio of 70-80
% 
Sample 8
Three samples each of contaminated and cleaned soil from the Air
France/Garbage Dump Mo. 1 Marienfelde were taken before and 20
minutes after the washing, respectively, on October 08, 1987.
^con. ^con. ^con. *cl. *cl. ^cl.
MOHC	123	84 110 12 10 28
PAHCi
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benso(a)anthracene
Chrysene
Benzo(b+k)fluo-
ranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylen
Indeno(1,2,3-cd)-
pyrene
Benzo(ghi)perylen
Sun of all PAHCs*
These samples are also relatively low in their initial
contamination. Except for the mineral oil content they could be
classified 'Class I'. The cleaned soil definitely is of 'Class I'
quality. A cleaning ratio of about 70 % haB been reached.
Baqple 9
Three samples each of contaminated and cleaned soil - origin
"Bisstadion Wilmersdorf/HKW Moabit" (containing light oil) - were
taken before and 20 minutes after the washing, respectively, on
November 10, 1987.
0,2
0,1
0,6
<0,1
0,1
<0,1
0,3
0,3
1,0
<0,1
0,1
<0,1
0,3
0,2
0,6
0,1
0,3
0,1
2,8
1,3
4,8
0,6
1,8
1,0
0,7
0,6
1,5
0,1
0,7
0,2
4,6
2,9
M
0,8
2,2
1,2
4,4
2,9
6,3
0,7
1,8
1,2
3,8
1.5
3,7
0,3
1,0
0,6
2,8
1,8
3,5
0,5
0,9
0,5
4,1
2,3
4,8
0,6
1,2
0,9
M
1,1
2,1
0,2
0,3
0,2
2,1
1,4
2,4
0,2
0,6
0,3
0,4
0,3
0,4
<0,1
0,1
n.i
1,7
0,8
1,3
0,1
0,3
0,2
1,*
0,7
1,7
0,1
0,2
0,3
33.0
18.4
41.5
4.6
12.0
6.9
D-16

-------
Mixed samples, one of contaminated and one of cleaned soil, were
created and analysed for their content of water and cyanidest
contaminated	cleaned
Water content	6.7 %	13,9 %
Total content of cyanides	53.4 mg/kg	6.5 ng/Jeg
MOHC
PAHCi
Naphtaline
Acenaphtene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benso{a)anthracene
Chcjaaao
Benso(b+k)fluo-
IBUbllOJlS
Benso(e)pyrene
Benso(a)pyrene
Perylen
Indeno(l,2,3-cd)-
pyrene
Benso (ghi) perylen.
Sum of all PAHCat
con.
^con.
3
Jcon.
xcl.
2cl.
3d.
214
147
179
47
42
69
0,3
0,3
0,3
0,2
0,1
0,2
0,2
0,5
0,3
0,3
0,2
0,5
13
0,9
1,2
0,8
1.2
1.7
5,5
3,4
2,8
5,0
5,*
7,1
1,4
0,8
0.5
1,2
1,4
1,3
7,7
5,0
5,3
6,6
5,9
7,3
8,7
5,7
5,7
5,5
5,2
6,4
*. *
*.*

f,Q
i.n
3.4
3,3
3,6
3,3
2,1
2,0
2,6
o,s
,v
,v
>


3,0
2,5
2,5
1,4
1,5
1,'
3,5
2,6
2,
1,5
1,6
2,2
0,9
1,0
0,5
0,3
0.6
0,6
3,0
2,2
2,3
1,
i,e
1,9
2,2
1.8
2,1
0,*
1,2
1,2
51.8
38.6
37.1
34.0
34.9
42.9
Referring to its mineral oil content, the contaminated soil
belongs to 'Class II', referring to the total content of cyanides
even to 'Class IV' (heavily polluted, to be disposed of). The
washing significantly reduced the MOHC content.
Tn t-.htt ram of cyanides this raault does not apply. Althouoh
there is an overall reduction of pollutants of approximately 50
%, the soil still has to be classified 'Class IV' referring to
its total content of cyanides. Except for the highly toxic 'free'
cyanides, the total content of cyanides also includes relatively
innocuous cyanides, though, so that no Biateneni eon bo givon on
the actual menace emanating from the soil.
D-17

-------
Sample 10
On November 27, 1987, three samples of contaminated and cleaned
soil originating from KBrtestraAe, Berlin 61, were taken from the
running conveyor belt and analyzed.
Mixed samples	Water content Total cyanides Phenole
contaminated soil
6.4 
0.5
mg/kg
< 0.1
cleaned soil
14.5 %
0.3
mg/kg
...

1con. 2con.
^con.
*cl.
2cl. ^cl.
MOHC (mg/kg)	1,090 2,390 3,850 121 112 113
Referring to their mineral oil content the contaminated as well
as the cleaned soil are ranking 'Class II' although the cleaning
ratio for MOHCs is 80-90 %. In this case the target ratio has not
been met.
3.3 Summary of the Results
sampxes or concanmacea son prior to tne wasmng process ana or
cleaned soil after the washing process in the plant on Treidelweg
were chemically analyzed for their content of pollutants. The
soil originated from several locations within the city of Berlin.
The results show that the goal of receiving 'Class I' soil has
been achieved in most cases. The cleaning ratios reached from 70
up to 95 %, depending on the initial degree of contamination.
In very few cases, the total content of cyanides could not
putliulwitljf Lb abJuuoUi Zlia Lu Lai wwuUeuL w  wjfBitlUeo
some relatively innocuous cyanides, though. A threat from 'free'
cyanide could not be stated*
The pollutants accumulate in the residual concentrate of the
plant as it is intended. This residue usually belongs to 'Class
II', i.e. it has to be disposed of but can be deposited in a
toxic waste dump without problem.
D-18

-------
This shows that the easily volatile substances must have - at
least partly - vaporised, and that the water-solvent pollutants
most likely have been carried away by the waste water. As long as
the exhaust air and the waste water are duly treated/ the
high-pressure soil washing process is appropriate for soil which
is mainly contaminated with mineral oil hydrocarbons, organic
solvents, polycyclic aromatee, and - with reservation - heavy
metals.
Finally, the main advantage of the method is the possibility to
adjust its parameters according to the soil's structure and the
kind and degree of contamination given. If there is only a low
degree of initial contamination, an experienced operator will be
able to run the plant in a way that the actual cleaning ratios do
not exceed the taroet ratios too much. Therefore the efficiency
of the plant can constantly be ensured.
4. Conclusion and Prospects
The expertises by order of AFU as well as those by the
independent experts show that the pilot project on the cleaning
of contaminated soil in a high-pressure soil washing plant on
Treidelweg has met the goals in almost all cases. During the
^ASBW'SSr'B! 8ST
values for the remaining pollution in air and water have always
been significantly lower than the permitted limits.
Since April 1989, a third-generation high-pressure soil washing
plant is running in Dtisseldorf-Lierenfeld. Within six months,
70,000 tons of contaminated soil are going to be cleaned on the
site of a former tube rolling mill. Compared with the previous
generation, its efficiency has been raised by additional
aggregates. In detail,
-	an enclosed coarse screening machine,
-	a steam injection,
-	two additional stageB in the jet pipe,
-	large-scale scavenging technology for the soil,
-	process water treatment by flotation and separation,
-	regenerable activated carbon filters with attached
solvent regeneration
have been added to the plant.
At the moment, the project in DUsseldorf-Lierenfeld is the
largest environmental rehabilitation project carried out with
this innovative technology in the Federal Republic of Germany.
D-19

-------
OECOTEC High-Pressare SdJ Washing P1anl2000
Clwmiag efficiency at the farmer WRW alte hi Dftwclmi f-LkwHd
Mot period: 11/5/1989 - 36/61989
ftmimj rfrtfHM^Adrfa{PetwM>)frBM584l


MM
Unwind nil

lteqMMtwte
Mkrimm value
teniae
Maxnrao value
ISrinuniitae
MhbviIsc
Raxhnm vahx
lypecf pothrtanl
mjfc*
mg
mgflg

"8/kg
roi/kl
mg/lg
ptuwi ByBWwfflim
<1J00
no
4K
980
1,230
2.100
9/M

< 10
1.
(1

6JS
14.5
5.3

< 3.5

< (6


2.8


< Oil
< 0.06
1.009
0.087
as
113


-------