United States
Environmental Protection
Agency
Research and Development Technology Transfer
Permitting
Hazardous Waste
Land Disposal
Facilities
Seminars for
Hazardous Waste
Land Disposal Facility
Permit Writers,
Inspectors, and
Operators
February 4-5,1987
Atlanta, GA
February 25-26, 1987
Dallas, TX
March 2-3, 1987
Philadelphia, PA
April 1-2, 1987
Chicago, IL
April 27-28, 1987
San Francisco, CA
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a&o
(I
fn
CO\ CONTENTS
Subject Page
Agenda US EPA
List of Speakers riis&dcjusrtsrs ^rid C"iฉmica! Librariss v-j
EPA Vves? BiJg Room 3340
Speaker Resumes ivteiicode 3404T vii
. . . , . . . 1301 Constitution Ave NW
List of Contacts Washington DC 20004 1X
Speaker Slides and Handouts 202-566-0556
Liner Compatibility 1
Laboratory Testing for Double Liner Systems 10
Method 9090 29
Leachate Collection System Compatability 45
Bob Landreth, EPA, HWERL
Construction Quality Assurance 68
Dave Anderson, K.W. Brown
Ground-Water Cleanup Technologies 96
User's Manual for CapZone/Veldstr Program 112
Joe Keeley, Ph.D., P.Hg., FAIC, Oregon Graduate Center
Soil Sampling Consideration for Land Disposal Facility Permit
Writers, Inspectors and Operators 188
Tom Pedersen, Camp Dresser & McKee
Current Developments on Closure Regulations 226
Jim Bachmaier, EPA
Vulnerable Hydrogeology Guidance 271
Art Day, EPA
Guidance on Alternative Concentration Limits 317
Jerry Garman, EPA
Land Disposal Restrictions 335
Steve Wei 1, EPA
Hazardous Waste Treatment or Storage in Tanks 339
Chester Oszman, EPA
i i i
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DAr ONE
Time
9:00
9:05
9:15
10:15
10:30
12:00
1:15
3:15
3:30
5:00
DAY TWO
Time
8:30
10:30
10:45
11:45
1:00
2:30
2:45
4:15
AGENDA
Permitting of Hazardous Waste Land Disposal Facilities
Seminar Series
Topic
Speaker
Purpose of Seminar
Welcome; Opening remarks
Linear Compatibility:
- Representative leachate
- Testing of geofrabrics, piping, and soils
- Status of HDPE
Norman Kulujian (CERI)
-P^t-^Fobin-f-RegronW-l
II Honker K'/
Bob Landreth (HWERL)
Break
Construction Quality Assurance
- Summary of recent guidance
- Considerations for covers, dikes, and liners
Dave Anderson (K.W. Brown)
Lunch
Ground-Water Cleanup Technologies:
- Pump and treat
- Intercept drains
- Treatment (in situ and above ground)
- Supplemental systems (e.g., slurry walls)
Break
Soil Sampling
- Choice of soil profiles
- Sampling instruments
- Statistical significance of samples
Adjourn
Joseph Keely, Ph.D.
(Oregon Graduate Center)
Tom Pedersen (CDM)
Topic Speaker
Current Developments on Closure Regulations: Ken Schuster
- Subpart G amendments (closure regulations) Chris Rhyne (EPA)
- Closure of surface impoundments
Break
Vulnerable Hydrogeology Guidance Glen Galen (EPA)
Lunch
ACL Guidance Vernon Myers (EPA)
- Comparison with CERCLA
- Role of fate and transport
- Screening process
Break
Land Disposal Restrictions Steve Weil (EPA)
- Current rule
- Land disposal ban petitions
Adjourn
V
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LIST OF SPEAKERS
Da.y 1
Mr. Robert Landreth
U.S. Environmental Protection Agency
Hazardous Waste Engineering Research
Laboratory
26 West St. Clair Street
Cincinnati, Ohio 45246
(513) 569-7836
Mr. David C. Anderson
K.W. Brown & Associates, Inc.
6A Graham Road
College Station, Texas 77840
(409) 690-9280
Dr. Joseph F. Keely
Assistant Professor
Oregon Graduate Center
Department of Environmental Science
& Engineering
Water Research Laboratory
19600 NW Von Neumann Drive
Beaverton, Ohio 97006-1999
(503) 690-1183
Mr. Chester Oszman
Incineration/Storage PAT Section
Permits & State Programs Division
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4499
Mr. Tom Pedersen, C.P.S.S./Ag
Principal Scientist
Camp Dresser & McKee, Inc.
One Center Plaza
Boston, Massachusetts 02108
(617) 742-5151
Day 2
Mr. Matt Hale
Mr. Jim Bachmaier
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4740
Mr. Glen Galen
Mr. Art Day
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4654
Ms. Janette Hansen
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4754
Mr. Vernon Myers
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4495
Mr. Steve Weil
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
(202) 382-4740
vi
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SPEAKER RESUMES
Robert E. Landreth is an environmental engineer with the EPA Hazardous Waste
Environmental Research Laboratory. He directs technical and administrative
aspects of complex extramural research projects on solid and hazardous waste
pollution, including multimedia research to establish land disposal guide-
lines and a consensus standard for flexible membrane liners in waste manage-
ment facilities. Mr. Landreth works closely with the Land Disposal Division
in developing RCRA guidance. He assembled and guided a team in developing
guidance on use of double liners. He developed four Technical Resource
Documents relted to RCRA. His input included the areas of flexible membrane
liners, chemical fixation, and covers. Mr. Landreth has B.S. and M.S. de-
grees in Civil Engineering.
David C. Anderson is a certified Professional Soil Scientist with K.W. Brown
and Associates. Mr. Anderson authored the soil liner portions of both the
Minimum Technology Guidance Document for Double Liners and the Construction
Quality Assurance Manual. He developed and taught training seminars on soil
liners and final cover systems to EPA Regional and State RCRA permit writers.
He has conducted compatibility tests on a variety of hydraulic barrier mate-
rials and liquids. Mr. Anderson has a B.S. in Agronomy and an M.S. in Soil
Science.
Joseph F. Keely is a contaminant hydro!ogist with the Oregon Graduate Center.
Mr. Keely received his Ph.D. in Civil Engineering from Oklahoma State Univer-
sity; he received his B.S. in Chemistry and M.S. in Hydrology from the Uni-
versity of Idaho (Moscow). He was recently employed as a hydrologist for the
Ground Water Research Branch at EPA's Robert S. Kerr Environmental Research
Laboratory, where his efforts were directed toward geohydraulic and hydrogeo-
chemical investigations of ground-water contamination incidents, coordination
of ground-water modeling research, and instructional assistance. He sits on
the Policy Board of the International Ground Water Modeling Center and serves
as expert witness to the U.S. Department of Justice for Superfund cases.
Chester J. Oszman, Jr. ("Chet") is a staff environmental engineer for the
Incineration/Storage PAT Section, Assistance Branch, Permits and State Pro-
grams Division, Office of Solid Waste, Headquarters. Chet provides technical
assistance to the Regions and States regarding RCRA treatment and storage
permits. He holds a BSCE from the University of Iowa and has worked within
the Office of Solid Waste for almost 10 years.
Tom A. Pedersen is a certified professional agronomist and soil scientist
with Camp Dresser & McKee, Inc. He has extensive experience in the evalua-
tion of the fate and migration of contaminants in soils. He has been respon-
sible for development of design criteria for land application of municipal
vi i
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and industrial wastewaters and sludges; for undertaking soil investigations
at uncontrolled hazardous waste sites and active industrial facilities; for
developing soil and groundwater management programs; and for managing inter-
disciplinary teams in the preparation of environmental information documents
and performing field investigations. He has EPA certification in Personnel
Protection and Safety, and Hazard Evaluation and Environmental Assessment,
and continuing education units in land treatment system design. Mr. Pedersen
has a B.S. in Agronomy and an M.S. in Soil Science.
Matthew Hale, Ph.D. is Chief of the Permits Branch in the Office of Solid
Waste. He is responsible for regulations affecting permitting closure pro-
cedures and financial responsibility demonstrations. Before joining OSW,
Matt worked for six years in the EPA Office of Toxic Substances where he
worked on new chemical reviews and asbestos regulations.
Jim Bachmaier is Acting Chief for the Disposal Technology Section Land Dispo-
sal Branch of OSW. In his eight years with the Office of Solid Waste, Jim
has been involved in the development of land disposal permitting standards of
Part 264 and the land disposal restriction standards of Part 268. Jim has a
M.S. in Environmental Sciences from Miami University of Oxford, Ohio.
Art Day is Chief of Technical Guidance Section in the Waste Management Divi-
sion in OSW. His experience has been in developing regulations and guide-
lines for dealing with the locations of hazardous waste facilities and in the
corrective action program for releases from hazardous waste facilities. Art
has been with the EPA for seven years and spent 4ฃ years working for the
State of Maine. He has a M.S. in geology from the University of Maine and a
B.A. in geology and anthropology from N.Y. University.
Jerry Garman is an environmental scientist in the Groundwater Section of OSW.
He currently works on the groundwater regulations for EPA. Prior to joining
EPA he worked as an environmental engineer for Ford Motor Company. Jerry has
a Master of Public Health in Water Quality from the University of Michigan
School of Public Health and a B.S. in environmental biology.
Steve Weil is Chief of the Land Disposal Restrictions Branch in the Office of
Solid Waste. He is responsible for implementation of the congressionally -
mandated prohibitions of land disposal of untreated hazardous wastes. Steve
has M.S. and B.S. degrees in Chemical Engineering and an MBA. He has been
with EPA since 1976.
Walter DeRieux is an environmental engineer in EPA1s Waste Management Divi-
sion within OSW. He is responsible for developing regulations and guidance
on leak detection systems, minimum technology for double liner systems and
construction QA for hazardous waste treatment, storage, disposal facilities.
Prior to his work with OSW, Walt managed the development of the Publically
Owned Treatment Works Performance Certification Program within EPA1s Office
of Water. Prior to joining EPA, Walt worked as a permit writer and construc-
tion inspector for the State of Maryland and for an environmental engineering
consulting firm.
viii
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LIST OF CONTACTS
Environmental Protection Agency, Office of Solid Waste Programs
Branch and Permit Section Chiefs
Region 1
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Michael R. Deland
Merrill S. Hohman
Linda Murphy
Acting Chief
Mary Jane O'Donnell
John F. Kennedy Building
Haste Management Division
MA Waste Management Branch
CN/ME Waste Management Branch
Chief, VT, RI and NW Waste
Boston, Massachusetts 02203
(HHA)
(HRL-1300)
(HEL)
Regulation Section
FTS 8-223-7210
FTS 8-223-5186
FTS 8-223-5655
FTS 8-223-1591
John F. Kennedy Building
(617) 223-7210
(617) 223-5186
(617) 223-5655
(617) 223-1591
Boston, MA 02203
Region 11
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Christopher J. Daggett
Conrad Simon
Rich Walka
Stan Siegel, Chief
Andrew Bellina, Chief
(2RA RM 900)
(2AWM-SQ RM 1000)
(2AWM-SW 9th Floor)
(2AWM-SW 10th Floor)
New York Permits Section
26 Federal Plaza
Air S Waste Management
Sol id Waste Branch
NY Compliance 4 Enforcement
26 Federal Plaza
New York, New York 10278
Division
FTS 8-264-0504/5
Section
New York, New York 10278
FTS 8-264-2525
FTS 8-264-2302
(212) 264-0504/5
FTS 8-264-8356
(212) 264-2525
(202) 264-2302
(212) 264-8456
Barry Tornlck, Chief
Carribean Permits Section
26 Federal Plaza
New York, New York 10278
Laura Amato, Chief
New Jersey Permits Section
26 Federal Plaza
New York, New York 10278
Region III
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
James M. Seif (3RA00)
Stephen R. Wassersung
Robert L. A1len
Bruce P. Smith, Chief
Robert Greaves, Chief
841 Chestnut Street
Hazardous Waste Management
Waste Management Branch
Hazardous Waste Enforcement
RCRA Pennsylvania Section
Philadelphia, PA 19107
Division (3HW00)
(3HW30)
Branch (3HW10)
841 Chestnut Building
FTS 8-597-9814
FTS 8-597-8131
FTS 8-597-0980
FTS 8-597-8175
Philadelphia. PA 19107
(215) 597-9814
(215) 597-8131
(215) 597-0980
(215) 597-8175
Cindy Clark, Chief
RCRA MD/DE/CE Section
841 Chestnut Building
Philadelphia, PA 19107
John Humpries, Acting Chief
RCRA WV/VA Section
841 Chestnut Building
Philadelphia, PA 19107
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LIST OF CONTACTS (continued)
Region IV
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Jack E. Raven
345 Courtland Street, N.E.
Atlanta Georgia 30365
FTS 8-257-4727
(404) 347-4727
Pat Tobin
Air and Hazardous Materials
Division
FTS 8-257-3016
(404) 347-3454
James H. Scarbough
Residuals Management Branch
FTS 8-257-3016
(404) 347-3016
Allen Antley, Chief
c/o James Scarbough
Waste Compliance Section
FTS 8-257-4552
(404) 347-4552
Douglas McCurry, Chief
Waste Engineering Section
345 Courtland Street, N.E.
Atlanta, Georgia 30308
Region V
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Valdas V. Admakus
230 South Dearborn Street
Chicago, Illinois 60604
(5RA14)
FTS 8-353-2000
(312) 353-2000
Bill Constantelos
Waste Management Division
(5H13)
FTS 8-886-7579
(312) 886-7579
David Stringham
Solid Waste Branch (5HS13)
FTS 8-886-7435
(312) 886-7435
Bill Miner, Chief
Hazardous Waste Enforcement
Branch (5HE13)
FTS 8-886-4568
(312) 886-4668
Karl Bremer, Chief
Technical Programs Section
230 South Dearborn Street
Chicago, Illinois 60604
Region VI
Regional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Dick Whittington, P.E.
Inter First Two Building
1201 Elm Street
Dallas, Texas 75270
FTS 8-729-2600
(214) 767-2600
A1 lyn M. Davis
Hazardous Waste Management
Division (6H)
FTS 8-729-2730
(214) 767-2730
Randy Brown, Chief
Hazardous Waste Programs
Branch (6H-H)
FTS 8-729-9885
(214) 767-9885
Sam Becker, Chief
Hazardous Waste Compliance
Branch (6H-C)
FTS 8-729-2645
(214) 767-9732
Bill Honker, Chief
Permit Section
1201 Elm Street
InterFlrst Two Building
Dallas, Texas 75270
Erlece Allen, Chief
Technical Section (6H-1T)
1201 Elm Street
InterFirst Two Building
Dallas, Texas 75270
Region VII
Regional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Morris Kay
726 Minnesota Avenue
Kansas City, Kansas 66101
FTS 8-757-2800
(919) 236-2800
David Wagoner
Waste Management Division
FTS 8-757-2850
(913) 236-2850
Mike Sanderson
RCRA Branch
FTS 8-757-2852
(913) 236-2852
Steven L. Wilhelm, Chief
RCRA Compliance Section
FTS 8-757-2891
(913) 236-2891
Lyndell Harrington, Chief
Permits Section
726 Minnesota Avenue
Kansas City, Kansas 66101
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LIST OF CONTACTS (continued)
Region VIII
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
John Welles
One Denver Place
Suite 1300
999 18th Street
Robert L. Duprey
Air & Hazardous Materials
Division
FTS 8-564-1719
Louis W. Johnson
Waste Management Branch
FTS 8-564-1662
(303) 293-1662
Diana Shannon, Chief
RCRA Compliance Section
FTS 8-564-1500
(303) 293-1500
Larry Wapensky, Chief
RCRA Permits Section
One Denver Place/Suite 1300
999 18th Street
Denver, Colorado 80202 (303) 293-1717 Denver, Colorado 80202
FTS 8-564-1603
(303) 293-1603
Region IX
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Judith E. Ayres
215 Fremont Street
San Francisco, CA 94105
FTS 8-454-8153
(415) 974-8153
Jeff Zelickson
Toxics S Waste Management
Division (T-l)
FTS 8-454-7460
(415) 974-7460
Philip Bobel
Waste Programs Branch (T-2)
FTS 8-454-8119
(415) 974-8119
Paul Blais, Chief (T-2-4)
Enforcement Section
Waste Programs Branch
FTS 8-454-8129
(415) 974-8119
Jim Breitlow, Chief
Permits Section
215 Fremont Street
San Francisco, CA 94105
Chuck Flippo, Chief
State Programs Section
Waste Programs Branch
215 Fremont Street
San Francisco, CA 94105
Larry Bowerman, Chief
Alternate Technology Section
215 Fremont Street
San Francisco, CA 94105
Region X
Reqional Administrator
Division Director
RCRA Branch Chief
RCRA Enforcement Contract
Permit Section Chiefs
Ernesta B. Barnes
1200 6th Avenue
Seattle, Washington 98101
(Mail Stop 601)
FTS 8-399-5810
(206) 442-5810
Charles Findley
Hazardous Waste Division
(Mail Stop 529)
FTS 8-399-1352
(206) 442-1352
Kenneth D. Feigner
Waste Management Branch
(Mail Stop 533)
FTS 8-399-2782
(206) 442-2782
Chuck Rice, Chief
RCRA Compliance Section
Waste Management Branch
(Mail Stop 533)
FTS 8-399-0695
(206) 442-0695
George Hofer, Chief
RCRA Permits Section
Hazardous Waste Division
1200 6th Avenue
(Mall Stop 529)
Seattle, Washington, 98101
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xii
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LIST OF CONTACTS
STATE SOLID AND HAZARDOUS WASTE AGENCIES
Environmental Protection Agency
Office of Solid Waste
April 1, 1986
ALABAMA
Daniel E. Cooper, Chief
Land Division
Alabama Department of
Environmental Management
1751 Federal Drive
Montgomery, Alabama 36130
CML (205) 271-7730
ALASKA
Stan Hungerford, Supervisor
Air & Solid Waste Management
Dept of Environmental Conservation
Pouch 0
Juneau, Alaska 99811
CML (907) 465-2635
AMERICAN SAMOA
Pati Faiai, Executive Secretary
Environmental Quality Ccmmission
Government of American Samoa
Pago Pago, American Samoa 96799
Overseas Operator
(Canmercial Call 663-4116)
ARIZONA
Ronald Miller, Manager
Office of Waste and Water
Quality Management
Arizona Department of Health Services
2005 North Central Avenue, Room 300
Phoenix, Arizona 85004
CML (602) 257-2305
ARKANSAS
John Ward, Chief
Solid & Hazardous Waste Division
Department of Pollution Control
and Ecology
P.O. Box 9583
8001 National Ctive
Little Rock, Ark >;isas 72219
CML (501) 562-7444
CALIFORNIA
John Ramsey, Assistant Chief
Deputy Director & Chief of Staff
Toxic Substances Control Programs
Department of Health Services
714 P Street, Roan 1253
Sacramento, California 95814
CML (916) 322-7202
Raymond Walsh, Interim Executive Director
State Water Resources Control Board
P.O. Box 100
Sacramento, California 95801
CML (916) 445-1553
Sherman E. Roodzant, Chairman
California Waste Management Board
1020 Ninth Street, Suite 300
Sacramento, California 95814
CML (916) 322-3330
COLORADO
Kenneth L. Waesche, Director
Waste Management Division
Colorado Department of Health
4210 E. 11th Ave.
Denver, Colorado 80220
CML (303) 320-8333 Ext. 4364
xi i i
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COMMONWEALTH OF NORTHERN MARIANA ISLANDS
George Chan, Director
Division of Environmental Quality
Count)rrwea 1th of the Northern
Mariana Islands
Office of the Governor
Saipan, Mariana Islands 96950
Overseas Operator: 6984
Cable address: GOV. MMI Saipan
CONNECTICUT
Dr. Stephen Hitchcock, Director
Hazardous Material Management Unit
Department of Environmental Protection
State Office Building
165 Capitol Avenue
Hartford, Connecticut 06106
CML (203) 566-4924
Micheal Cawley,
Connecticut Resource Recovery
Authority
179 Allyn St., Suite 603
Professional Building
Hartford, Connecticut 06103
CML (203) 549-6390
DELAWARE
William G. Razor, Supervisor
Solid Waste Management Branch
Department of Natural Resources
and Environmental Control
P.O. Box 1401
Dover, Delaware 19903
CML (302) 736-4781
Gerard L. Esposito, Deputy Director
Division of Water Resources
P.O. Box 1401
Dover, DE 19903
CML (302) 736-5722
Robert J. Touhey, Director
Division of Air & Waste Management
P.O. Box 1401
Dover, DE 19903
CML (302) 736-4764
DISTRICT OF COLUMBIA
Angelo C. Tompros, Chief
Department of Consumer &
Regulatory Affairs
Pesticides & Hazardous Waste
Materials Division
toon 114
5010 Overlook Avenue, S.W.
Washington, D.C. 20032
CML (202) 767-8414
FLORIDA
Robert W. McVety, Administrator
Solid & Hazardous Waste Section
Department of Environmental
Regulation
Twin Towers Office Building
2600 Blair Stone Rd.
Tallahassee, Florida 32301
CML (904) 488-0300
GEORGIA
John D. Taylor Jr., Chief
Land Protection Branch
Industrial and Hazardous Waste
Management Program
Floyd Towers East
205 Butler St., S.E.
Atlanta, Georgia 30334
CML (404) 656-2833
GUAM
James Branch, Administrator
Guam Environmental Protection Agency
P.O. Box 2999
Agana, Guam 96910
Overseas Operator
(Ccnmercial Call 646-8863)
xiv
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HAWAII
IOW*
James Ikeda, Deputy-Director
Environmental Health Division
Department of Health
P.O. Box 3378
Honolulu, Hawaii 96801
CML (808) 548-4139
IDAHO
Steve Provant, Acting Chief
au of Hazardous Materials
Department of Health and Welfare
450 West State Street
Boise, Idaho 83720
CML (208) 334-2293
ILLINOIS
Bill Child, Acting Manager
Division of Land Pollution Control
Environmental Protection Agency
2200 Churchill Rd., Room A-104
Springfield, Illinois 62706
CML (217) 782-6760
William Child, Deputy Manager
Division of Land Pollution Control
Environmental Protection Aqency
2200 Churchhill Rd., Room A-104
Springfield, Illinois 62706
CML (217) 782-6760
INDIANA
D. Lamm, Director
Division of Land Pollution Control
State Board of Health
1330 West Michigan Street
Indianapolis, Indiana 46206
CML (317) 243-5026
Luetta Flournoy
Hazardous Materials Branch
USEPA Region VII
726 Minnesota Avenue
Kansas City, Kansas 66101
FTS 8-757-2888
CML (913) 236-2888
KANSAS
Dennis Murphey, Manager
Bureau of Waste Management
Department of Health and Environment
Forbes Field, Building 321
Topeka, Kansas 66620
CML (913) 862-9360 Ext. 290
KENTUCKY
J. Alex Barber, Director
Division of Waste Management
Department of Environmental Protection
Cabinet for Natural Resources and
Environmental Protection
Ft. Boone Plaza, Bldg #2
18 Reilly Rd.
Frankfort, Kentucky 40601
CML (502) 564-6716 Ext. 214
LOUISIANA
Gerald D. Healy Jr., Administrator
Solid Waste Division
Office Of Solid and Hazardous
Waste
Department of Environmental Quality
P.O. Box 44307
Baton Rouqe, Louisiana 70804
CML (504) 342-1216
Glenn Miller, Administrator
Hazardous Waste Division
Office of Solid and Hazardous Waste
Department of Environmental Quality
P.O. Box 44307
Baton Rouge, Louisiana 70804
CML (504) 342-9072
xv
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George Cramer, Mministrator
Ground water Division
Department of Environmental Ouality
P.O. Box 44307
Baton Rouge, Louisiana 70804
(504) 342-8950
MAINE
Alan Prysunka, Director
Bureau of Oil & Hazardous
Materials Control
Dept. of Environmental Protection
State House Station #17
Augusta, Maine 04333
Department of Natural Resources
CML (207) 289-2651
MARYLAND
Bernard Bigham
Maryland Waste Management
Administration
National Resources Planner
Dept. of Health Mental Hyqiene
201 W. Preston Street, Room 212
Baltimore, Maryland 21201
CML (301) 225-5649
Ronald Nelson, Director
M*~'land Waste Management
Administration
Office of Environmental Programs
Dept. of Health & Mental Hygiene
201 West Preston Street/Rn. 212
Baltimore, Maryland 21201
CML (301) 225-5647
MASSACHUSETTS
William F. Cass, Director
Division of Solid & Hazardous Waste
Department of Environmental Quality
Engineering
One Winter Street, 5th Floor
Boston, Massachusetts 02108
CML (617) 292-5589
MICHIGAN
Delbert Rector, Chief
Hazardous Waste Division
Environmental Protection Bureau
Box 30028
Lansing, Michigan 48909
CML (517) 373-2730
Allan Howard, Unit Chief
Technical Services Section
Hazardous Waste Division
Department of Natural Resources
Box 30023
Lansing, Michigan 48909
CML (517) 373-2730
MINNESOTA
Richard Svanda, Acting Director
Solid and Hazardous Waste Division
Pollution Control Agency
1935 West County Rd. B-2
Roseville, Minnesota 55113
CML (612) 296-7282
MISSISSIPPI
Jack M. McMillan, Director
Division of Solid & Hazardous
Waste Mgmt.
Bureau of Pollution Control
Department of Natural Resources
P.O. Box 10385
Jackson, Mississippi 39209
CML (601) 961-5062
xv i
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MISSOURI
.NEW HAMPSHIRE
Dr. David Bedan, Director
Waste Management Program
Department of Natural Resources
117 East Dunklin Street
P.O. Box 1368
Jefferson City, MO 65102
CML (314) 751-3241
MONTANA
Duane L. Robertson, Chief
Solid & Hazardous Waste Bureau
Department of Health and
Environmental Siences
Cogswell Bldg., Rocm B-201
Helena, Montana 59620
CML (406) 444-2821
NEBRASKA
Mike Steffensmeier
Section Supervisor
Hazardous Waste Management Section
Department of Environmental Control
State House Station
P.O. Box 94877
Lincoln, Nebraska 68509
CML (402) 471-2186
NEVADA
Verne Rosse, Director
Waste Management Program
Division of Environmental Protection
Department of Conservation and
Natural Resources
Capitol Ccmplex
201 South Fall Street
Carson City, Nevada 89710
CML (702) 885-4670
John A. Minichiello, Assistant Director
Division of Public Health Services
Office of Waste Management
Department of Health and Welfare
Health and Welfare Building
Hazen Drive
Concord, New Hampshire 03301
CML (603) 271-4609
NEW JERSEY
Dr. Marwan Sadat, Director
Division of Waste Management
Department of Environmental Protection
32 E. Hanover Street, CN-027
Trenton, New Jersey 08625
CML (609) 292-1250
NEW MEXICO
Ernest Rebuck, Chief
Groundwater & Hazardous Waste Bureau
Environmental Improvement Division
Health & Environment Department
P.O. Box 968
Santa Fe, New Mexico 87504-0968
CML (505) 827-2918
Peter Pache, Program Manager
Hazardous Waste Section
Groundwater & Hazardous Waste Bureau
Environmental Improvement Division
Health and Environment Department
P.O. Box 968
Santa Fe, New Mexico 87504-0968
CML (505) 827-2924
NEW YORK
Nonran H. Nosenchuck, Director
Division of Solid & Hazardous Waste
Department of Environmental
Conservation
50 Wolf Rd., Roan 209
Albany, New York 12233
CML (518) 457-6603
xvii
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NORTH CAROLINA
PENNSYLVANIA
William L. Meyer, Head
Solid & Hazardous Waste Management
Branch
Division of Health Services
Department of Human Resources
P.O. Box 2091
Raleigh, North Carolina 27602
CML (919) 733-2178
NORTH DAKOTA
Martin Schock, Director
Division of Hazardous Waste
Management and Special Studies
Department of Health
1200 Missouri Ave., Roan 302
Box 5520
Bismarck, North Dakota 53502-5520
CML (701) 224-2366
OHIO
Steven White, Chief
Division of Solid & Hazardous
Waste Management
Ohio EPA
361 East Broad Street
Columbus, Ohio .43215
CML (614) 466-7220
OKLAHOMA
Dwain Farley, Chief
Waste Management Service
Oklahcma State Dept. of Health
P.O. Box 53551
1000 N.E. 10th Street
Oklahoma City, Oklahcma 73152
CML (405) 271-5338
OREGON
Mike Downs, Administrator
Hazardous & Solid Waste Division
Department of Environmental Quality
P.O. Box 1760
Portland, Oregon 97207
CML (503) 229-5913
Donald A. Lazarchik, Director
Bureau of Solid Waste Management
Pennsylvania Department of
Environmental Resources
P.O. Box 2063
Harrisburg, Pennsylvania 17120
CML (717) 787-9870
PUERTO RICO
Santos Rohena, President
Environmental Quality Board
P.O. Box 11488
Santurce, Puerto Rico 00910-1488
CML (809) 725-0439
RHODE ISLAND
John S. Quinn, Jr., Supervisor
Solid Waste Management Program
Dept. of Environmental Management
204 Cannon Building
75 Davis Street
Providence, Rhode Island 02908
CML (401) 277-2797
SOUTH CAROLINA
Robert W. King, Chief
Bureau of Solid and Haz. Waste Mgtm.
Department of Health & Environmental
Control
2600 Bull Street
Columbia, South Carolina 29201
CML (803) 758-5681
SOUTH DAKOTA
Joel C. Smith, Administrator
Office of Air Quality & Solid Waste
Department of Water & Natural Resources
Foss Building, Roan 217
Pierre, South Dakota 57501
CML (605) 773-3153
iii
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TENNESSEE
VIRGIN ISLANDS
Tan Tiesler, Director
Division of Solid Waste Management
Tennessee Department of Public Health
701 Broadway
Customs House, 4th Floor
Nashville, Tennessee 37219-5403
CML (615) 741-3424
TEXAS
L.D. Thurman, Acting Chief
Bureau of Solid Waste Management
Texas Department of Health
1100 West 49th Street, T-601A
Austin, Texas 78756-3199
CML (512) 458-7271
Bryan W. Dixon, Director
Hazardous and Solid Waste Division
Texas Water Commission
1700 North Congress
P.O. Box 13087, Capitol Station
Austin, Texas 78711
CML (512) 463-7760
UTAH
Dr. Dale Parker, Director
Bureau of Solid and Hazardous
Waste Management
Department of Health
P.O. Box 45500
State Office Bldg.
Salt Lake City, Utah 84140
CML (801) 533-4145
VERMONT
John MaIter, Director
Waste Management Division
Agency of Environmental Conservation
State Office Building
Montpelier, Vermont 05602
CML (802) 828-3395
Angel Lois Le Bron, Commissioner
Department of Conservation and
Cultural Affairs
P.O. Box 4399, Charlotte Amalie
St. Thomas, Virgin Islands 00801
CML (809) 774-6420
VIRGINIA
William F. Gilley, Director
Division of Solid and Hazardous
Waste Management
Virginia Department of Health
Monroe Building 11th floor
101 North 14th Street
Richmond, Virginia 23219
CML (804) 225-2667
Dr. Wladimir Gulevich, Director
Bureau of Hazardous Waste Management
Virginia Department of Health
Monroe Building - 11th Floor
101 North 14th Street
Richmond, 23219
CML (804) 225-2667
WASHINGTON
Earl Tower, Supervisor
Solid & Hazardous Waste Mgmt. Division
Department of Ecology
Mail Stop PV-11
Olympia, Washington 98504
CML (206) 459-6316
Nancy Ellison, Manager
Air Programs
Department of Ecology
Mail Stop PV-11
Olympia, Washington 98504
CML (206) 459-6000
xix
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WEST VIRGINIA
Timothy T. Laraway, Branch Head
Solid and Hazarous Waste/Ground
Water Branch
Division of Water Resources
1201 Greenbrier Street .
Charleston, West Virginia 25311
CML (304) 348-5935
Ronald A. Shipley
Special Ass't to the Director
Wtest Virginia Department of
Natural Resources
1800 Washington Street, East
Charleston, West Virqinia 25305
CML (304) 348-2761
WISCONSIN
Paul Didier, Director
Bureau of Solid Waste Management
Dept. of Natural Resources
P.O. Box 7921
Madison, Wisconsin 53707
CML (608) 266-1327
WYOMING
Charles A. Porter, Supervisor
Solid Waste Management Program
State of Wyoming
Dept of Environmental Quality
122 West 25th Street
Herschler Bldg. ฆ
Cheyenne, Wyoming 82002
CML (307) 777-7752
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LINER COMPATIBILITY
by
Robert Landreth
U.S. Environmental Protection Agency
Hazardous Waste Engineering Research Laboratory
Cincinnati, Ohio
1
-------
Compatibility Test for Wastes
and Membrane Liners
Robert Landreth
HWERL, ORD
Cincinnati, OH
Areas of Concern
Exposure Chamber
Representative Leachate
Testing of Components
Status of PE
Legal Requirements
Section 3004 (0) and 3015 of RCRA
as Amended by HSWA
Section 264.221 (a), 264.251 (a),
and 264.301 (a)
Minimum Technology Requirements
2
-------
Method 9090
Listed in SW-846 (9/86)
Liner Immersed in Chemical
Environment for at least 120 days
Two Temperatures
Comparison of Physical Properties
Seams and Sheet
c
Start
)
i
'
7.1
Obtain Sample
of Waste Fluid
<
7.2
Perform
lesis on
Unexposed
Samples of
Liner Material
3
-------
7.7
Perform Tests
on Exposed
Samples
1
7.8
Report and
Evaluate Data
( Stฐp )
Representative Leachate
Existing Facilities
New Facilities
4
-------
Representative Leachate
Permit Applicants Guidance Manual
for LT, S, D Facilities
Chapter 5 pp. 15-17
Chapter 6 pp. 18-21
Chapter 8 pp. 13-16
Tests to be Performed
Tear Resistance
Puncture Resistance
Tensile Properties
Hardness
Tests to be Performed
(continued)
Elongation at Break
Modules of Elasticity
Volatiles
Extractables
5
-------
Tests to be Performed
(continued)
Specific Gravity
Ply Adhesion
Hydrostatic Resistance
Environmental Stress Crack
Issues Raised for Method 9090
Environmental Stress Crack
Changing of Leachate
Testing of Other Components
Environmental Stress Crack
0
-------
Changing of Leachate
Testing of
Other Components
Plastic Pipe
PVC or HDPE
As in Method 9090
using ASTM D 2412
Alternate
Section of Pipe Lengthwise
Ring of Cross Section
7
-------
Drainage Nets
* No Standard Tests
Expose to Waste
While under Load
Creep
Loss of Transmissivity
As in Method 9090
Test
Test
Name
Method Number
Thickness
ASTM D17778
Mass/Unit area
ASTM D3776-84
Percent Open Area
CWO 22125-86
Permittivity
ASTM D4491
Equivalent
CWO 02215
Opening Size
Puncture
ASTM D3787
(Modified)
Test
Test
Name
Method Number
Mullen Burst
ASTM D3786
Grab Tensile/
ASTM D1682b
Elongation
(Wide-width Strip)
Ultraviolet Resistance
ASTM D4355c
Transmissivity
ASTM D35 Committee
Draft Designation
03.84.02
8
-------
Gravels, Sands, Clay
r . ASTM D-1883 Bearing Ratio
travels ASTM D_2434 Permeability
Clay Method 9100 (SW-846)
Status of HOPE
r,"
HDPE, LLDPE, LDPE
Finger Printing
Finger Printing
Ensure What Was Tested Is
What Is Installed
Liners, Pipes, Geo Nets, Geo Textiles
Aggressive Agents and
Liner Performance
9
-------
Finger Print Analysis
Volatiles, Ash,
Extractables, Sp. Gr.
GC
TGA
DSC
Summarize Data
By Test
By Temperature
Plot/Graph Data
Data Interpretation
By Expert in Area
Expert System
10
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LABORATORY TESTING OF GEOSYNTHETICS AND PLASTIC PIPE
FOR DOUBLE-LINER SYSTEMS
by
Henry E. Haxo, Jr.
Muriel J. Waller
Matrecon, Inc.
Oakland, CA 94623, U.S.A.
to be
presented
at the
Geosynthetics '87 Conference
New Orleans, Louisiana
February 24-26, 1987
11
-------
INTRODUCTION
The use of polymeric products in civil ^-engineering .applications has increased
dramatically over the past decade, particularly in the design and construction of
waste management facilities. These products include various rubber and plastic
membranes that have very low permeability, woven and nonwoven textiles that have
various degrees of permeability, special open constructions designed for high
permeability and liquid flow, and plastic pipes (_1). Except for plastic pipe,
these products are called geosynthetics.
Of particular importance is the wide range of functions that polymeric products
perform in double-liner systems for hazardous waste disposal facilities. These
products are based on a wide range of polymers including rubbers (elastomers),
plastics, fibers, and resins. With this great diversity in materials and products,
an array of laboratory tests are being performed on the materials and the products
to assess their quality and ability to perform in a specific application. Even for
hazardous waste containment applications when a single type of material is the
material of choice, thorough testing ^and evaluation of candidate materials are
necessary due to the differences in polymers and additives used in both geosyn-
thetics and plastic pipe.
This paper reviews some of the basic characteristics of the polymeric materials and
products that are used in the construction of double-liner systems and indicates
the effects of these characteristics on field performance and laboratory testing of
these products. Emphasis is placed on the testing of polymeric geomembranes and
compatibility testing.
POLYMERIC PRODUCTS IN A DOUBLE-LINER SYSTEM
Each construction material in a double-liner system requires testing and evaluation
in terms of the specific facility and condition in which it is designed to perform.
Thus, if a material will probably be exposed to a waste liquid or its vapors, it
must be compatible with that particular waste stream and be able to maintain its
properties over extended periods of time. Similarly, if the material is to be
subjected to loads and to elevated temperatures, it must be able to function as
required without failure.
12
-------
The following polymeric materials of construction are being used or being 2
suggested for use in double-liner systems (2):
GeomembranesTo provide a barrier between hazardous substances and mobile
polluting substances and the groundwater; in the closing of landfills to
provide a low-permeability cover barrier to prevent intrusion of rain
water.
GeotextilesTo provide separation between solid wastes and drainage
material and the leachate collection.system or between the membrane and
cover or embankment soils; to reinforce the membrane against puncture
from the subgrade; to provide drainage, such as in leachate collection
and Kik-detection systems; to provide filtration around drainage pipes.
Drainage NetsTo provide drainage above and between liners; to provide
reinforcement for side slopes and embankments.
Plastic PipeTo provide drainage in leachate collection and leak-detec-
tion systems^ Pipe is also used in the construction, of monitoring ports,
manholes, and system cleanouts.
Figure 1 presents a schematic of a double-liner system with indications of poten-
tial failure modes for the polymeric components used in the subsystems.
BASIC CHARACTERISTICS OF POLYMERIC MATERIALS
All of the geosynthetic materials, as well as plastic pipe, discussed in this paper
are based on polymers, which are products of the chemical, plastics, rubber, and
fiber industries. From the viewpoint of composition, an almost infinite range of
polymeric materials can be produced. The polymeric materials used in the manufac-
ture of geosynthetics and pipe are given in Table 1. Polymers within a type can
vary according to grade and manufacturing process. In addition, considerable
variation among compositions based on the same polymer is introduced by the product
manufacturer through compounding with ingredients designed to enhance or develop
specific characteristics. Knowledge of the composition of each geosynthetic and
pipe can be important when dealing with waste liquids containing organics.
Four general types of polymeric materials are used in geosynthetics:
- Thermoplastics and resins, such as PVC and EVA.
- Crosslinked elastomers, such as neoprene and EPDM.
- Semi crystal line plastics, such as polyethylenes.
- Highly crystalline, oriented polymers, such as polypropylene and
polyester fibers.
As all of these materials are polymeric, they have characteristics in common and
require a broad array of tests to characterize them (_3). In designing containment
facilities and designing the tests needed to assess important design properties,
recognition must be given to basic characteristics of polymers. Some of the
important characteristics of the polymers used in products for the construction of
double-liner systems are briefly discussed.
13
-------
Protective
Soil or Cover
(optional),
Filter Medium
(eg geotextiles)
Top Liner
(polymeric
geomembrane)
n i. i u n i n 111) n > m 11111111) i fi 1111111 n 111 ti i
Drainage Mctwial Drain
Qtaywet.) Q+- pipB -ปQ
Primary Leachate
Collection and
Removal Syrtem
Secondary Leachate
Collection and
Removal System
Drainage Material \ Drain
Qteggaonatt) _^Q
pmpmnw
Native Soil Foundation
Bottom .Composite
'Liner
Upper Component
(polymeric geomembrane)
Lower Component
(compacted toil)
(not lo scale)
Figure 1. Schematic of a polymeric geomembrane/composite double-liner system for
a landfill [2) and potential failure modes of the different components.
Potential failure modes of geomembranes:
1. Puncture due to settlement of components in leachate collection
system or from irregularities in the subgrade.
2. Environmental stress-cracking of liner at bends and creases.
3. Bridging caused by localized subsidence in the subgrade.
4. Sloughing of protective soil cover due to low coefficient of
friction between membrane and soils.
5. Tensile stress under load.
6. Thermal cycling.
7. Loss of properties due to waste incompatibility.
Potential failure modes of geotextiles:
8. Loss of properties due to waste incompatibility leading to
reduced fluid flow.
9. Clogging or blinding of filter material by particles 1n the waste.
10. Tensile stress under load.
Potential failure modes of drainage nets:
11. Intrusion of membrane into the net, leading to clogging.
12. Loss of properties, leading to reduced fluid flow.
13. Collapse of the materials under waste load.
Potential failure modes of plastic pipe:
14. Collapse of pipe under load, particularly if Incompatible with
wastes.
14
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TABLE 1. POLYMERS USED IN THE MANUFACTURE OF MAJOR .PRODUCTS FOR
THE CONSTRUCTION OF WASTE MANAGEMENT FACILITIES
4
Product
Geogrids
Geomem- Geo- and drain-
Polymer
Type
branes
textiles
age nets
Pipes
Acrylonitrile butadiene styrene
Resin
X
Chlorinated polyethylene
Rubber
X
*
Chlorosulfonated polyethylene
Rubber
X
*
Ethylene propylene rubber
Rubber
X
Ethylene vinyl acetate
Rr'nn
X
Neoprene (chloroprene rubber)
Rubber
X
Polyamide (nylon)
Fiber/resin
Xa
X
Polybutylene
Resin
X
~
X
Polyester
Fiber/resin
Xa
X
X
Polyester elastomer
Resin/rubber
X
Polyethylene:
Linear low-density
Resin
X
High-density
Resin
X
X
X
Polypropylene
Resin
X
X
Polyurethane
Resin/rubber
X
Polyvinyl chloride
Plasticized
Resin
X
Unplasticized
Resi n
X
aUsed as reinforcing fabric in
geomembranes.
Polymers Vary in Modulus and in
Elongation at
Break
Polymeric materials range from soft foam-like materials to high modulus structural
materials. Polymeric materials that are used in waste management facilities are
intermediate in modulus or stiffness. However, their elongation at break ranges
from 15% to as much as 1000%. Both properties are .important considerations in
designing geosynthetics and plastic pipe.
Polymers are Sensitive to Organic Liquids and Vapors
As the polymeric compositions used in double-liner systems are organic in nature,
they are sensitive to organic liquids; they can absorb organics from waste liquids
and vapors and swell or can be leached and shrink. In either case, several prop-
erties of the composition can simultaneously change and their performance charac-
teristics can be altered. This sensitivity to organics shows the need for compati-
bility testing.
Polymers are Viscoelastic and Sensitive to Temperature and Rate of Deformation
All polymeric materials are viscoelastic, that is, when undergoing a deformation
they show, in varying degrees, both viscous and elastic behavior. The elastic
component behaves like a spring and is independent of rate of deformation. The
viscous component behaves like a dashpot and is highly dependent upon the rate
of deformation and upon temperature. Rubbers, such as natural rubber and some
15
-------
polyurethanes, tend to have highly elastic components, whereas many of the 5
plastics have highly viscous components. In performing tests in extension
or compression, the temperature and rate of deformation become important,
Most of the polymers used in geosynthetics and pipe vary greatly in properties with
temperature, even within the temperature range in which waste containment facil-
ities operate. At low temperatures some become glassy and brittle, and at high
temperatures the thermoplastic polymers become soft and plastic. These character-
istics will greatly affect the applications in which a polymeric material can be
used.
Due to the viscous component of polymeric compositions, the speed at which they are
deformed greatly affects the magnitude of the values that are obtained, e.g., ten-
sile or tear values. At high test speeds, modulus values generally are consider-
ably higher; the effect on-tensile strength and elongation at break values varies
with the polymer. In the case of semicrystalline materials, such as HDPE, high-
speed testing will not allow time for crystals to align themselves during the test,
thus resulting in lower tensile at break values than those obtained at lower
speeds. In service environments deformation rates can range from rapid impacts to
slow creep.
Polymers Tend to Creep and Relax in Stress
Polymeric materials have a relatively high tendency to creep, that is, to increase
in length or change dimensions under load or to relax in stress when placed in
constant strain. This characteristic is important to long-term exposure such as
would be encountered in a double-liner system. For example, in-place drainage nets
and pipes are under constant load and a geomembrane placed over a protrusion is
under constant stress. The absorption of organics can aggravate this tendency.
High Coefficient of Thermal Expansion
All polymeric materials have thermal coefficients approximately 10 times greater
than those of metals and concrete. For soft geomembranes, this is not a major
problem; however, for stiff membranes, such as the polyethylenes, changes -in
temperature can' cause considerable deformation and flexing of a liner when exposed
to normal weather and high stress in the liner when exposed to cold weather.
Importance of Thermal and Strain History
Polymeric materials tend to have "memory," that is, the deformation during process-
ing and forming into sheets leaves residual strain in many polymers, which is why
tensile and tear testing should be performed in both machine and transverse direc-
tions. Residual strain can cause shrinkage in the machine direction and expansion
in the transverse direction when the sheeting is warmed.
Elongation Under Biaxial Straining
Most of the tensile and tear testing for specification purposes is performed uni-
axially, which can yield high elongations. Performing the tests biaxially, that
is, deforming the materials simultaneously in machine and transverse directions,
yields considerably lower elongation values. This can show up in the testing of
puncture and hydrostatic resistances and in actual service.
16
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Broad Range of Permeability
6
The permeability of the polymeric compositions to various gases and vapors can vary
over several orders of magnitude. Generally, the presence of plasticizers in-
creases permeability and the presence of crystalline structure reduces permea-
bility. Also of importance is the relationship between the solubility character-
istics of the permeant and the polymer; the more soluble the permeant is in the
geomembrane, the higher the probability of permeation.
Stress-Cracking and Static Fatigue
Polymeric materials, as with other types of materials, are subject to fracture
after being under stress and strain for extended periods of time, A material under
constant Stress loses tensile strength and elongation at break. Semi crystal!ine
polymeric compositions, when placed under stress in environments that affect the
surface of the material, can crack or craze. This phenomenon occurs with some
grades of polyethylene and polyester elastomers. The stress-cracking resistance of
semi crystal line polymers that might be used in contact with waste liquids over long
periods of time should be assessed.
Amorphous and Crystalline Phases in Semi crystal!ine Polymers
Semicrystalline polymers, such as polyethylene, contain two basic phases: 1) an
amorphous phase in which the molecular structure is random, such as in a rubber;
and 2) a crystalline phase in which the molecular structure is highly ordered. The
crystalline phase imparts stiffness to the polymer and resists the absorption of
organic species, and the amorphous phase can absorb and transmit organics. Deform-
ation of a semicrystalline polymer results over time in molecular rearrangement in
the crystalline phase. Excessive deformation results in yielding and orientation
of the crystalline phase and subsequent loss in strength in the direction perpen-
dicular to the deformation.
Highly Resistant to Degradation
With proper protection through the use of stabilizers and antidegradants, poly-
mers used in the manufacture of geosynthetics and pipe can be highly resistant to
degradation, that is, with no adverse changes in molecular structure. Polymeric
compositions are still subject to loss in properties due to swelling, but polymer
molecular structure remains essentially undamaged.
Polymers in polymeric compositions are also highly resistant to biodegradation;
however, some compounding ingredients, such as plasticizers, may be biodegradable.
Biodegradation in such cases may result in adverse changes in the properties.
Combinations of Properties in Polymeric Compositions
A given polymer will tend to have a distinct pattern of properties which can be
modified somewhat by compounding. Assessing materials based upon a single pro-
perty, such as tensile strength, can lead to an incorrect selection of materials
because of inadequate values for other important properties, such as chemical
compatibility. For this reason, a group of tests are usually performed on a
material and the resulting test values are assessed as a group before a selection
should be made.
17
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PURPOSE AND TYPES OF LABORATORY TESTS
7
A double-lined waste management facility is a complex system, each component of
which must meet performance criteria for the service life of the facility. Failure
of a single component could lead to failure of the system. Due to the inaccessi-
bility of components of double-liner systems, rational selection and evaluation of
each component is of critical importance to the long-term functioning of the
facility. Rigorous testing programs designed to assess the properties of these
materials are an indispensable part of the design process.
Laboratory tests are performed for the following reasons:
- To assess the ability of certain materials to perform in specific field
environments.
- To aid in the selection of materials for the construction of a specific
facility.
- To assess durability under some extreme conditions.
- To develop data useful in the designing of containment facilities.
- To ascertain for quality assurance purposes that the materials of con-
struction placed in the field meet design specifications.
- To identify the materials and follow changes in composition during
service.
- To monitor the properties of the liner during service.
Laboratory tests designed to assess the ability of these polymeric construction
materials to perform as required in the design and to meet the challenges of the
field environment are needed.
The types of tests'--used .to assess the attributes of polymeric construction mate-
rials fall into several categories. Tests of mechanical properties are most
commonly used to assess the characteristics of these materials. The test values
are then used in the material specifications that are incorporated into the de-
sign documents. "At the present state of liner technology, the relationships
between mechanical properties of particular geosynthetics as measured in the
laboratory and their field performance have not been well defined. Thus, when only
laboratory test data on mechanical properties are available, the designer will
often rely upon his experience in the field as the basis for design judgment.
Performance tests are designed to assess the ability of one or more materials
to perform under a specific set of conditions that simulate those that exist in the
field. Performance tests are generally complex, usually involve many steps, and
need considerable control. Such tests are beginning to evolve for geosynthetics
and plastic pipe in double-liner systems. EPA Test Method 9090 for liner compati-
bility with a waste liquid is a performance type of test because an actual waste
liquid is used as the immersion medium .(ฃ).
A major difficulty in designing performance tests of the various materials under
conditions encountered in double-liner systems is the necessity of reproducing in
18
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the tests the field conditions in which the liner system will perform. For
example, they might need to include identical soils, at the correct mois-
ture contents, wastes, and construction materials that will be used. Tests that
have been used and which relate to some aspects of field peformance include:
- Permeability of geomembranes, e.g., pouch test (5J.
- Frictional properties at the soil, membrane, and geotextile interface.
- Strength and elongation of geomembranes tested biaxially, e.g.,
hydrostatic resistance.
- Transmissivity, permittivity, and filter properties of geotextile,
soil, and geogrid systems.
Most performance tests of geosynthetics and plastic pipe in waste containment
applications as they exist today are in the early stages of development and
require additional research in order to understand and control the test variables
aand ~to interpret, the .test results. At present, field verification data and long
histories of use of these construction materials-in waste liquid environments are
meager.
Analytical tests are used to determine the composition of materials and to evaluate
changes in composition over time under waste and environmental exposures (6). They
include analyses for volatiles, ash content, analysis of the ash for trace metals,
extractables (amount and composition), gas chromatography of extractables and by
pyroprobe, differential scanning calorimetry of semi crystalline compositions,
thermogravimetric analysis, and specific gravity. These tests can be used to
"fingerprint" a polymeric material for quality control purposes.
The testing of the various polymeric components used or potentially used in double-
liner systems are discussed in the following sections.
TESTING OF GEOMEMBRANES
The basic requirements of a geomembrane liner are low permeability to waste con-
stituents, compatibility with the waste liquid to be contained, durability for the
lifetime of the facility, and ease of construction and installation. Labora-
tory tests of these materials need to be selected or designed to assess these
attributes. It is also desirable to be able to identify each geomembrane in order
to be certain that an approved membrane is used in the final construction and to
follow the effect of an exposure on a geomembrane through testing samples of the
exposed liner. Table 2 presents a list of test methods that are being used in
assessing the various types of polymeric geomembranes. The testing of geomembranes
for use in the lining of waste disposal facilities has been discussed by Haxo
(7_) and in the an EPA Technical Resource Document (jJ). Specific test methods,
including the modification of some ASTM methods, have been adopted by the National
Sanitation Foundation (9).
Permeability
As the primary function of a liner is to prevent the flow of mobile liquids and
other chemical species, permeability of the geomembrane to these species must
19
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TABLE 2. APPROPRIATE OR APPLICABLE TEST METHODS FOR UNEXPOSED POLYMERIC GE0MD6RAXES
Meabrane Liner Without Fabric Reinforcement
Property
Thermoplastic
Crossltnked
Sealcrystalllne
Fabric reinforced
Analytical properties
Volatile*
Extractables
Ash
Specific gravity
Thental analysts:
Differential scanning
calorlaetry (DSC)
Theraogravlaetry (T6A)
Physical properties
Thickness - total
Coating, over fabric
Tensile properties
Tear resistance
Modulus of elasticity
Hardness
Puncture resistance
Hydrostatic resistance
Seas strength:
In shear
In peel
Ply adhesion
KIH-1*
KIM-?*
ASTM 0297.
Section 34
ASTM D792. Ntd A
na
yes
ASTM D638
na
ASTM DR82,
ASTM D638
ASTM 01004
(aod)
ASTM 02240
Dure A or D
FTMS 101B.
Htd 2065
na
Environmental and
aging effects
Ozone cracking
Environmental stress-
cracklng
Low temperature testing
Tensile properties at
elevated temperature
Dimensional stability
Air-oven aging
Hater vapor trans-
mission
Hater absorption
laertlon In standard
liquids
I aversion In waste
liquids
Soil burial
Outdoor exposure
Tub test
ASTM 0882.
Htd A (nod)
ASTH D413, Mach
Htd Type 1 (aod)
na
ASTM 01149
na
ASTH D1790
ASTM 0638 (mod)
ASTM D1204
ASTM DS73 (aod)
ASTH E96, Htd BU
ASTH D570
ASTH D471. OS43
EPA 9090
ASTH D3083
ASTH D4364
b
KTM-1ป
HTM-2*
ASTM D297.
Section 34
ASTH 0297.
Section IS
na
- yes
ASTH D412
na
ASTH 0412
ASTH 0624. Die C
ASTM 02240
Ouro A or 0
FTMS 101B.
Htd 2065
ASTM 0882.
Htd A (aod)
ASTM 0413, Mach
Htd Type 1 (aod)
ASTH D1149
na
ASTM 0746
ASTH 0412 (aod)
ASTM 01204
ASTH DS73 (aod)
ASTM E96, rttd BU
ASTH 0471
ASTM 0471
EPA 9090
ASTH 03083
ASTH D4364
b
HTM-ia
HTH-2ป
ASTH 0297.
Section 34
ASTH 0792. Htd A
yes
yes
ASTH 0638
na
ASTH D638 (aod)
ASTH D1004
ASTM 0882, Htd A
ASTH D2240
Ouro A or 0
FTMS 101B,
Htd 2065
ASTH 0751. Htd A
ASTH 0882.
Htd A (aod)
ASTH 0413, Hach
Htd Type 1 (aod)
na
ASTH 01693
ASTH 01790
ASTH 0746
ASTH 0638 (aod)
ASTM 01204
ASTH 0573 (aod)
ASTH E96. Htd BU
ASTH DS70
ASTH PS43
EPA 9090
ASTH 03083'
ASTH 04364
b
HTtt-1"
(on selvage and
reinforced sheeting)
HTM-2*
(on selvage and rein-
forced sheeting)
ASTH 0297,
Section 34
(on selvage)
ASTM D792, Htd A
(on selvage)
na
yes
ASTH 0751, Section 6 {
Optical Method j
ASTH 0751. Htd A and B I
(ASTH D638 on selvage)
ASTH D751, Tongue Htd
(aodlfled)
rvj
ASTH 02240
Ouro A or D
(selvage only)
FTMS 101B,
Htd 2U31 and 2065
ASTH 07S1, Htd A
ASTH D7S1,
Htd A (aod)
ASTM 0413, Hach
Htd Type 1 (aod)
ASTH 0413, Hach
Htd Type 1
ASTH D751, Sections 39-42
ASTH 01149
na
ASTH 02136
ASTH D751 Htd B (aod)
ASTH 01204
ASTH D573 (aod)
ASTH E96, Htd BU
ASTH 0570
ASTH 0471, 0543
EPA 9090
ASTM 03083
ASTH 04364
b
ฆSee reference (8).
*Se* reference (12).
na ฆ lot applicable.
20
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be assessed. Transport through a geomembrane occurs on a molecular 10
level and depends on the solubility of the permeating species and its dif-
fusibility in the membrane.L A__jconcentration or partial pressure gradient across
the membrane is the driving force for the direction and rate of transport. The
species migrates through the membrane from higher to lower concentration; at a
small difference in concentration, the transmission can approach zero for specific
species. In contrast, soils and clays are porous and the driving force for per-
meation is the hydraulic head. Test methods that are available and have been used
to assess the permeability of polymeric geomembranes include:
- ASTM D814, for determining organic vapor transmission.
- ASTM D1434, for determining gas transmission (10).
- ASTM E96, for determining moisture, vapor, and modified- for organic
vapor transmission (10).
- Pouch test, for determining transmission of organics in dilute solu-
tions (5J.
The permeability of geomembranes to different species can vary by orders of mag-
nitude, depending on the composition and solubility of the migrating species in the
geomembrane QO, _U). The permeation of a given species is also affected by such
factors as crystallinity, filler content, density, crosslink density of the poly-
mer, thickness of the geomembrane, temperature, and the driving force across the
membrane. Also, swelling of a geomembrane during service can significantly in-
crease its permeability to some species.
Compatibility with Wastes
The selection of a geomembrane depends on whether it is compatible with the
liquid to be contained (12). A liner is compatible with a liquid if, on long
exposure, its properties, e.g., permeability and mechanical properties, do not
change more than reasonable amounts depending on the type of membrane. In the
absence of criteria for determining the success or failure of materials under
exposure to specific wastes, experience is required in interpreting changes or
trends that develop over time.
EPA Test Method 9090 was designed to assess the compatibility of geomembranes and
waste liquids by simulating some of the conditions a geomembrane would encounter as
an unstretched coupon in representative samples of the waste liquids or leachates
to be contained (4). In this test, liner samples in slab form are immersed for up
to four months at 23 and 50ฐC in the waste liquid. Testing is performed on the
unexposed membranes for baseline data and on samples exposed to the waste liquids
for 30, 60, 90, and 120 days to assess the effects of immersion. Testing required
by the method includes determination of tensile properties, tear resistance,
puncture resistance, and hardness. In addition, the weight and dimensions of the
individual test slabs before and after exposure are measured.
A major challenge in conducting the 9090 test is maintaining, as closely as pos-
sible, the composition of the waste liquid in the test cells for the duration
of the tests as it would be encountered in the "real world." Changes in the
concentration of dissolved constituents in a waste liquid can occur because of loss
21
-------
of volatiles from the immersion cell or absorption by the -geomembrane under 11
test. Consequently, if the leachate contains volatile organics, it is
necessary to seal the cells in which samples are inmersed and to test the samples
promptly after removal. Also, though not required by the 9090 test method, it may
be necessary to change the liquid monthly at the time the sample is removed in
order to maintain a constant concentration of the organics. Table 3 illustrates
partitioning of organics between water and HDPE and the degree that organics are
absorbed by the HDPE sample immersed in an aqueous solution of 10 organics in a
9090-type test. The acetone and methyl ethyl ketone preferentially partitioned to
water, whereas the other 8 organics partitioned to the HDPE.
TABLE 3. PARTITIONING OF ORGANIC SOLVENTS BETWEEN WATER AND
AN HDPE MEMBRANE AFTER 30 DAYS OF EXPOSURE IN A 23ฐC AQUEOUS
SOLUTION SPIKED WITH TEN ORGANICS
Concentration
Concentration
Initial
in water at
in HDPE membrane
spike3
30 daysb
at 30 daysc
Ratio1*
Organic in spike
(mg/g)
(mg/g)
(mg/g)
CpE/^w
Acetone
0.198
e
0.000
Methyl ethyl ketone
0.201
0.201
0.000
<0.002
Trichloroethane
0.335
0.000
1.42
>1400
Benzene
0.220
0.018
0.46
26
Trichloroethylene
0.366
0.032
1.58
49
Toluene
0.217
0.031
2.63
85
m-Xylene
0.072
0.0089
1.46
164
o-Xylene
0.073
0.0034
1.17
344
Tributyl phosphate
0.243
0.016
0.32
20
Di(ethyl hexyl) phthalate
0.247
0.0057
0.11
19
aBased upon the solubility of individual organic in water.
''Concentration determined by gas chromatography.
Concentration determined by headspace gas chromatography.
dRatio of concentration of the organic in the HDPE membrane divided by the
concentration in water.
eNot detectable by the gas chromatograph.
Partial results of a 9090 test of an 80-mil HDPE geomembrane in a waste liquid
containing organics are presented in Table 4. The test was conducted in a manner
to prevent loss of volatiles and to maintain concentration of the organic con-
stituents in the waste liquid. Determination of the volatiles and extractables of
the exposed sample improves the interpretation of the results. The current EPA
Test Method 9090 does not include testing of seams and the effect of strain on a
geomembrane (4). Inclusion of such testing would enhance the method and make
conclusions regarding compatibility more reliable.
Durability
A polymeric geomembrane used to line a hazardous waste storage and disposal
facility must maintain its integrity and performance characteristics over the
designed life of the facility. Liners must resist physical damage during in-
stallation and service; the integrity of the seams must be maintained so that
cracks, breaks, tears, and other holes do not develop in the liner system. Fabric
22
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reinforcement is used with CSPE, CPE, and t)ther polymers to increase 12
durability, particularly during installation. Ultimately, the service life
of a given liner will depend on the intrinsic durability of the material and on
the conditions under which it is exposed during service (13).
TABLE 4. PARTIAL RESULTS OF COMPATIBILITY TESTING OF AN
80-MIL HDPE GEOMEMBRANE ON IMMERSION IN A LEACHATE3 AT 23ฐC
Original Values of Properties and Percent Retention of Values after One,
Two, Three, and Four Months of Immersion at 23ฐC
Direction Initial Exposure time, months
Property
of test
values
1
2
3
4
Analytical properties
Test
values
Volatiles, %
0.1
2.64
2.89
3.26
3.13
Extractables, %
ฃ0.6
0.90
1.43
1.40
b
Dimensional properties
Percent change
Wei ghtc
ซ
+5.5
+6.0
+6.0
+5.9
Physical properties
Percent
retention
Tensile at yield
Machine
18.5 MPa
90
88
89
89
Transverse
18.8 MPa
90
92
90
91
Tensile at break
Machine
29.9 MPa
89
91
102
93
Transverse
30.7 MPa
91
82
97
83
Elongation at break
Machine
835%
98
99
105
98
Transverse
830%
100
93
96
93
Stress at 100%
Machi ne
13.0 MPa
90
89
90
90
elongation
Transverse
12.7 MPa
91
93
92
91
Modulus of elasticity^
Machine
855 MPa
73
e
60 .
62
Transverse
811 MPa
75
69
63
61
Tear strength
Machine
148 kN/m
89
93
89
88
Transverse
148 kN/m
86
91
89
88
Puncture resistance
Maximum stress, normalized
Test
values
for 100-mil sheeting,
N
717
725
669
657
672
Retention of stress for
100-mil sheeting, %
100
101
93
92
94
Elongation at puncture,
mm
15.5
19.3
18.0
17.0
18.3
Hardness, Duro D points
Change
in points
5-second reading
63
-8
-8
-9
-7
aLeachate was changed monthly.
^Not measured.
cWeight gain may be due to swell and/or encrustation of sample.
^Measured using 12.7 mm x 203-mm strip specimens with an initial jaw separation
of 10 mm and an initial strain rate of 0.1 mm/mm min. Using a specimen with a
250-mm gage length, recommended as standard in ASTM D882-83, would result in
somewhat higher values.
Unreliable result.
23
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Laboratory tests for assessing the durability of geomembranes under dif- 13
ferent environmental conditions range from chemical analyses to tests of
mechanical properties (e.g., tensile properties, tear resistance, puncture re-
sistance, and impact resistance) under various exposures in aggressive environ-
ments, such as exposure to high and low temperatures, to ozone while under strain,
to ultraviolet light, to stress and strain for extended periods of time, and to
the combined effects of chemicals and stress. Specific tests to assess these
properties are listed in Table 2 for different types of geomembranes.
Important in long-term service of a polymeric geomembrane liner is its ability to
resist the effects of creep and biaxial strain that will occur when it is under
load and rests on a nonplanar or irregular surface, such as exists at the bottom of
a containment facility. Cracks and breaks can occur in a polymeric geomembrane
at significantly lower stress values than are encountered in the simple uniaxial
tensile test.
As with compatibility testing, maximum changes in properties that can take place
without affecting overall performance have not been established. Nevertheless,
laboratory testing of several properties can yield data indicative of durability.
Seamability and Quality of Seams
In constructing a large continuous leakproof liner from prefabricated sheeting,
pieces of sheeting must be seamed. Sheetings of a roll width less than 1.8 m
are seamed together in a factory to form panels which are brought to the field and
seamed. Sheeting of a roll width greater than 6 m is brought to the field in
rolls which are then seamed. In either case, the geomembrane must be seamable and
yield reliable seams that are mechanically sound and can withstand exposure to
waste liquids for extended periods of time. Thermoplastic materials which can melt
or which can be dissolved in a solvent yield seams that can be monolithic and/or
homogeneous, i.e., the interface between the layers has been eliminated. This
contrasts to sheetings which are seamed with adhesives of a composition different
from the parent material. Seams are tested in both peel and shear modes in
accordance with methods given in Table 2. In addition, static tests can be run in
peel and shear by dead-weight loading. All of these tests can be performed at
elevated temperatures, after various aging periods, and after immersion in solvents
or in waste liquids as part of EPA Test Method 9090.
Various measurements and observations can be made to assess the quality of the
seams. In making an assessment, it is important not only to know the force re-
quired to break seams, but also to know the durability of the seam and the manner
in which a test specimen of the seam breaks. The quality of a seam can be assessed
by the following observations:
- Locus of breaka break in the parent material is desirable, such as a
"film tearing bond." Failure at the interface between bonded surfaces
is undesirable as it may be indicative of inadequate retention of
adhesion on long exposure.
- Time to break when tested under tensile load in the static mode.
- Effects of temperature and other exposures on the magnitude or locus
of break.
24
-------
These observations can be used in setting specifications for seam quality. 14
Laboratory tests should be performed on samples of seams cut from liners
installed in the field as part of quality assurance.
Fingerprinting of Geomembranes
Because of the wide range of polymeric geomembranes that may be encountered,
analysis and fingerprinting can be useful. For example, the analysis and finger-
printing of a polymeric geomembrane liner that has been tested for compatibility
with, a giyen waste liquid in accordance with EPA Test Method 9090 can be used at
the time of liner installation for the following purposes:
- As a means of characterizing and identifying the specific sheeting.
- As a baseline for monitoring the effects of exposure on the liner.
- To determine which constituents of the waste liquid were absorbed
during the 9090 test and thus could affect the chemical compatibility
of the waste and liner in service.
Specific analyses that may be used for fingerprinting are suggested by Haxo {6).
Table 2 lists specific test methods for many of these analyses.
TESTING OF GEOTEXTILES
The tests for characterizing geotextiles that have not been exposed to wastes are
fully described by Koerner (14). Also, ASTM Committee D35 is developing specific
test methods which can characterize the properties associated with the respective
functions. Currently used test methods are:
Property
Thickness
Mass/unit area
Percent open area
Permittivity
Equivalent opening size
Puncture
Burst strength
Grab tensile/elongation (wide-width strip)
Ultraviolet resistance
Transmissivity
a2 kPa loading.
^Section 16 (Grab test G) using 100 nm x 200-mm sample, 75-mm gauge length,
25-mm wide x 50-mm long grip, strain rate 305 mm/minute, using a constant
rate of extension tester.
c500 hours.
For assessing geotextiles for use in waste containment applications, exposure to
waste liquid for four months under EPA Test Method 9090 conditions is suggested.
The laboratory performance testing of geotextiles in waste liquids under load poses
a problem due to the size of the test specimens and the handling of large amounts
Test method number
ASTM D1777a
ASTM D3776-84
CW0 22125-86
ASTM D4491
CW0 02215
ASTM D3787 (modified)
ASTM D3786
ASTM D1682b
ASTM D4355c
ASTM D35 Committee Draft,
Designation 03.84.02
25
-------
of waste liquids. In our laboratory we have performed compatibility 15
testing of 75 mm x 150-mm geotextile specimens in accordance with ASTM D751
by the grab method. Wet specimens were tested throughout. The unexposed speci-
mens were first immersed in water and then tested. The exposed specimens were
dewatered with a roller and then wrapped in a thin polyethylene film and tested.
As the elongation properties of the film exceeded that of the fabric, it did not
break; thus, the waste liquid was contained.
Performance testing of geotextile/soil systems to determine filter characteristics
are reported (15, 16). Martin et al, also performed tests on drainage material/
soil systems to study the effects of overburden pressures on transmissivity of
geotextiles (17). Raumann conducted similar tests on geogrids (18). Performance
tests have aTso been conducted on geomembrane/geotextile/soil systems to evaluate
the frictional coefficient at the material interfaces (14).
TESTING OF DRAINAGE NETS
This group of geosynthetics, which includes geogrids, geonets, and a variety of
open constructions, are based primarily on polyethylenes and polypropylenes. As
such, some of their attributes are similar to those of polyethylene geomembranes.
Geonets that are used for drainage in double-liner.-systems must maintain their
drainage capability over extended periods of time. As these materials are poly-
meric, they are subject to creep and compression under loads, which will tend to
reduce their transmissivity. The polymeric geogrid probably will absorb organic
constituents from the waste liquid, which will cause it to soften and lose compres-
sive strength and result in greater creep and further loss of transmissivity. If
the lateral mechanical stability decreases, the three-dimensional structure of the
net could collapse and lose drainage capacity.
A test that would be indicative of the performance of the geogrid as a drainage
medium is to place the geogrid between two stiff liners or plates while in contact
with the waste liquid and under load, during which time the transmissivity is
measured. It would be expected that the geonet would compress and creep with time.
Reduction in transmissivity would be expected, but the magnitude would vary with
the material, temperature, load, and chemical absorption; however, no test of this
type has yet been developed.
A modified test procedure would involve testing samples of geonet for transmis-
sivity after they have been exposed to a waste liquid. A load that corresponds in
magnitude to service conditions would be applied and the transmissivity determined.
This procedure would require that the load be applied for a sufficient length of
time to allow for creep and compression of the tested sample. If water instead of
waste liquid is used to determine transmissi vity, some of the organics in the
geogrid may leach out and cause changes in the properties of the geonet.
An alternate test procedure which we have followed to measure compatibility of
geonets with waste liquids is to irmierse samples of geonets for up to four months
in a manner similar to that used for geomembranes, and measure such properties as
tensile and compression modulus as a function of exposure time. Weight changes,
volatiles, and extractables are also measured. Test results are treated similarly
to those obtained on geomembranes.
26
-------
TESTING OF PLASTIC PIPE
16
A wide variety of test methods for characterizing plastic pipe has been published
by ASTM, the Plastic Pipe Institute, the Gas Research Institute, and the National
Sanitation Foundation. Due to their good chemical resistance, plastic pipes have
found considerable use in the handling of chemicals. However, the resistance can
vary considerably from polymer to polymer. In waste containment facilities, PVC
and HDPE pipes are used predominately. Nevertheless, pipes have collapsed due to
organic solvent absorption and softening of the pipe.
Inasmuch as the leachate collection and leak-detection systems of double liner
systems must function for extended periods of time, it is desirable to assess the
compatibility of the pipe with the waste liquid. This can be done by exposing
sections of pipe in waste liquid under conditions similar to those used in the EPA
9090 test and testing the sections after exposure in accordance with a method
selected from ASTM D2412. The size of the pipe, e.g., 150 mm in diameter, and the
need for replication may require large tanks and a considerable amount of waste
liquid. The relatively large mass of the pipe could absorb considerable portions
of the organic constituents in the liquid, resulting in a reduction of their
concentrations and the need to replace the waste liquid.
In an alternate procedure which we have conducted, the pipe is tested for tensile
properties parallel to the length of the pipe and for compressive modulus of a ring
cut through the cross section. In this procedure, two types of specimens cut from
the pipe are exposed and tested: cross-sectional rings 25 nm in length and longi-
tudinal strips cut radially and machined to the proper thickness. The strips are
tested for weight change, extractables and volatiles, tensile strength, elongation,
and modulus of elasticity before and after immersion as in EPA Test Method 9090.
The rings are tested in compression before and after exposure to the waste liquid
to measure changes in modulus. Also measured are weight and hardness to determine
changes in these properties.
DISCUSSION
As yet, maximum changes in properties which correlate with serviceability limits
have not been established. Inasmuch as the effects of environmental exposures vary
with the polymer, each material would have a separate set of maxima. Expert sys-
tems are being evolved by the U.S. Environmental Protection Agency to aid in asses-
sing compatibility of liners and waste liquids (_19). However, feedback from the
field performance of liners and from testing liners that have been in service is
needed to established correlation between field performance and laboratory testing.
ACKNOWLEDGMENTS
The major portion of the work reported in this paper was performed under Contract
68-03-2173, "Evaluation of Liner Materials Exposed to Hazardous and Toxic Wastes,"
Contract 68-03-2969, "Long-term Testing of Liner Materials," and Contract 68-03-
3213, "Use of Cohesive Energy Determinations for Predicting Membrane/Waste Chemical
Compatibility and Service Life Estimates," with the Hazardous Waste Engineering
Research Laboratory of the U.S. Environmental Protection Agency, Cincinnati, Ohio.
27
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REFERENCES
17
1. Giroud, J. P. 1984. Geotextiles and Geomembranes. Geotextiles and Geomem-
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Environmental Protection Agency. Washington, D.C.
3. Mark, H. F, N. G. Gaylord, and N. M. Bikales. 1965-76. Encyclopedia of
Polymer Science and TechnologyPlastics, Resins, Rubbers, Fibers. Inter-
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28
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Proceedings of the International Conference on Geomembranes, Denver, CO.
Volume I. Industrial Fabrics Association International, St. Paul, Minnesota,
pp. 191-196.
18. Raumann, G. 1982. In-plane Permeability of Compressed Geotextiles. In:
Proceedings of the Second International Conference on Geotextiles, Las Vegas,
NV. Volume I. Industrial Fabrics Association International, St. Paul,
Minnesota, pp. 55-60.
19. Rossman, Lewis A., and H. E. Haxo. 1985. A Rule-Based Inference system for
Liner/Waste Compatibility. In: Proceedings of the 1985 Speciality Conference
of the American Society of Civil Engineers. ASCE, New York. pp. 583-590.
29
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METHOD 9090
COMPATIBILITY TEST FOR WASTES AND MEMBRANE LINERS
1.0 SCOPE AND APPLICATION
1.1 Method 9090 1s Intended for use In determining the effects of
chemicals 1n a surface Impoundment, waste pile, or landfill on the physical
properties of flexible membrane liner (FML) materials intended to contain
them. Data from these tests will assist 1n deciding whether a given Uner
material 1s acceptable for the Intended application.
2.0 SUMMARY OF METHOD
2.1 In order to estimate waste/liner compatibility, the Uner material
is limiersed 1n the chemical environment for minimum periods of 120 days at
room temperature (23 + 2#C) and at 50 + 2#C. In cases where the FML will be
used 1n a chemical environment at elevated temperatures, the Immersion testing
shall be run at the elevated temperatures 1f they are expected to be higher
than 50#C. Whenever possible, the use of longer exposure times 1s
recommended. Cooparlson of measurements of the ฆeinbrane's physical
properties, taken periodically before and after contact with the waste fluid,
1s used to estimate the compatibility of the Uner with the waste over time.
3.0 INTERFERENCES (Not Applicable)
4.0 APPARATUS AND MATERIALS
NOTE: In general, the following definitions will be used 1n this method:
1. Sample a representative piece of the Uner ปater1al proposed for
use that 1s of sufficient size to allow for the removal of
all necessary specimens.
2. Specimen a piece of material, cut from a sample, appropriately
shaped and prepared so that 1t 1s ready to use for a test.
4.1 Exposure tank: Of a size sufficient to contain the samples, with
provisions for supporting the samples so that they do not touch the bottom or
sides of the tank or each other, and for stirring the liquid 1n the tank. The
tank should be compatible with the waste fluid and impermeable to any of the
constituents they are Intended to contain. The tank shall be equipped with a
means for maintaining the solution at room temperature (23 + 2* C) and 50 +
2*C and for preventing evaporation of the solution (e.g., use a cover equipped
with a reflux condenser, or seal the tank with a Teflon gasket and use an
airtight cover). Both sides of the Uner material shall be exposed to the
chemical environment. The pressure Inside the tank must be the same as that
outside the tank. If the Uner has a side that (1) 1s not exposed to the
9090 - 1
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Date September 1986
30
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waste 1n actual use and (2) 1s not designed to withstand exposure to the
chemical environment, then such a Uner may be treated with only the barrier
surface exposed.
4.2 Stress-strain machine suitable for measuring elongation, tensile
strength, tear resistance, puncture resistance, modulus of elasticity, and ply
adhesion.
4.3 JMg for testing puncture resistance for use with FTMS 101C, Method
2065.
4.4 Liner sample labels and holders made of materials known to be
resistant to the specific wastes.
4.5 Oven at 105 + 2#C.
4.6 Dial micrometer.
4.7 Analytical balance.
4.8 Apparatus for determining extractable content of Uner materials.
NOTE: A minimum quantity of representative waste fluid necessary to
conduct this test has not been specified in this method because
the amount will vary depending upon the waste compostlon and the
type of liner material. For example, certain organic waste
constituents, if present in the representative waste fluid, can be
absorbed by the liner material, thereby changing the concentration
of the chemicals 1n the waste. This change 1n waste coa*5os1t1on
may require the waste fluid to be replaced at least monthly in
order to maintain representative conditions 1n the waste fluid.
The amount of waste fluid necessary to maintain representative
waste conditions will depend on factors such as the volume of
constituents absorbed by the specific liner material and the
concentration of the chemical constituents in the waste.
5.0 REAGENTS (Not Applicable)
6.0 SAMPLE COLLECTION, PRESERVATION, AND HANDLING
6.1 For Information on what constitutes a representative sample of the
waste fluid, refer to the following guidance document:
Permit Applicants' Guidance Manual for Hazardous Waste Land Treatment,
Storage, and Disposal Facilities; Final Draft; Chap. 5, pp. 15-17;
Chap. 6, pp. 18-21; and Chap. 8, pp. 13-16, May 1984.
9090 - 2
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Date September 1986
31
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7.0 PROCEDURE
7.1 Obtain a representative sample of the waste fluid. If a waste
sample 1s received 1n more than one container, blend thoroughly. Note any
signs of stratification. If stratification exists, 11ner saaples must be
placed 1n each of the phases. In cases where the waste fluid 1s expected to
stratify and the phases cannot be separated, the number of inaersed samples
per exposure period can be Increased (e.g., 1f the waste fluid has two phases,
then 2 samples per exposure period are needed) so that test samples exposed at
each level of the waste can be tested. If the waste to be contained In the
land disposal unit Is In solid form, generate a synthetic leachate (See Step
7.9.1).
7.2 Perform the following tests on unexposed samples of the polymeric
membrane Uner material at 23 + 2*C and 50 ~ 2'C (see Steps 7.9.2 and 7.9.3
below for additional tests suggested for specific circumstances). Tests for
tear resistance and tensile properties are to be performed according to the
protocols referenced 1n Table 1. See Figure 1 for cutting patterns for
nonrelnforced liners. Figure 2 for cutting patterns for reinforced liners, and
Figure 3 for cutting patterns for semi crystal line liners. (Table 2, at the end
of this method, gives characteristics of various polymeric Uner materials.)
1. Tear resistance, aachlne and transverse directions, three specimens
each direction for nonrelnforced liner materials only. See Table 1
for appropriate test method, the recommended test speed, and the
values to be reported.
2. Puncture resistance, two specimens, FTMS 101C, Method 2065. See
Figure 1, 2, or 3, as applicable, for sample cutting patterns.
3. Tensile properties, machine and transverse directions, three tensile
specimens in each direction. See Table 1 for appropriate test
method, the recommended test speed, and the values to be reported.
See Figure 4 for tensile dumbbell cutting pattern dimensions for
nonrelnforced Uner samples.
4. Hardness, three specimens, Duro A (Duro 0 1f Duro A reading 1s
greater than 80), ASTM 02240, The hardness specimen thickness for
Duro A 1s 1/4 1n., and for Duro D 1t 1s 1/8 in. The specimen
dimensions are 1 1n. by 1 1n.
5. Elongation at break. This test 1s to be performed only on membrane
materials that do not have a fabric or other nonelastooeric support
as part of the Uner.
6. Modulus of elasticity, machine and transverse directions, two
specimens each direction for semi crystalline Uner materials only,
ASTM D882 modified Method A (see Table 1).
7. Volatlles content, SW 870, Appendix III-D.
8. Extractables content, SW 870, Appendix III-E.
9090 - 3
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Date September 1986
32
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Tabic I. Physiol lasting of avowdRabriniS In ltner-ซeste llciild eoapatlblllty test
T>pe of cxapouod and
construction
Croisl lr*ed or vulcanized
Thermoplastic
McryiUlltn
ftbr lc-faWซrcrf
Tensile properties aethod
Type of speclaen
Matter of spec 1am
Speed of test
Values to be reported
ttxlilus of elasticity attind
Tjpe of jpeclwn
Hinfcer of speclaans
Speed of tast
Values reported
Tear resistance Method
Tjpe of yeclaen
fUfcer of speclaens
Speed of tast
Values reported
Puncture resistance aethod
Typo of speclam
Meter of 3>eclaens
Speed of test
Values r^orted
ASTHD412
ftefcbellb
3 In each direction
20 Ipa
Tensile strength, psl
Elongation at break, t
Tensile set after break, t
Stress at 100 and 2001
elongation, psl
ASM 0624
01a C
3 In each direction
20 Ipa
Stress, ppl
F1H5 I0IC. Method 2065
2 In. square
2
20 Ipa
Cage, all.
Stress, 1b
Elongation. 1n.
AS IX 0638
CUifcbellb
3 In each direction
20 Ipa
Tensile strength, psl
Elongation at break, t
Tensile set after break, X
Stress at 100 and 20(11
elongation, psl
ASTM 1004
3 In each direction
20 Ipa
Stress, ppl
FTM5 101C. Method ?06S
2 In. scparw
2
20 Ipa
toge, all
Stress. lb
flongatlon, In.
ASTM 0638
0urt)bel1b
3 In each direct"-n
2 Ipa
Tensile strength at yield, psl
Elonoatlon at yield, 1
Tensile set at break, psl
Elongation at break, psl
Tensile set after break, t
Stress at 100 and 20TT&
elongation, psl
ASTM 0682, Method A
Strip: 0.5 In. wtdป and 6. In long
at a 2 In. Jar separation
2 In each direction
0.2 Ipa
Greatest slope of Initial strest -
strain curve, psl
ASTM 01004
2 In each direction
2 Ipa
MmImub stress, ppl
rms 10IC. Method 2065
2 In. sqiare
2
20 Ipa
Cage, all
Stress. 1ฎ
Elonrntlon, In.
ASTM 0751. tethod B
1-ln. Midi strip and 2-ln. J a*
separation
3 In each direction
12 ipa
Tensile at fArlc break. n>l
Elongation at fabric tx , 1
Temlle at ulttaate break, ppt
Elonoatlon at eltlaate bซ . p
Tensile set after break. 1
Stress at 100 and ?nm
elongation. psl
nป6 101C. Method V*A
2 In. stpare
2
20 Ipe
Cage. ซ1ปK
Stress. Iฎ
Elongation. In.
ฎCan be theraplastlc, crossl Inked, or vulcanized aentirane.
"See Fl^re 4.
9tot performed on this aaterlal.
tear resistance test Is i emiwmtlnd for f/torlc-rolnfortftri sheetings In I he Imrrslon slurfy.
"Sam as ASTM 0ซ4. Ole C.
-------
IrnvwrM direction
Mot to Kale
Figure 1 . Suggested pattern for cutting test specimens from
nonreinforced cross linked or thermoplastic Innersed
liner samples.
9090 - 5
Revision o
Date September 1986
34
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10*
Hoc to scale
Figure 2 . Suggested pattern for cutting test specimens from
fabric reinforced inmersed ;iner samples. Note: To
void edge effects, cut specimens 1/8 - 1/4 Inch in
from edge of imnersed sample.
9090 - 6
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Date September 1986
35
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Hoc to scale
Figure 3 . Suggested pattern for cutting test specimens from
semi crystal line lumersed Hner samples. Note: To
void edge effects, cut specimens 1/8 - 1/4 Inch
1n from edge of lavnersed sample.
9090 - 7
Revision
Date September 1986
36
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wo
w
ฆ L-
- D-
LO-
w
Width of narrow section
L
Length of narrow section
WO
Width overall
LO
Length overall
G
Gage length
D
Distance betwerr. 5r.ps
0.25 inches
1.25 inches
0.625 inches
3.SO inches
1.00 inches
2.00 incnes
Figure 4. Die for tensile dumbbell (nonreinforced liners) having the following
dimensions.
9090 - 8
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September 1986
37
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9. Specific gravity, three specimens, ASTM D792 Method A.
10. Ply adhesion, machine and transverse directions, two specimens each
direction for fabric reinforced Hner materials only, ASTM D413
Machine Method, Type A 180 degree peel.
11. Hydrostatic resistance test, ASTM D751 Method A, Procedure 1.
7.3 For each test condition, cut five pieces of the tlnlng material of a
size to fit the sample holder, or at least 8 1n. by 10 1n. The fifth sample
Is an extra sample. Inspect all samples for flaws and discard unsatisfactory
ones. Liner materials with fabric reinforcement require close Inspection to
nsure that threads of the samples are evenly spaced and straight at 90*.
Samples containing a fiber scrim support may be flood-coated along the exposed
edges with a solution recommended by the liner manufacturer, or another
procedure should be used to prevent the scrim from being directly exposed.
The flood-coating solution will typically contain 5-151 solids dissolved 1n a
solvent. The solids content can be the liner formula or the base polymer.
Measure the following:
1. Gauge thickness, In. average of the four comers.
2. Mass, lb. to one-hundredth of a lb.
3. Length, In. average of the lengths of the two sides plus the
length aeasured through the Hner center.
4. Width, 1n. average of the widths of the two ends plus the width
measured through the liner center.
NOTE: Do not cut these liner samples Into the test specimen shapes shown
1n Figure 1, 2, or 3 at this time. Test specimens will be cut as
specified 1n 7.7, after exposure to the waste fluid.
7.4 Label the Hner samples (e.g., notch or use metal staples to
Identify the sample) and hang 1n the waste fluid by a wire hanger or a weight.
Different Hner materials should be Immersed 1n separate tanks to avoid
exchange of plastlclzers and soluble constituents when plastlcized membranes
are being tested. Expose the liner samples to the stirred waste fluid held at
room temperature and at 50 + 2*C.
7.5 At the end of 30, 60, 90, and 120 days of exposure, remove one Hner
sample from each test condition to determine the membrane's physical
properties (see Steps 7.6 and 7.7). Allow the Hner sample to cool 1n the
waste fluid until the waste fluid has a stable room temperature. Wipe off as
much waste as possible and rinse briefly with water. Place wet sample 1n a
labeled polyethylene bag or aluminum' foil to prevent the sample from drying
out. The liner sample should be tested as soon as possible after removal from
the waste fluid at room temperature, but 1n no case later than 24 hr after
removal.
9090 - 9
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Date September 1986
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7.6 To test the Immersed sample, wipe off any remaining waste and rinse
with delonlzed water. Blot sample dry and measure the following as 1n Step
7.3:
1. Gauge thickness, 1n.
2. Mass, lb.
3. Length, 1n.
4. Width, 1n.
7.7 Perform the following tests on the exposed samples (see Steps 7.9.2
and 7.9.3 below for additional tests suggested for specific circumstances).
Tests for tear resistance and tensile properties are to be performed according
to the protocols referenced 1n Table 1. D1e-cut test specimens following
suggested cutting patterns. See Figure 1 for cutting patterns for
nonrelnforced liners, Figure 2 for cutting patterns for reinforced liners, and
Figure 3 for semi crystal line liners.
1. Tear resistance, machine and transverse directions, three specimens
each direction for materials without fabric reinforcement. See Table 1 for
appropriate test method, the reconmended test specimen and speed of test, and
the values to be reported.
2. Puncture resistance, two specimens, FTMS 101C, Method 2065. See
Figure 1, 2, or 3, as applicable, for sample cutting patterns.
3. Tensile properties, machine and transverse directions, three
specimens each direction. See Table 1 for appropriate test method, the
recommended test specimen and speed of test, and the values to be reported.
See Figure 4 for tensile dumbbell cutting pattern dimensions for nonrelnforced
Uner samples.
4. Hardness, three specimens, Duro A (Duro D 1f Duro A reading 1s
greater than 80), ASTM 2240. The hardness specimen thickness for Duro A 1s
1/4 1n., and for Duro D 1s 1/8 1n. The specimen dimensions are 1 1n. by 1 1n.
5. Elongation at break. This test 1s to be performed only on membrane
materials that do not have a fabric or other nonelastomerlc support as part of
the Uner.
6. Modulus of elasticity, machine and transverse directions, two
specimens each direction for semi crystal line Uner materials only, ASTM D882
modified Method A (see Table 1).
7. Volatlles content, SV 870, Appendix III-D.
8. Extractables content, SW 870, Appendix III-E.
9090 - 10
Revision 0
Date September 1986
39
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9. Ply adhesion, aachlne and transverse directions, two specimens each
direction for fabric reinforced Uner materials only, ASTM D413 Machine
Method, Type A -- 180 degree peel.
10. Hydrostatic resistance test, ASTM 0751 Method A, Procedure 1.
7.8 Results and reporting:
7.8.1 Plot the curve for each property over the time period 0 to
120 days and display the spread In data points.
7.8.2 Report all raw, tabulated, and plotted data. Recommended
methods for collecting and presenting Information are described 1n the
documents listed under Step 6.1 and 1n related agency guidance manuals.
7.8.3 Summarize the raw test results as follows:
1. Percent change 1n thickness.
2. Percent change In mass.
3. Percent change 1n area (provide length and width dimensions).
4. Percent retention of physical properties.
5. Change, in points, of hardness reading.
6. The modulus of elasticity calculated 1n pounds-force per
square Inch.
7. Percent volatlles of unexposed and exposed liner material.
8. Percent extractables of unexposed and exposed Uner material.
9. The adhesion value, determined 1n accordance with ASTM 0413,
Section 12.2.
10. The pressure and time elapsed at the first appearance of
water through the flexible membrane Uner for the hydrostatic
resistance test.
7.9 The following additional procedures are suggested 1n specific
situations:
7.9.1 For the generation of a synthetic leachate, the Agency
suggests the use of the Toxicity Characteristic Leaching Procedure (TCLP)
that was proposed 1n the Federal Register on June 13, 1986, Vol. 51, No.
114, p. 21685.
7.9.2 For semi crystalline membrane liners, the Agency suggests the
determination of the potential for environmental stress cracking. The
9090 - 11
Revision 0
Date September 1986
40
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test that can be used to make this determination Is either ASTH D1693 or
the National Bureau of Standards Constant Tensile Load. The evaluation
of the results should be provided by an expert 1n this field.
7.9.3 For field seams, the Agency suggests the determination of
seam strength 1n shear and peel modes. To determine seam strength 1n
peel mode, the test ASTM D413 can be used. To determine seam strength 1n
shear mode for nonrelnforced FMLs, the test ASTM D3083 can be used, and
for reinforced FMLs, the test ASTM D751, Grab Method, can be used at a
speed of 12 1n. per m1n. The evaluation of the results should be
provided by an expert 1n this field.
n.O QUALITY CONTROL
8.1 Determine the mechanical properties of identical nonlmmersed and
Immersed liner samples In accordance with the standard methods for the
specific physical property test. Conduct mechanical property tests on
nonlmmersed and Immersed Uner samples prepared from the same sample or lot of
material 1n the same manner and run under Identical conditions. Test liner
samples Immediately after they are removed from the room temperature test
solution.
9.0 METHOD PERFORMANCE
9.1 No data provided.
10.0 REFERENCES
10.1 None required.
9090 - 12
Revision
Date September 1986
41
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TABLE 2. POLYMERS USED IN FLEXIBLE MEMBRANE LINERS
Thermoplastic Materials (TP)
CPE (Chlorinated polyethylene)3
A family of polymers produced by a chemical reaction of chlorine on
polyethylene. The resulting thermoplastic elastomers contain 25 to 451
chlorine by weight and 0 to 25X crystal Unity.
CSPE (Chlorosulfonated polyethylene)2
A family of polymers that are produced by the reaction of polyethylene
with chlorine and sulfur dioxide, usually containing 25 to 43S chlorine
and 1.0 to 1.4X sulfur. Chlorosulfonated polyethylene 1s also known as
hypalon.
EIA (Ethylene Interpolymer -alloy)3
A blend of EVA and polyvinyl chloride resulting 1n a thermoplastic
elastomer.
PVC (Polyvinyl chloride)3
A synthetic thermoplastic polymer made by polymerizing vinyl chloride
monomer or vinyl chloride/vinyl acetate monomers. Normally rigidf and
containing 50X of plastlclzers.
PVC-CPE (Polyvinyl chloride - chlorinated polyethylene alloy)3
A blend of polyvinyl chloride and chlorinated polyethylene.
TN-PVC (Thermoplastic n1tr1le-polyvinyl cholorlde)3
An alloy of thermoplastic unvulcanlzed nltrlle rubber and polyvinyl
chloride.
Vulcanized Materials (XL)
Butyl rubber3
A synthetic rubber based on Isobutylene and a small amount of Isoprene to
provide sites for vulcanization.
3Also supplied reinforced with fabric.
9090 - 13
Revision
Date Septeinber 1986
42
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TABLE 2. (Continued)
EPDM (Ethylene propylene dlene monomer)4ป&
A synthetic elastomer based on ethylene, propylene, and a small amount of
nonconjugated dlene to provide sites for vulcanization.
CM (Cross-1 Inked chlorinated polyethylene)
No definition available by EPA.
CO, ECO (Ep1cHlorohydr1n polymers)4
Synthetic rubber, Including two eplchlorohydrln-based elastomers that are
saturated, h1gh-molecular-we1ght aliphatic polyethers with chloromethyl
side chains. The two types Include hoaopolymer (CO) and a copolymer of
eplchlorohydrln and ethylene oxide (ECO).
CR (Polychloroprene)3
Generic name for a synthetic rubber based primarily on chlorobutadlene.
Polychloroprene 1s also known as neoprene.
Semicrystalline Materials (CX)
HOPE - (H1gh-dens1ty polyethylene)
A polymer prepared by the low-pressure polymerization of ethylene as
the principal monomer.
HDPE - A (H1gh-dens1ty polyethylene/rubber alloy)
A blend of h1gh-dens1ty polyethylene and rubber.
LLDPE (Liner low-density polyethylene)
A low-density polyethylene produced by the copolymerlzatlon of ethylene
with various alpha olefins 1n the presence of suitable catalysts.
PEL (Polyester elastomer)
A segmented thermoplastic copolyester elastomer containing recurring
long-chain ester units derived from dlcarboxyllc acids and long-chain
glycols and short-chain ester units derived from dlcarboxyllc acids and
Iow-mo1ecular-we1ght dlols.
aAlso supplied reinforced with fabric.
^Also supplied as a thermoplastic.
9090 - 14
Revision
Date September 1986
43
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TABLE 2. (Continued)
PE-EP-A (Polyethylene ethylene/propylene alloy)
A blend of polyethylene and ethylene and propylene polymer resulting 1n a
thermoplastic elastomer.
T-EPOH (Thermoplastic EPDM)
An ethylene-propylene dlene monomer blend resulting 1n a thermoplastic
elastomer.
9090 - 15
Revision 0
Date September 1986
44
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mctnoo aoso
compatibility test ron >ซiTit uc ปซปซiuNe lzncm
( " )
7.1
OBtaln (aaปlซ
of ซaata fluid
7.2
Par (am
taata on
inexpoaed
ฆaploa or
aterial
81
liner
7.3
Cut
ilecoa of
arterial
lach taat
mdltlon
llnlni
for
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7.4
Laeal
teat epaciaana
and eapoae
to oaata fluid
6
O
7.3
Oataraina
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proportlaa at
30 day
lrittrvซU
7.6
To test
axpoaca
OIClMfll.
aaaagra gauge
tntckuif.
langtri. xtdth
7.7
Parfor* taata
on aaooaad
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7.6
Raoort ana
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^ ttop ^
9090 - 16
45
Revision o
0ate September 1986
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8480 V 00=1 3
-------
-2-
'9'480*00-l 3
Long-term immersion test results from low level exposure to
chemicals of concern showed measurable deterioration of HDPE
properties. Therefore, low concentrations of chemicals of
concern must be tested for liner compatibility if they will be
present in the waste.
EPA has been asked by the Institute of Chemical Waste
Management (ICWM) to consider approving HDPE liners as being
chemically resistant to certain classes of wastes without
chemical resistance testing. EPA is investigating this
possibility by reviewing the available data and by discussing
this issue with technical experts in the polymer chemistry
field. At this time we have not completed our review of the
technical issues or received enough data to grant blanket
approvals for HDPE. In addition, preliminary conclusio-ns
from an EPA meeting with polymer chemistry experts indicate
that in the case of a typical land disposal unit, they do not
have the-ability at this time to establish classes of chemicals
that specific flexible membrane liner materials are universally
chemically resistant to, primarily because of the complexity
of the wastes, liner stresses posed by the typical land disposal
environment (e.g., temperature ranges and differential loading),
and variations in liner properties [See also response to next
question].
Therefore, in general, EPA is unable at this time to approve
HDPE (or any other liner material) for use at any hazardous waste
unit without unit-specific verification of chemical resistance
based on the specific liner material and waste for that unit.
(Method 9090 or equivalent).
Does the generic term HDPE imply that all HDPE's are alike?
No. Polyethylene plastics, as defined by ASTM D 1248
(Polyethylene Plastics Molding and Extrusion Materials), are
plastics or resins prepared by the polymerization of no less
than 85% ethylene and no less than 95% of total olefins, by
weight. Within this category HDPE is defined as having a density
of greater than 0.940g/cmJ. This higher density is an indication
of increased crystallinity that, with all other things being
equal, produces a material that is harder, stiffer, more chemical
and heat resistant, and stronger than less crystalline material.
As density increases, the properties of elongation, resistance
to environmental stress cracking, impact strength and permeability
decrease. In addition, comonomers are added during resin manufacture
that affect the degree of crystallinity and other material properties
(depending on the processing technique and the type and amount
of comonomer). Process type and process additives, such as
carbon black, thermal/ultraviolet stabilizers and antiblocks,
will also affect material properties.
47
-------
uoviLn ruuoi n.^iivL i,u. ~
94801. 00- 1 3 :
When the sheet extruder gets the resin he will, in turn,
extrude the material into a sheet using his own proprietary
additives. The physical and chemical properties of the finished
product will again be affected by the additives and type of
extrusion process. (Even the handling of the material immediately
after extrusion can affect material properties.)
As can be seen from the above description, individual
HDPE liner properties can vary, depending on chemical com-
position and a number of processing factors.
EPA also notes that the ASTM designation for HDPE is not
as meaningful as when originally proposed. Advances in resin
manufacturing (such as the addition of new comonomers) have
blurred the characteristic distinction between high density
and medium density and even low density polyethylenes.'
Materials are being marketed that are technically medium
density polyethylenes, but are labelled high density poly-
ethylene, and, in fact, may exhibit some of the physical
characteristics of high density polyethylene. Therefore,
the density of the polyethylene is not necessarily as key to
overall chemical performance as it once was. Since the
designation HDPE is no longer as relevant as when first
published by ASTM, EPA prefers to designate the various
polyethylenes as 11 polyethylene" and distinquish one from
another by their other properties, including resistance to
environmental stress cracking, chemical resistance, yield
strength, impact strength, seamability, etc. Density is but
one of the factors affecting overall field performance.
For these reasons EPA is continuing to insist that
owners and operators verify liner/leachate compatibility on
the specific waste and liner material that will be used in
each disposal unit. Verifying the compatibility of waste/
leachate with a particular polyethylene does not guarantee
in itself compatibility with other polyethylenes.
Therefore, permit writers should require owners and
operators to demonstrate the chemical resistance (immersion
testing) of the specific liner material(s) they expect to
use in the actual construction. When the owner or operator
has already performed the immersion test, and proposes to
install a different manufacturer's polyethylene or a different
"batch" or formulation of polyethylene, he must demonstrate
that the alternate polyethylene is compatible by either
running Method 9090 (or equivalent) on the material selected
for installation or demonstrate material equivalence through
a "fingerprinting" process (see attachment).
48
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-4-
9480'.'00ฃ-l 3
The attached guidance for "fingerprinting" is very general.
If the owner or operator selects this option, agreeing on the
nature of the testing program and interpreting test results
will present difficulties. The effect of a change in any given
"fingerprinting" characteristic (e.g., percent ash) is poorly
understood.
What other liner and leachate collection system components
are required by current regulations to be compatible with
wastes?
Landfill design and operating requirements state that the
leachate collection and removal system, as well as the liner,
must be constructed of materials that are chemically resistant
to the waste managed at the landfill and the leachate 'expected
to be generated (ง264.301(a)(2)). Landfill, waste pile, and
surface impoundment design and operating requirements also
state that liners and leachate collection systems must protect
human health and the environment. It is, therefore, incumbent
upon owners and operators to assure EPA that each component of
the liner(s) and leachate collection system(s) is compatible
with the leachate or waste to which it is subjected. Suggested
general procedures for various components are as follows;
1. Piping - Piping should be prepared for strength
testing per ASTM D 2412 or equivalent. At least
one prepared sample should be subjected to the
same immersion test as performed on the liner
material (e.g., the immersion test outlined in
Method 9090). After the immersion test, the pipe
sample should be dried (per Method 9090) and
subjected to a strength test (see especially ASTM
D 2412 paragraphs 6-9). Testing of a control
specimen (a sample not subjected to the immersion
test) should be performed. A report should be
prepared similar to that outlined in ASTM D 2412
paragraph 11 (including 11.1.7 and 11.1.9) comparing
the test results of the immersed and control
samples.
2. Geotextiles - Geotextiles can be used to perform
any of three major functions in the land disposal
unit: 1) protection of the flexible membrane
liner, 2) use as filtering media, or 3) use in
the transmission of liquid (water or leachate).
Testing procedures for a given geotextile depend
on its function. When the geotextile is used
either as a filter or as a protective media for
the flexible membrane liner, immersion testing
like that for flexible membrane liners should be
performed. After drying the immersed specimen(s),
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948 0.00-1 $
both the immersed speciraen(s) and identical control
specimen(s) should be subjected to the ASTM D
1682 Grab Strength Test and the ASTM D 751 Puncture
Strength Test to determine if a significant loss
of strength has occurred.
Synthetic fabrics used for drainage, such
as nets, should also be immersed in the expected
waste/leachate. Following immersion, both a
control specimen and the immersed specimen should
be tested for in plane transmissivity. At this
time no ASTM method exists to evaluate in-plane
transmissivity; however, the Federal Highway
Administration's Geotextile Engineering Manual
references a technique by Koerner and Bove.1 "
This method (or another method to determine
in-plane transmissivity) can-be used -to compare the
in-plane transmissivity of the immersed specimen to a
control specimen.
Two specific recommendations need to be made
to implement the test.
(1) The final pressure exerted on the geotextile
should be at least 1.5 times the maximum expected
pressure to be experienced during the active
life and post-closure period of the unit.
(2) The geotextile should be placed in the
apparatus under expected field conditions;
i.e., both sides Of the geotextile should be
placed against the materials experienced in
the field (e.g., soil, sand/gravel, flexible
membrane liner, or other geotextile).
3. Earthen Materials - When rock or gravel are used in
the leachate collection system, the owner or operator
should verify that the mineral content of the rock is
compatible with the waste/leachate mixture. The
owner or operator will need to demonstrate that the
rock will not be dissolved or form a precipitant that
would clog the leachate collection system.
1. Koerner, R.M. and Bove, J.A., "In-Plane Hydraulic
Properties of Geotextiles ," Geotextile Testing Journal,
GTJODJ, Vol. 6, No. 4, Dec. 1983, pp. 190-195.
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Uantn. ruuui ujncuiift IW.
9480.00-1 3
For soil used as a liner or a component of a liner,
the material should be subjected to EPA Method 9100,
using the expected leachate to determine its effect
on the hydraulic conductivity of the compacted low
permeability soil. The owner or operator may use the
fixed-wall or triaxial test. (Note: Method 9100 is
currently under revision.)
Should environmental stress cracking be considered
as a modification to Method 9090?
Although environmental stress cracking (ESC)
is not currently included in Method 9090, recently
reviewed data and discussions with technical
experts, including polymer manufacturers, havie
reemphasized the need to require an ESC test for
crystalline and semicrystalline polymeric membrane
liners. "We are currently making revisions to Method
9090 that will outline available that ESC testing
be methods.
Until specific test procedures for ESC can be
developed that represent land disposal facility
conditions, we suggest that permit writers discuss
the need for ESC data on these materials and suggest
that the owner or operator conduct ESC testing.
The type of test and initial interpretation of
the data would be the responsibility of the
applicant.
Should the leachate be changed during the immersion
test?
Some of the constituents of greatest concern
in the chemical resistance immersion test are those
that are volatile or that enter into the material
being tested. The owner or operator must assure that
the chemical composition of the leachate remains
relatively constant during the test to provide a
representative atmosphere for samples being immersed.
The owner or operator must attempt to seal the
immersion vessel as tightly as possible to prevent
loss of volatiles. In addition, the concentration
of chemicals in the leachate that are suspected to
affect the samples (such as aliphatic and halogenated
hydrocarbons) must be determined prior to immersion
testing, and should be checked when samples are
removed at the first 30-day testing period (for
Method 9090). If the composition of the leachate
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9480v00ซl 3
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has changed significantly, the owner or operator
should change the leachate in the immersion vessels
and continue to change the leachate on a frequent
basis (frequency to be negotiated with the permit
writer) to assure that the liner samples are experi-
encing exposure conditions similar to those in
the field.
Attachment
cc: RCRA Branch Chiefs, Regions I-X
RCRA Permits Section Chiefs, Regions I-X
Paul Ingrisano, Region II
Frank Langone, Region II
Greg Uetrecht, Region VI
Harvey King, State of New York, DEC
Bob Tonetti
Ken Shuster
Terry Grogan
Les Otte *
Robert Landreth^r
Chris Rhyne
Peter Guerrero
Ana Aviles
Agnes Ortiz
Dave Friedman
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ANALYSIS AND FINGERPRINTING OF UNEXPOSED AND EXPOSED
POLYMERIC MEMBRANE LINERS
Henry E. Haxo, Jr.
Matrecon, Inc.
Oakland, California 94623
ABSTRACT
A plan is presented for analyzing polymeric mer.ibrane liners for waste storage and
disposal impoundments before and after laboratory or ^i lot-scale exposure and field ser-
vice. These analyses can be used to fingerprint a material and to follow the changes
that take place in a polymeric membrane liner during exposure to'waste. They can also be
used to determine components of a waste liquid that are absorbed and are aggressive to
polymeric liners.
This analysis plan includes determination of.volati1es, extractables, specific
gravity, ash and crystallinity of polymeric liners. The plan also includes gas chroma-
tography and infrared analysis of the extractables (and possibly of the organic volatlles)
and thermogravimetric analysis of the liner. Also suggested is the use of pyrolysls gas
chromatography, which can be performed directly on unexposed and exposed liner materials.
Typical analytical results for unexposed and exposed liners are presented.
INTRODUCTION
Because of the wide range of composi-
tions and constructions of flexible poly-
meric membrane liners that are currently
available and being developed for lining
waste impoundments, analysis and finger-
printing of the membranes 1s needed for a
number of purposes. For example, a liner
manufacturer needs to test his sheeting as
new polymers are used and as new compounds
and constructions are developed. He also
needs tests to control the composition of
the liner being manufactured.
The analysis of a polymeric membrane
liner at the time of placement can be used
for three purposes: first, as a means of
characterizing and identifying the specific
sheeting; second, as a baseline for moni-
toring the effects of exposure on the liner;
and third, to assess the aggresive ingredi-
ents in the waste liquid to determine
chemical compatibility.
During exposure to waste liquids,
polymeric liners may change in composi-
tion in various ways that may affect their
performance and result 1n actual failures.
Polymeric materials may absorb water,
organic solvents and chemicals, organo-
metallic materials, and possibly some inor-
ganics 1f the liners become highly swollen.
On the other hand, the extractable materials
in the original liner compound may be
leacneu out and result 1n stiffening and
even brlttleness on the part of the liner
membrane. The solid constituents of a
polymeric compound (which Include carbon
black, inorganic fillers, and some of the
curing agents) will be retained in the Uner
compound, as will the polymer of which the
liner 1s made (particularly 1f the polymer
is crossllnked). If organic materials are
similar to the Uner 1n solubility and
hydrogen bonding characteristics, the liner
may swell excessively. Some thermoplastic
53
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lining materials may even dissolve, when in
contact with some solvents.
The objective of this paper is to
present an analytical methodology that can
be used to fingerprint and identify liner
materials and to give a baseline for
assessing the changes in composition of
these materials when they are under test or
in service. Also presented are the analy-
tical procedures for testing exposed liner-
materials to determine these changes. Data
on representative liner materials, before
and after waste exposure, are presented.
POLYMERS USED IN MEMBRANE LINER MANUFACTURE
Polymers used in the manufacture of
lining materials include rubbers and
plastics differing in polarity, chemical
resistance, basic composition, etc.,
and can be classified into four types:
- Rubbers (elastomers)
erally crosslinked
that are gen-
(vulcanized),
- Plastics that are generally unvul-
canized (such as PVC),
- Plastics that have a relatively
high crystalline content (sucn as
the polyolefins), and
- Thermoplastic elastomers that do not
need to be vulcanized.
Table 1 lists the various types of
polymers that are used and indicates whether
they are used in vulcanized or nonvulcanized
form and whether they are reinforced with
fabric. The polymeric materials most fre-
quently used in liners are polyvinyl chlo-
riae (PVC), chlorosulfonated polyethylene
(CSPE), chlorinated polyethylene (CPE),
butyl rubber (11R), '.ethylene propylene
rubber (EPDM), neoprene (CRT, and high-den-
sity polyethylene (HOPE). The thickness of
polymeric membranes for liners ranges from
20 to 120 mils, witn most in the 20 to 60-
mi1 range.
TABLE 1.POLYMERIC MATERIALS USED IN LINERS
Polymer
Use in liners
Thermo-
plastic Vulcanized
Fabric
reinforcement
With
W/0
Butyl rubber
No
Yes
Yes
Yes
Chlorinated polyethylene
Yes
Yes
Yes
Yes
Chlorosulfonated polyethylene
Yes
Yes
Yes
Yes
Elasticized polyolefin
(partially crystalline)
Yes
No
No
Yes
Elasticized polyvinyl chloride
Yes
No
Yes
No
Epichlorohydrin rubber
Yes
Yes
Yes
Yes
Ethylene propylene rubber
Yes
Yes
Yes
Yes
Neoprene (chloroprene rubber)
No
- Yes
Yes
Yes
Nitrile rubber
Yes
...
Yes
...
Polyethylene (partially crystal-
line)
Yes
No
No
Yes
Polyvinyl chloride
Yes
No
Yes
Yes
158
54
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Most polymeric lining materials are
based on single polymers, but blends of two
or more polymers (e.g., plastic-rubber
alloys) are being developed and used in
liners. Consequently, it is difficult to
make generic classifications based on
individual polymers in the liners, even
though one polymer may predominate. Blend-
ing of polymers introduces the long-range
possibility of the need for performance
specifications, but long-term liner per-
formance in the field cannot presently be
completely defined by current laboratory
tests.
The basic compositions of the different
types of compounds are shown in Table 2.
The crosslinked rubber compositions are
usually the most complex because they con-
tain a crosslinking system that requires
more ingredients (e.g., tne sulfur system).
Thermoplastics, except for CSPE compounds,
contain no curatives. Although supplied as.
thermoplastic membranes, CSPE liners con-
tain inorganic crosslinxing chemicals that
allow the compound to crosslink slowly over
time during service. Crystalline materials
have the simplest composition and generally
consist of polymer, a small amount of carbon
black for ultra-violet protection, and
antidegradants.
Of the various-liner components (except
for the polymer), the following are poten-
tial extractables:
--Small amounts in the original polymer
(i.e., stabilizers and antidegrad-
ants)
- Oils and plasticizers
- Antidegradants added to the compound.
- Organic constituents of the sulfur
crosslinking system (e.g., vulcaniza-
. tion accelerators and activators).
These ingredients are extracted in the de-
termination of extractables.
Most of the polymei c membrane liners
currently manufactured are based on unvul-
canized or uncross 1 inked compounds and thus
are thermoplastic. Even *if the polymer in
the vulcanized form is more chemically
resistant (such as CPE and CSPE), it is
generally supplied unvulcanized because it
is -easier to obtain reliable seams and to
make repairs in the field. Thermoplastic
polymers can be heat-sealed or seamed with
a solvent or bodied solvent (a solvent con-
taining dissolved polymer to Increase the
viscosity and reduce the rate of evapora-
tion). Crystalline sheetings, which are
also thermoplastic, are seamed by thermal
welding or fusion methods. Information on
individual polymers and liners is presented
in the EPA Technical Resource Document on
liners (Matrecon, 1982).
TABLE 2.BASIC COMPOSITIONS OF POLYMERIC MEMBRANE LINER COMPOUNDS
Type of polymeric compound
Component
Crosslinked
Thermoplastic
Crystal 1i ne
Polymer or blends (alloys)
100
100
100
Oi 1 or plasticizer
5-40
5-40
0-10
Fillers:
Carbon black
Inorganics
5-40
5-40
5-40
5-40
2-5
Antidegradants
1-2
1-2
1
Crosslinking system:
Inorganic system
Sulfur system
5-9
5-9
(*)
~An inorganic curing system that crosslinks over time is incorporated
in CSPE liner compounds.
159
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ANALYSIS AND FINGERPRINTING OF UNEXPOSED
POLYMERIC LINING MATERIALS
Analyses of liners run before and after
exposure to different environments include:
- Volatiles
- Ash
- Extractables
- Gas chromatography
- Thermogravimetric analysis
- Differential scanning calorimetry
1f Hner material is crystalline
- Specific gravity
The following subsections describe the
tests performed on unexposed polymeric
linings.
Volatiles
The volatile fraction is represented by
the weight lost by an unexposed specimen of
the Hner on heating in a circulating air
oven at 105ฐC for 2 hr. Polymeric compo-
sitions generally contain a small amount of
volatiles (<1.0%), usually moisture. The
recommended specimen is a disk cut from the
membrane.
The volatiles test can also be used to
determine the direction of the grain that
has been introduced in the membrane during
manufacture. By identifying the orientation
of the 2-in. disk specimen witn respect to
the sheeting at the time the specimen was
died out, the grain direction can be iden-
tified. The grain direction must be known
so that tensile and tear properties can be
determined in machine (grain) and transverse
directions. Upon heating in the oven at
105ฐC, sheeting with a grain will shrink
more in the grain direction than in the
transverse direction (Figure 1).
Volatiles need to be removed before
determining ash, extractables, and spec-
ific gravity. Ash and extractables are
reported on a dry basis (db). Volatiles
contents of representative membrane liners
are presented in Table 3. Monomeric plas-
ticizers that are generally used in PVC
compositions have a limited volatility and
can slowly volatilize at 105ฐC. Thus the
air oven test must be limited to 2 hr.
After air oven heating
2 hr. at 105ฐC
Figure l.Macnine direction determinations.
A standard test for the volatility of
plasticizers in PVC compounds is performed
in accordance with ASTM D1203. In this
test, activated charcoal is used to absorb
volatilized plasticizer.
Asn
The ash content of a liner material is
tne inorqanic fraction that remains after a
devolati1ized sample is thorouqnly burned at
55Qฐฑ2bJC. The ash consists of (1) the
inorganic materials that have been used as
fillers and curatives in the polymeric
coating compound, and (2) ash residues in
tne polymer. Different liner manufacturers
formulate their compounds differently, and
determining the ash content can be a way to
"fingerprint" a polymeric liner compound.
The residue obtained by ashinq can be
retained for other analyses (such as metals
content) needed for further identification
and for providing.a reference point to
determine trace metals that may have been
absorbed by the liner. The test metnod
160
56
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described in ASTM D297, Section 34, is
generally followed in performing this
analysis. Ash contents of representative
membrane liners are presented in Table 3.
Extractables
The extractable content of a polymeric
sheeting is the fraction of the compound
that can be extracted from a devolati1ized
sample of the liner with a solvent that
neither decomposes nor dissolves the poly-
mer. Extractables consist of piasticizers,
oils, or other solvent-soluble constituents
that impart or help maintain specific
properties such as flexibility and proces-
sability. A measurement of extractable
content and an analytical study of the
extract can be used as part of the finger-
printing of a sheeting.
During exposure to a waste, tne ex-
tractable constituents in a liner may be
removeu.and result in.-property changes. At
the same time during exposure, the liner
might absorb nonvolatiIizable constituents
from a waste. Measuring the extractable
content of unexposed lining materials is
therefore useful for monitoring the effects
of exposure. The extract and the extracted
liner obtained by this procedure can be used
for further analytical testing (e.g., gas
chromatography, infrared spectroscopy, ash,
thermogravimetry, etc.) and fingerprinting
of the liner.
The procedure for extraction generally
follows ASTM D3421, "Extraction and Analysis
of Plasticizer Mixtures from Vinyl Chloride
Plastics". Also see ASTM D297, "Rubber
Products-Chemical Analysis", paragraphs
16-18.
Because of the wide differences among
the polymers used in liner manufacture, a
variety of extracting media must be used.
TABLE 3. ANALYSIS OF UNEXPOSED POLYMERIC MEHBRANE LINERS*.+
Base polymer.
Speci fic
Volatiles,
Extractables,
Asn,
Polymer
specific gravity
gravity .
X
X
1
Butyl rubber
0.92
1.206
1.176
0.45
0.46
10.96
11.79
5.25
4.28
CMorinated polyetnylene
1.16-1.26
1.360
1.362
1.377
0.10
O.OO
0.05
7.47
9.13
14.40
12.56
17.37
Chlorosulfonated poly-
ethylene
1.11
1.433
1.343
0.84
0.51
1.49
3.77
33.95
3.28
Elasticized polyolefln
0.92
0.93b
0.15
5.50
0.90
Epichloronydrin rubber
1.27-1.36
1.490
0.63
7.27
4.49
Ethylene propylene rubber
0.86
1.173
1.122
1.199
0.38
0.50
0.31
23.41
31.77
18.16
6.78
5.42
0.32
Neoprene
1.25
1.503
1.480
1.390
0.76
0.19
0.37
10.15
13.43
21.46
12.98
13.43
4.67
Polybutylene
0.91
0.915
0.12
...
0.08
Polyester elastomer
1.17-1.25
1.236
0.26
2.74
0.3a
Polyetnylene (low density)
0.92
0.921
0.18
2.07
0.13
Polyetnylene (high density)
0.96
0.961
0.12
0.49
0.46
Polyetnylene (high density)
al loy
0.95
0.949
0.11
2.09
0.32
Polyvinyl chloride
1.40
1.275
1.264
1.231
1.280
1.308
0.11
0.09
0.05
0.31
0.03
33.90
37.25
38.91
35.86
25.17
6.20
5.81
3.65
6.94
5.67
Source of some of the data
^Multiple figures represent
: Haxo et al. (1982).
materials from different manufacturers.
161
57
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Table 4 lists the recommended solvents for
extraction of membrane liners of each
polymer type.
Typical values for the extractables in
polymeric membranes are given in Table 3.
Gas Chromatography
Gas chromatography can be used to find
the level of the plasticizer (e.g., diethyl-
hexyl phthalate (OEHP), a dioctyl phthalate)
compounded into a PVC liner material. Fig-
ure 2 shows the quantification of DEHP in
the solvent extract of a PVC liner material.
The weight percent of the DEHP 1n the liner
can then be calculated, assuming the extrac-
tion to be 100% efficient. A typical
procedure is summarized below.
A weighed sample of liner is extracted
with an appropriate solvent. The extract is
evaporated to dryness over a steam bath.
The dry residue is redissolved irr solvent
and brought to an accurately known volume.
Following the development of appropriate
chromatographic conditions, injection of
this solution into the instrument will
separate 1t Into chemically pure components
characterized by different retention times.
An Injection of a DEHP standard solution
will identify the retention time of the DEHP
component. Comparison of the peak height
<
X
PEAK HEIGHT IN CM
Figure 2.Gas chromatograph determination
of the d i ethy 1 ne"xy 1 phthalate
content in an extract of a PVC
membrane. Column: 6'xl/8" 3% 0V
101 on Chromosorb WHP. Tempera-
ture: 200ฐ-300ฐC at 8ฐC/min. He
carrier gas: at 30cc/min.
(area) data obtained from the injection of
equal volumes of the extract solution and
from quantitatively prepared standard
solutions allows the interpolation of the
DEHP concentration in the extract solution
(Figure 2).
TABLE 4. SOLVENTS FOR EXTRACTION OF kuLYhtRIC MEMBRANES*
Polymer type
Butyl rubber (11R)
Chlorinated polyethylene (CPE)
Chlorosulfonated polyethylene (CSPE)
Elasticized polyolefin
Epichlorhydrin rubber (CO and ECO)
Ethylene propylene rubber (EPDM)
Neoprene
Nitrile rubber (vulcanized)
Nitrile-modified polyvinyl chloride
Polyester elastomer
High-density polyethylene (HOPE)
Polyvinyl chloride (PVC)
Thermoplastic olefinic elastomer
Extraction solvent
Methyl ethyl ketone
n-Heptane
Acetone
Methyl ethyl ketone
Methyl ethyl ketone or acetone
Methyl ethyl ketone
Acetone
Acetone
2:1 blend of carbon tetrachlo-
ride and methyl alcohol
Methyl ethyl ketone
Methyl ethyl ketone
2:1 blend of carbon tetrachlo-
ride and methyl alcohol
Methyl ethyl ketone
*Because lining materials can be sheetings based on polymeric aloys mar-
keted under a trade name or under the name of only one of polymers, this
list can only be taken as a guideline for choosing a suitable solvent for
determining the extractables. Once a suitable solvent has been found, it
is important that the same solvent be used for determining the extract-
ables across the range of exposure periods.
162
58
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Pyrolysis gas chromatography
Pyrolysis gas chromatography is an
alternative method for measuring a plas-
ticizer in liner materials. In this tech-
nique, a small, weighed sample of liner is
heated very rapidly to a temperature suf-
ficient to volatilize all of its organic
components. The plasticizer and other
lower-molecular weight organics will be
driven off as chemically unchanged vapors.
The polymer will undergo pyrolysis, or high
temperature decomposition, and will vola-
tilize as 1ower-molecular-weight organic
compounds. The resulting volatiles may be
separated and quantified by gas chroma-
tography as previously described, and the
plasticizer content of the liner may be
calculated.
This method has the strong advantage of
not requiring extraction of the liner
sample, but it may not be as reliable a
means of quantification because of the very
small sample size and the large number of
components that must be separated by the gas
chromatograph.
Thermogravimetric analysis (TGA)
T6A is a thermal technique for asses-
sing the composition of a material by its
loss in weight on heating at a controlled
rate in an inert or oxidizing atmosphere.
For example, when a material is heated in an
inert atmosphere from room temperature to
600ฐC at a controlled rate, it will vola-
tilize at different temperatures until only
carbon, char and ash remain. The intro-
duction of oxygen into the system will burn
off the char and carbon black. Thus from
the weight-time curve which can be related
to weight and temperature, the amounts of
volatiles, plasticizer, polymer, carbon
black, and asn can be calculated. In some
cases, thermogravimetric analysis can
replace measurements of the volatiles, ash,
and extractables contents discussed above.
The TGA curve and the derivative of the TGA
curve can thus be used as part of a finger-
print of a polymeric composition. This
technique is described by Reich and Levi
(1971).
A Rerkin-Elmer TGS-2 thermogravi-
metric system, consisting of an analyzer
unit, balance control unit, heater control
unit, and first derivative computer, is used
in our laboratory. Temperature control is
supplied by the temperature controller on
the Perkin-Elmer DSC-2 (Differential Scan-
ning Calorimeter). A double side-arm fur-
nace tube was used to allow rapid changing
of the atmosphere from inert (N2) to oxi-
dative (N2/U2 mixture). For the oxida-
tive atmosphere, N2 purge is maintained
through the analyzer unit head, and O2
is introduced at the upper side arm where
it mixes with the N2 to burn the carbon
black and any carbonaceous residue that
forms during the pyrolysis of the polymer.
Use of the double side-arm furnace tube
shortens the turnaround time because it
eliminates the need to flush the analyzer
head completely to remove Op between runs,
as would be necessary if &2 were intro-
duced through the head. A dual pen recordt,
Perkin-Elmer Model 56 allows a simultaneous
display of thermocouple temperature in the
furnace <ปnd tne change in weight of the
specimen or the first derivative of the
change in weight.
An example of the TGA procedure for the
analysis of a polymeric liner is described
below.
A 5-mg specimen of the liner was placed
in the balance pan and weighed in a nitrogen
flow of 40 cc/min. The instrument was
adjusted to give a 100% full-scale deflec-
tion for the weight of the sample, so the
percent of weight change can be read
directly from the chart.
The specimen was heated to 110ฐC and
held there for 5 min to determine whether
measurable volatiles were present; it was
then heated from 110ฐ to 650ฐC at a rate of
20ฐC/min in a nitrogen atmosphere. The
specimen was held at 650ฐC until no more
weight loss occurred, usually 2 to 3 min,
after which it was cooled to 500ฐC and O2
was introduced at a rate of 10 cc/min with
an N2 flow rate of 30 cc/min.
Typical thermograms for HDPE and EPDM
appear in Figures 3 and 4, respectively.
Analyses of a variety of polymeric mentorane
liners are presented in Table 5.
Differential Scanning Calorlmetry (DSC)
DSC is a thermal technique for measur-
ing the melting point and the amount
of crystallinity 1n partially crystalline
polymers such as the polyolefins polyethy-
lene, polypropylene, and polybuty1ene.
This technique measures the heat of fu-
sion of a crystalline structure; it can
also give an indication of the modification
of crystalline sheeting with other polymers
163
59
-------
COMPOSITION
FROM TGA
0
Oil
0
Polymer
95 S
Carbon 8lack
45
Ash
0
Tenpersture y
S
/
/
s
s
' Rait o' rut 20ฐC/mm
ฆ % of Ortpnal
v ฃ
Nitrofltn Armoie*>ซft -
I t L-
=t^.
12 16 30 24 28 3? 38 40
TIME. MINUTES
SO ?
o
s
o
40 O
J*
Figure 3.TGA of an unexposed black HDPE liner. The plots of sample weight and temperature
as a function of time are shown. Under an Ng atmosphere, trie black HDPE sample
lost approximately 95.5% of its mass as hydrocarbons were evolved. The carbon
black added as an ultraviolet light absorber remained as a carbonaceous residue
and was not volatilized until it was oxidized when oxygen was allowed into the
system.
?8 3? 36
TIME. MINUTES
Figure 4.Thermogravimetric analysis of an unexposed EPDM liner membrane. The dotted line
shows the temperature program and the solid line shows the percent of tne original
specimen weight. At 46 minutes the atmosphere was changed from nitrogen to air
to burn the carbon black.
164
60
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TABLE 5.THERMOGRAVIMETRIC ANALYSIS OF POLYMERIC MEMBRANE LI-NERS
Volati1es,
Polymer,
ui1 or pias-
Carbon
Ash,
Polymer type
%
%
ticizer, %
black, %
%
Butyl rubber
0
45.0
12.2
37.1
5.7
Chlorinated
polyethylene
0
72.2
7.6
5.3
14.9
0
71.3
9.1
6.5
13.1
0.4
53.9
13.9
21.0
10.8
Chiorosulfonated
polyethylene
1.0
49.3
1.5
45.6
2.6
0.9
47.7
3.2
45.2
3.0
0.1
58.1
5.5
9.8
26.5
Elasticized
polyolefin
0
93.1
1.7
4.0
1.2
Epicnlorhydri n
.
rubber
0
49.3
8.2
37.7
4.8
Ethylene propylene
rubber
0.1
30.8
32.9
30.9
5.3
0.2
33.5
23.2
35.5
7.6
Neoprene
1.0
42.3
10.7
34.9
11.1
0
44.0
10.7
33.8
11.5
Polyethylene (high
density)
0
97.9
U
2.1
0
95.6
0
4.2
0.2
0
97.0
0
1.8
1.2
Polyvinyl chloride
0
48.7
38.2
6.2
6.9
0
46.0
42.1
7.8
4.1
0
51.0
35.0
7.0
7.0
by alloying. Thus this type of analysis can
be used as a means of fingerprinting crys-
talline polymeric liner materials (partic-
ularly high-density polyethylene) and
assessing the effects of aging and exposure
to wastes. This technique is described by
Boyer (1977) and Ke (1966).
The differential scanning calorimeter
used in this work was the Perkin-Elmer
Model DSC-2C, equipped with an Intracooler I
subambient temperature accessory to provide
an operating temperature range of -AO to
725ฐC.
The equipment is used to characterize
the thermal transitions of materials
such as melting, boiling, and changes in
crystal structure. A sample and reference
cell are provided. A weighed sample is
placed in the sample holder; the reference
cell is generally run empty to provide an
absence of thermal transitions. The two
cells are simultaneously heated or cooled so
that the average cell temperature follows a
preset program. When the sample undergoes
a thermal transition, an endothermlc or
exothermic reaction will occur. The
change in power required to maintain the
sample cell at the same temperature as the
reference cell 1s recorded as a deflection
of the recorder pen. The recorder plots the
temperature (ฐC) versus the differential
energy flow (mcal/sec) required to maintain
the sample cell temperature. An endothermlc
transition such as melting 1s shown as a
positive peak; an exothermic reaction such
as crystallization is shown as a negative
peak. The magnitudes of these peaks and the
temperatures at which they occur are charac-
teristic of the material analyzed.
An example of the use of the DSC to
determine the polyethylene crystal Unity 1n
an HOPE liner 1s shown in Figure 5.
165
61
-------
u
w
M
J
<
U
Z
LU
<
c
S
o
_J
u.
t-
<
Ul
X
370 380 390 400 410
TEMPERATURE. KELVIN
Figure 5. DSC determination of the poly-
ethylene crystal 1inity in an
HDPE liner. The x-axis is the
temperature which was raised at
5ฐC/min. The y-axis is cali-
brated in mcal/sec, or rate of
energy flow. A positive deflec-
tion of the plot indicates that
the sample is absorbing energy
(e.g., during melting). The
amount of energy absorbed during
the melting process may be
determined by calculating the
peak area and relating it to the
peak area resulting from the
melting of an Indium standard of
known weight. The energy absorb-
ed is termed the "heat of fusion"
( Hf). Assuming tnat Hf for
the fully crystalline polymer is
known, the degree of crystallin-
ity of the sample can be deter-
mined as a simple ratio.
Specific gravity
Specific gravity is an important
characteristic of a material and is gen-
erally easy to determine. Because of dif-
ferences in the specific gravities of the
base polymers, specific gravity of the liner
compound can give an indication of the com-
position and identification of the polymer.
Specific gravities of base polymers and of
different liner compounds based on them
are presented in Table 3. They show the
the differences among polymers and the
variations in compounds from one manu-
facturer to another.
ASTM Method D792, Method A-l, and D297,
Section 15.1.2, Hydrostatic Method, are
generally used in performing this test.
ANALYSIS AND FINGERPRINTING OF EXPOSED
POLYMERIC MEMBRANE LINERS
During service, several processes can
take place to change the composition of a
liner and thus affect physical properties
and possiDly performance. First, the liner
can absorb waste liquids including water,
various organics, and possibly some inor-
ganic substances. The composition of the
absorbed chemicals will probably reflect
that of the waste liquid, but it will vary
depending on the relative solution charac-
teristics and the waste liquid constituents.
The absorbed organics can be both volatile
and nonvolatile. The total amount generally
softens the liner, resulting in possible
loss of tensile strength and other mechan-
ical properties, loss of elongation, and
increased permeability. While the organic
constituents are being absorbed, some of the
extractables such as plasticizer and oils
may migrate out of the compound, either by
evaporation, dissolution in waste liquid, or
biodegradation. Severe loss of plasticizer
could result in stiffening and loss in
mechanical properties. Losses in properties
can occur also through UV degradation and
oxidation of the polymer if the liner is
exposed to the weather. Figure 6 schemati-
cally represents the compositions of a
polymeric liner before and after exposure
and after extractions.
In assessing the long-term effects of
exposure to wastes and the other conditions
in a disposal facility, it is necessary to
know which waste constituents have affected
the lining material and what degradation may
have taken place. An analysis of exposed
liners is most useful to determine these
factors. Figure 7 illustrates a proposed
plan of analysis that we have used in our
analyses of exposed materials, recovered
from the laboratory or the field.
The various tests that are performed on
exposed membranes are the same as those
discussed in the previous section for
unexposed lining materials, with mod-
ifications and special precautions required
in each test for the exposed materials.
These individual tests are described in the
following subsections.
166
62
-------
POLYMER
XL OB TP
original
LINER
T[
. WASTE
* LIQUID
PlASTICIZER
WASTE .
' LIQUID ,
PLASTICIZER
EXPOSED
LINER
fc WEIGHT INCREASE
VOLATILES
REMOVED
EXTRACTA0LES
VOLATILES
AND
EXTRACTABLES
N VOLATILES EXTRACTABLES
Moisture Nonvolttii* W9anict
0*9ซnrcs
Figure 6.Schematic presentation of changes in composition of a polymeric liner compound on
exposure to a waste liquid, on removal of volatiles, and on extraction with
an appropriate solvent.
Air oven
2 hours. 105ฐC
Aih
TGA
GC
IR
CHONS
RhkJuiI soiwnt
Polymrr
Carbon B>ซck
Alh
TGA ฆ thecmogravimetric analysu
GC ฆ gas chromatography
IR - infrซr*d spectroscopy
AAS * atomic Jbtorption tpectroscopy
CHONS ฆ carbon, hydrogen. n$rrogen oxygen, a nd sulfur determmjtton
Figure 7.Plan for the analysis of exposed polymeric lining materials.
167
63
-------
Volatiles
The initial analytical test generally
performed is a determination of the vola-
tiles content, which gives an indication of
the amount of waste liquid that has been ab-
sorbed by the Uner. As an approximation,
the weight Increase can be calculated by
dividing the percent of volatiles by the
percent of nonvolatiles. For example, if
the volatiles are 15%, and the nonvolatiles
are 85%, the percent increase in weight
based on the original Uner would be 17.6%.
Inasmuch as' the volatiles contain
both water and organic components, it
1s desirable to separate these two. A
study was made to dehydrate the speci-
mens of the exposed Uner to remove the
water. A series of deslccants was stud-
led at room temperature and 50ฐC. Four
days of exposure of the exposed liner at
50ฐC 1n a small Individual desiccator
containing calcium chloride removed the
moisture from the 2-1n. disk specimen
without removing organic constituents.
After removal of the water, a 2-hr heating
of the specimen in a circulat-ing air oven
removed the remaining organic volatiles.
Collection of the organic volatiles and
determination of composition by gas
chromatography would be desirable but
has not been attempted to date. The
water and the organic volatiles equal
the volatiles obtained 1n bypassing the
desiccator exposure. Such a bypass removes
the moisture by exposure at room temperature
for 1 week in moving air followed by heating
1n a circulating air oven for 20 hr at 50ฐC
and 2 hr at 105ฐC. We have found, however,
that the highly swollen CPE liner may take
up to 6 days at 50ฐC to come to constant
weight. The time required to remove
volatiles depends on the thickness and
permeability of the liner and the care taken
to avoid the "skin" that forms on the
surface of the specimen when using too high
an initial temperature to devolatilize.
After the volatiles are removed, the
exposed materials can be subjected to
the other tests, Including specific gravity,
extractables, ashing, etc.
Total volatiles can also be determined
through the use of TGA which is discussed
below.
Extractables
Extractables of exposed materials
will probably differ from the original
values because of the loss to the waste
liquid and absorption of nonvolatile
organics (e.g., oils). After the vol-
atiles have been removed from the liner,
the extractables are determined by the same
method used on the unexposed liner materi-
als. Examples of extractable contents after
exposure are given In Table 6. If the liner
has been 1n contact with wastes containing
nonvolatile constituents, the extractables
recovered may be greater than the original
values. Analysis of the extractables by gas
chromatography and infrared analysis may
give an indication of the nonvolatile
organics that were absorbed. The analysis of
the extractables will give an indication of
the constituents of the waste that are
aggressive to the liner, as they are the
constituents that have been absorbed. They
may show up 1n minor amounts in a waste
analysis, but because of their chemical
characteristics such as solubility parame-
ters and hydrogen bonding, they may be
scavenged by the polymeric liner.
Ash
Thp ash content of an exposed membrane
liner 1s determined after the volatiles have
been removed from the specimen. As in the
case of the unexposed membrane, the exposed
liner is ashed in a muffle furnace at
550ฐC. The ash value usually differs from
that of the unexposed material, depending on
how many nonvolatile organics were lost or
gained during the exposure period. If plas-
ticizer is lost, the value will increase
because of the nonash content of the plasti-
cizer. Also, if any organic metal compounds
are absorbed by the liner, they will show as
an increased ash content. A comparison of
the elemental analysis of the ash with that
of tne original liner will determine whether
any absorption of metal species occurred
during the exposure. No such absorption has
been observed, but metal organics mignt be
absorbed by a liner. In general, the in-
organics that make up the ash are retained
in the liner and maintain a constant ratio
with respect to the polymer content, as
polymer is generally not dissolved by the
waste liquid.
Thermogravimetric analysis
The TGA analysis can be used to give a
quick analysis of the composition of an
exposed polymeric membrane liner. The test
is run similarly to that of the unexposed
material, except that care must be taken in
handling the small specimens of exposed
64
-------
TABLE 6.EXTRACTABLES OF DIFFERENT POLYMERIC MEMBRANE LINERS
BEFORE AND AFTER VARIOUS EXPOSURES
Polymer
Unexposed
Type of exposure
by waste
Extractables
after exposure
Butyl rubber
11.79
Aromatic oil
Spent caustic
Oil 104
27.23
10.87
40.34
Chlorinated
polyetnylene
9.13
Oil 104
Roof exposure
17.00
5.99
Chiorosulfonated
polyethylene
4.08
Aromatic oil
Oil 104
Slop water
59.81
15.92
3.70
Elasticized
polyolefin
5.50
Oil 104
Aromatic oil
Slop water
20.74
23.37
2.96
Ethylene prop-
ylene rubber
23.64
Aromatic oil
Oil 104
Spent caustic
38.35
43.45
22.89
Neoprene
21.46
Aromatic oil
Oil 104
Slop water
58.47
23.85
17.63
Polyvinyl
chloride
33.90
Aromatic oil
Roof exposure
Pesticide
Oi1 104
40.55
26.27
35.38
17.95
liners that contain the volatiles. These
volatiles can be easily lost. Figure 8 is a
thermogram of an exposed PVC membrane liner
that had absorbed more than 7% of the waste
liquid, which was predominantly water. The
results are shown on the figure, but the
losses show the effect of the char formation
of the PVC when it is heated in a nitrogen
atmosphere. Chlorinated polymers lose HC1
and leave a char for which correction must
be made in the calculations of the polymer
content. These calculations have been made
on the figure, ana the results compare fa-
vorably with those obtained by direct analy-
sis of the volatiles, extractables, and ash.
Specific gravity
The specific gravity of exposed mem-
brane liners is also determined after the
membrane specimen has been thoroughly de-
volatilized. Three steps must be taken to
avoid the formation of bubbles in the Uner
mass during a direct devolatilizing process
(which would affect the specific gravity
results). First, the specimens must be
allowed to "dry" at room temperature 1n an
air stream in a hood until constant weight
is achieved, which could take several days.
Second, they must be placed 1n an oven at
70ฐC for 16 hr; and third, they must be
heated at 105ฐC for 2 hr.
The specific gravity of an exposed
membrane can differ from that before ex-
posure, depending on how much of the origi-
nal extractable material was lost and how
much material from the waste was absorbed
during exposure. The procedure followed was
ASTM D297 using the hydrostatic method.
65
-------
-1 1100
% Original Weight
of Sample
300ฐC
60 2%
/ 650ฐC
490ฐC
Nitrogen Armoiphere
1
68%
*- Air
H
r
o
60 uj
s
<
z
40 2
cc
o
s<
60 80
TIME, MINUTES
100
Figure 8. TGA of an exposed polymeric PVC liner.
Weight loss A
Weight loss B
Weight loss C
Weight loss D
7.0% volatiles = moisture + possible organics.
60.2% = plasticizer + HC1 from the polymer (PVC).
16.0% = residual polymer.
10.0% = carbonaceous polymer residue + carbon black,
Residue weight E = 6.8% = ash.
Composition of the exposed liner as received calculated from above data.
Values by direct analysis are shown in parentheses.
Volatiles
Polymer (PVC)
Plasticizer
Carbon black
Ash .
7.0% (7.9)a
44.7% ,
34.1% (32.2% as extractables.)3
7.4%
6.8% (6.4)a
aBy di rect analysis.
SUMMARY AND CONCLUSIONS
A protocol is presented for the analysis
of polymeric membrane lining materials
before and after exposure to waste liquid.
The results of the analysis can be used
as a fingerprint of the unexposed liner and
as a baseline for assessing the changes that
occurred during exposure to a waste liquid.
The analysis of an exposed liner
furnishes information regarding the change
in the composition of the membrane and the
chemical materials that are actually absorb-
ed during exposure. This latter information
indicates the constituents of the waste that
are aggressive to the lining material.
Thermal analysis and gas chromatography
are particularly useful in the analysis
and fingerprinting of polymeric membranes.
The use of gas chromatography coupled
with mass spectroscopy needs to be investi-
gated to determine the specific chemicals
that are absorbed by a polymeric liner.
The use of this analysis may lead to
techniques which will better predict the
service life of a flexible membrane liner.
ACKNOWLEDGEMENTS
Th*ป work reported in this paper was
performed under Contracts 68-03-2134
("Evaluation of Liner Materials Exposed to
Leachate"), 68-03-2173 ("Evaluation of Liner
Materials Exposed to Hazardous and Toxic
Wastes"), and 68-03-2969 ("Long-term Testing
of Liner Materials") with the Municipal En-
vironmental Research Laboratory of the U. S.
Environmental Protection Agency, Cincinnati,
Ohio.
66
-------
The author wishes to thank Robert E.
Landreth, Project Officer, for his support
and guidance in these projects.
REFERENCES
ASTM Standards, American Society for Testing
and Materials, Philadelphia, PA.
D297-81, Rubber Products - Chemical
Analyses: Section 15, Density (Hydro-
static Method); Section 34, Fillers,
Referee Ash Method
D792-66, Specific Gravity and Density of
Plastics by Displacement; Method A-l
for Testing Solid Plastics in Water,
Sections 6-12.
D1203-67, Volatile Loss from Plastics
Using Activated Carbon Methods.
D3421-75, Extraction and Analysis of
Plasticizers from Vinyl Chloride
Plastics
Boyer, R. F. 1977. Transitions and Relaxa-
tions. In:. Encycl. Polymer. Sci.
Technol. Supplement, Vol. 2. pp
745-839.
Haxo, H. E. -1983. Liner Materials Exposed
to Hazardous and Toxic Wastes. Final
Report. Contract 68-02-2173. U. S.
Environmental Protection Agency,
Cincinnati, OH. In preparation.
Haxo, H. E., R. M. White, P. D. Haxo, and M.
H. Fong. 1982. Liner Materials
Exposed to Municipal So lid Waste
Leachate. Final Report. Contract
68-03-2134. U. S. Environmental
Protection Agency, Cincinnati, OH. In
press.
Ke, B. 1971. Differential Thermal Analy-
sis. In: Licycl. Polymer. Sci.
Technol. Vol 5, pp 37-65.
Matrecon, Inc. l'982 .. Lining of Waste
Impoundment and Disposal Facilities.
SW-870, Second Edition. U.S. Environ-
mental Protection Agency, Washington,
DC. In press.
Reich, L., and D. W. Levi. 1971. Thermo-
gravimetric Analysis. In: Encycl.
Polymer Sci. Technol. Vol 14. pp
1t41.
171
67
-------
CONSTRUCTION QUALITY ASSURANCE
FOR
LINERS, COVERS, AND DIKES
by
David C. Anderson
K. W. Brown & Associates, Inc.
68
-------
Table ot Contents
Page
Introduction 1
Context 1
Guidance 1
Definition: Construction Quality Assurance (CQA) 1
CQA Plan 2
Elements of a CQA Plan 2
Responsibility and Authority 3
Personnel Qualifications 3
Inspection Activities 4
Sampling Activities 4
Documentation 5
Facility Components Included in the Plan 5
Liner Systems 5
Soil Liners 8
Preconstruction 8
Construction . 18
Postconstruction 18
r'MLs . 19
Preconstruction 19
Construction. ..... 19
Postconstruction 20
Dikes 21
Preconstruction 22
Construction 22
Postconstruction 22
Cover Systems 23
Preconstruction 23
Construction. . .. 24
Postconstruction 26
i i
69
-------
CONTEXT
ฐ Statutory (HSWA)
ฐ Regulatory (40 CFR 264 & 270)
ฐ Guidance
GUIDANCE
Minimum Technology Guidance
(EPA/530SW85014)
0 Construction Quality Assurance
for Hazardous Waste Land Disposal
Facilities (EPA/530-SW-86-031)
CONSTRUCTION QUALITY ASSURANCE
(CQA)
Ensuring that the facility
is constructed to meet
design specifications
70
-------
ELEMENTS OF A CQA PLAN
Responsibility and authority
CQA personnel qualifications
Inspection activities
Sampling activities
Documentation
CQA PLAN
ฐ Specifies the type and
frequency of all inspection
activities.
ฐ Provides framework to
ensure all inspections are|
-carried oCit..
CQA PLAN (CONT.)
ฐ Describes how inspection
results will be used to
verify that the facility has
been constructed as designed.
ฐ Included with permit
application and reviewed for
completeness; implementation
should be confirmed.
71
-------
CQA RESPONSIBILITY AND AUTHORITY
Permitting Agency
Owner/Operator
Design Engineer
Construction Contractor
CQA Officer
Supporting Inspection Staff
CQA PERSONNEL QUALIFICATIONS
CQA OFFICER:
ฐ Academic training
ฐ Practical, technical and
managerial-experience
ฐ Communication "skills
CQA PERSONNEL QUALIFICATIONS (CONT. )
SUPPORTING INSPECTION STAFF:
ฐ Formal training
Practical, technical and
administrative skills
0 Demonstrated knowledge of
construction techniques,
testing procedures
72
-------
CQA INSPECTION ACTIVITIES
Observations and tests to
determine if properties,
composition, and performance
of materials and installed
components meet design
specifications.
INSPECTION ACTIVITIES
ฐ ^reconstruction
0 Construction
* Postconstruction)
CQA SAMPLING ACTIVITIES
0 Methods
e Size
0 Location
0 Frequency
0 Criteria for rejection
and acceptance
73
-------
CQA DOCUMENTATION
Daily summary reports
Inspection data sheets
Problem identification
Corrective measures reports
Block evaluation reports
Design acceptance reports
Final documentation
Provisions for storage of
records
FACILITY COMPONENTS INCLUDED
IN THE PLAN
ฐ Foundations
ฐ Leachate collection systems
ฐ Liner systems
ฐ Cover systems
ฐ Dikes
LINER SYSTEMS
DOUBLE LINERS OPTIONS
ฐ FML/comDosite
ฐ FML/compacted soil
74
-------
SECONDARY
LEACHATE
COLLECTION
1 f
PRIMARY
LEACHATE
COLLECTION
-2
I x 10 cm/sec
DRAINAGE \ ^
A TILES ^
DRAINAGE
MEDIUM
^ COMPACTED SOIL
COMPONENT (^lxlO~^cm/sec)
UNSATURATED ZONE
SECONDARY
COMPOSITE
LINER-,
36" COMBATED
SOIL LINER
PRIMARY FML
SECONDARY FML
SECONDARY
LEACHATE
COLLECTION
PRIMARY LEACHATE COLLECTION
& DRAINAGE
*v TILES
_2
I x 10 cm/sec
DRAINAGE
MEDIU
PRIMARY
FML
THICK COMPACTED SOIL
LINER felx IO~7cm/sec)
//7'>
UNSATURATED ZONE
LANDFILL DOUBLE LINER OPTIONS
A. FML/COMPOSITE
B. FML/COMPACTED SOIL
75
-------
FML/COMPOSITE
0 Primary FML liner
Secondary composite liner
COMPOSITE LINER
Upper FML liner
Lower compacted soil
OF IlO"'CM/SEC OR LESS
FML/COMPOSITE LINER
76
-------
COMPOSITE LINER
FML UPPER COMPONENT
Improves efficiency of
secondary leachate
collection
# Earlier detection of
primary FML leak
SOIL LINERS
PRECONSTftUCTION (SOIL LINERS)
~ Material Inspection
ฐ Test Fill
PRECONSTRUCTION INSPECTION OF MATERIALS
(AT STORAGE PILE/CONSTRUCTION
SITE/BORROW PIT)
ฐ Visual-manual soil inspections
ฐ Atterberg Limits
ฐ Moisture/density/permeability
ฐ Natural moisture content
ฐ Maximum clod size
0 Particle size distribution
Potential volume change
ฐ Susceptibility to frost damage
77
-------
SOIL LINER REQUIREMENTS
No structural nonuniformities
which might increase the
field permeability
Lifts not to exceed 6 inches
SOIL LINER REQUIREMENTS (CONT.)
Free of rocks, roots, and rubbish
At least 3 ft. thick
Chemically resistant to waste
Protected from damage
SOIL LINER REQUIREMENTS (CONT.)
Break up clods
Uniform moisture distribution
Protect from desiccation/freezing
78
-------
SOIL LINER REQUIREMENTS (CONT.)
Scarification between lifts
Smooth upper surface (composite)
Adequate thickness to prevent
failure
SOIL LINER REQUIREMENTS (CONT.)
CQA plan
Field permeability < 1 x 10"^ cm/sec
Performance verified in a test fill
TEST FILL SHOULD BE USED
TO DETERMINE DENSITY/
H20/PERMEABILITY RELATION TO:
Mixing method
Lift thickness
Compaction method
Number of passes
Compaction equipment speed
79
-------
SCHEMATIC OF A TEST FILL.
-AT LEAST THREE LIFTS OF COMPACTED SOIL
DRAINAGE LAYER OR UNDERDRAINAGE COLLECTION SYSTEM
00
o
Roller Type Equipment
L
L = Distance required for construction equipment to reach normal running speed
W = Distance at least four times wider than the widest piece of construction equipment
Wh - Area to be used for testing
-------
TEST FILL REQUIREMENTS
Use soil, equipment, and
procedures which will be
used in the full-scale
facility
ฐ Implement CQA plan
TEST FILL REQUIREMENTS (CONT.)
ฐ Verify density - H2O -
permeability relations
0 Validate all design and
construction procedures
TEST FILL DETAILS
0 - Four times wider than the
widest piece of construction
equi pment
0 Long enough to allow
construction equipment to
reach normal running speed
before entering the area
used for testing
81
-------
TEST FILL DETAILS (CONT.)
At least three 6-inch lifts
of compacted soil
An underlying drainage layer
TEST FILL DETAILS (CONT.)
ฐ Facilitate field infiltration
tests and/or quantification
of underdrainage
Facilitate collection of
undisturbed samples for use
in lab permeability tests
Capable of measuring values
Large enough to detect any
macrofeatures
SEALED DOUBLE RING INFILTROMETER
82
FIELD PERMEABILITY
TEST REQUIREMENTS
less than 1 x 10"^ cm/sec
GROUT
-------
TEST FILL EQUIPPED FOR UNDERDRAINAGE.
-------
LABORATORY VS. FIELD PERMEABILITY
sourcfs nf mn-firii) PFmfABii irr ufasiipfmfkt fimk
Compaction water content
Chunk size
Roots and Rocks in the field
* Use of static or impact compaction rather than kneading compaction
Compactiye effort
Air in laboratory samples
Excessive hydraulic ซradient leading to particle migration
" No steady state due to stress change i the laboratory measurement
Sample size
Dessication cracks in the field
* These are the only errors that cause lab-measured
VALUES TO BE HIGHER THAN ACTUAL FIELD VALUES.
EFFECT OF SAMPLE SIZE ON HYDRAULIC CONDUCTIVITY
Sample
1
2
3
Sample Diameter
1.5 INCHES
2.5 inches
8.0 FEET
Hydraulic
(-nwnncTivtTV
1 x 10"^ cm/sec
8 x 10"^ cm/sec
3 x 10"^ cm/sec
Samples 1 and 2 were carved from a field-compacted liner
AND TESTED IN THE LABORATORY
SAMPLE 3 WAS TESTED IN THE FIELD ON THE SAME LINER WITH
AN 8-FOOT DIAMETER SINGLE RINS INFILTROMETER
COMPARISON OF HYDRAULIC CONDUCTIVITIES FROM FOUR CASE HISTORIES
Hydraulic Conductivity (cm/sec)
Back-calculated
Casf Laboratory Fifld" FROM Leakasf FlFi n/1 an
1 5 x 10"10 to 8 x 10'7 1 x 10"5 2 to 5 x 10-5 25 to 100,000
2 2 x 10"9 to 2 x 10"7 2 x 10~6 2 to t x 10*6 10 to 2,000
5 2 x 10"7 to 3 x 10"7 , -- 1 to 2 x 10"5 30 to 1G0
<ป 1 x 10"ฎ to 4 x 10~7 2 to 5 x 10"7 2 x 10"^ 5 to 200
Source- Daniel
"Details or field tests
Case 1: 2.^ ซ single king infiltrometer
Case 2: Double ring infiltrometer; inner ring 15 cm. outer rimg "6 cm
Case ^ 2 m single ring infiltroheter
34
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TEST FILL/FULL-SCALE FACILITY
INDEX PROPERTIES
ฐ Permeability (undisturbed samples)
* Inplace density/^O
0 Maximum clod size
0 Particle size distribution
0 Atterberg limits
o rrr't/-t2- ,
EOUIPMENT USED TO COLLECT UNDISTURBED
SCML SAMPLES FOR USE IN PERMEABILITY
TESTS.
85
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TECHNIQUE USED TO LOAD
UNDSTUR8ED SOIL SAMPLES
INTO DOUBLE-RING PERMEAMETERS.
TRIAXIAL PERMEAMETERS USED TO
DETERMINE PERMEABILITY OF THE
UNDISTURBED SOIL SAMPLES
86
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CONSTRUCTION INSPECTIONS
To assure that soil liner is
constructed with soil materials,
procedures, and equipment that
were evaluated in preconstruc-
tion activities.
CONSTRUCTION INSPECTIONS (CONT.)
0 Continuously observe compaction
ฐ Testing of compacted liner
at specified intervals (per unit
surface area of a lift and
liner section, per unit volume '
of soil)
POSTCONSTRUCTION ACTIVITIES
* Inspection of soil liner prior to
placement of protective cover
* Repair of all defective areas
0 Final inspection of sidewall slopes,
liner thickness and coverage, and
integrity of protective cover
ฐ Protection from desiccation and
freezi ng
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INSPECTION METHODS (SOIL LINERS)
Factor
Soil type
Outsized materials
Thickness/slope
Moisture-density
Permeability (Lab)
Permeability (Field)
Method
ASTM 2488, D422, D4318
and D2487
Observation
Surveying/observati on
ASTM D1557
Fixed wall/flexible wall
Large field infiUrometer
FMLs
PRECONSTRUCTION (FML)
ฐ Manufacture
0 Fabrication
ฐ Transport
ฐ Storage
ฐ Lower bedding
FML REQUIREMENTS
ฐ At least 30 mils thick
ฐ Chemically resistant to
waste/leachate
Seam tests
88
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FML REQUIREMENTS (CONT. )
Free of blemishes
Protected from damage (above
and below)
Gas venting in bedding
FML REQUIREMENTS (CONT.)
Avoid nonessential penetrations
Avoid bridging and stressed
conditions
Allow slack for shrinkage
CONSTRUCTION (FML)
Placement
Seami ng
Anchors and seals
Upper bedding
89
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POSTCONSTRUCTION (FML)
0 Test for leaks
0 Locate/repair
0 Retest for leaks
INSPECTION METHODS (FML)
FACTOR METHOD
Thickness
Tensile Properties
Tear Strength
Seaming
Anchoring/Coverage/
Penetrations
ASTM D1593, D751
ASTM D638, D751,
and D882
ASTM D751, D1004
ASTM D413, D4437,
D751, and D3083
Observation
DIKES
DIKES
Retaining walls to resist lateral forces
of stored waste
Aboveground extension of foundation
Support to overlying facility components
Constructed with soil compacted to
specified strength
Designed to maintain integrity if liner
fail s
90
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PRECONSTRUCTION (DIKES)
Materials inspection
0 Test fill
Foundation preparation
CONSTRUCTION (DIKES)
0 Compacted fill
ฐ Dike shell
ฐ Drainage system
ฐ Erosion control
POST-CONSTRUCTION (DIKES)'
0 Survey slopes
0 Visual inspection
ฐ Width/height/thickness/
areal dimensions
0 Vegetative cover
INSPECTION METHODS (DIKES)
FACTOR METHOD
Slope
Dimensions
Compaction
Erosi on
Strength (Lab)
Consistency (Field)
Surveying
Surveying, observation
(see soil liners)
(see covers)
ASTM D2166
ASTM D3441, D2573
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COVER LAYERS
ฐ Vegetated protective surface
layer
0 Drainage layer
0 Hydraulic barrier layer
* Gas vent layer
PRECONSTRUCTION ACTIVITIES FOR
VEGETATED PROTECTIVE SURFACE LAYER
Screen incoming materials including:
- Agronomic properties of soil
- Fertilizer
- Soil conditioners
- Seeds
Experimental plots to verify the
proposed soil/vegetation will
perform as expected
- CONDITIONS THAT SHOULD BE CONSIDERED
IN EXPERIMENTAL PLOTS
Local climate
Cover soil type, depth and compaction
Tolerance of vegetation
92
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PRECONSTRUCTION - FOUNDATION SOIL
Evaluation of waste placement records
- Uniformity of placement
- Degree of compaction
- Presence of voids between containers
Observations
- Unsuitable foundation materials
- Unfilled voids
PRECONSTRUCTION ACTIVITIES -
DRAINAGE AND VENT LAYERS
Inspections of materials to assure
they meet design specifications
Inspection of base for drain or
vent layer
Inspections of protrusions such
as vents or standpipes
CONSTRUCTION ACTIVITIES -
DRAINAGE AND VENT LAYERS'
Observe thickness and slopes
Determine if grain size and
conductivities are obtained
Observe filling process around
vents and standpipes to prevent
damage or misalignment
93
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CONSTRUCTION
- FOUNDATION SOIL
0 Observations
- Excessively wet or dry SDots
- Removal of unsuitable materials
- Compaction of soil backfill
- Surface finishing/proof rolling
- Sterilization
ฐ Tests
- Compaction
- Slope
- Particle size
- Atterberg Limits
- Soil classification
- Strength
CONSTRUCTION ACTIVITIES
For the filter layer (above drainage layer),
monitor the following:
Granular Geotexti 1e
Grain Size Type and Certification
Uniformity/Thickness Seaming/Overlap
Common to Both
Coverage -
Slope
Intersection with Surface Drainage
CONSTRUCTION ACTIVITIES - TOPSOIL
Nutrient status
Organic matter
Uniformity of application
Excessive compaction
Oamage to vents/penetrations
94
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CONSTRUCTION ACTIVITIES
- SEEDING
Seedbed preparation
Application rate for seeds/additives
Seed type/quality/quantity
Damage to vents/penetrations
Hydromulching/watering instructions
Bare spots
ฐ Sideslopes
"Time of seeding
POSTCONSTRUCTION ACTIVITIES
ฐ Complete visual check of completed
final cover
ฐ Survey final slopes, correct any unusual
depression
ฐ Inspect vents/penetrations
ฐ Surface drainage systems/drainage layer
outlets should be inspected
ฐ Continue to inspect vegetation until
vegetation has been fully established -
Professional agronomist should inspect
vegetation at least once/month for first
6 months
ฐ After the 6 month period, a final overall
check of the final cover should be made
INSPECTION METHODS (COVER SYSTEM)
FACTOR
METHOD
Burner system
Topsoil thickness
SI ope
Coverage
Soil chemistry
Vegetation type/
seeding time
(see liners)
Observation/surveyi ng
Observation/surveying
Observation
Methods of soil analysis
by A.L. Page et al. (1982)
Supplier recommendations
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GROUND-WATER CLEAN-UP TECHNOLOGIES
by
Joseph F. Keely, Ph.D., P.Hg., FAIC
Ground-Water Quality Consultant
Beaverton, Oregon
Copyright by
Joseph F. Keely, Ph.D., P.Hg., FAIC
January, 1987
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GROUND-WATER CLEAN-UP TECHNOLOGIES
Joseph F. Keely, Ph.D., P.Hg., FAIC
Introduction
There are a number of specialized techniques that are in use today for
the clean-up of ground-water contamination, but perhaps the most common
technique is the 'pump-and-treat system1 (PAT). The basis of the PAT is
hydrodynamic, relying on the modification [by pumpage] of local hydraulic
gradients and flow velocities to effect physical flushing of the contaminated
water from the aquifer. Another very popular technique is the 'subsurface
gravity drain system'(SGD), which is also hydrodynamically based. The primary
design objectives for hydrodynamically based systems are the establishment and
maintenance of pressure drops that are sufficient to control the movement of
all targeted zones of the aquifer, the reduction of contaminants to target
levels as rapidly as possible, and the removal of the minimum possible volume
of uncontaminated water.
In-situ- treatment (1ST) of wastes is the most rapidly emerging ground-
water clean-up technology. It can be either chemically- or biologically-
driven; but it is always hydrodynamically dependent, as well. The exact
mechanism of chemically-driven 1ST depends upon the properties of the
contaminant (e.g., the formation of insoluble precipitates for the removal of
metals, wet oxidation for organics, etc.), and the exact mechanism of
biologically-driven 1ST varies with the amount of nutrients, dissolved oxygen
levels, and contaminant levels. In each case, however, the role of
hydrodynamics in delivering reactants to the proper sites so that 1ST can be
effective is an overriding one.
There are other clean-up tools, such as partial excavation and subsurface
barrier walls (SBW), which, while inappropriate as singular solutions to
ground-water contamination problems, are appropriate in supplimentary roles.
SBW's, for example may be used to minimize the amount of uncontaminated water
available to PAT's and SGD's. They may also be used to gain more precise
control over the residence time of ground-water undergoing 1ST.
In view of the fundamental role of hydrodynamics in effecting ground-
water clean-ups, this discussion will highlight practical considerations in
the design, construction, operation, and performance monitoring of
hydrodynamically based ground-water clean-up systems. The treatment of
contaminated water that is collected by such systems will also be discussed,
by brief review of commonly employed methods (e.g., air stripping, GAC
filtration, precipitation, etc.).
This discussion makes extensive use, by reference, of the U.S.EPA
Handbook Remedial Action at Waste Disposal Sites (EPA, 1985). While the
author of this document was not involved in producing the EPA Handbook, he
believfes that - the EPA Handbook is generally well written_;and. complete. He
intends, therefore, that the EPA Handbook (specifically, Chapters 5, 9, 10,
and 11) be used as a companion document. to this brief summary of his verbal
presentation. Mention is made here of those instances where his opinion
differs from material presented in the EPA Handbook. Due to the extensive
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nature of the citations from the EPA Handbook, they will appear with the
table, figure or chapter-page number in the parenthetical reference; e.g.,
'(EPA, 1985: cp.5-1)'. Similarly, a few of the author's earlier works are
frequently cited (e.g., "Optimizing Pumping Strategies for Contaminant Studies
and Remedial Actions"), and their references therefore appear with specific
table, figure, or page numbers. Other sources of information are referenced
in the usual format. A complete list of references appears at the end of this
synopsis.
Pump-and-Treat Systems (PAT's)
There is probably no more effective method of generating substantial
changes in the direction and rate of flow of ground water than by the ..action
of pumping and injection wells. The principle involved is purely physical;
lower or raise the pressure locally and an immediate convergence or divergence
of flow lines is centered on the source of the pressure change. In terms of
well hydraulics, the regional flow system suffers a local disturbance; the
flow system becomes nearly radial close to the well. Not only does ground-
water flow to a pumping well from the [pre-operational] upgradient side of the
well, but from the [pre-operational] downgradient side also. The distance
downgradient that a pumping well will be able to draw waters-back to itself is
defined by Keely and Tsang (1983: p.702) as the 'stagnation point'.
The stagnation point of a single pumping well is defined more precisely
as occuring at that distance downgradient where the velocity of flow back to
the well, caused by pumpage, is directly offset by the velocity of flow away
from the well caused by the natural flow system. The stagnation point is the
downgradient limit of the 'capture zone' of a single pumping well; the lateral
limits of the capture zone are found at a distance from the centerline (e.g.,
the line that bisects the well along the upgradient-downgradient axis) equal
to pi times the stagnation point distance. The capture zone is that portion
of the aquifer that contains ground water that will be eventually 'captured'
and discharged by the pumping well; it does not include the entire zone of
pressure influence (drawdown cone) generated by the pumping well, unless the
natural flow system velocity is zero (Keely, 1984: p.65 and fig.l).
By reversing the frame of reference, it can be seen that a stagnation
point forms upgradient of injection wells. The push of waters out of the well
in the [pre-operational] upgradient direction is directly countered by the
movement of the natural flow system in the [pre-operational] downgradient
direction. The stagnation point that forms in this circumstance is at the
upgradient limit of the 'rejection zone'; the lateral limits of the rejection
zone are, of course, found at a distance from the centerline equal to pi times
the stagnation point distance. The rejection zone is that portion of the
aquifer which will eventually contain only injected water (the native water in
the formation is displaced first), and which does not allow the entry of
additional native waters. It does not include the entire zone of pressure
influence (injection cone) generated by the injection well, unless the natural
flow system velocity is zero.
Unfortunately,- most -publications still do not -provide adequate
distinction between the capture zone and the zone of pressure influence of a
well. One of the most popular ground-water textbooks (Freeze and Cherry,
1979) makes no mention of such a distinction, or of capture zones generally.
The same is true of a highly respected industry text (Driscoll, 1986). Todd
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(1980), does provides the mathematical description of. a capture zone, but does
not discuss the practical ramifications of its delineation. The EPA Handbook
provides some discussion of capture zones (EPA, 1985: cp.5-19 and 5-22), but
it couches design recommendations primarily in terms of drawdown (water level
declines caused by pumpage). It also does not carry the idea of capture zones
over into key figures (e.g., EPA, 1985: Fig.'s 5-2, 5-3, 5-5, 5-6), leaving
the reader a bit unsure of the message. The discussion of two or more wells
operating together (EPA, 1985: cp.5-12 and 5-15) focuses on drawdown effects
only.
When there are two or more pumping wells operating in unison, and they
are spaced closely enough, their individual capture zones coalesce into a
single collective capture zone. When that happens, the individual stagnation
points coalesce into a stagnation zone that is shared by the wells. If the
wells are not properly spaced, their individual capture zones will remain
intact and the portions of the aquifer lying between adjacent capture zones
will be free to move on downgradient (Keely, 1984: Fig.'s 4,5,6). Similarly,
when two or more injection wells are operating in unison, their individual
rejection zones will coalesce to form a single collective rejection zone only
if their spacing is appropriately close.
A number of approaches have been used to determine the optimal spacing of
pumping and injection wells. The most traditional approach is the use of well
hydraulics formulas to estimate the position and shape of the zone of pressure
influence surrounding a well (Lohman, 1972; Todd, 1980; EPA, 1985; Driscoll,
1986). This information is usually obtained as point estimates of the
drawdown caused by pumping wells or the piressure increase caused by injection
wells. When taken together with pre-operational water levels, estimated
drawdowns and pressure increases can be used to generate net/resultant water
level elevation maps for the operating conditions of a PAT. Capture zones and
rejection zones are identifiable on net water level elevation maps by their
elevation divides and closed contours; but the resolution of their positions
by this approach is subject to a number of errors due to the imperfect nature
of well hydraulics theory to date.
The mechanics of pumping and injection wells have been studied
intensively for a number of years, but there are still a number of gaps in the
theories that describe their hydraulic effects. For instance, the Theis
equation is completely satisfactory for describing the time-development of
pressure changes induced by a flowing well in a confined aquifer, provided
that the well is screened throughout the entire saturated thickness of the
aquifer and that certain other assumptions are met. No such equation exists
to satisfactorily describe the time-development of pressure changes induced by
a flowing well in an unconfined aquifer (also: 'water-table' or 'phreatic'
aquifer). Nor does an equation exist for the satisfactory description of
partial penetration and partial screening effects in unconfined aquifers. The
latter theoretical shortcomings are not inconsequential, since most PAT's for
ground-water clean-ups will involve the use of partially penetrating,
partially screened wells in unconfined aquifers and will have varying
operational characteristics over time.
Numerical models can be used in lieu of the Theis equation or other
analytical models to determine the effects of pumping and injection wells, and
they offer the advantage of being able to incorporate complex aquifer
boundaries; but numerical models have their limitations too. The ability to
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incorporate complex boundary conditions is useful only if one can accurately
establish the type and orientation of the boundary. Moreover, numerical
solutions are grid-block-by-grid-block discretized approximations of the real
world, as opposed to the exact continuous representations offered by
analytical models. Hence, numerical models may incur errors, such as
numerical dispersion and numerical oscillation, that are not encountered with
analytical models.
Having stated the preceeding, it may seem that the author believes that
neither the theories nor the tools exist to properly design PAT's; but this is
not so. Rather, it is important to place what is known in perspective; the
magnitude of errors arising from the simplifying assumptions of analytical
models and the discrete approximations of numerical models must be understood
and estimated on a site-specific basis. Just as importantly, the natural
processes that control contaminant movement (e.g., advection, dispersion,
sorption, biotransformation, etc.) must be identified and their relative roles
estimated for each situation (Keely and others, 1986).
The importance of understanding the effects of natural flow systems on
PAT's is that the same well spacings and flow rates that provide effective
hydrodynamic control over a target zone, will not be-able to-maintain control
when the natural flow system velocity increases by a modest amount; e.g., as
by seasonal shifts in the direction and magnitude of the local hydraulic
gradient (Keely, 1984: Fig.'s 2-6). Recent field experiments indicate that
the hydraulic conductivity distribution, particularly its changes with depth,
causes the majority of the spreading of a contaminant plume over time due to
the velocity stratification, that results (Molz and others, 1986). True
hydrodynamic dispersion, contrary to previously held beliefs, provides very
little dilution or spreading.
PAT's are often protracted in heterogeneous aquifers, because
contaminants located in low permeability strata move very slowly (often,
diffusion limited) relative to those in adjacent strata of higher
permeability, and because the strengths of sorptive and biotransformation
influences that contaminants exhibit apparently change with the grain size and
organic carbon content .of each stratum. Conventionally, PAT's are designed to
operate continuously, at constant pumping rates. Under these circumstances,
steady-state flowpaths and contaminant transport pathways are generated.
Given such conditions, the combined rapid contaminant removal from high
permeability strata and slow contaminant removal from low permeability strata
will produce an exponential decline of contaminant concentrations in the
discharge of the pumping wells. The 'tail' of this exponentially declining
concentration curve represents ongoing contributions from reserves of
contaminants in low permeability strata, long after the high permeability
strata are 'clean'.
If a continuous operation is shut down prior to being able to remove
contaminant reserves in low permeability strata, then it is likely that
contaminant concentrations in adjacent high permeability strata will soon
increase. In the absence of pumping, contaminants continue to slowly diffuse
out of low permeability strata and into adjacent high permeability strata
where their levels soon reach maximum, equilibrium concentrations. This
situation can be taken advantage of, by purposely operating the PAT
intermittently (e.g., 'resting' and 'duty' cycles) so that the minimum volume
of contaminated water is extracted.
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The removal of contaminants from an aquifer is only one function of
PAT's, however. PAT's also effect hydrodynamic control over plumes,
preventing their further migration. There is thus a need to provide a means
for maintaining hydrodynamic control when a PAT is in the 'resting' cycle.
Additional pumping and/or injection wells, somewhat removed from the immediate
vicinity of the plume, can be used for this purpose.
The latter point raises questions about how one ought to monitor the
performance of PAT's. Neither contaminant distributions nor velocity
distributions are constant throughout the 'zone of action1- (that portion of an
aquifer that is actively being manipulated, as by remediation with a PAT) .
Consequently, monitoring strategies must be cognizant of the need to detect
rapid, sporadic changes in the quality of ground water at any specific point
in the zone of action. What this means in practice is that tracking the
effectiveness of PAT's is quite complicated chemically; the frequency and
density of samplings must consider the detailed flowpaths that have been
generated by the PAT. It also means that it may be necessary to move the
chemical compliance points during the course of a remediation.
Nor 'are evaluations of the hydrodynamic performance--of PAT's easily
accomplished. For example, it is usually required that an inward hydraulic
gradient be maintained at the periphery of a contaminant plume. This
requirement is imposed to ensure that no portion of the plume is free to
migrate away from the zone of action. To adequately assess this performance,
the hydraulic gradient must be accurately measured in three dimensions between
each pair of adjacent pumping or injection wells.
The design of an array of piezometers (small diameter wells with very
short screened intervals, that are used to measure the pressure head of
selected positions in an aquifer) is not as simple as one might first imagine.
Two points define a line, and three points define a plane; but many more are
needed to define the kind of convoluted surface that develops between adjacent
pumping or injection wells. Not only are there velocity divides in the
horizontal plane near active wells, but in the vertical plane, too; the
pressure influence of wells does not extend to infinite depths.
Subsurface Gravity Drain Systems (SGD's)
The manner in which SGD's function is similar to PAT's, because the
operating principle is again hydraulic. The driving force, however, is
primarily gravity drainage, using a horizontally laid system of buried
perforated laterals and collector pipes (EPA, 1985: cp.5-46). Some pumpage is
required, for removal of the fluids accumulated by gravity flow to central
collection sumps. Because of these construction differences, most SGD's are
designed to operate at low flow rates and in shallow submergence situations.
Ground-water levels are depressed locally by the loss of fluid to the
perforated laterals and collectors of SGD's. As depicted in the Handbook
(EPA, 1985: Fig. 5-17), these depressions are linear, due to the straight-pipe
configuration of"SGD's. Theflowrate at which the fluids are removed from the
aquifer depends on the diameter of the lateral and collector pipes, the slope
of their installation ('drain grade'), and to some degree on the rate at which
the collector sump is pumped. This relationship is limited by the ability of
the formation to yield fluid to the system under gravity drainage, especially
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when the laterals and collectors - are not completely submerged. There is a
lower limit of operation, also; the flow velocity inside the lateral and
collector pipes must exceed 1.4 feet per second to avoid siltation of
particles, unless a fabric filter protects all pipe perforations (EPA, 1985:
cp.5-60).
Two variations of SGD's are common, interceptor drain systems and relief
drain systems; with the variations based on intended use. Interceptor drain
systems are installed perpendicular to the direction of ground-water flow, and
are typically used to remove an advancing contaminant plume. The orientation
"of a relief drain system depends on the objective^ Relief drains are usually
installed parallel to the direction of ground-water flow when they are used in
conjunction with interception drains; the relief drains provide control of the
hydraulic gradient laterally (EPA, '.985: Fig.5-21). Relief drains are also
installed circumferentially when the objective is strictly hydrodynamic
control of the enclosed area.
Note, however, that the effects of SGD's do not extend to significant
depths below the horizontal pipes, despite the radial flow that develops when
they are not resting on a low permeability stratum (EPA, 1985: Fig.s 5-24 and
5-25). Note also that SGD's must be installed by trench.:jand-fill methods;
which means that it may not be possible to install them onsite. Because of
these limitations, and the low flowrates usually achievable, SGD's normally
can not be used to perform the same functions as PAT's.
Clogging of SGD's by chemical precipitates or biological growth is. a
major operational concern. Chemical precipitation occurs readily where the
chemistry of the contaminated ground water differs markedly (especially in pH
and dissolved oxygen level) from that of the native ground water. The same
conditions often promote growth of anaerobic bacterial slimes (e.g., from
iron- and sulfur-utilizing bacteria). Biofouling also may result from
byproducts of biotransformation, since the biota may use contaminants as
carbon sources to build proteins and mucous polysaccarides.
Monitoring the performance of SGD's is fraught with the same difficulties
that attend monitoring the performance of PAT's. The flowpaths and
contaminant transport pathways that develop during operation of SGD's again
ensure that rapid and sporadic contaminant concentrations will occur. The
water levels also become a convoluted surface during operation of the system,
and are subject to radical changes with seasonal variations in the local
hydraulic gradient.
Above Ground Treatment Systems fAGT's')
It is beyond the scope of this presentation/synopsis to detail the
operational characteristics of each of the possible AGT's. Consequently, the
appropriate uses, advantages, and limitations of several widely employed AGT's
will be discussed. Special considerations in the design of treatment trains
(specific arrangements of unit treatment processes) will also be discussed.
Finally, the reader will be directed to specific readings for additional
details.
Water has been successfully treated for the removal of contaminants for
centuries. Some of the ancient practices form the basis of advanced
technology today, such as sand filtration, air stripping, and polishing with
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charcoal/activated carbon. Other techniques have been developed and improved
since the turn of the century (e.g., biological and chemical treatments); and
still others have been pioneered much more recently (e.g., selective resins,
reverse osmosis, and electrodialysis).
The choice of which treatment to use is dependent on the kinds and
concentration levels of contaminants in the water to be treated. Ground-water
contamination can arise from a large number of possible sources, however, so
it has no predictable treatment characteristics. As a result, the only sure
way to determine the probable efficiency of a particular AGT is to perform
treatability studies (Canter and Knox, 1985; Tchobanoglous and Schroeder,
1985). These are usually bench-scale experiments, that yield treatment
parameters; such as the biological oxygen demand generated in the treatment
process, and the optimal residence time and temperature.
There are some useful generalizations about AGT's, however. Nyer (1985)
indicates that highly contaminated water may be treated by the same methods
used to treat industrial wastewaters. He notes that biological treatments are
especially useful in removing organic compounds. These include aerated
lagoons, activated sludge chambers, fixed film reactors, etc.; the highest
percentage of removal (>99% of specific organics) is achieved with activated
sludge treatment, and the lowest with aerated lagoons (50-70% of the
biodegradable organics). The cost per pound of contaminant removed is usually
quite low for aerated lagoons, and much greater for fixed film and activated
sludge AGT's.
Chemically-based AGT'S are also used to treat highly contaminated water.
These typically include neutralization, precipitation, flocculation, and
filtration steps (Tchobanoglous and Schroeder, 1985; EPA, 1985). These steps,
or unit processes, can be ordered in any number of sequences so that specific
compounds can be removed to low levels. Chemically-based AGT's are most often
used in conjunction with other AGT's, such as selective resins and carbon
filtration, that serve to further reduce the contaminant concentrations.
At moderately low concentrations (ug/L to low mg/L) air stripping is
usually the most efficient and cost-effective AGT; for nonvolatile compounds,
of course, this generalization does not hold. At very low concentrations (low
ug/L or less) , the most effective AGT is usually activated carbon or compound-
selective resins. Reverse osmosis and electrodialysis AGT's are effective
over a broad range of concentrations, as is activated carbon, but they also
share much of its prime disadvantage: high cost.
The literature is ripe with information on each of the unit processes;
e.g., the Cheremisinoff reviews of liquid filtration equipment (1985a),
volatile organic solvent recovery systems (1985b), and fluid flow measurement
devices (1985c), the discussion of powdered carbon treatment of high-strength
landfill leachate by Copa and Meidl (1986), the special report on chemicals
for wastewater treatment by Newton (1985), the description of a major air
stripping installation for the removal of TCE and other solvents from a City
of Tacoma, Washington well (1985), the results of a bench scale treatability
study for cleanup and closure of a PCB contaminated pond (1986) , BAT design
recommendations for treatment of chrome electroplating waste (1983), various
incineration options (Erlandsson, 1983; Williams,1982; McBride and Heimbuch,
1982), and updates on wastewater treatment (Cheremisinoff, 1986) and water
pollution control (Lorenz and Sellars, 1985).
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There are also a number of comprehensive technical information transfer
documents that have been prepared by or for the EPA; e.g., the compendium on
hazardous waste treatment by Brown and Associates (1980), the guidance on
managing hazardous waste leachate by Shuckrow and others (1980) , the
proceedings of a conference on the land disposal of hazardous waste as edited
by Shultz (1982), the discussion of treatment of petroleum refinery sludges
using land application techniques by Streebin and others (1984), the EPA brief
on alternatives to hazardous waste landfills (1986) , the EPA Handbook on
remedial action at waste disposal sites (1985), the EPA summary report on
remedial response at hazardous waste sites (1984), and a compilation of case
studies of the reclamation and redevelopment of contaminated land by Kingsbury
and Ray (1986) . In addition, the collection of papers on the land treatment
of hazardous waste as edited by Parr, Marsh and Kla (1983^ provides much
useful material, as do standard textbooks on the treatment of water and
wastewater (e.g., Tchobanoglous and Schroeder, 1985).
In-Situ Treatment Systems (IST's)
The most sociopolitically attractive treatment is that which can remove
the contaminant "threat in place, in-situ. In -situ treatment, at least the
biologically-driven kind, also holds promise to be the most cost-effective
treatment method. The principles of 1ST are essentially the same as for
AGT's. The neutralization and precipitation of metals, the wet chemical
oxidation of nonbiodegradable contaminants, and the biological destruction of
susceptible contaminants are all possible. There are a number of differences
between 1ST and AGT that do not favor 1ST, however.
The tremendous variability of mineral composition and physical properties
of the subsurface over very short distances means that treatment must occur in
an environment that is teeming with possible interferences and side-reactions.
Treatment efficiencies are therefore likely to be very poor, unless the
treatment can be made highly compound-specific. The latter is possible for
biologically-driven 1ST, because indigenous organisms can be aclimated and
adapted to the utilization of a specific contaminant as their food source or
energy-trading partner. Hence, a number of successful instances of
biologically-driven 1ST have been reviewed (Brown and Brubaker, 1985; Wilson
and others, 1986; Amdurer and others, 1986).
By far, the best success has been with biodegradation of naturally
derived chemical contaminants, such as petroleum products. Chlorinated
solvents have been partially degraded, and while the efficiencies of the
individual compound transformations that have taken place are impressive,
there is concern that the daughter products from these transformations may be
more toxic and mobile than the parent compound; e.g., the successive reductive
dehalogenation of tetrachloroethene to yield trichloroethene, trans-1,2
dichloroethene, and vinyl chloride (Keely and others, 1986).
Chemically-driven 1ST has its own advantages and disadvantages.
Oxidizing agents can be used to promote the formation of insoluble metal
oxides and hydroxides. The destruction of hydrolyzable organic compounds such
as amines and epoxides can be affected by altering the pH locally (Amdurer and
others, 1986). Reducing agents can be used to facilitate the deposition of
certain trace metals and nonmetals (e.g., mercury, selenium, and arsenic), and
to drive common mineral reactions toward the appearance of more reduced
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contaminant species (e.g., Fe++ and Cu+). Surfactants are useful for the
mobilization of immiscible oils and solvents. The formation of stable
complexes (e.g., metal chelates) may be useful in certain situations; just as
it is now relied on in mining and petroleum recovery.
A high degree of compound-specificity is probably .unachievable with
chemically-driven 1ST, however, because of the ability of so many different
contaminants and minerals to react with the same chemical reagents. The poor
efficiencies that might result are not of as much concern as the additional
water quality degradation that is possible (e.g., the 1ST chemicals
themselves, and the compounds they might bring into solution inadvertantly). ~
The most overriding concern for both chemically- and biologically-driven
1ST is for the hydrodynamic difficulties that must be overcome to get
effective delivery of the chemicals or nutrients and oxygen to the targeted
contaminants, and to effectively recover the reaction products and excess
reactants from the reaction sites. Wilson and others (1986) make this point
clear in their review of biologically-driven 1ST, as does Nyer (1985) in his
overview of ground-water treatment technology. The EPA Handbook (1985: ch.9)
provides a good overview of IST's, including some cost estimates. The most
comprehensive study of this issue to date, however, is a report prepared for
EPA by Amdurer and others (1986), which discusses delivery and recovery
systems in great detail and presents case studies of both chemically- and
biologically-driven IST's.
Supplemental Systems
Subsurface barrier walls (SBW's), partial excavation (PE), and lining and
capping (LC) are all useful adjuncts to PAT's, SGD's, and IST's. The
conjunctive use of these systems with other source control measures is well
known and accepted. Their uses have not as consciously extended to specific
enhancement of clean-up and treatment technologies. For example, it is common
to use SBWs to either divert upgradient ground water from flowing through the
contaminated zone (limiting local recharge), or to restrict further movement
of the contaminant plume with a downgradient cut-off wall. It is almost
unheard of, on the other hand, to emplace an SBW specifically to increase the
degree of hydrodynamic control exerted by a PAT or an SGD (through the
increased drawdown that wells and drains develop near barriers).
In this role, an SBW can be used to improve the cost-effectiveness of the
overall remediation. The greater drawdowns that result from SBW's being
placed adjacent to a PAT or SGD mean that the local gradients are steeper than
without the SBW and thus result in increased ground-water and contaminant
transport velocities; the remediation can be completed sooner. Alternatively,
the flowrates of pumping wells can be reduced and yet maintain the desired
degree of hydrodynamic control, compared with the situation where an SGD is
installed; this is desirable if one is simply trying to isolate a plume with
the minimum of treatment of withdrawn fluids. The most obvious advantage to
the conjunctive use of SBW's is that the contaminated zone, or a highly-
contaminated subsection, may be effectively isolated from clean ground-water
in the formation. This ensures "that only the minimum volume of fluids are
extracted over the life of the remediation. It also ensures that the fluids
that are extracted will be at the highest concentrations possible, so that
contaminants are removed in the most efficient range of the treatment process.
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Closing Comments
Ground-water clean-up technologies are still evolving. There is much to
be learned about how to design and conduct highly specific and cost-effective
remedies. Much more than is presently being done, however, could be
accomplished if the processes that govern the environmental behavior and
treatability of contaminants were actively investigated at each site. The
past history of performing the bare minimum of field characterization efforts
(other than chemical samplings) has not led to complete or satisfactory
remediations, generally. This penny-wise/pound-foolish approach must give way
to a more site-characterization-intensive approach before meaningful
improvements in the specificity and cost-effectiveness of remediations can be
realized (Keely and others, 1986).
There are a lot of misconceptions and misunderstandings regarding the
effects that key hydrodynamic, chemical, and biological processes have on the
transport of contaminants in the subsurface. Some of these, such as the
confusion over capture zones and drawdown cones of pumping wells that was
discussed early in this document, are relatively easy to address by
educational efforts. Others, such as the controversy over just what
hydrodynamic dispersion is in a physical sense, or the. way,Jthat sorption and
biotransformation rate constants ought to be derived and subsequently used in
predictive models, can only be addressed by further studies. These studies
should not be restricted to the artificially constructed, tightly controlled
environment of academic laboratories or special experimental field plots.
Rather, the earliest opportunities to conduct such work at actual hazardous
waste sites is needed. The SITE (Superfund Innovative Technology Evaluation)
program of the EPA is a positive step in this direction.
References
Amdurer, M., R.T. Fellman, J. Roetzer, C. Russ. 1986. Systems to accelerate in
situ stabilization of waste deposits. U.S. EPA Office of Research and
Development, publication no. EPA/540/2-86/002. U.S. EPA, Hazardous Waste
Engineering Laboratory, Cincinnati, OH; 264 pages.
Brown, K.W. and Associates, Inc. 1980. Hazardous waste land treatment. U.S.
EPA Office of Research and Development, contract no. 68-03-2940. U.S.
EPA, Municipal Environmental Research Laboratory, Cincinnati, Ohio, 974
pages.
Brown, R.A., R.D. Norris and G.R. Brubaker. 1985. Aquifer restoration with
enhanced bioreclamation. Pollution Engineering. November, 1985 issue; pp.
25-28.
Canter, L.W. and R. C. Knox. 1985. Ground water pollution control. Lewis
Publishers, Inc.. Chelsea, Michigan; 526 pages.
Chacey, K., L. Mellichamp and B. Williamson. 1983. Chrome electroplating waste
b.a.t. Pollution Engineering. April, 1983 issue; pp. 20-23.
Cheremisinoff, P. N. 1985a. Special editorial report: liquid filtration
equipment. Pollution Engineering. February, 1985 issue; pp. 43-53.
Cheremisinoff, P. N. 1985b. Special report: volatile organic compounds.
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Pollution Engineering. March, 1985 issue; pp. 29-38.
Cheremisinoff, P. N. 1985c. Special report: fluid flow measurement. Pollution
- Engineering. November, 1985 issue; pp. 17-23.
Cheremisinoff, P. N. 1986. Update on wastewater treatment. Pollution
Engineering. September, 1986 issue; pp. 20-25.
Copa, W. M. and J. A. Heidi'. 1986. Powdered carbon effectively treats
toxic leachate. Pollution Engineering. July, 1986 issue; pp. 32-34.
Driscoll, F.G. 1986. Groundwater and wells, second edition. Johnson Division,
UOP Inc., St. Paul, Minnesota; 1089 pages.
Erlandsson, K. I. 1983. Co-incineration/energy recovery of liquid and solid
wastes. Pollution Engineering. April, 1983 issue; pp. 36-39.
EPA. 1984. Summary report: remedial response at hazardous waste sites.
U.S. EPA. Office of Research and Development and Office of Emergency
and Remedial Response, publication no. EPA-540/2-84-002a. U.S. EPA,
Municipal Environmental Research Laboratory, -Cincinnati, OH. and U.S.
EPA, Washington, D.C., 93 pages.
EPA. 1985. Handbook - remedial action at waste disposal sites (revised). U.S.
EPA Office of Emergency and Remedial Response, publication no. EPA/625/6-
85-006. U.S. EPA Office of Research and Development, Hazardous Waste
Engineering Research Laboratory, Cincinnati, Ohio (numbered by chapter).-
EPA. 1986. Treatment technology briefs - alternatives to hazardous
waste landfills. U.S. EPA publication no. EPA/600/8-86/017. U.S. EPA,
Hazardous Waste Engineering Research Laboratory, Cincinnati, OH, 35
pages.
Freeze, R.A. and J.A. Cherry. 1979. Groundwater. Prentice-Hall, Inc.,
Englewood Cliffs, New Jersey; 604 pages.
Kane, J.E. and J.V. Mehta. 1986. Cleanup and closure of a pcb contaminated
pond. Pollution Engineering. July, 1986 issue; pp. 28-30.
Keely, J.F. 1984. Optimizing pumping strategies for contaminant studies and
remedial actions. Ground Water Monitoring Review, v.4, no.3, pp.63-74.
Keely, J.F., M.D. Piwoni, and J.T. Wilson. 1986. Evolving concepts of
subsurface contaminant transport. Journal Water Pollution Control
Federation, v.58, no.5, pp.349-357.
Keely, J.F. and C.F. Tsang. 1983. Velocity plots and pumping centers for
ground-water investigations. Ground Water, v.21, no.6, pp.701-714.
Kingsbury, G.L. and R.M. Ray. 1986. Reclamation and redevelopment of
contaminated land: volume i. u.s. case studies. U.S. EPA Office of
Research and Development, publication no. EPA/600/2-86/066. U.S. EPA,
Hazardous Waste Engineering Research Laboratory, Cincinnati, OH, 186
pages.
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Lorenz, W. T. and C. A. Sellers. 1985. Water pollution control
industry in the 80s. Pollution Engineering. September, 1985 issue; pp.
25-28.
McBride, J.A. and J.A. Heimbuch. 1982. Skid mounted system gives California
haz wastes hot time. Pollution Engineering. July, 1982 issue; pp. 24-26.
Molz, F.J., 0. Guven, J.G. Melville, and J.F. Keely. 1986. Performance and
analysis of aquifer tracer tests with implications for contaminant
transport modeling. U.S. EPA Office of Research and Development
publication no. EPA/600/2-86-062. U.S. EPA Office of Research and
Development, Robert S. Kerr Environmental Research Laboratory, Ada,
Oklahoma, 88 pages.
Newton, J.J. 1985. Special report: Chemicals for wastewater treatment.
Pollution Engineering. November, 1985 issue; pp. 42-47.
Parr, J.F., P.B. Marsh, and J.M. Kla. 1983. Land treatment of hazardous waste.
Noyes Data Corporation, Park Ridge, NJ, 419 pages.
Schilling, R.D. 1985.-Air stripping provides fast solutiorv-JEor polluted well
water. Pollution Engineering. February, 1985 issue; pp. 25-27.
Schultz, D.A. (ed.) 1982. Land disposal of hazardous waste., Proceedings of
the eighth annual research symposium at Ft. Mitchell, Kentucky, March 8-
10, 1982 U.S. EPA Office of Research and Development, publication no.
EPA-600/9-82-002, U.S. EPA, Municipal Environmental Research Laboratory,.
Cincinnati, OH, 534 pages.
Shuckrow, A.J., A.P. Pajak and C.J. Touhill. 1980. Management of hazardous
waste leachate. U.S. EPA Office of Research and Development, no. SW-871,
U.S. EPA, Municipal Environmental Research Laboratory, Cincinnati, OH.
Streebin, L.E., J.M. Robertson, H.M. Schornick, P.T. Bowen, K.M. Bagawandoss,
A. Habibafshar, T.G. Sprehe, A.B. Callender, C.C. Carpenter, and V.J.
McFarland. 1984. Land treatment of petroleum refinery sludges. U.S. EPA
Office of Research and Development, publication no. EPA-600/2-84-193.
U.S. EPA, R.S. Kerr Environmental Research Laboratory, Ada, OK, 181 pages
Tchobanoglous, G. and E.D. Schroeder. 1985. Water quality. Addison-Wesley
Publishing Co., Menlo Park, CA, 706 pages.
Todd, D.K. 1980. Groundwater hydrology, second edition. John Wiley and Sons,
New York; 535 pages.
Williams, I.M. Jr. 1982. Pyrolytic incineration destroys. Pollution
Engineering. July, 1982 issue; pp. 34-36.
Wilson, J.T., L.E. Leach, M. Henson, and J.N. Jones. 1986. In situ
biorestoration as a ground-water remediation technique. Ground Water
Monitoring Review, v.6, no.4, pp.56-64.
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ABSTRACT
COST-EFFECTIVENESS: SITE CHARACTERIZATION VS. REMEDIAL ACTION EFFORTS
Joseph F. Keely
Oregon Graduate Center
Dept. of Environ. Science & Engr.
The recent passage of the Superfund Extension and Reauthorization Act
(SERA) marks a major turning point in the Nation's efforts to clean up the
most potentially harmful of its 25,000+ uncontrolled hazardous waste sites.
SERA brought to the Superfund program enormously increased funding, improved
regulatory authority, specified clean-up levels and timetables, and direct
community involvement. Congress made it clear that these improvements are to
lead to permanent solutions; 'mitigation' of the "imminent and substantial
endangerment to human, health and welfare - and the environment" posed by such
sites is no longer sufficient. Innovative technologies are to be encouraged,
as well.
Each of the foregoing facts underscores the need for ever more careful
and detailed site investigations. Where past site investigations often
generated little more than a handful - of chemical and hydraulic snapshots of.
site conditions, future site studies should routinely incorporate state-of-
the-art tools and techniques that can elucidate preferential pathways for
contaminant migration. These include vertically clustered wells, aquifer
tests, geophysical surveys, and sorption and biotransformation experiments.
By employing such tools and techniques, the likelihood of determining the true
extent and geometry of the contaminated zone is markedly improved; so the
problem can be properly conceptualized. Similarly, the degree of certainty
regarding specific pathways along which future contaminant migration will
occur is greatly increased; so the remedy selected will be the most
appropriate, and its implementation will occur in the most effective manner.
Hence, increased costs associated with more detailed site characterization
efforts should be more than offset by reduced clean-up costs. Other,
associated costs may be significantly reduced, too. Examples include the
acceleration of negotiations with potentially responsible parties, the
establishment of more specifically targeted monitoring and compliance points,
and improved support for natural resource damage claims.
To be presented at:
NWWA's Focus Northwest Conference
Portland, Oregon
May 5-7, 1987
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ABSTRACT
MONITORING WELL INSTALLATION, PURGING, AND SAMPLING TECHNIQUES
PART I: CONCEPTUALIZATIONS & PART II: CASE HISTORIES
Joseph F. Keely and Kwasi Boateng
The degree to which hollow-stem augering disturbs the near-borehole
environment, and how this may result in the movement of contaminated solids or
fluids from one stratum to another can be of great concern. The smearing of
natural clays into sand and gravel strata exposed in the borehole, for
example, can result in decreased permeabilities locally and disproportional
flow contributions from the exposed strata to the completed monitoring well.
The difficulty rt emplacing an effective filter pack and the generally poor
quality of well development that is possible using hollow-stem augers are
other disadvantages.
Mud rotary and reverse rotary drilling often must use a heavy drilling
fluid, which may conduct or affect contaminants; even if pure water is used as
the drilling fluid, there are concerns as to how the large volumes used will
affect the distribution of contaminants locally. Cable-to^l drilling is an
exceptionally good method in that a temporary casing is used that shields each
stratum encountered from those above it, and a large diameter (e.g., 12in /
30cm) borehole is available within which an effective filter pack can be
properly emplaced around a modest diameter monitoring well (e.g., 4-6in / 10-
15cm); unfortunately, it is somewhat slow and expensive. Despite a similar
use of a temporarily driven casing, the potential- for excessive . emmissions of.
dangerous vapors from the borehole while drilling with air rotary equipment
makes it a questionable choice at many waste sites. A hybrid drilling
technique, augering with a temporary casing, is able to provide the
advantages, and minimize the disadvantages, of the foregoing drilling methods.
Inadequate purging prior to sampling has been consistently identified as
a major factor that adversely affects the accuracy and precision of sample
data. There have been a number of studies that recommend how many borehole
volumes to purge, but little has been said regarding the placement of the
purge device. For those monitoring wells that have appreciable volumes of
water in casing storage above the screen, a 'staged' purging method provides
the best removal of stored water. Without this method, bailers may sample a
mixture of stagnant casing waters and fresh aquifer waters.
Studies of sampling devices to date may not have adequately considered
the performance of mechanically-driven positive-displacement devices. An ad
hoc field experiment indicates that one such device, a stainless - steel
submersible pump specifically designed for monitoring wells, performed at
least as well as did a stainless-steel bailer. There is a need for much more
work in the way of field verification of laboratory studies on the effects of
sampling materials and devices.
Case histories are presented to underscore thesecomments.
To be presented to:
NWWA's Focus Northwest Conference
Portland, Oregon
May 5-7, 1987
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ABSTRACT
CHALLENGING THE STATUS QUO OF GROUND-WATER MONITORING
Joseph F. Keely
Oregon Graduate Center
Dept. of Environ. Science & Engr.
For most of the past decade, ground-water scientists and engineers have
avidly debated the salient features of various monitoring well designs and
sampling devices, all in the name of obtaining a 'valid' ground-water sample.
Cries continue to be heard for the establishment of mandatory sampling
protocols, but these typically dote on the materials that wells and samplers
are made of, the number of borehole volumes that must be purged prior to
sampling, and how the sample is to be preserved for analysis. What most often
goes unspoken are the concerns that one ought to have for what portion of the
subsurface each sample truly represents.
The normal circumstance has been much like the response Alice received in
Wonderland from Humpty Dumpty ( "When I use a word it means just what I choose
it to mean, no more and no less."); paraphrasing, 'when I take a sample it
represents just what I choose it to represent, no more and no less'. If the
sample was obtained from the only monitoring well that is located on a three
acre portion of a study area, then data generated, from analyses of that ..sample
will be assumed to represent the entire three acres. If a model is being
constructed the measured data point will be used to generate numerous
additional point estimates (e.g., at grid nodes) by an interpolation scheme.
When the model is calibrated, the measured data points will be the final
arbiter. If the measured data values cannot be faithfully regurgitated by the
model, then the modeler ends up adjusting estimates of important parameters
(i.e., hydraulic conductivity and dispersivity). Unfortunately, those
parameters are physically based and unique to the situation being modeled;
changing them arbitrarily risks proliferation of the 'black box' plague.
Examination of data obtained by the chemical time-series sampling
technique indicates that concentration levels can vary over orders of
magnitude as the sample size is increased. Such data may possess identifiable
trends or they may be random; regardless, they provide a means of estimating
the statistical properties of concentrations at the well. An obvious use of
such data is improvement of estimates of the mean concentrations of
contaminants locally. A second, important use is to provide larger
calibration targets; e.g., an acceptable match is found if the modelled value
falls within two standard deviations of the mean concentration value.
Finally, by such an approach it may be possible to determine just what a given
sample does represent so that previously noncomparable data (e.g., from
municipal supply wells vs. monitoring wells) may be made comparable.
To be presented to:
NWWA's Outdoor Action Conference
Las Vegas, Nevada
May 18-21, 1987
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USER'S MANUAL FOR CAPZONE/VELDSTR PROGRAM
Version 1.0
(for Radio Shack PC-2 and Sharp PC-1500 microcomputers)
by
Dr. Joseph F. Keely, P.Hg.
Copyright ฐ 1986 by Joseph F. Keely, Jr.
All Rights Reserved
No part of this publication may be
photocopied, photographed, or reproduced
electronically or by other means,
whether for personal or public use,
without the express written consent
of the author.
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USER'S MANUAL FOR CAPZONE/VELDSTR PROGRAM
(Radio Shack PC-2 / Sharp PC-1500 Version)
by
Joseph F. Keely
Introduction
The CAPZONE/VELDSTR (CAPture ZONE / VELocity DiSTRibution) program
is a BASIC language code that computes:
(1) regional velocities from, field data (e.g., hydraulic
conductivity, hydraulic gradient, and effective porosity),
(2) the dimensions of the capture zone of a single pumping well
(specifically, the distance to the downgradient stagnation
point and the maximum width upgradient), and
(3) the net velocity vector characteristics at an arbitrary number
of observation points for an arbitrary number of pumping and
injection wells. Outputs include the X- and Y-components, the
magnitude, and the compass bearing of the velocity vector (in
degrees).
The BASIC language code for this program was developed on a Radio
Shack PC-2 handheld microcomputer (same as the Sharp PC-1500), and is
presented in typed form in Attachment A. A hardcopy of the code is
presented in Attachment B (using CSIZE 2 as the printing font), obtained
by entering the LLIST command after uploading the code into the program
memory core of the PC-1500". During execution of the program, prompts
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appear on the liquid crystal display of the unit and a hardcopy is output
to the paper-tape printer; these are explained below. Several examples
of the simulations possible with this code appear in Attachment C, and are
explained in a section following the discussion of prompts.
Theory
The supporting theory for computations of regional velocity
estimates, capture zone dimensions, and velocity distribution estimates
is fairly explicitly described in "Velocity Plots and Capture Zones of
Pumping Centers for Ground-Water Investigations" by Keely and Tsang
(Ground Water, vol.21, no.6, pp.701-714), so it will not be repeated
here.
Using CAPZQNE/VELDSTR
The CAPZONE/VELDSTR program is loaded into the memory of the Radio
Shack PC-2 or the Sharp PC-1500 per the standard instructions for
keystroke entry, or loading from a cassette (e.g., CLOAD
"CAPZONE/VELDSTR"). After loading into memory, the RUN command is
entered by keystroke and program execution begins immediately, with the
program title displayed on the liquid crystal display (LCD) at the same
time as it is being printed on the paper tape.
As soon as the title has been printed, a prompt appears on the LCD:
IS REG.VEL. KNOWN?(YorN)
If the regional velocity is known, the user enters Y (y is not allowed -
an error message will occur); if not, the user enters N. If N is entered,
a prompt appears on the LCD for the hydraulic conductivity of the aquifer
in question:
HYD.COND.(GPD/SQ. FT .)?
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The user enters the estimated value and the printer immediately lists the
same information. For convenience, equivalent values of hydraulic
conductivity are computed in feet per day and centimeters per day, and
also appear on the paper tape. A prompt then appears on the LCD for the
hydraulic gradient, which the user responds to in kind. This process is
repeated once more, for the effective porosity estimate. As sonn as this
is done, the regional velocity estimate is computed and is printed on the
paper tape in both feet per day and centimeters per day.
After the regional velocity estimate is printed, a prompt appears on
the LCD, which is the same prompt that would have appeared had Y been
entered in response to IS REG.VEL. KNOWN?(YorN):
C-ZONE or V-DISTR.?(CorV)
If C is entered a series of prompts will appear on the LCD for the
regional velocity, the effective saturated thickness, the effective
porosity, and the flow rate of the well in question. The user responds to
each of these, the printer confirms the entries, and the dimensions of the
capture zone (distance to downgradient stagnation point and maximum width
of the capture zone upgradient) are printed on the paper tape. The
program then asks the user if more calculations are desired:
MORE CALCULATIONS? (YorN)
If Y is entered, the IS REG. VEL. KNOWN (YorN)? prompt appears again.
If N is entered, PROGRAM OVER, THANK YOU is printed on the paper tape
and execution of the program ceases; the > prompt appears on the LCD,
indicating that the computer is ready for a new BASIC command
(CAPZONE/VELDSTR remains in the core memory of the computer, but must be
activated with another RUN command).
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If V had been entered in response to C-ZONE or V-DISTR.?(CorV),
the velocity distribution part of the code would have been invoked. The
user would have been prompted for the regional velocity, the direction of
regional flow in compass bearing degrees (Figure 1), the effective
saturated thickness, the effective porosity, and the total number of
pumping and injection wells involved. At this point, the computer would
begin prompting for the flow rate and X- and Y-coordinates of each well
(see Figure 1 for the orientation of the X- and Y-coordinates, relative to
the regional flow).
In this program, pumping wells have positive flow rate values,
injection wells have negative flow rates. If too many wells are
accidentally asked for, entering a zero flow rate for a well is allowed
and results in effectively removing it from the analysis. When the
information for all wells has been entered, the computer will prompt for
the nunber of observation points desired. It then sequentially prompts
for the X- and Y-coordinates of the first observation point. As soon as
the user has entered these, the X- and Y-components of the net velocity,
the net velocity itself, and the net flow direction of the aquifer at that
observation point are printed on the paper tape. This process is repeated
for all observation points, after which the MORE CALCINATIONS? (YorN)
prompt appears on the LCD.
Capture Zone Simulations
Typical runs of CAPZONE/VELDSTR are shown in Figures 2 through 5.
The first of these illustrates computations of capture zone dimensions.
As shown there (Figure 2), 'calculation no.l' included estimation of the
116
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regional velocity, which was 1.002673797 ft/day. [The large nunber of
digits behind the decimal are included only for comparisons of the
computational precision of certain problems the actual nunber of
significant digits for field use is, of course, limited to only one or
two]. This value of regional velocity is then used in a computation of
the dimensions of the capture zone that would result from a well pimping
50 gal/min from a 100-foot thick aquifer; the stagnation point would be
found 101.8591636 feet downgradient, and the maximum width of the capture
zone upgradient would be 640.0000001 feet.
'Calculation no.2' of Figure 1 assumes that the regional velocity is
negligible (0.001 ft/day), just to show that the capture zone would be
essentially infinite in the absence of regional flow, as is true of the
cone of depression (the two are identical when regional velocity is
zero). The dimensions of the capture zone are indeed practically
infinite; the distance to the downgradient stagnation point is more than
100,000 feet and its maximum width upgradient is more than 600,000 feet.
It is probably time to coin a new term to describe the problem
illustrated by -'calculation no.3' in Figure 1. As it happens, the effects
of an injection well are the mirror image of the effects of a pumping
well. Hence, a stagnation point forms upgradient of an injection well,
and there is a maximum width downgradient of the injected water flowing
away from the well. So, keeping all other inputs the same as for
'calculation no.l' of Figure 1, but specifying a pumping rate of -50
gal/min, the dimensions of what might be called the 'release zone' of the
injection well are computed.
117
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Lo and behold, the dimensions computed in 'calculation no.3' of
Figure 2 are identical to those computed for a positive pumping rate, but
these now carry a negative sign indicating that the stagnation point
and maximum width occur on the opposite side of the well as would happen
with a positive pupping rate. This might be useful, for example, to
estimate the amount of clean water injection necessary to create a
hydraulic 'umbrella' to shield a portion of an aquifer from an advancing
plune. This might be cheaper than punping and treating the plume,
particularly if the plune is of limited extent (as from a spill) and would
flow to less sensitive areas as a result.
In 'calculation no.A' of Figure 2 a new regional velocity estimate is
first computed (2.896613191 ft/day), using field estimates of key
parameters measured at the Chem-Dyne Superfund site. The capture zone
dimensions of a well punping 100 gal/min from a 100-foot thick aquifer
having that regional velocity are then computed; the stagnation point is
35.25894124 feet downgradient (pretty close to the well) and the maximum
width of the capture zone upgradient is 221.5384615 feet (not too
impressive, given the more than 1200-foot wide plume at Chem-Dyne).
Let's double the punping rate ('calculation no.5' of Figure 2) and
see what happens: the capture zone dimensions exactly double also, to
70.51788247 feet and 443.076923 feet, respectively (shazzam!). A larger
capture zone is still needed, however, so boost the pumping rate up to 500
gal/min ('calculation no.6' of Figure 2). Sure enough, the resulting
dimensions (176.2947062 feet and 1107.692308 feet, respectively) are
precisely five times those computed earlier for a 100 gal/min pumping
113
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rate. Still, in the context of the Chem-Dyne example, this falls short of
what is desired.
Before running another simulation with an even greater pimping rate,
it might be fruitful to note that a plume extraction well does not need to
be screened over a full 100-foot saturated thickness of the aquifer at
Chem-Dyne, since the plume generally occupies only about half that
thickness in most areas. Keeping all other inputs the same as the last
calculation, but changing the estimated effective thickness of the
aquifer to 50 feet ('calculation no.7') gives a distance to the
downgradient stagnation point of 352.5894615 feet and a maximum width
upgradient of 2215.384615 feet. In other words, reducing the effective
thickness to half its former value caused the capture zone dimensions to
double precisely (surprised?).
Just to show that this works both ways, the estimated effective
thickness used in 'calculation no.8' is 200 feet, and the capture zone
dimensions are half of those computed when the effective thickness was
100 feet.
Okay, so pumping rates and effective thickness estimates have the
direct influence on capture zones that theory says they should; what
about porosity? If only the porosity estimate is changed in the input
data for 'calculation no.6' of Figure 2, from 0.3 to 0.2, then
'calculation no.9' of Figure 2 shows us that the stagnation point is now
found at 264.4420593 feet downgradient and the maximum width upgradient
is 1661.538462 feet. The porosity estimate was decreased to 2/3rds its
former value and the capture zone dimensions increased to 3/2s of their
former values. A tighter porosity gave a proportionately greater capture
zone, right? NO WAY!!!
119
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Porosity affects the regional velocity estimate, something that was
inadvertantly kept constant in the preceding example. To determine the
true influence that changing the porosity estimate has on the capture
zone dimensions, it is necessary to first recalculate the regional
velocity with the new porosity value. 'Calculation no.10' of Figure 2
s^ows that when this is done, the new regional velocity estimate is
A.331551 ft/day. When this revised regional velocity estimate is then
input into the capture zone computations, the resulting dimensions are
identical to the case where the porosity estimate was 0.3 ('calculation
no.6'). In other words, changing the porosity estimate has absolutely no
effect on the dimensions of the capture zone. This is quite sensible,
since porosity occurs in the denominator of both sides of the
relationship defining the stagnation point, and is therefore
self-cancelling:
regional velocity = pumping velocity
or
(K x I) / 0e = Q/(2xDxrxhx 0e)
where: K is the hydraulic conductivity,
I is the hydraulic gradient,
0e is the effective porosity,
Q is the flowrate of the well
r is the distance to the downgradient stagnation point,
h is the effective saturated thickness, and
n is the nunerical constant 'pi' (3.14159265...).
See the work of Keely and Tsang (1983) referenced above, for more
detail.
120
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Velocity Plot Simulations
Tired of capture zones? Ready to move on to velocity plots? Figure 3
is an example of the use of that part of the CAPZONE/VELDSTR program. In
this example, a single pumping well is being studied. It punps 500
gal/min from a 100-foot thick aquifer with 30% porosity and is centered at
the origin of an X,Y coordinate system (Figure 1). In this example, the
regional velocity will be set to zero so that the computational accuracy
of the code can be examined. When the regional velocity is zero, the
velocity distribution should be perfectly symmetrical about the well.
Observation point #1 lies 500 feet due west of the well (X=-500,
Y=0), and the net velocity is 1.702191905 ft/day; the net flow direction
is due east (90 degrees). Observation point #10 lies 500 feet due east of
the well (X=500, Y=0), and the net velocity is again 1.702191905 ft/day;
the net flow direction is due west (270 degrees), as it should be.
Observation point #11 lies 500 feet due south of the well (X=0, Y=-500),
and the net velocity is 1.702191905 ft/day; the net flow direction is due
north (0 degrees). Observation point #20 lies 500 feet due north of the
well (X=500, Y=0), and the net velocity is again 1.702191905 ft/day; the
net flow direction is due south (180 degrees), as it should be.
Compare observation points 2, 9, 12, and 19 at 400 feet each from the
well, or compare observation points 3, 8, 13, and 17 at 300 feet each from
the well, or any other group of points located at equal radial distances
from the well they will consistently show a perfectly symmetrical
velocity distribution. Hence, the net velocities and flow directions
check out precisely as they should. Also check out the X- and
Y-components of velocity reported for each observation point. Those
121
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observation points lying on the X-axis (V-coordinates equal to zero) all
have Y-components of zero, and those observation points lying on the
Y-axis (X-coordinate equal to zero) all have X-components of zero, just
as is supposed to be the case. Hence, the mathematical correctness of the
code is at least partly established.
Now consider the case (Figure 4) where the same problem has been
modified to incorporate the ffects of a strong regional flow velocity
(2.896613191 ft/day, per the Chem-Dyne situation alluded to earlier).
With the regional flow direction due east (90 degrees, or in the direction
of the positive X-axis), there should be much higher velocities
upgradient or west of the pumping well than are found east of the pimping
well. A stagnation point should exist downgradient (east) of the well.
Finally, the velocity distribution should be symmetrical on either side
of the X-axis.
The computations in Figure 4 show that all of these expectations are
met. The net velocity from the upgradient side of the well (west, or
negative X-axis) increases at observation points closer and closer to the
well, until it is 8.003188905 ft/day at observation point #5, 100 feet
upgradient of the well (X=-100, Y=0); the net flow direction is due east
(90 degrees), or directly toward the well. 100 feet downgradient of the
well, observation point #6 has a net velocity of only 2.209962523 ft/day,
and flow is headed back to the well (270 degrees, or west); neat, no?
Let's do a simple check on the logic and mathematics. If the velocity
due to pumping alone (5.106575714 ft/day, from obs.points 5 or 6 in Figure
3) is added to the specified regional velocity in this example
(2.896613191 ft/day), the result is 8.003188905 ft/day precisely the
122
-------
same as the computed net velocity upgradient. If the regional velocity is
subtracted from the velocity due to punping alone (5.106575714 ft/day -
2.896613191 ft/day), the result is 2.209962523 ft/day precisely the
same as the computed net velocity downgradient. These checks make sense,
because the regional flow and pumpage combine to bring water to the well
from upgradient areas; whereas the effects of punpage oppose the regional
flow on the downgradient side of the well.
Now for the pifece de resistance.
At observation point #7, located 200 feet downgradient of the well,
the net flow direction has reversed and is not back to the well, but is
again firmly in line with the regional flow (90 degrees, or east).
Recalling that the position of the stagnation point is at 176.2947062
feet directly downgradient of the pumping well ('calculation no.6' of
Figure 2), it is only sensible that the net flow direction for more remote
points directly downgradient be away from the well, aligned with the
regional flow direction. Need more proof? Examine observation point
#21. It's purposely.been located at the X,Y position of the stagnation
point, and voil&!, the net velocity is indeed computed to be precisely
zero.
The net flow direction of observation point #21 is given as 270
degrees, or straight back to the well, but it could just as easily have
been 90 degrees, directly away from the well, or any other direction of
the compass. The computer had to toss the dice on this part of the
computation, since the X- and Y-components of velocity were both zero.
Only the philosophers will get hung-up on the significance of the
computed flow direction in this situation anyway, since there is nowhere
to go when the velocity is zero (What is the sound of one hand clapping?).
123
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There are other niceties that can be discussed with the example given
in Figure A, such as comparisons of pairs of observation points lying
equal distances on opposite sides of the X-axis (e.g., 11 and 20, or 12
and 19, etc.) to show that the velocity distribution is indeed
symmetrical about the direction of regional flow (along the X-axis, in
this case). The potential user can examine the remaining points and
discover what other patterns are evident. Similarly, an example that has
two pumping wells is presented in Figure 5 for the interested reader.
Closing Comments
Hopefully, the discussions thus far have served to amply demonstrate
the mathematical correctness, and the utility, of the CAPZONE/VELDSTR
program. As presently constituted, the program allows up to 50 pumping
and/or injection wells to be input, and up to 50 observation wells to be
requested. This can be easily changed, by altering lines 50, 60, and 70
of the code:
50:DIM XWELL(50),YWELL(50),FLRT(50)
60:DIM X0BS(5O),YOBS(5O)
70:DIM KXVEL(50),WYVEL(50)
Lines 50 and 70 contain the dimension statements for the arrays
associated with the pimping or injection wells. Line 60 contains the
dimension statement for the arrays associated with the observation
points.
Incidentally, you may have noticed some sloppy output (poor spacing,
compressed lines, overwriting) in some of the examples discussed; e.g.,
observation points 15 through 20 of Figure 3. Well, the computer gets
124
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tired too. When this happens, resist the temptation to brutalize the
little critter. Just walk away (do noi turn the computer off) for a few
hours while it continues to recharge. The display automatically goes
blank after seven minutes of non-use (whether you are sitting there or
not), but the simulation is alive and well in standby mode. All you have
to do to pick up where you left off is to touch the 'on' button once;
whatever was on the display when you walked away is there again, ready tc
continue.
A Parting Gift: The Illogical Model
Remember the example where the effective porosity estimate was
changed to determine its effect on the dimensions of the capture zone? A
logic error was committed because something was taken for granted. The
model listed below proves two is equal to one, something politicians and
lovers have been trying to do for years. Each operation is perfectly
straightforward and mathematically correct in the abstract, but
something has been taken for granted. This is just a reminder that models
are only tools; they can be 'abused1 by simply not thinking through the
ramifications of each step. (No hints...you're on your own!).
1. Assume: X=1 and Y=1
2. By association: X*X = X*Y
or
3. By subtraction:
X2 - Y2 = XY - Y2
A. Factoring:
(X - Y)*(X + Y) = (X - Y)*Y
5. Cancellation of
similar terms
(X + Y) = Y
6. By substitution:
2 = 1
125
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Attachment A. CAPZONE/VELDSTR Program: Typed Version
10:WAIT 50:PRINT "CAP.ZONE/VEL.DSTR.-J.KEELY"
20:LF 5:CSIZE 5:COLOR 1
30:LPRIMT "CAPZONEVELDSTRPROGRAM"
40:CSIZE 3:CX)L0R 2:LPRINT "by J.F.KEELY"
50:DIV XWELL(50),YWELL(50),FLRT(50)
60:DIM XOBS(50),YOBS(50)
70:DIM WXVEL(50),WYVEL(50)
80:CSIZE 2:COLOR 0:LF 3:CALCINDEX=0:DEGREE
85:CALCINDEX=CALCINDEX+1:LPRINT "CALCULATION NO.";CALCINDEX:LF 3
89:Y=1:N=0
90:INPUT "IS REG. VEL. KNOWN?(YorN) ";CHOICE
100:IF CHOICE=1THEN GOTO 200
110:LPRINT " REG. VEL. INPUTS ":GRAPH :LINE (0,0)-(216,50),2,3,
B:TEXT :LF 2:COLOR 0
120:INPUT "HYD.COND.(GPD/SQ.FT.)? ";HYDCND
125:LPRINT HYD.COND(GPD/FT2)=",HYDCND
126:HUSA=HYDCND/7.48
127:LPRINT " (or in FT/DAY)=",HUSA
128:HMTR=(HYDCND/7.48)*30.48
129:LPRINT " (or in CM/DAY)=",HMTR
126
-------
130-.INPUT "HYD.GRAD.(FT/FT)? ";GRDNT
135:LPRINT "HYD.GRAD(FT/FT)=",GRDNT
140:INPUT "EFF.POROSITY(DECIMAL)? ";PRSTY
145:LPRINT "EFF.P0R0SITY(DEC)=",PRSTY
150:REGVEL=(HYDCND/7.48)*GRDNT/PRSTY
160:LF 1:CSIZE 3:C0L0R 2
165'.LPRINT "REG.VELOCITY (FT/DAY)" :CSIZE 2-.C0L0R 0:LPRINT "
";REGVEL:LF 1
166:CSIZE 3:C0L0R 2:RVKTR=REGVEL*30.48
167:LPRINT " (CM/DAY)"tCSIZE 2:C0L0R O-.LPRINT " ";RVMTR:LF 1
170:CSIZE 3:COLOR 2:LPRINT "ซซซปปป":COLOR 0:CSIZE 2:LF 4
199:V=1:C=0
200:INPUT "C-ZONE or V-DSTR.?(CorV) ";CZVD
210:IF CZVD=1THEN GOTO 700
220:LPRINT " CAPT.ZONE INPUTS ":GRAPH :LINE (0,0)-(216,50),2,3,B:TEXT
:LF 2:COLOR 0
230:INPUT "REG.VEL.(FT/DAY)? ";REGVEL
240:LPRINT "REG.VEL.(FT/DAY)=",REGVEL
250:INPUT "EFF.SAT.THICK.(FT)? ";SATHK
255:LPRINT "EFF.SAT.THICK(FT)=",SATHK
260:INPUT "EFF.POROSITY(DECIMAL)? ";PRSTY
265:LPRINT "EFF.POROSITY(DEC)=",PRSTY
270:INPUT "FLOW RATE(GPM)? ";FLRT
275:LPRINT "FLOW RATE(GPM)=",FLRT
280:LF 1:CSIZE 3:COLOR 2
285:LPRINT "CAPTURE ZONE DIMENSIONS ":CSIZE 2:C0L0R 0
290:ST AGPTDWNGR=(FLRT *1440/7.48)/(2*n *SATHK*PRSTY*REGVEL)
127
-------
295:LPRINT 11 STAGNATION POINT":LPRINT " DOWNGRADIENT(FT)",STAGPTDWNGR
300:UPGRCPZNWDTH=2*n*STAGPTDWNGR
305:LPRINT "MAXIMUM UPGRADIENT":LPRINT "CAP.ZONE
WIDTH(FT)",UPGRCPZNWDTH
306:LF l-.CSIZE 3:C0L0R 2:LPRINT "ซซซปปป":COLOR 0:CSIZE 2:LF U
309:Y=1:N=0
310:INPUT "MORE CALCULATIONS?(YorN) ";AGAIN
320:IF AGAIN=1THEN GOTO 85
330:LF 2:CSIZE A:COLOR 1
3A0:LPRINT "PROGRAM OVER, THANK YOU":LF 3:COLOR 0:CSIZE 2:END
700-.CSIZE 2:COLOR 0:LPRINT "VEL.DSTR. INPUTS"
705".GRAPH :LINE (0,0)-(216,50),2,3,B:TEXT :COLOR 0:LF 2
710:INPUT "REG.VEL.(FT/DAY)? ";REGVEL
715:LPRINT "REG.VEL.(FT/DAY)=",REGVEL
720:INPUT "REG.FLOW DIR.(N=0,E=90)?";THETA
725:LPRINT"REG.FLOW DIRECTION":LPRINT "(COMPASS DEGREES)=",THETA
730:INPUT "EFF.SAT.THICK.(FT)? ";SATHK
735:LPRINT "EFF.SAT.THICK(FT)=",SATHK
740:INPUT "EFF.POROSITY(DECIMAL)? ";PRSTY
7A5:LPRINT "EFF.POROSITY(DEC)=",PRSTY
750:INPUT "# OF WELLS(MAX=50)?";W:LF 2
755:FOR J=1T0 W:CSIZE 3:COLOR 2
757:LPRINT " WELL NO.";J:CSIZE 2:C0L0R 0
760:INPUT "FLOW(GPM:+PUMP,-IN'J)? " ;FLRT( J)
765:LPRINT "FLOW RATE(GPM)=",FLRT(J)
770:INPUT "WELL X-COORD.(FT)? ";XWELL(J)
775:LPRINT "WELL X-COORD.(FT)=",XWELL(J)
128
-------
780:INPUT "WELL Y-COORD.(FT)? ";YWELL(J)
785:LPRINT "WELL Y-COORD.(FT)=",YWELL(J):LF 1
790:NEXT 3
800:INPUT "# OF OBS. P0INTS(MAX=50)?";N:LF 2
810:FOR I=1T0 N-.CSIZE 3:C0L0R 2
815:LPRINT "0BS.P0INT";I:CSIZE 2:C0L0R 0
820:INPUT "X-COORD.(FT)? ";XOBS(I)
825:LPRINT "X-COORD.(FT)=";XOBS(I)
830:INPUT "Y-COORD.(FT)? H;YOBS(I)
835:LPRINT "Y-COORD.(FT)=";YOBS(I):LF 1
836:CSIZE 3:C0L0R 2-.LPRINT "ซซซปปป" :COLOR 0:CSIZE 2
838:WXVEL=0:WYVEL=0
840:FOR J=1T0 W
845:A=XOBS(I)-XWELL(3):B=YOBS(I)-YWELL(J)
850:WXVEL(J)=((FLRT(J)*1440/7,A8)/(2*n*SATHK*PRSTY))*(A/(A^2+B"2))
85l:WYVEL(J)=((FLRT(J)*1440/7.48)/(2*n*SATHK*PRSTY))*(B/(A"2+B'2))
856:WXVEL=WXVEL+WXVEL(J)
857:WYVEL=WYVEL+WYVEL(3)
858:NEXT 3
860:XVEL=(REGVEL*SIN THETA)-WXVEL
861:YVEL=(REGVEL*C0S THETA)-WYVEL
862:LPRINT "VEL. X-COMPONENT":LPRINT "(FT/DAY)=",XVEL
863:LPRINT "VEL. Y-COMPONENT":LPRINT "(FT/DAY)=",YVEL
865: NET VEL=\/( XVEL ^2+YVEL * 2)
866:LPRINT "NET VEL.(FT/DAY)=",NETVEL
870:IF YVEL=OTHEN GOTO 873
872:G0T0 885
129
-------
873:IF SGN XVEL=+1THEN GOTO 883
874:BETA=THETA+180
875:IF BETA>360THEN GOTO 878
876:G0T0 895
878:BETA=BETA-360: GOTO 895
883:BETA=T1-""TA: GOTO 895
885:BETA=ATN (XVEL/YVEL)
886:IF SGN YVEL=-1THEN GOTO 893
887:IF SGN BETA=-1THEN GOTO 890
888:G0T0 895
890:BETA=BETA+360:GOTO 895
893:BET A=BETA+180
895:LPRINT "NET FLOW DIRECTION":LPRINT "(COMPASS DEGREES)=",BETA:LF 1
896:CSIZE 3:COLOR 2:LPRINT "ซซซปปป":COLOR 0:CSIZE 2
900:LF 1:NEXT I
909:Y=1:N=0
910:INPUT "MORE CALCULATIONS?(YorN) AGAIN
920:IF AGAIN=1THEN GOTO 85
930:LF 2:CSIZE A:COLOR 1
9A0:LPRINT " PROGRAM OVER, THANK YOU":LF 3:C0L0R 0;CSIZE 2:END
130
-------
Attachment B. CAPZONE/VELDSTR Program: Hardcopy Version
131
-------
CAPZONE
UELDSTR
PROGRAM
by J.F.KEELV
10: UIA1 T 50: PRINT
"CAP.ZONE/UEL.
DSTR.-J.KEELY"
20:LF 5:CSI2E 5:
COLOR 1
30:LPRINT "CAPZON
EUELDSTRPROGRA
M"
40:CSI ZE 3:COLOR
2:LPRINT "by J
.F.KEELY"
45:CSIZE 2:LF 2:
COLOR 3:LPRINT
"TinE=";nriE
50:Din XWELLC50),
VWELLC50), FLRT
(50)
60:Din XOBSC50), Y
OBSC50)
70:DIM UXUELC50),
IaJYUEL (50)
80:CSIZE 2:COLOR
0:LF 3:CALCIND
EX=0:DEGREE
85:CALCINDEX=CALC
INDEX+1:LPRINT
"CALCULATION N
0.";CALC1NDEX:
LF 3
89:Y=1:N=0
90:INPUT "IS REG.
UEL. KNOUN? (Yo
rN) "j CHOICE
100:IF CH0ICE=1
THEN GOTO 200
110:LPRINT REG.
UEL. INPUTS ":
GRAPH :LINE <0
, 0>-<216, 50), 2
,3, B: TEXT : LF
2:COLOR 0
120:INPUT "HYD.CON
D.(GPD/SQ.FT.)
? ";HYDCND
125:LPRINT "HYD.CO
ND(GPD/FT2)-"J
HYDCND
126:HUSA^HYDCND/2.
48
127:LPRINT " (or
In FT/DAY) = ", H
USA
128:HnTR=(HYDCND/?
.48)*30.48
129:LPRINT " (or
in Cn/DAY)-", H
nTR
130:INPUT "HVD.GRA
D.(FT/FT)? ";G
RDNT
135:L?RI NT "HYD.GR
AD(FT/FT> = ", GR
DNT
140:INPUT "EFF.D0R
OS ITY(DECIHAL)
? ";PRSTY
145:LPR1 NT "EFF.PO
R0S1TY(DEC)="j
PRSTY
i 50:REGUEL = (HYDCND
.48)*GRDNT/P
RSTY
132
-------
160:LF 1:CSI2E 3:
COLOR 2
165:LPRINT "REG.UE
LOCI TV (FT/DA
v)":CS12E 2:
COLOR 0:LPR1NT
" ";REGUEL:LF
1
166:CSI2E 3:C0L0R
2: RUriTR=REGUEL
*30.48
167: LPR1NT " >>>>>":
COLOR 0:CSIZE
2: LF 4
199:U=1:C=0
200:INPUT "C-ZONE
or U-DSTR.?)>>>>"
-tCOLOR 0: CSI ZE
2: LF 4
309:Y=1:N=0
310:INPUT "MORE CA
LCULATIONS?(Yo
rN) AGAIN
320:IF AGAIN^ITHEN
GOTO 85
330:LF 2:CSIZE 4:
COLOR 1
340:LPRINT " PROGR
AH ODER, TH
133
-------
ANK YOU":LF 3:
COLOR 0:CSIZE
2: END
780:CS1Zฃ 2:C0L0R
3:LPRINT " UEL
.DSTR. INPUTS"
705:GRAPH :LINE (0
, 0)- (216, 50), 2
, 3, B i nXT :
COLOR 0:LF 2
710:INPUT "REG.UEL
.(FT/DAY)? ";R
EGUEL
715:LPRINT "REG.UE
L.CFT/DAY) = ", R
cGUEL
720:INPUT "REG.FLO
u! DIR. (N-0, E=9
0)?" ;THETA
725:LPR1 NT "REG.FL
OU DIRECTION":
LPRINT "(COriDA
SS DEGREES)-",
THETA
730:INPUT "EFF.SAT
.THICK.(FT)? "
;SATHK
735:LPRINT "EFF.SA
T.THICK(FT)-",
SATHK
740:INPUT "EFr.POR
OSITYCDECIHAL)
? ";PRSTY
745:LPRI NT "E^F.PO
ROS1TYCDEC)=",
DRST Y
750:INPUT "S OF WE
LLS(HAX=50)?"J
ul: LF 2
755:J=1T0 W:
CSIZE 3:COLOR
2
757:LPR1 NT " WELL
NO.";J:CSIZE 2
:COLOR 0
7c0:INPUT "rLOW(GP
1: +PUF1P, -INJ)?
";FLRT(J)
755:LPRINT "FLOW R
ATE(GPH) = ", FLR
T(J)
770:INPUT "WELL X-
COORD.(FT)? ";
XWELL(J)
775:LPRINT "WELL X
-COORD.?";N:LF 2
310:FOR 1 = 1 TO N:
CS1ZE 3:COLOR
2
815:LPRINT "0BS.D0
INT";I:CS1ZE 2
:COLOR 0
820:INPUT "X-COORD
.(FT)? ";XOBS(
1)
S25:LPR1NT "X-COOR
D. (FT ) = ";XOBSC
I)
830:INPUT "Y-COORD
.(FT)? YOBS(
1 )
835 it-PR INT "V-COOR
D. (F"!") =V03S(
I):LF 1
336:CSIZE 3:C0L0R
2:LPRI NT "<<<<
<< >>>>>>":
COLOR 0:CSIZE
2
S38:WXUEL=0:WYUEL=
0
S^i^OR J=1TQ W
645:A=XOBSCI)-XWEL
134
-------
L( J):B=YOBS(I)
-YUELL(J)
850:WXUEL(J)=((FLR
T(J)*1440/7.48
>/(2*Jl*SATHK*P
RSTY)>*(A/(A^2
+B^2))
851:WYUEL(J)=((FLR
T(J>*1440/7.48
)/(2*JI*SATHK*P
RSTY)>*(B/(A^2
+B^2))
856:WXUEL=UXUEL+UX
UEL(J>
857:WYUEL=UYUEL+UY
UEL(J>
858:NEXT J
860: XUEL=(REGUEL'*
SIN THETA)-WXU
EL
861:YUEL=(REGUEL*
COS THETA)-UIYU
EL
862:LPRINT "UEL. X
-COnPONENT":
LPRINT "(FT/DA
Y)="jXUEL
863:LPRINT "UEL. Y
-COHPONENT":
LPRINT "(FT/DA
Y)="jYUEL
865: NETUEL=4"(XUEL1^
2+YUELA2)
866:LPR1 NT "NET UE
L. (FT/DAY)="3N
ETUEL
870:IF YUEL=0THEN
GOTO 873
872:GOTO 885
873:IF SGN XUEL=+1
THEN GOTO 883
874:BETA=THETA+180
875:IF BETA>360
THEN GOTO 878
876:GOTO 835
378:BETA=BETA-360:
GOTO 835
883:BETA=THETA:
GOTO 895
885:BETA=ATN (XUEL
/YUEL) .
886:IF SGN YUEL=-1
THEN GOTO 893
887:IF SGN BETA=-1
THEN GOTO 890
888:GOTO 895
890:BETA=BETA+360:
GOTO 895
893:BETA=BETA+180
895:LPRINT "NET FL
OW DIRECTION":
LPRINT "(COriPA
SS DEGREES)^",
BETA:LF 1
896:CSI2E 3:C0L0R
2:LPRINT "<<<<
<<>>>>>>":
COLOR 0:CSI2E
2
900:LF 1:NEXT I
909:Y=l:N=0
910:INPUT "MORE CA
LCULATIONS?(Yo
rN) " ; AGAIN
920:IF AGA1N=1THEN
GOTO 85
930:LF 2:CSI2E 4:
COLOR 1
940:LPRINT " PROGR
An OUER, TH
ANK YOU":LF 3:
COLOR 0:CSIZE
2- END
PROGRAM
OUER,
"HANK YOU
135
-------
Attachment C. CAPZONE/VELDSTR Program Example Simulations
136
-------
Figure 1. CAPZONE/VELDSTR Program Axis Orientation Illustration
North, Uฐ
+ Y axis
X axis
+ X axis
West, 270ฐ
East, 90ฐ
South, 180ฐ
Y axis
137
-------
Figure 2. CAPZONE/VELDSTR Program Simulation Example No.l:
Regional Velocity and Capture Zone Computations
CAPZONE
UELDSTR
PROGRAM
by J.F.KEELV
CALCULATION NO. 1
REG.UEL. INPUTS
HYD.C0ND(GPD/FT2)=
75
(or in FT/DAY)=
10.02673797
(or in CI1/DAY)-
305.6149733
HYD.GRAD(FT/FT)=
0.015
EFF.POROSITY(DEC)=
0. 15
REG.UELOCI TV
(FT/DAY)
1.002673797
(CM/DAY)
30.56149733
<<<<<<>>>>>>
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY)=
1.002673797
EFF.SAT.THICK(FT)=
100
EFF.POROSITY(DEC)=
0. 15
FLOW RATE(GPn)=
"0
CAPTURE ZONE
DI MENS IONS
STAGNATION POINT
DOWNGRADIENT(FT)
101.8591636
HAXinUn UPGRADIENT
CAP.ZONE UIIDTH(FT)
640.0000001
<<<<<<>>>>>>
CALCULATION NO. 2
CAPT.ZONE INPUTS
REG.UEL.
-------
STAGNATION POINT
DOUNGRADIENT(FT)
102131.5143
riAxiriuri upgradient
CAP.ZONE WIDTH>>>>>
CALCULATION NO. 3
CAPT.ZONE INPUTS '
REG.UEL. >>>>>
CALCULATION NO. *
REG.UEL. INPUTS
HYD.C0ND(GPD/FT2)=
5000
(or In FT/DAY>=
668.4491979
(or in CIVDAY) =
20374.33155
HYD.GRAD(FT/FT)=
0.0013
EFF.POROSITY(DEC)=
0.3
REG.UELOCI TV
(FT/DAY)
2.896613191
(CM/DAY)
88.28877006
<<<<<<>>>>>>
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY>=
2.896613191
EFF.SAT.THICK(FT)=
100
EFF.POROSITY
-------
mXIMUM UPGRADIENT
CAP.ZONE IJIDTH(FT)
221.5384615
<<<<<<>>>>>>
CALCULATION NO. 5
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY>=
2.896613191
EFF.SAT.TH1CK(FT)=
100
EFF.POROSITY(DEC)=
0.3
FLOW RATE>>>>>
CALCULATION NO. 6
CAPT.ZONE INPUTS
REG.UEL.=
500
CAPTURE ZONE
DIMENSIONS
STAGNATION POINT
DOUINGRADIENT (FT )
176.2947062
maximum upgradient
CAP.ZONE UIDTH(FT)
1107.692308
<<<<<<>>>>>>
CALCULATION NO. 7
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY)=
2.896613191
EFF.SAT.THICK(FT)-
50
EFF.POROS1TY=
0.3
^LOUI RATE(GPM)=
500
140
-------
CAPTURE ZONE
~ I HENS IONS
STAGNATION POINT
DOWNGRADIENT (FT)
352.5394124
HAXIMUM UPGRADIENT
CAP.ZONE WIDTH(FT)
2215.384615
<<<<<<>>>>>>
CALCULATION NO. 8
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY)=
2.896613191
EFF.SAT.THICK(FT)=
200
EFF.POROSITY(DEC)=
0.3
FLOW RATE(GPf1) =
500
CAPTURE ZONE
DIMENSIONS
STAGNATION POINT
~OUINGRAD1ENT (FT)
88.14735309
MAXIMUM UPGRADIENT
CAP.ZONE UIDTH(FT)
553.8461538
<<<<<<>>>>>>
CALCULATION NO. 9
CAPT.ZONE INPUTS
REG.UEL.(FT^DAY)=
2.896613191
EFF.SAT.THICK=
100
EFF.POROSITY(DEC)=
0.2
FLOW RATE(GPM)=
500
CAPTURE ZONE
DI HENS IONS
STAGNATION POINT
DOWNGRADIENT(FT)
264.4420593
MAXIMUM UPGRADIENT
CAP.ZONE WIDTH(FT)
1661.538462
<<<<<<>>>>>>
CALCULATION NO. 10
REG*.UEL. INPUTS
HYD.C0ND(GPD/FT2)=
5000
(or in FT/DAY)-
668.4491979
(or in CM/DAY)=
20374.33155
HYD.GRAD(FT/FT)=
0.0013
141
-------
EFF.P0R0S1TY(DEC)=
0.2
REG.UELOCITY
(FT/DAY)
4.344919786
(Cn/DPY)
132.4331551
<<<<<<>>>>>>
CAPT.ZONE INPUTS
REG.UEL.(FT/DAY)=
4.344919786
EFF.SAT.TH1CK(FT)=
100
EFF.POROSITY(DEC)=
0.2
FLOW RATE(GPn>=
500
CAPTURE ZONE
DIMENSIONS
STAGNATION POINT
DOWNGRADIENT(FT)
176.2947052
nAxinun upgradient
CAP.ZONE WIDTH(FT)
1107.692308
<<<<<<>>>>>>
PROGRAM
OUER.3
THANK YOU
142
-------
Figure 3. CAPZONE/VELDSTR Program Simulation Example No.2:
Single-Well Velocity Distribution (Reg.Vel.= 0)
CAPZONE
UELDSTR
PROGRAM
by J.F.KEELY
CALCULATION NO. 1
UEL.DSTR. INPUTS
REG.UEL.=
90
EFF.SAT.THICK(FT)=
100
EFF.POROSITY(DEC)=
0.3
WELL NO. 1
FLOW RATE(GPn>=
500
WELL X-COORD. (FT> =
0
WELL Y-COORD.(FT> =
0
OBS.POINT 1
X-COORD.(FT)=-500
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY>=
1.021315143
UEL. Y-COnPONENT
=
90
<<<<<<>>>>>>
OBS.POINT 2
X-COORD.(FT >=-400
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-C0I1P0NENT
(FT/DAY)=
1.276643929
UEL. Y-COMPONENT
(FT/DAY>=
0
NET UEL.(FT/DAY)=
1.226643929
NET FLOW DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 3
X-COORD.(FT)=-300
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
1.702191905
"Jt'L. Y-COHPONENT
(FT/DAY > =
143
-------
0
NET UEL.(FTVDAY>=
1.702191905
NET FLOW DIRECTION
(COHPftSS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 4
X-COOPO.(FT)=-200
V-COORO.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
2.553287857
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY>=
2.553287857
NET FLOU DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 5
X-COORD.(FT)=-100
Y-COORD.(FT) = 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
5.106575714
UEL. v-COriPONENT
(FT-/DAY) =
0
NET UEL.(FT/DAY)=
5.106575714
NET FLOW DIRECTION
(COMPASS DEGREES)^
90
<<<<<<>>>>>>
OBS.POINT 6
X-COORD.(FT)= 100
Y-COORD.(FT ) = 0
<<<<<<>>>>>>
UEL. X-COnPONENT
(FT/DAY)=
-5.106575714
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY>=
5.106575714
NET FLOUI DIRECTION
(COI1PASS DEGREES)=
270
<<<<<<>>>>>>
OBS.POINT 7
X-COORD.(FT ) = 200
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-2.553287857
UEL. Y-COnPONENT
(FT/DAY)=
0
NET UฃL.(FT/DAY)=
2.553287857
NET FLOU DIRECTION
(COMPASS DEGREES)=
270
<<<<<<>>>>>>
OBS.POINT 8
X-COORD.(FT)= 300
Y-COORD.(FT> = 0
144
-------
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY>=
-1.702191905
UEL. V-COnPONENT
=
1.702191905
NET FLOW DIRECTION
(COMPASS DEGREES)=
270
<<ซซปปป
OBS.POI NT 9
X-COORD.(FT ) = 400
Y-COORD.(FT) = 0
<<<<<<>>>>>>
UEL. X'-COriPONENT
(FT/DAY>=
-1.276643929
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY)=
1.276643929
NET FLOW DIRECTION
(COMPASS DEGREES) =
270
<<<<<<>>>>>>
OBS.POINT 10
X-COORD.(FT >= 500
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-1.021315143
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY)=
1.021315143
NET FLCW DIRECTION
(COMPASS DEGREES>=
' 270
<<<<<<>>>>>>
OBS.POINT II
X-COORD.(FT>= 0
Y-COORD.(FT)=-500
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY>=
0
UEL. Y-COMPONENT
(FT/DAY>=
1.021315143
NET UEL.(FT/DAY)=
1.021315143
NET FLOW DIRECTION
(COMPASS DEGREES)=
<<<<<<>>>>>>
OBSPOI NT 12
X-COORD.(FT)= 3
v-COORD.(FT)=-400
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT>>>> >
145
-------
OBS.POINT 13
X-COORD.(FT) = 0
Y-COORD.(FT>=-300
<<<<<<>>>>>>
JEL. X-COMPONENT
(FT/DAY)=
0
UEL. Y-COMPONENT
CFT/DAY)-
1.702191905
NET UEL.(FT/DAY)=
1.702131305
NET FLOW DIRECTION
(COMPASS DEGREES)^
0
<<<<<<>>>>>>
OBS.POI NT 14
x-coord.(FT ) = 0
Y-COORD.(FT)=-200
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
0
UEL. v-conPONENT
(FT/DAY)=
2.553287857
NET UEL.(FT/DAY)=
2.553287857
NET FLOW DIRECTION
(COMPASS DEGREES)^
0
<<<<<<>>>>>>
OBS.POI NT 15
X-CCORD.(FT ) = 0
V-COORD.(FT >=-10B
^C^KP^KE^I? ^
=
5.1065757 i 4
NET FLOW DIRECIION
(COHPASS DEGREES)=
0
<<<<<<>>>>>>
OBS.POINT 16
X-COORD.(FT ) = 0
Y-COORD.(FT)= 100
<<<<<<>>>>>>
UEL. X-COMPONENT
CFT/DAY)=
0
UEL. Y-COMPONENT
(FT/DAY>=
-5.106575714
NET UEL.(FT/DAY)=
5.106575714
-ET FLOW DIRECTION
(COMPASS DEGREES)=
180
<<<<<<>>>>>>
OBS.POINT 17
X-COORD.(FT)= 0
V-CC'ฃ)RD. (FT)= 200
<<<<<<>>>>>>
ฆJEU jk^QnPONENT
0
UEL. Y-COHPONENT
(FT/DAY)=
-2.553287857
NET UEL.(FT/DAY>=
2.553287357
180
146
-------
<<<<<<>>>>>>
OBS.POINT 18
X-COORD.(FT)= 0
V-COORD.>>>>>
UEL. X-COHPONENT
=
1.702191305
t FLOW DIRECTION
''-OIIPASS DEGREES)^
180
<<<<<<>>>>>>
UEL. X-COHPONENT
fFT/DAY)=
rL. V-COHPONENT 0
(FT/DAY)=
-1.021315143
NET UEL.(FT/DAY)=
1.021315143
NET FLOW DIRECTION
(COMPASS DEGREES)=
130
<<<<<<>>>>>>
PROGRAM
OUER?
THANK YOU
OBS.POINT 19
X-COORD.(FT)= 0
Y-COORD.>>>>>
UEL. X-COHPONENT
(FT/DAY)=
0
OEL. Y-COMPONENT
CFT/DAY)=
-1.276643929
NET UEL.(FT/DAY)=
1.276643929
NET FLOW DIRECTION
CCOHPASS DEGREES)=
180
<<<<<<>>>>>>
OBS.POINT 20
X-COORD.= 0
Y-COORQ.(FT)= 500
<<<<<<>>>>>>
147
-------
Figure A. CAPZONE/VELDSTR Program Simulation Example No.3
Single-Hell Velocity Distribution (Reg.Vel.ป 0)
CAPZONE
UELDSTR
PROGRAM
by J.F.KEELY
CALCULATION NO. 1
UEL.DSTR. INPUTS
REG.UEL.(FT/DAY>=
2.896613191
REG.FLOW DIRECTION
(COriPASS DEGREES)=
90
EFF.SAT.THICK(FT)=
100
EFF.POROSITY(DEC)=
0.3
WELL NO. 1
FLOW RATE(GPf1) =
500
WELL X-COORD. (FT) =
0
WELL Y-COORD. (FT) =
0
OBS.POINT 1
X-COORD.(FT)=-500
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
3.317928334
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY>=
3.917928334
NET FLOW DIRECTION
(COriPASS DEGREES> =
90
<<<<<<>>>>>>
OBS.POINT 2
X-COORD.(FT >=-400
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
4.17325712
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY>=
4.17325712
NET FLOW DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 3
X-COORD.(FT)=-300
v-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
4.598805096
JEL. Y-COnPONENT
(FT /'DAY) =
148
-------
0
NET UEL. =
4.538805036
NET FLOW DIRECTION
(COMPASS DEGREES)=
30
<<<<<<>>>>>>
DBS.POINT 4
X-COORD.=-200
Y-COORD.(FT >= 0
<<<<<<>>>>>>
UEL. X-COnPONENT
(FT/DAY>=
5.443901048
UEL. Y-COnPONENT
(FT/DAY)=
0
NET UEL.(FT'DAY>=
5.449901048
NET FLOW DIRECTION
(COHPflSS DEGREES)=
30
<<<<<<>>>>>>
OBS.POINT 5
X-COORD.(FT)=-100
Y-COORD.(FT > = 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
8.003188305
UEL. Y-COMPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY > =
8.003188305
NET FLOW DIRECTION
COHPASS DEGREES>=
90
<<<<<<>>>>>>
OBS.POINT 6
X-COORD.(FT)= 100
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY>=
-2.203362523
UEL. Y-COHPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY)=
2.203362523
NET FLOW DIRECTION
(COMPASS DEGREES)=
270
<<<<<<>>>>>>
OBS.POINT 7
X-COORD.(FT)= 200
Y-COORD.(FT)= 0
<ซซ<ป>ป>
UEL. X-COI1PONENT
(FT/DAY)=
0.343325334
UEL. Y-COHPONENT
(FT/DAY)=
0
NET UEL.(FT/DAY)=
0.34332533d
NET FLOW DIRECTION
(COMPASS DEGREES)=
30
<<<<<<>>>>>>
OBS.POINT 8
x-COORD.(FT)= 300
v-COORD.(FT)= 0
149
-------
<<<<<<>>>>>>
UEL. X-COriPONENT
=
1.194421286
NET FLOW DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 3
X-COORD.(FT ) = 400
v-COORD.(FT ) = 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
1.619969262
UEL. Y-COMPONENT
(FT/DAY>=
0
NET UEL.(FT/DAY)=
1.619969262
NET FLOU1 DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 10
X-COORD.= 500
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
1.875293043
UEL. Y-COMPONENT
(FT/DAV)=
0
NET UEL.(FT/DPY>=
1.875298043
NET FLOUI DIRECTION
(COMPASS DEGREES)=
90
<<<<<<>>>>>>
OBS.POINT 11
X-ClORD.(FT)= 0
Y-COORD.(FT)=-500
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
2.896613131
UEL. Y-COMPONENT
(FT/DAY>=
1.021315143
NET UEL.(FT/DAV)=
3.071332616
NET FLOUI DIRECTION
(COMPASS DEGREES)=
70.57788924
<<<<<<>>>>>>
OBS.POINT 12
X-COORD.(FT)= 0
v-COORD.(FT)=-400
<<<<<<>>>>>>
UEL.^X-COMPONENT
(FT/DAY) =
2.8966]3191
UEL. Y-COMPONENT
(FT/DAY)=
1.276643929
NET UEL.(FT/DAY)=
3.165468006
NET FLOW DIRECTION
150
-------
OBS.POINT 13
X-COORD.(FT) = 0
Y-COORD.(FT)=-300
<<<<<<>>>>>>
UEL. X-COnPONENT
(FT/DAY)=
2.896613191
UEL. Y-COnPONENT
(FT/DAY)=
1.702191905
NET UEL.=
3.359735891
NET FLOW DIRECTION
(COMPASS DEGREES)=
59.55941725
<<<<<<>>>>>>
OBS.POINT 14
X-COORD.(FT ) = 0
v-COORD.(FT)=-200
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY>=
2.896613191
UEL. Y-COMPONENT
(FT/DAY>=
2.553287857
NET UEL.(FT/DAY)=
3.861301187
NET FLOUI DIRECTION
(COMPASS DEGREES)=
48.60467689
<<<<<<>>>>>>
OBS.POINT 15
X-COORD.(FT)= 0
Y-COORD.(FT)=-100
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DPV)=
2.896613191
UEL. Y-COMPONENT
(FT/DAY)=
5.106575714
NET UEL.(FT/DAY)=
5.870901421
NET FLOW DIRECTION
(COMPASS DEGREES)=
29. 56329" ">8
<<<<<<>>>>>>
OBS.POINT 16
X-COORD.(FT)= 3
v-COORD.(FT)= 100
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
2.896613191
UEL. Y-COMPONENT
(FT/DAY)=
-5.106575714
NET UEL.(FT/DAY)=
5.870301421
NET FLOW DIRECTION
(COMPASS DEGREES)=
150.4367052
<<<<<<>>>>>>
OBS^POINT 17
X-COORD.(FT)= 0
v-COORD.(FT)= 200
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
2.896613191
UEL. Y-COMPONENT
<. - T/D^v ) =
-2.553237857
151
-------
NET UEL. (FT/DAY)=
3.861301137
NET FLOW DIRECTION
(COMPASS DEGREES)^
131.3953231
<<<<<<>>>>>>
OBS.POINT 18
X-COORD.(FT ) = 0
v-COORD.(FT ) = 300
<<<<<<>>>>>>
'JEL. X-COMPONENT
=
-1.702191905
NET UEL.(FT/DAV)=
3.359735891
NET FLOW DIRECTION
(COMPASS DEGREES)=
120.4405823
<<<<<<>>>>>>
OBS.POINT 19
X-COORD.(FT)= 0
v-COORO.(FT)= 400
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
2.896613191
UEL. Y-COMPONENT
(FT/DAY>=
-1.276643929
NET UEL.(FT/DAY)=
3.165468006
NET FLOW DIRECTION
(COMPASS DEGREES > =
113.7848515
<<<<<<>>>>>>
OBS.POINT 20
X-COORD.(FT)= 0
Y-COORD.(FT ) = 500
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
2.896613191
UEL. Y-COMPONENT
(FT/DAY>=
-1.021315143
NET UEL.(FT/DAY)=
3.071392616
NET FLOW DIRECTION
(COMPASS DEGREES)=
109.4221108
<<<<<<>>>>>>
OBS.POINT 21
X-COORD.(FT)= 176.
2947062
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
0
UEL. Y-COMPONENT
(FT/DAY > =
0
NET UEL.(FT/DAY)=
0
NET SLOW DIRECTION
COMPASS DEGREES) =
270
<<<<<<>>>>>>
PROGRAM
OUER?
THANK YOU
152
-------
Figure 5. CAPZONE/VELDSTR Program Simulation Example No.A
Two-Well Velocity Distribution (Reg.Vel.ป 0)
CAPZONE
UELDSTR
PROGRAM
by J.F.KEELY
CALCULATION NO. 1
REG.UEL. INPUTS
HYD.C0ND(GPD/FT2>=
750
(or in FT/DAY)=
100.2673797
(or In CM/DAY>=
3056.149733
HYD. GRAD(FT/"FT >-
0.0025
EFF.POROSITY(DEC)=
0. 25
REG.UELOCITV
(FT/DPY)
1.002673797
(CM/DAY)
30.56149733
<<<<<<>>>>>>
UEL.DSTR. INPUTS
REG.UEL. =
-50
WELL Y-COORD.(FT>=
0
UJELL NO. 2
FLOW RATE(GPM)=
50
WELL X-COORD.(FT>=
50
WELL Y-COORD.(FT>=
0
OBS.POINT 1
X-COCfcD. (FT)= 0
Y-COORD.(FT)=-40
<<<<<<>>>>>>
UEL. X-C0I1P0NENT
(FT/DAY)=
0
UEL. Y-COHPONENT
(FT/DAY)=
2.198359818
NET UEL.(FT/DAY)=
2.198359818
153
-------
NET FLOW DIRECTION
(COMPASS DEGREES)-
0
<<<<<<>>>>>>
OBS.POINT 2
X-COORD.(FT ) = 0
Y-COORD.(FT)=-20
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
0
UEL. Y-COI1PONENT
>>>>>
OBS.POINT 3
X-COORD.(FT ) = 0
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
0
UEL. Y-COI1PONENT
(FT/DAY)-
1.002673797
NET UEL.(FT/DAY)-
1.002673737
NET FLOW DIRECTION
(COMPASS DEGREES)-
0
<<<<<<>>>>>>
OBS.POINT 4
X-COORD.(FT)= 0
Y-COORD.(FT>= 20
<<<<<<>>>>>>
UEL. X-COnPONENT
(FT/DAY)-
0
UEL. Y-COMPONENT
(FT/DAY)=
1.574474718E-01
NET UEL.(FT/DAY>=
1.574474718E-01
NET FLOW DIRECTION
(COMPASS DEGREES)=
0
<<<<<<>>>>>>
OBS.POINT 5
X-COORD.(FT)= 0
Y-COORD.(FT)= 40
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
0
UEL. Y-COHPONENT
(FT/DAY)=
-0.193012224
NET UEL.(FT/DAY)=
0.193012224
NET ฃJ_OW DIRECTION
(COMPASS DEGREES)-
180
<<<<<<>>>>>>
OBS'. pO I NT 6
X-COORD.(FT ) = 20
Y-COORD.(FT)=-40
<<<<<<>>>>>>
154
-------
UEL. X-COnPONENT
=
2.36023731
NET UEL. (FT/"DAY) =
2.36144201
NET FLOW DIRECTION
(COMPASS DEGREES)-
1.830235019
<<<<<<>>>>>>
OBS.POINT 7
X-COORD.(FT)= 20
Y-COORD.(FT)20
<<<<<<>>>>>>
UEL. X-COriPONENT
(FT/DAY)=
6.047845835E-01
UEL. Y-COMPONENT
(FT/DAY)=
2.176667401
NET UEL.(FT/DAY)-
2.259124912
NET FLOLJ DIRECTION
(COMPASS DEGREES)-
15.52789257
<<<<<<>>>>>>
OBS.POINT 8
X-COORD.(FT ) = 20
Y-COORD.(FT )- 0
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
1.167217305
UEL. Y-COMPONENT
(FT/DAY) =
1.002673797
NET UEL.(FT/DAY)-
1.538749812
NET FLOW DIRECTION
(COMPASS DEGREES)-
^9.33645739
<<<<<<>>>>>>
OBSPOI NT 9
X-COORD.(FT) = 20
Y-COORD.>>>>>
UEL. X-COMPONENT
(FT/DAY)-
6.047845835E-01
UEL. Y-COMPONENT
-
-0.171319807
NET UEL.(FT/DAY)=
6.285816325E-01
NET FLOLJ DIRECTION
(COMPASS DEGREES)-
105.8160521
<<<<<<>>>>>>
OBS.POINT 10
X-COORD.(FT>= 20
V-COORD. (FT )- 40
<>>>>>
UEL. X-COMPONENT
(FT/DAY)-
7.54201952E-02
UEL. .Y-COMPONENT
(FT/DAY)-
-0.354889716
NET UEL.(FT/DAY)-
3.628152648E-01
NET FLOW DIRECTION
'COMPASS DEGREES)-
168.0021537
155
-------
<<<<<<>>>>>>
OBS.POINT 11
X-COORD.(FT)= 40
Y-COORD.(FT)=-40
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-2.081030248E-01
UEL. Y-COMPONENT
(FT/DAY>=
2.697226399
NET UEL.(FT/DAY)=
2.705243123
NET FLOW DIRECTION
(COMPASS DEGREES)^
355.588117
<<<<<<>>>>>>
OBS.POINT 12
X-COORD.(FT)= 40
Y-COORD.(FT)=-20
<<<<<<>>>>>>
UEL. X-COMPONENT
>>>>>
OBS.D01 NT 13
X-COORD. cFT )- <30
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COflPONENT
(FT/DAY)=
5.447014095
UEL. Y-COMPONENT
(FT/DAY)=
1.002673797
NET UEL.(FT/DAY)=
5.538530247
NET FLOUJ DIRECTION
(COMF'-SS DEGREES)=
79.56988574
<<<<<<>>>>>>
OBS.POINT 14
X-COORD.(FT ) = 40
Y-COORD.(FT ) = 20
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
5.767426685E-01
UEL. Y-COMPONENT
(FT/DAY)=
-1.532668213
NET UEL.(FT/DAY>=
1.633878432
NET FLOW DIRECTION
(COMPASS DEGREES)^
160.0334855
<<<<<<>>>>>>
OBS.POINT 15
X-COORD.(FT)= 40
Y-COORD.(FT)= 40
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-2.081030248E-01
UEL. Y-COMpONENT
'FT/DAY) =
156
-------
-0.691879405
NET UEL.(FT/DAY)=
7.224984291E-01
NET FLOW DIRECTION
(COMPASS DEGREES)=
196.7402009
<<<<<<>>>>>>
OBS.POINT 16
X-COORD.("T>= 60
Y-COORD.(FT >=-40
<<<<<<>>>>>>
UEL. X-COr!PONENT
(FT/DAY>=
-8.524846019E-01
UEL. Y-COHPONENT
(FT/DAY>=
2.62344699
NET UEL.(FT/DAY)=
2.758478585
NET FLOW DIRECTION
(COMPASS DEGREES)=
341.9985184
<<<<<<>>>>>>
OBS.POINT 17
X-COORD.(FT ) = 60
Y-COORD.(FT)=-20
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-1.764832567
UEL. Y-COHPONENT
(FT/DAY)=
3.551876394
NET UEL.(FT/DAY)=
3.966164382
NET FLOU1 DIRECTION
(COMPASS DEGREES)^
333.5784451
<<<<<<>>>>>>
OBS.POINT 18
X-COORD.(FT>= 60
Y-COORD.(FT>= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
-6.684971844
UEL. Y-COHPONENT
=
6.75974876
NET FLOW DIRECTION
(COMPASS DEGREES)=
278.5301623
<<<<<<>>>>>>
OBS.POI NT 19
X-COORD.(FT)= 60
Y-COORD.(FT) = 20
<<<<<<>>>>>>
UEL. X-COHPONENT
CFT/DAY)=
-1.764832567
UEL. Y-COriPONENT
CFT/DAY)=
-1.5465288
NET UEL.(FT/DAY)=
2.34655834
NET FLOW DIRECTION
(COMPASS DEGREES)=
228.7718055
<<<<<<>>>>>>
OBS.POINT 20
X-COORD.(FT>= 60
Y-COORD.(FT)= 40
157
-------
<<<<<<>>>>>>
UEL. -X-COMPONENT
(FT/DAY)=
-8.524846019E-01
UEL. Y-COMPONENT
(FT/DAY>=
-0.618033336
NET UEL.(FT/DAY>=
1 .052984733
NET FLOW DIRECTION
(COMPASS DEGREES)=
234.055771
<<<<<<>>>>>>
OBS.POINT 21
X-COORD.(FT ) = 80
Y-COORD. (FT >=-40
<<<<<<>>>>>>
UEL. X-CONPONENT
(FT/DAY)=
-1.16595545
UEL. Y-COMPONENT
(FT/DAY>=
2.115631272
NET UEL.(FT/DAY)=
2.415646454
NET FLOW DIRECTION
(COMPASS DEGREES)^
331.1401956
<<<<<<>>>>>>
OBS.POINT 22
X-COORD.(FT)= 8B
Y-COORD.(FT)=-20
<<<<<<>>>>>>
UEL. X-COHPONENT
=
317.0851615
<<<<<<>>>>>>
OBS.POINT 23
X-COORD.(FT)= 80
Y-COORD.(FT)= 0
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
-2.514006505
UEL. Y-COHPONENT
(FT/DAY)=
1.002673797
NET UEL.(FT/DAY)=
2.706581507
NET FLOW DIRECTION
(COMPASS DEGREES)^
291.7438439
<<<<<<>>>>>>
OBS.POINT 24
X-COORD.(FT)= 80
Y-COORD.(FT) = 20
<<<<<<>>>>>>
UEL. X-COMPONENT
(FT/DAY)=
-1.874606007
UEL. Y-COMPONENT
(FT/DAY)=
NET UEL^I/B^A1
1.87463782
NET FLOW DIRECTION
(COMPASS DEGREES)^
269.666203
1*8
-------
<<<<<<>>>>>>
8?5
Y-COORD.(FT)= 40
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
-1.16595545
UEL. Y-COHPONENT
fFT/DAY)=
-0.110283678
NET UEL.>>>>>
OBS.POINT 26
X-COORD.(FT)= 100
Y-COORD.(FT)=-40
(FT/DAY)=
-1.128707758
UEL. Y-COHPONENT
fFT/DAY>=
1.70222454
NET UEL.(FT/DAY)=
2.042437169
NET FLOU DIRECTION
(COMPASS DEGREES)^
326.4525148
<<<<<<>>>>>>
DBS.POINT 27
X-COORO.(FT)= 100
Y-COORD.(FT)=-20
<<<<<<>>>>>>
UEL. X-COHPONENT
(FT/DAY)=
-1 .*57323137
UEL. v-cOHPONENT
(FT/DAY)=
1.^78805657
NET UEL.(FT/DAY)=
2.076633344
NET FLOU DIRECTION
(COMPASS DEGREES)^
315.4074125
'<<<<<>>>>>>
OBS.POINT 28
X-COORD.(FT)= 100
Y-COORD.(FT >= 0
<<<<<<>>ป>>
UEL. X-COMPONENT
CFT/DAY)=
-1.634104228
UEL. Y-COMPONENT
(FT/DAY)=
1.002673737
NET UEL.(FT/DAY)=
1.917198835
NET FLOU DIRECTION
(COHPASS DEGREES)=
301.5323585
<<<<<<>>>>>>
OBS.POINT 29
X-COORD.(FT)= 100
Y-COCfRD. >>>>>
UEL. X-COHPONENT
(FT/DAY)=
-1 .457323137
UEL. Y-COHPONENT
-t/DAV) =
0.526541937
Klv!T UEL. (FT/DAY) =
1.550032347
NET FLOU DIRECTION
159
-------
(COMPASS DEGREES)^
ซซ8?>5?>3
OBS.DOINT 30
X-COORD.(FT)= 100
Y-COORD.>>>>>
UEL. X-COHPONENT
>>>>>
PROGRAM
OUER,
THANK YOU
-------
161
-------
SOIL SAMPLING CONSIDERATION FOR LAND DISPOSAL FACILITY
PERMIT WRITERS, INSPECTORS AND OPERATORS
Tom A. Pedersen, CPSS
Principal Scientist
Camp Dresser & McKee, Inc.
Boston, Massachusetts
188
-------
SOIL SAMPLING CONSIDERATIONS FOR LAND DISPOSAL FACILITY
PERMIT WRITERS, INSPECTORS AND OPERATORS
INTRODUCTION
Soil resources serve as repositories for wastes and as media in which waste
treatment can be effected. Waste materials and contaminants may also enter
the soil environment as a result of accidental discharges or deliberate
dumping. Regardless of how a contaminant enters the soil, its fate will be
dictated in large part by the characteristics of the soil.
This paper discusses basic concepts of soil science as they relate to the
management of wastes on land. Although the majority of the discussions
deal with the aspects of soil sampling associated with hazardous waste land
disposal facilities, the principles presented are applicable to any
situation in which soil evaluations with respect to environmental
contaminants are undertaken. For example, the soil sampling approaches and
methodology used in support of a permit application are in essence
identical to those used during RCRA Facilities Investigations (RFI) and
Superfund Remedial Investigation/Feasibility Study (RI/FS) activities.
Providing guidance on techniques for obtaining soil samples is the primary
aim of this paper. Attendant to the mechanics of soil sampling are issues
related to regulatory requirements, soil and waste characteristics and
sampling strategies, which are by necessity also reviewed herein.
REGULATORY CONSIDERATIONS
In undertaking any soil sampling activity consideration must be given to
what the data will be used for. In many cases data needs are driven to
some extent by regulatory requirements or goals. Where data requirements
are specifically identified by regulations, the data collection activities
may be more easily structured than in case where data is being collected to
define the spatial distribution of contaminants to a known level of
certainty for example.
189
-------
The Solid Waste Disposal Classification Criteria (40CFR257) clearly specify
the need to determine soil pH and soil cation exchange capacity (CEC) for
crop land on which wastes will be disposal (Table 1). Soil testing to
ascertain whether a clay meets the 1x10"^ cm/sec permeability requirement
for a soil based liner system may also be relatively easy to design.
However, it is more difficult to develop a soil sampling strategy that
demonstrates for instance that "imperfections including lenses, cracks,
channels, root holes, or other structural non-uniformities that may cause
an increase in (its) permeability" do not exist for RCRA landfill soil
based and admixed liners and covers (40CFR264.303).
Likewise, soil sampling strategies for Part B permit applications
(40CFR270.20) must be carefully developed in order to ensure that the data
collected provide meaningful insight into the applicants proposed:
o measures to control pH
o methods to enhance microbial or chemical reactions
o methods to control soil moisture
o methods for unsaturated zone monitoring
In developing waste management plans for land treatment facilities and
landfills sampling strategies must be defined to address the following
broad issues related to soils (40CFR270.20 & 270.21):
o the volume, physical and chemical characteristics of the wastes,
including their potential to migrate through soil or to volatilize
or escape to the atmosphere;
o the attenuative properties of underlying and surrounding soils or
materials;
o the mobilizing properties of other materials co-disposed with these
wastes; and
190
-------
TABLE 1
FOOD-CHAIN CROP LAND APPLICATION LIMITS
Annual Cadmium Loading -
0.5 kg/ha
Cumulative Cadmium Loading (kg/ha)
Soil CEC Soil pH
(meq/lOQg) <6.5 >6.5
<5 5 5
5-15 5 10
>15 5 20
Restrictions on PCB when concentrations
> 10 mg/kg in waste
Source: 40CFR257
191
-------
o the effectiveness of additional treatment design or monitoring
techniques.
In order to ensure that the soil samples collected, and the analyses
performed, provide useful information, a systematic approach or strategy
for data collection should be employed and an understanding of basic soil
characteristics is required.
SOIL CHARACTERISTICS
Soil is comprised of unconsolidated weathered mineral and organic materials
on the earths surface. Soils are comprised of elements in solid, liquid
and gaseous phases. Soil solids include mineral and organic matter; soil
liquids include water and various solutes; and soil gas is the atmosphere
present within the soils pore space. In an idealized mineral soil, these
components are present in the proportions shown in Figure 1. Organic soils
such as peats or mucks would be predominantly comprised of the organic
fraction as opposed to the mineral fraction. These major components, as
well as some minor components such as microbial populations, determine to a
large extent the ability of a soil to serve as a receptacle or treatment
medium for wastes.
Soil Mineralogy - The solid fraction of soils is comprised of minerals
which have weathered from geologic materials such as sandstone or shale.
Soil characteristics differ based on the geologic material from which they
developed and based on the environmental conditions such as temperature and
rainfall which they were exposed to during development.
Soils contain primary minerals such as quartz (SiC^) and feldspar as well
as secondary clay minerals which are weathered aluminosilicates. Clay
minerals are comprised of crystalline octahedral alumina and tetrahedral
silica sheets. The secondary clays are the most chemically active of the
mineral components of a soil. These materials have a net negative
electrical charge due largely to the substitution of alumina octehedra
+3 A
(A1 ) for silica tetrahedra (Si+ ) in the mineral layers.
192
-------
45%
MINERAL
FIGURE 1
IDEAL SOIL
193
-------
Cation Exchange - Positive ions in soil solutions are attracted to the
negative charge sites in soils. The exchange of cations between the soil
solution and the negative charge sites on soil particles is termed cation
exchange. The cation exchange capacity (CEC) of a soil is the total amount
of cations that can be adsorbed by soil expressed as milliequivalents/100
grams (meq/lOOg). CEC is used in assessing the ability of a soil to retain
cationic contaminants, however the retention of metallic ions in soil is
more appropriately attributed to precipitation or covalent bonding
mechanisms ฆ lan to dynamic cation exchange reactions. Nevertheless, CEC
can be used as a relative measure of a soils chemical activity with respect
to contaminant retention/migration..
Soil Reaction - Soil reaction, commonly expressed as pH, has a profound
effect on the fate of contaminants in soils. Some contaminants become more
soluble as soil conditions become more acidic or conversely less soluble.
In strongly acidic soils, hydrogen and aluminum ions predominate in the
soil solution, whereas in neutral soils the soil solution and exchange
+2 + 2
sites are occupied principally by exchangeable bases (Ca ,Mg+ ).
Particle Size - The solid fraction of most soils contain particles of
various sizes ranging from boulders and stones to colloidal clays and
organics. The particle size distribution of a soil is a significant
characteristics with respect to waste management because of the influence
it has on the chemical activity of a soil and the rate at which liquids and
gases can more through the soil. Soil particles are generally defined as
sand, silt or clay sized, however the limits which define these particle
size classes differs widely as shown in Figure 2.
Soil particles are separated by use of sieves down to the silt size
fraction; and by use of hydrometers or pipette techniques (ASA, 1986) for
clays. The information derived from these tests are plotted to yield
particle size distribution curves. By determining the relative proportions
of sand, silt and clay in a soil, its texture can be defined by use of a
textural triangle as shown in Figure 3. Soils which contain 30 percent
clay, 10 percent silt and 60 percent sand for instance would be classified
as sandy clay loams according to the USDA Classification System (USDA,
194
-------
PARTICLE
DIAMETER
in. mm
UNIFIED
-10.1-
-256 -
0.8 20
- 0.16-
0.11 2.83-
0.10 2.50-
0.08:2.0-
-10
0.061.41-
-14 ฆ
-0.04 1 .00 1 1 8
-0.03 0.71 25-
-0.02 0. 50 35-
-0.35-
0.010.25-
0.177-
-45-
-60-
-80-
0.125-
-0.100-
0.088
0.074 -
-0.062-
ฆ0.050
ฆ 0.044
-120
170
200 ฆ
230-
325
-0.031
-0. 0039-
-0. 0020
Cobbles
Coarse Gra\}I
Fine Gravel
Coarse
Sand
Medium
Sand
Fine
San d
Silt
o r
Clay
USDA
AftSHO
WENTWORTH 'INTERNATIONAL Phi
-------
100%
sand
percent sand
FIGURE 3
USDA TEXTURAL TRIANGLE
196
-------
1975). The Unified Classification System makes use of additional
properties of the soil such as Atterberg limits and plasticity in order to
classify soils into groups.
Surface Area - The specific surface area of a soil is of importance with
regard to waste disposal on land because of its relationship to chemical
reactions and adsorption phenomena. The surface area of soil particles per
unit volume increases exponentially as the size of the soil particles
decrease. Table 2 illustrates this concept for equal volumes of different
sized particles.
Soil Structure - The grouping together of individual particles leads to the
formation of soil structure. Soil structure can be described by the
physical appearance of the individual soil peds or grouping of particles.
Structural morphology can be described as platy, prismatic, columnar,
blocky, subangular blocky, granular or single grain.
The bulk density and rate at which water moves through a soil is influenced
by soil structure. Soil bulk density is defined as the ratio of soil mass
to volume and is expressed as g/cm3. Surface soils generally have bulk
densities in the range of 1.2 to 1.7 g/cm3. Bulk densities greater than 2.0
3
g/cm indicate that the soil is compacted and fluid and gas movement may be
restricted. Soil bulk density determinations are generally made by
obtaining a soil core sample of known volume and determining its oven dry
weight. Excavation of a known volume of soil can be accomplished by use of
sand cone or rubber balloon techniques to determine bulk density. Gama ray
transmission techniques can also be used to determine soil density in-situ.
Porosity - The structure of a soil also influences its pore space. Soil
pore space is significant in that it can be used to determine the maximum
amount of water which can be retained by soil or the ease with which gases
or fluids will move through a sovl. The percentage pore space of a soil
can be calculated using the following empirical equation:
PS(%)=l-(bulk density/specific gravity) 100
where: the specific gravity for typical soils
is assumed to be 2.65 gm/cm3
197
-------
TABLE 2
RELATION OF SURFACE AREA TO PARTICLE SIZE
(per unit volume of 1 cm )
Textural
Class
Gravel
Coarse Sand
Very Fine Sand
Silt
Clay
Clay
Diameter
(mm)
10
1
0.1
0.02
0.002
0.0005
Surface Area
(cm2)
3.14 (.5 in2)
31.42
314.16
1570.8
15708
62,832 (68 ftJ)
Source: Baver, Gardner & Gardner, 1972.
198
-------
Void ratio is an other expression used to report the relative amount of
pore space in soils. Void ratio is simply the ratio of the volume of the
voids to the volume of the solids particles.
Soil Organic Hatter - Soil organic matter results mainly from decomposition
of plant materials in undisturbed soils. Soils therefore, generally have
higher organic matter contents in the upper most horizons. Because organic
matter is chemically active, it tends to be of primary concern with respect
to waste disposal. Mineral soils typically have CECs of 15 meq/lOOg or
less; whereas the presence of organic matter in the range of 2 percent can
increase the CEC value by a factor of two or more. Organic matter has a
high chemical activity because of the presence of unsatisfied negative
charge sites.
Contaminants can form complexes or chelates with organic matter. This fact
can increase the attenuation of contaminants in soils but has also
reportedly lead to increased migration of some contaminants. This occurs
when chelates form and the contaminants move through the soil attached to
the organic particle.
Soil Moisture - Soil moisture status varies depending on geographic
location, landscape position, and soil structural features. In low
rainfall areas soils may never reach saturation, whereas in areas of high
rainfall even well drained soils may become saturated at times. Soils
located at toeslopes or downgradient of large watersheds may remain wet for
longer periods of time than those at higher and dryer landscape positions.
Soil structure which impedes drainage of water also influences the moisture
status of a soil. For example fragipans, or cemented horizons may lead to
the creation of perched water table conditions.
Oxidation/Reduction Potential - The moisture status of a soil influences
the manner in which contaminants behave in soils. In saturated soils
reducing conditions predominate and anaerobic or facultative microorganisms
are encountered, whereas in well drained soils oxidative conditions and
aerobic reactions predominate. Redox potentials can be used in conjunction
199
-------
with pH values to determine if a soil is anaerobic or aerobic. Soils with
redox potentials of greater than 400 millivolts (mv) are generally aerobic
whereas anaerobic conditions predominate at 100 mv or less.
Mineral soils which are continual wet exhibit gleying (gray coloring),
whereas soils in which water tables fluctuate exhibit mottling. These
features can be used to infer depth to water tables or seasonal high water
tables respectively.
Hydraulic Conductivity - Soil hydraulic conductivity is often evaluated
with respect to its ability to restrict the migration of contaminants.
However, the rate at which water moves through soil may not be at all
representative of the rate at which an organic solvent would move through
the soil. Therefore, hydraulic conductivity tests should be performed
using the permeant (i.e. leachate) to which the soil will be exposed. In
cases where the hydraulic conductivity of soil to water is of interest, a
soil moisture solution, such as deaerated 0.005M CaSOA which approximates
the ionic strength of soil moisture in the humid northeast, may be used.
Detailed information on hydraulic conductivity testing is contained in
SW-925 (EPA, 19846).
Soil Microbes - Soils have been referred to as living filters because of
the presence of indigenous organisms which can biodegrade contaminants.
The major classes of microorganisms responsible for degradation of wastes
in soils are bacteria, actinomycetes and fungi. Although soils microbes
have an ability to assimilate wastes to a certain extent, some waste
constitutes are highly toxic to microorganisms or recalcitrant and thus not
subject to microbial metabolism. In considering soils with respect to use
for biodegration, the environmental factors which would inhibit microbial
survival must be considered including moisture content and nutrient status.
200
-------
WASTE CHARACTERISTICS
The properties of vastes affect the manner in which they migrate through
soil and the manner and rate by which they are attentuated in soils. The
RCRA Facilities Investigation Guidance (EPA, 1986) identifies the major
waste characteristics below as items to be addressed during an RFI.
Identity and Composition - The chemical characteristics of the waste are of
primary significance as this is the first step in establishing whether the
material is considered a hazardous waste. When records of discharges or
facility operations exists it may be a relatively straight forward exercise
to determine if the waste streams are listed as hazardous or are identified
in Appendix VIII. Testing of waste streams to determine if they are corro-
sive, or toxic may also be required. Where no information is available on
the composition of the materials which have been disposed, a more extensive
testing of the contaminated soils may be required. This testing should
include priority pollutant analysis at a minimum.
Quantity - The quantity and rate at which wastes will be applied to land or
were previously disposed should be determined. This information can
provide clues to the vertical and horizontal extent of contamination which
may have occurred. In designing land treatment systems, rate of disposal
must be controlled so as not to result in overloading the soils hydraulic
assimilative capacity or the soil microbial populations capacity to degrade
the contaminants.
Physical State - The movement and behavior of the waste in soil will differ
depending on whether it is a solid, liquid or gas. The point at which the
release occurs in the soil must also be evaluated whether it be by
subsurface injection or surface application.
Viscosi ty - Thick viscous materials such as crude oil may be less likely to
migrate great distances in soils. However, lighter petroleum fractions
such as gasoline, which is less viscous than water, will migrate through
soils at a rate greater than that which would be approximated by using soil
water hydraulic conductivity values for instance.
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Density - Compounds with densities greater than water may tend to move
through a soil and sink to the bottom of the water table. Whereas,
materials with densities less than that of water may float on the water
table surface.
Dissociation Constant - Compounds which ionize, such as organic and
inorganic acids and bases, phenols, metal salts and other inorganic
complexes, may be more subject to the electrostatic charges present in a
soil and thereby may be less mobile than neutral compounds. The
dissociation constant (pk ) of compounds should therefore be evaluated in
cL
light of the pH expected to be encountered in the soil environment.
Solubility - Highly water soluble compounds would tend to be more mobile in
soils than less soluble compounds. Insoluble compounds could be present as
a separate phase in soil/water systems.
Henry's Law Constant - Henry's Law Constant (Hc) is the partitioning ratio
of a chemical in a liquid phase (such as water) to the vapor phase at
equilibrium. As Hc increases the tendency of a chemical to move from the
liquid (water) phase to the soil air or atmosphere increases.
Octanol/Vater Partition Coefficient - The distribution of a compound
between an aqueous phase and an organic phase (octanol) is termed the
octanol/water partition coefficient (K ). The K of a compound can be
v y ow ow K
used to evaluate the amount of a compound which will remain as free product
versus that which will become dissolved in water.
Organic Carbon Partition Coefficient - The organic carbon partition
coefficient (KQC) can be used to evaluate the tendency of an organic
compound dissolved in water to be adsorbed by organics in soil. Kqv values
can be converted to K. as follows:
oc
K = 0.63 K F
oc ow oc
where: Fqc is the fraction by weight of organic carbon in soil.
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Compounds with high Rqc values are more prone to absorption onto soil.
Biodegradability - Information on the rate and mechanics of biodegradation
of contaminations in the soil environment can provide insight into the
potential for land treatment by metabolism or cometabolism. Much
information is available in the literature on the degradation of specific
compounds of concern.
SOIL SAMPLING METHODS
Soil sampling methods should be selected which will ensure that the sample
is obtained in a manner which will not influence the analytical results.
Soil sampling techniques include those which result in collection of
samples to be subjected to chemical or physical analysis which do not
require that the structural integrity of the sample be maintained. These
types of samples can be obtained using shovels, trowels, punch augers,
bucket augers or split spoon samplers. When testing requires that an
"undisturbed" soil sample be obtained, use of core samplers are generally
required. Soil testing can also be undertaken on soils in the field
(in-situ), whereas soil gas samples are generally obtained by extracting
soil atmosphere and subjecting it to analysis. Identified following are
some basic soil sampling implements.
Trowel - Trowels are implements consisting of scooped blades 4 to 8 inches
long and 2 to 3 inches wide, attached to a handle. Trowels may be used for
obtaining surface soil or sediment samples which do not require excavation
beyond the depth of a few inches. Trowels may also be used to obtain
subsoil samples from profiles exposed in test pits. Trowels are generally
only practical when sample volumes of 1 pint or less will be obtained.
Trowels should be fabricated from stainless steel or teflon.
Shovels - Shovels or tiling spades ("sharpshooters") are used when larger
quantities of materials than those practically attainable using trowels are
required. Shovels are also used when subsurface samples at depths of up to
A feet are to be obtained by hand excavation.
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Trier - Triers are tubes 1 to 2 inches in diameter and generally 24 to 36
inches long, which have been cut lengthwise to form a trough. The edges of
the top of the trier are ground to form a sharp tip for ease of insertion
into sediment or soil. The trier is equipped with a handle for insertion.
Samples are obtained by inserting the trier at angles of up to 45 degrees
from horizontal into sediment or soil. The trier is rotated to cut a core
and then pulled from the material being sampled. The sample is then
transferred to the ippropriate container. Triers are used to sample
materials to depths of 1 foot or less.
Core Sampler - Core samplers are cylindrical metal implements with
diameters of 1/2 to 3 inches. Hand operated core samplers are used in a
manner similar to triers but can be used to obtain samples at depths of up
to 4 feet in non-compacted materials. The core itself is generally 12 to
18 inches in length, and extension rods are used to reach depths of greater
than 1 foot. The sampler is pushed into the soil at 45 degrees to 60
degrees from the horizontal and rotated when desired depth is reached. The
core is then removed and the sample placed into an appropriate container.
Hand Auger - Auger samplers are constructed of sharpened spiral blades
attached to a hardened metal central shaft. The diameters of hand augers
are generally in the range of 1 to 1-1/2 inches and are used to obtain
samples in materials through which hand core samplers cannot be used. Hand
augers are generally more appropriate for sampling in soils with greater
stone or gravel content or higher bulk densities. Hand augers can be used
to obtain samples at depths of up to 3 feet.
The hand auger is screwed into the soil at an angle between 45 degrees to
90 degrees from the horizontal. The auger is pulled from the material
being sampled when the entire auger blade has penetrated soil. The sample
is removed by forcing or knocking it out of the auger.
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Large diameter augers (greater than 3 inches) used in conjunction with
portable gasoline or propane powered engines can be used to obtain samples
at depths of up to about 12 feet. Samples obtained using augers are
disturbed in nature and it is difficult to determine the exact depth at
which samples were obtained.
Bucket Augers - Bucket augers are generally made of two cutting blades
attached to a 3- to 4-inch diameter core 4 to 6 inches long. The bucket is
attached to a hard metal shaft generally 4 to 5 feet in length with a
perpendicular handle attached for rotating the bucket. The bucket auger is
rotated while exerting downward pressure until the bucket is full. The
bucket is then removed from the boring and the sample is transferred to the
appropriate container.
Bucket augers are used to obtain disturbed samples at depths of up to 12
feet. Bucket augers should be utilized in stony or dense materials in
which use of hand operated core or screw augers is not practical. Bucket
augers with closed blades are utilized in single grain materials or
saturated materials which cannot generally be retrieved in core samplers.
Test Pit Sampling - Test pit excavations are usually constructed using
backhoes from which soil samples can be obtained. Test pits expose shallow
soil units in order to obtain detailed soil descriptions and multiple
samples from specific soil horizons. Back hoes equipped with front end
loader attachments are generally used for excavation. The front end bucket
facilitates backfilling of the test pit following completion or work.
Soil sampling within test pits is accomplished following general soil
sampling procedures, using trowels, shovels, trier, core samplers or
augers. Core samplers can be used to obtain both vertical and horizontal
soil samples for use in hydraulic conductivity determinations from test
pits.
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Borehole Sampling - Subsurface soil samples from boreholes can be obtained
at specified depths or continuously. Several techniques can be utilized
for advancing borings including jetting, wash boring, auger boring, or
rotary drilling.
The boring techniques utilized to excavate a borehole result in
considerable disturbance of soil and do not allow for accurate
determination of the depth from which soil materials have been excavated.
Therefore split spoon, thin wall tubes or othe sampling techniques must be
used in conjunction with boring operations to obtain soil samples.
Subsurface samples may be obtained at predetermined depths, at every change
in lithology or continuously. Continuous sampling provides the most
accurate record of subsurface conditions for interpretive purposes.
o Split Spoons - Split spoons are devices used to obtain subsurface
samples of up to 2.5 feet in length within hollow stem auger flights,
cased borings, and mudded holes. The 1.75 to 2.5 in ID split spoon
samplers are advanced into the undisturbed material beneath the
bottom of the casing or borehole by use of weighted hammer and drill
rod. The relationship between hammer weight, drop and blows required
to advance the split spoon in 6-inch increments is an indication of
density or consistency of subsurface soils. After the split spoon
has been driven the prescribed depth, it is removed carefully to
avoid loss of soil materials. In non-cohesive or saturated soils a
nest is used to help retain the sample. Following removal of the
split spoon from the casing, it is detached from the drill rod and
opened to allow for visual classification of the sample.
o Thin Wall Tubes - Thin wall tubes are hollow pipes which are pressed
or driven into the soil without rotation to obtain core samples of
relatively undisturbed soils. Thin wall tube samplers are generally
1.875 in ID, 2 in OD, and 2 to 3 feet long, but may be of any size
convenient for sampling. The thin wall tube has a sharp cutting edge
and a positive inside clearance. Thin wall tube samplers may be
pushed or driven into soils inside hollow stem auger flights, wash
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bore casings or uncased boreholes. The tubes are pushed into the
soil without rotation, until the desired depth is attained, or to
refusal. If the sample tubes cannot be advanced by pushing, it may
be necessary to drive the tube into the soil, without rotation, using
hammers and drill rods. The tubes are generally allowed to remain in
the boring for 10 to 15 minutes to allow buildup of skin friction
prior to removal. The sampler is then rotated to shear the sample
from the soil and carefully removed from the borehole.
Pore Water Sampling - Pore water samples can be obtained under suction
using a vacuum lysimeters, consisting of a porous ceramic cup, connected by
tubing to a collection flask and vacuum pump (Figure 4). The lysimeter cup
is permanently installed in a borehole of the appropriate depth, and the
hole is backfilled vith sand. Suction from the pump pulls water out of the
soil. The primary advantage of this method is that the installation is
"permanent", allowing multiple samples from one spot, to detect changes in
contamination levels with time (EPA, 1986). Zero tension lysimeters can
also be utilized to obtain soil pore water samples.
Soil Gas Sampling - Soil gases can be extracted from the soil and analyzed
for presence of volatile organics using basic soil gas sampling devices as
illustrated in Figure 5.
Additional information on soil sampling methods is contained in the RCRA
Facility Investigation Guidance (EPA, 1986) and in "Characterization of
Hazardous Waste Sites" (Ford et al 1983).
SOIL INVESTIGATION APPROACHES
Development of a soil investigation strategy for a specific project can be
developed around the generic approach presented in Figure 6. The
performance of any field investigation involves a step wise approach to the
collection of data. The iterative nature of the investigation requires
that a re-evaluation of the data quality objectives be undertaken each at
step of the process.
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ACCESS LINES
(1/ IT POLYETHYLENE
TUB ING)
V DIAMETER
FIGURE 4
SUCTION LYSIMETER
SOURCE: EPA. 1986
208
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END CAP-
1/6" TUBING-
3/4" THREADS-
SHAFT-
TUBING NUT
1/2" THREADS
SAMPLING
PORTS
PROBE TIP
~l
FIGURE 5
LOCKHEED GAS ANALYSIS SYSTEM PROBE
209
SOURCE: KERFOOT & BARROWS. 1986
-------
REPORT
FINDINGS
ro
I1
o
DEVELOP
SAMPLING/
ANALYTICAL
APPROACH
COLLECT
DATA
A
SPECIFY DATA
REQUIREMENTS
DEVELOP/REFINE
CONCEPTUAL
MODEL I
REVIEW AND 1
^
EVALUATE I
DATA 1
CJ
DEFINE
OBJECTIVES
J
FIGURE 6
INVESTIGATION APPROACH
-------
Define Objectives - As part of the development of the objectives for an
investigation, the decision making process should be outlined. Specific
decisions that will be made, when they will be made, and by whom they will
be made are critical in the sampling strategy development. Critical
decisions need to be considered when defining the data to be collected, the
sampling and analytical methods, statistical evaluations, the sensitivities
of the methodologies, and the method detection limits.
Project objectives should address major areas of concern including:
characterizing the site with respect to the environmental setting,
proximity and size of human population, and nature of the problem;
identifying potential remedies; and determining specific performance levels
of the potential remedies. Soil sampling objectives are further defined to
ensure that the data collected can be used to support decisions regarding
remedial actions for the site or its suitability for use in land treatment
technologies. Specifying the objectives can be thought of as identifying
problems to be solved.
The expression of these objectives in clear precise decision statements is
the first step toward the development of a cost-effective program for
collection of sufficient data for decision making. The following are some
general questions which should be addressed when developing project
objectives:
o Is land treatment a viable option at this site?
o What are migration pathways?
o What are potential receptors?
o Are contaminants present above levels of concern at points of
receptors?
o Is background an appropriate comparison?
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o Are contaminants above levels of concern as determined from
available standards or technical guidance?
o What are the three-dimensional (spatial) and time boundaries, of
contaminant migration that will be evaluated?
o Are there migration concentration gradients that could be handled
separately?
Data Review and Evaluation - A review and evaluation of the information
available for a site is undertaken initially to provide the foundation for
addition on-site activities. The evaluation of available information can
be summarized in a narrative report or in a file and should contain an
interpretation of the site conditions based upon a review of existing
information, and an the initial site inspection.
The data collected are confirmed by the initial site inspection in order to
develop an objective assessment of the site conditions. The initial site
inspection can be undertaken to:
o Obtain data on volatile chemical contaminants, radioactivity, and
explosivity hazards that may be present on-site in order to
determine appropriate health and safety levels to be utilized.
o Determine if any conditions pose an imminent danger to public
health.
o Confirm the information contained in previous documents.
o Record observable data identified as missing in previous documents.
o Update site conditions if undocumented changes have occurred.
o Perform an inventory of possible off-site sources of contamination.
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o Obtain data such as location of access routes, sampling points and
the site organization requirements for the field investigation.
Develop Conceptual Model - Conceptual models are narrative and illustrative
descriptions of an site and its environs which present hypotheses regarding
the contaminants present on site, their routes of migration, and their
potential impact on sensitive receptors. The hypotheses presented are
tested, redefined and modified during the course of the investigation.
Figure 7 depicts the basic elements of a conceptual model and Figure 8
presents a conceptual model illustration. These elements are expanded upon
to develop a written description of the site and its environs based on
available information.
Numerous techniques are available to evaluate the fate and migration of
contaminants in environmental media. Soil contamination evaluation models
which take into consideration soil properties (texture, pH, permeability),
the characteristics of the contaminant of concern (Koc, solubility) and
environmental factors (temperature, precipitation) are useful in estimating
the movement of contaminants. These types of models are especially
meaningful when used to relate risks at a receptor, for instance, to an
action level for remediation of soils on a site.
By determining the rate of migration of contaminants from a source to a
receptor by use of evaluation models a better understanding of the urgency
for implementation of corrective actions can be obtained.
The principal assumptions and calculation methods used to develop risk
assessments can also be utilized during the development of a conceptual
model to assist in identifying data needs. Although it is not practical to
assume that a detailed risk assessment can be performed during the initial
phases of a project, use of an abbreviated approach which takes facts such
as migration and concentration of contaminants at potential receptors into
consideration can be of value of developing the conceptual model.
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SOURCE
PATHWAY RECEPTOR
c
VARIABLES <
CONTAMINANTS
CONCENTRATION
TIME
MEDIA
RATE OF MIGRATION
TIME
TYPE
SENSITIVITY
TIME
ro
iฆ
-ts>
HYPOTHESIS
TO BE
TESTED
# SOURCE EXISTS
SOURCE CAN BE
CONTAINED
SOURCE CAN
I BE REMOVED
AND DISPOSED
# SOURCE CAN
BE TREATED
# PATHWAY EXISTS
PATHWAY CAN
* BE RENOVATED
PATHWAY CAN
BE ELIMINATED
RECEPTORS ARE NOT
IMPACTED BY MIGRATION
OF CONTAMINANTS
RECEPTOR CAN
BE RELOCATED
INSTITUTIONAL CONTROLS
CAN BE APPLIED
RECEPTORS CAN BE
PROTECTED
FIGURE 7
ELEMENTS OF A CONCEPTUAL MODEL
-------
POTENTIAL SOURCES
o
VOLATILIZATION o
o
o
/
SURFACE RUNOFF
LAGOON
PERCHED
WATER TABLE
GLACIAL TILL
CONTAMINATED
SOILS
DRUMS
4'
4'
I
MIGRATION
V
UNCONFINED AQUIFER
FIGURE 8
EXAMPLE CONCEPTUAL MODEL
ILLUSTRATION
215
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As an investigation proceeds the need to develop more sophisticated models
may become apparent. Use of ground water modeling or geostatistical
techniques may be necessitated in instances where defining the extent of
contamination or establishing total uncertainties associated with a
proposed corrective action is required.
One of the most common misconceptions about modeling and geostatistical
techniques is that they are applied only during the final stages of an
investigation, after all the data are collected. Whi] model application
at the final stages of an investigation may provide useful information,
modeling techniques could be applied throughout the project.
Specify Data Needs - The amount and quality of data required for an
investigation will vary by site. In most situations it may not be possible
to identify all data needs during the initial scoping of the project.
Rather, data needs will become more clearly defined as additional data are
obtained and evaluated.
The number of samples which should be collected can be determined using a
variety of approaches. The validity of the approach utilized is dependent
on the characteristics of the media under investigation and the assumptions
used to select sample locations. Experience and professional training are
the basis for making initial determinations of where samples should be
collected and how many are required. Usually the greater the quantity of
data available for making a decision regarding sample numbers, the higher
the chances are that data will be obtained which address the project
objectives. In situations where data are not available or are limited in
nature, sampling should be undertaken in a phased approach to allow for
collection of initial samples to characterize the general conditions at the
site. These data then can be used to guide in selection of the appropriate
number of samples to be obtained in subsequent phase of the investigation.
In the absence of available data, the data users and decision makers will
be required to develop a rationale for selecting sampling locations for the
216
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initial sampling phases. Questions to be asked to guide the data users in
selecting appropriate sampling numbers and locations could include:
o Do source materials still exist on the soil surface?
o Is there evidence of soil disturbance or vegetative stress based
upon review of aerial photographs?
o Do site conditions favor surficial soil erosion or wind erosion?
o Are sensitive receptors located in the vicinity of the site?
These types of questions can be addressed in the absence of any analytical
data and will assist in identifying additional data needs. Subsequent
discussions may lead to the recommendation that geophysical surveys or
field screening be conducted in areas of soil disturbance during the
initial sampling phases. Collection of a limited number of samples from
identified source materials or pathways, such as streams, may also be
considered during the initial investigations.
In situations where data are available, or as new dataware added to the
site's data base, statistical techniques may be utilized in determine the
number of data required. The Soil Sampling Quality Assurance User's Guide
(EPA 1984) provides guidance for applying statistical methods to estimate
data quantity requirements.
The types of analyses which will be performed on each sample must be
determined along with the number of samples to be obtained. The type of
analytical approaches available for use can be segregated into five levels
as follows:
o Level I - field screening or analysis using portable instruments.
Results are often not compound specific and not quantitative but
results are available in real-time.
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o Level II - field analyses using more sophisticated portable
analytical instruments; in some cases, the instruments may be set up
in a mobile laboratory onsite.
o Level III - all analyses performed in an offsite analytical
laboratory.
o Level IV - all analyses are performed in an offsite analytical
laboratory following rigorous QA/QC protocols and documentation.
o Level V - analysis by non-standard methods. All analyses are
performed in an offsite analytical laboratory. Method development
or method modification may be required for specific constituents or
detection limits.
The sampling and analysis methods selected must be capable of accurate
measurement at the level of concern. Since sampling accuracy is difficult
to evaluate or control, it is extremely important that the analytical
technique chosen has a detection limit well below the level of concern.
Regardless of the specified method detection limit, the actual detection
limit reported may be sample specific. This is especially true of samples
having complex sample matrices. Also, if the concentration of a particular
sample constituent is so high that it requires dilution prior to analysis,
the resulting detection limit for that sample will be raised by the
dilution factor.
In addition to media samples, allocation must be made for QA/QC samples per
the schedule outlined in Table 3.
Develop Sampling/Analytical Approach - In designing a sampling plan there
are a large number of factors which must be considered. Some of these
factors such as the physical characteristics of the site (geology,
hydrogeology, physiography) are unique to each site. There also are
several general factors which must be considered for all sites.
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TABLE 3
QA/QC PROCEDURES FOR SOIL SAMPLES
Procedure
Comments
Field Blanks
Sample Bank. Blanks
Reagent Blank
Calibration Check Standard
Spiked Extract
Spiked Sample
Total Recoverable
Laboratory Control Standard
Re-extraction
Split Extract
Triplicate Sample
Duplicate Sample
One for each sampling team per day. A sample
container filled with distilled, de-ionized
water, exposed during sampling then analyzed
to detect accidental or incidental
contamination.
The field blank, about 40% of them, passed
through the sample preparation apparatus,
after cleaning, to check for residual
contamination.
One for each 20 samples to check reagent
contamination level.
One for each 20 samples to check instrument
calibration.
One for each 20 samples to check for extract
matrix effects on recovery of known added
analyte.
One for each 20 samples. A separate aliquot
of the soil sample spiked with NBS Lead
Nitrate to check for soil and extract matrix
effects on recovery.
One for each 40 samples, a second aliquot of
the sample is digested by a more vigorous
method to check the efficacy of the protocol
method.
One for each 20 samples. A sample of NBS
River Sediment carried through the analytical
procedure to determine overall method bias.
One for each 20 samples. A re-extraction of
the residue from the first extraction to
determine extraction efficiency.
One for each 20 samples to check injection
reproducibility.
One for each 20 samples. The prepared sample
is split into three portions to provide blind
duplicates for the analytical laboratory and a
third replicate for the referee laboratory to
determine interlab precision.
One for each 20 samples to determine total
random error.
Source: EPA, 1984.
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Samples obtained during an investigation should be obtained in a
progressive manner to allow for expansion of the data base in a controlled
manner. Due to the heterogeneity of materials present and the variability
of environmental conditions at sites, it is difficult in most cases to
develop a work plan which will encompass all environmental measurement
activities which may be undertaken in order to satisfy the objectives of
the project at its outset. Because of the variable nature of sites,
investigations must be designed in a manner which allows for flexibility
and adjustment of sampling approaches based on data which are continually
obtained during field investigation. This type of progressive sampling
approach can be accommodated by implementation of a phased investigation.
In a phased approach, samples are collected in a series of independent
sampling events. The first phase may be undertaken for site
characterization purposes while subsequent phases use the information
generated by earlier phases to fill in data gaps. If a mobile lab is
utilized, phases may be continuous as results are analyzed and data gaps
are identified and filled.
A phased approach to sampling is, in most cases, a cost effective method
since areas of concern are identified in the early phases and are then
targeted for additional sampling. When sampling is performed in only one
phase, every conceivable target must be completely sampled. If one or
several of the targets prove to be uncontaminated, a large number of
unnecessary samples will have been taken.
Phased approaches must be developed on a site specific basis but generally
will follow sequentially from less intensive to progressively more
sophisticated field sampling and analysis programs as follows:
o Remote sensing
o Field screening
o Intrusive sampling
220
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o Pilot studies
Collect Data - Data review should be undertaken continually during a
project to allow for making adjustments to sampling strategies dictated by
data. The data generated is also used to refine the site model as needed.
Following data collection the sampling strategy steps are re-entered at the
review and evaluation step.
Ultimately, a determination will be made regarding whether the data
obtained is sufficient to meet the objectives initially specified for the
investigation. Part of the process of evaluating whether the objectives
have been met deals with an assessment of the consequences of a wrong
decision. For example, a decision may be made not to implement a
corrective action designed to mitigate the migration of contaminants in
soil because the data indicate that dispersion and degradation of the
contaminants will reduce concentrations to health-based levels within the
waste management boundary. If in actuality the contaminants migrated
beyond the waste management boundaries and were encountered in the ground
water system at elevated levels, it may be suggested that a wrong decision
was made. The consequences of this wrong decision made at a site where
neighboring residents derive their water from private water supply wells
tapping the contaminated aquifer would be different from the consequences
of contamination of an aquifer which was not used as a source of water
supply. The consequences of a wrong decision when individual water supply
are contaminated would generally be considered more serious than those
associated with contamination of an aquifer system not used as a water
supply.
The consequences of a wrong decision must be weighed for each major
decision to be made during the investigation process. Where the
consequences of a wrong decision carry significant public health, safety or
environmental impacts, greater attention must be paid to obtaining the data
required to ensure that the decision is sound.
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Prepare Report - In all sampling programs a report must be developed to
document findings and draw conclusions regarding the data. The report
prepared should identify all the steps in the sampling strategy and the
decisions made at each of the steps. The report will in most situations by
necessity go beyond a discussion of soil sampling considerations alone,
since soil is but one element of a complex environment in which wastes are
disposed or treated. The behavior of wastes in soils must therefore be
considered in a larger view which includes ground water, surface water,
atmospheric and biotic elements.
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REFERENCES
American Society of Agronomy. 1986 (a). Methods of Soil Analysis. Part 1
- Physical and Mineralogical Methods, Second Edition. Agronomy
Menograph No. 9 (Part 1) Madison, Wisconsin.
American Society of Agronomy. 1986 (b). Methods of Soil Analysis. Part 2
Chemical and Microbiological Properties, Second Edition. Agronomy
Monograph No. 9 (Part 2) Madison, Wisconsin.
Baver, L.D., W.H. Gardner and W.R. Gardner. 1972. Soil Physics, Fourth
Edition. John Wiley & Sons Inc., New York.
Brady, N.C. 1974. The Nature and Properties of Soils, Eighth Edition.
MacMillan Publishing Co., New York.
Ford, P. and P. Turina. 1985. Characterization of Hazardous Waste Sites
A Methods Manual. Volume I - Site Investigations EPA-600/4-84/075.
Ford, P.J., P.J. Turina and D.E. Seely. 1983. Characterization of
Hazardous Waste Sites A Methods Manual. Volume II - Available
Sampling Methods. EPA-600/4-3-040.
EPA. 1978. Compilation and Evaluation of Leaching Test Methods.
EPA-600/2-78-905.
EPA. 1982. Test Methods for Evaluating Solid Waste - Physical/Chemical
Methods. SW-846.
EPA. 1984 (a). Soil Sampling Quality Assurance User's Guide. EPA
600/4-84-043.
EPA. 1984 (b). Soil Properties, Classification and Hydraulic Conductivity
Testing - Draft Technical Resource Document for Public Comment. SW-925.
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EPA. 1985. Permit Writer's Guidance Manual for the Location of Hazardous
Waste Land Storage and Disposal Facilities. Phase I - Criteria for
Location Acceptability and Existing Regulations for Evaluating
Locations. Final Draft. February, 1985.
EPA. 1986(a). RCRA Ground-Water Monitoring Technical Enforcement Guidance
Documen t. 0SWER-9950.1.
EPA. 1986(b). RCRA Facility Investigation Guidance. Vol. I - Development
of an RFI Plan (Draft).
EPA. 1986(c). RCRA Facility Investigation Guidance. Vol. II -
Characterization of Subsurface Releases (Draft).
Kerfoot, H.B. and L.J. Barrows. 1986. Soil Gas Measurement for Detection
of Subsurface Organic Contamination. Preliminary Draft. EPA/EMSL.
Mason, B.J. 1983. Preparation of Soil Sampling Protocol. Techniques and
Strategies. EPA-600/4-83-020.
USDA. 1975. Soil Taxonomy - A Basic System of Soil Classification for
Making and Interpreting Soil Surveys. Agriculture. Handbook No. 436.
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CURRENT DEVELOPMENTS ON CLOSURE REGULATIONS
Matt Hale and Jim Bachmier
U.S. Environmental Protection Agency
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CLOSURE/POST-CLOSURE CARE REQUIREMENTS
FOR LAND DISPOSAL FACILITIES
EPA Seminar on Permitting
Hazardous Waste Land Disposal Facilities
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OVERVIEW
Background
o Universe of Land Disposal Facilities
o Status of Closures
Closure/Post-Closure Care Regulations
o Recent Amendments to Subparts G and H Requirements
o Process-Specific Standards
Post-Closure Permits
Closure/Post-Closure Implementation Issues
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UNIVERSE OF LAND DISPOSAL FACILITIES
Facilities Conducting
Final Closures = 648
(41%)
(expected to increase
to 1100-1200)
Facilities on Permit
Track
(no partial closures) =
348
(22%)
r ..... x Facility Status
Facilities on Permit Uncertain = S28
Track with Partial
Closures = 45
(3%) Disposal Universe = 1569 Facilities
(34%)
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STATUS OF CLOSURES OF LAND DISPOSAL FACILITIES
Closure Plan
Not Received = 366
(53%)
Closure Plan
Received and Under
Review =120
(17%)
Closure Plan
Approved = 108
(16%)
Public Notice of
Intended Approval
Issued = 99
(14%)
Universe of Closures = 693 Facilities (includes partial closures)
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CLOSURE/POST-CLOSURE CARE REGULATIONS
Recent Amendments to Subparts G and H Closure/Post-Closure Care
Requirements
w o Closure Performance Standard
o Closure/Post-Closure Plan Requirements
o Other Closure/Post-Closure Care Requirements
o Closure Schedules/Deadlines
o Cost Estimating Requirements
Technology-Specific Closure/Post-Closure Care Standards
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AMENDMENTS TO SUBPARTS G AND H REGULATIONS
Purpose of May 2, 1986 Amendments
o Incorporate Terms of Atlantic Cement Company Inc. v. USEPA
Settlement Agreement
o Clarify Ambiguities in Regulations
o Address Implementation Problems
Key Changes in the May 2, 1986 Rulemaking
o Closure/Post-Closure Care Requirements Imposed on a Unit Basis
o Closure after Final Receipt of Hazardous Wastes
o Loopholes in Closure Performance Standard Closed
o Removal of Contaminated Soils Required Explicitly
o Procedural Deadlines Eased
o Third-Party Costs
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CLOSURE PERFORMANCE STANDARD
Closure Procedures Must Address All Hazardous Wastes and Hazardous
Constituents
Hazardous Constituents Include All Appendix VIII Constituents
Technology-Specific Closure Requirements Incorporated into Closure
Performance Standard
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CLOSURE/POST-CLOSURE PLAN REQUIREMENTS
Applicability of Plan Requirements
o Closure/Post-Closure Plans
o Contingent Closure/Post-Closure Plans
Contents of Plans
o Description of Activities Necessary to Satisfy Closure Performance
Standard
o Scope of Closure/Post-Closure Care Activities
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APPLICABILITY OF CLOSURE/POST-CLOSURE PLAN
REQUIREMENTS
CLOSURE PLANS
POST-CLOSURE
PLANS
CONTINGENT
CLOSURE/POST-
CLOSURE PLANS
Landfills
Land Treatment Areas
Disposal Impoundments
All Interim Status Storage/
Treatment Impoundments
All Interim Status Waste Piles
Permitted StoragefTreatment
Impoundments That Satisfy
Double Liner Standards
Permitted Waste Piles That
Satisfy Liner Standards
Required only
if clean closure
not practicable
Permitted Storage/Treatment
Impoundments That Do Not
Satisfy Liner Standards
Permitted Waste Piles That
Do Not Satisfy Liner
Standards
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CONTENTS OF CLOSURE/POST-CLOSURE PLANS
Closure Plans
o Description of Activities Required to Close Each Unit Assuming
Maximum Extent of Operations at Any Time During Site Life
o Estimate of Maximum Inventory
o Description of Procedures for Removing Contaminated Equipment and
Soils
o Description of Other Activities (e.g., Ground-Water Monitoring)
o Closure Schedule for Each Unit
Post-Closure Plans
o Description of Planned Monitoring and Maintenance Activities
o Frequency of Activities
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OTHER CLOSURE/POST-CLOSURE CARE REQUIREMENTS
Closure/Post-Closure Care Certifications
ฃ> Survey Plat
Record of Waste and Survey Plat Filed with Local Land Authority
Notice in Deed
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CLOSURE SCHEDULES AND DEADLINES
Notification Required Prior to Closure of Each Disposal Unit
Wastes May Be Removed and Equipment Decontaminated Any Time
Prior to Notification
Closure Triggers
o Within 30 Days of Final Receipt of Hazardous Waste
o Within One Year of Most Recent Receipt of Hazardous Waste If
"Reasonable Likelihood" That Unit Will Receive Additional Hazardous
Wastes
Time Allowed to Complete Partial or Final Closure
o 90 Days to Remove Inventory
o 180 Days to Complete Closure
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CLOSURE SCHEDULE FOR LAND DISPOSAL UNITS
ฆ150
Interim
status
plans
submitted
Days
-30 0 30
90
180
240
300
Final
receipt
of
hazardous
waste
Inventory
removed
Closure
certifications
and survey
plat
submitted
Notification
of closure
of permitted
disposal
units and
interim status
units with
approved plans
Closure
begins
Closure
completed
Record of
wastes and
deed notice
filed; release
from closure
and third-
party liability
financial
assurance
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COST ESTIMATING REQUIREMENTS
Closure and Post-Closure Cost Estimates Required for All Disposal
Facilities
Contingent Cost Estimates for Units with Contingent Plans
Estimates Based on Third-Party Costs
o Costs to Hire a Third Party to Conduct Activities
o Costs of On-Site Treatment and Disposal Allowed if On-Site Capacity
Available
No Credit for Salvage Value of Equipment or Wastes Allowed
Estimates Adjusted Annually for Inflation
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POST-CLOSURE PERMITS
Contents of Post-Closure Permit Applications
o Post-Closure Plan, Cost Estimate, and Financial Assurance (Including
Corrective Action, If Applicable)
o Inspection Schedule
o Floodplain Data
o Ground-Water Data Demonstrating Compliance with Subpart F
Regulations
o Data on SWMUs and Releases
o Exposure Information
Additional Information on Case-by-Case Basis
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CLOSURE/POST-CLOSURE IMPLEMENTATION ISSUES
Technical Adequacy of Plans and Estimates
o Plans Do Not Describe All Activities Required
o Contaminated Soils Not Addressed
o Cost Estimates Do Not Provide Sufficient Detail to Evaluate
Adequacy
Integration of Corrective Action and Closure Requirements
o Closure Requirements at Units with Releases
o Impacts on Closure Deadlines/Schedules
Impacts of Land Disposal Restrictions and Capacity Problems on Closure
Timetables
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CLOSURE OF LAND DISPOSAL FACILITIES:
REGULATORY DEVELOPMENTS
1. Status of Closures at Land Disposal Facilities: General
Background
EPA priorities
Current status of closure approvals
2. Subpart G Closure Regulations
- Major changes in Hay 2, 1986 regulation
Current closure standards
3. Current Closure Issues
Closure at interim status facilities: Changes in
interim status; closure at LOIS facilities
Status of facilities that closed by removal: March
1986 proposal
Receipt of solid waste after final receipt of hazardous
waste
Closure and ง3008(h) corrective action
ATTACHMENT: Closure and Post-Closure Care Regulat ions--Summary
of 40 CFR Parts 264 and 265 Subpart G
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CLOSURE AND POST-CLOSURE CARE REGULATIONS
40 CFR PARTS 264 AND 265 SUBPART G
The following is a list of the current Subpart G closure and post-closure
care standards. The May 2, 1986 rule, which became effective on October 29,
1986, revised many of these standards. That rule was promulgated primarily to
reflect the results of a settlement agreement signed in the Atlantic Cement
Company, Inc. v. EPA lawsuit, D.C. Cir., No. 81-1387 and consolidated cases,
(formerly American Iron and Steel Institute v. EPA), and to clarify other
requirements. The following list includes all revisions made to the
regulations by that May 2, 1986 rule.
1. DEFINITIONS APPLICABLE TO CLOSURE AND/OR
POST-CLOSURE CARE (ง260.10)
A. Active Life of a facility means the period from the initial receipt
of hazardous waste at the facility until the Regional Administrator
receives certification of final closure.
B. Active Portion means that portion of a facility where treatment,
storage, or disposal operations are being or have been conducted
after the effective date of Part 261 of this Chapter (November 19,
1980) and which is not a closed portion.
C. Certification means a statement of professional opinion based upon
knowledge and belief.
D. Closed Portion means that portion of a facility which an owner or
operator has closed in accordance with the approved facility closure
plan and all applicable closure requirements.
E. Disposal means the discharge, deposit, injection, dumping,
spilling, leaking, or placing of any solid waste or hazardous waste
into or on any land or water so that such solid waste or hazardous
waste or any constituent thereof may enter the environment or be
emitted into the air or discharged into any waters, including ground
waters.
F. Disposal Facility means a facility or part of a facility at which
hazardous waste is intentionally placed into or on any land or water
and at which waste will remain after closure.
G. Facility means all contiguous land, and structures, other
appurtenances, and improvements on the land, used for treating,
storing, or disposing of hazardous waste. A facility may consist of
several treatment, storage, or disposal operational units (e.g., one
or more landfills, surface impoundments, or combinations of them).
H. Final Closure means the closure of all hazardous waste management
units at the facility in accordance with all applicable closure
requirements so that hazardous waste management activities under
Parts 264 and 265 of this Chapter are no longer conducted at the
facility unless subject to the provisions in ง262.34 (storage in
tanks or containers for less than 90 days).
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I. Hazardous Waste Management Unit is a contiguous area of land on or
in which hazardous waste is placed, or the largest area in which
there is significant likelihood of mixing hazardous waste
constituents in the same area. Examples of hazardous waste
management units include a surface impoundment, a waste pile, a land
treatment area, a landfill cell, an incinerator, a tank and its
associated piping and underlying containment system, and a container
storage area. A container alone does not constitute a unit; the
unit includes containers and the land or pad upon which they are
placed.
J. On-site means the same or geographically contiguous property which
may be divided by public or private right-of-way, provided the
entrance and exit between the properties is at a cross-roads
intersection, and access is by crossing as opposed to going along
the right-of-way. Non-contiguous properties owned by the same
person but connected by a right-of-way which he controls and to
which the public does not have access, is also considered on-site
property.
K. Operator means the person responsible for the overall operation of
a facility.
L. Owner means the person who owns a facility or part of a facility.
M. Partial Closure means the closure of a hazardous waste management
unit in accordance with the applicable closure requirements of Parts
264 and 265 of this Chapter at a facility that contains other active
hazardous waste management units. For example, partial closure may
include the closure of a tank (including its associated piping and
underlying containment systems), landfill cell, surface impoundment,
waste pile, or other hazardous waste management unit, while other
units of the same facility continue to operate.
2. APPLICABILITY OF REQUIREMENTS (งง264.110, 264.197,
265.110, and 265.197)
A. Closure Requirements (งง264.110(a) and 265.110(a))
Owners and operators of all hazardous waste management
facilities must comply with the closure requirements.
B. Post-Closure Care Requirements (งง264.110(b), 264.197(b),
265.110(b), and 265.197(b))
Owners and operators of all hazardous waste disposal
facilities, and
Owners and operators of all waste piles, surface impoundments,
and tank systems that must close as a land disposal unit must
comply with the post-closure care requirements.
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3. CLOSURE PERFORMANCE STANDARD (งง264.111 and 265.111)
A. Owners or operators must close the facility in a manner that
minimizes the need for further maintenance, and
B. Controls minimizes, or eliminates, to the extent necessary to
protect human health and the environment, the post-closure escape of:
Hazardous waste;
Hazardous constituents;
Leachate;
Contaminated run-off; and
Hazardous waste decomposition products to the ground or
surface waters or to the atmosphere, and
C. Complies with the process-specific closure requirements.
4. CLOSURE AND POST-CLOSURE PLAN REQUIREMENTS (งง264.112, 264.118,
264.197, 265.112, 265.118, and 265.197)
A. Requirements to Prepare Closure and Post-Closure Plans and to
Furnish Plans to the Regional Administrator (งง264.112(a),
264.118(a) and (c), 264.197, 265.112(a), 265.118(a) and (b), and
265.197).
Closure and post-closure plans may be kept at a firm's
off-site location rather than at the facility. For interim
status facilities without approved plans, the plans must be
furnished on the day of the inspection.
Until final closure has been completed and certified, a copy
of the plans and all revisions must be furnished to the Regional
Administrator upon request, including request by mail.
For permitted facilities and interim status facilities with
approved plans, the submitted plans must be the approved
plans with all approved revisions.
For interim status facilities without approved plans, the
submitted plans must be the most current plans.
After final closure has been certified and during the
post-closure period, the approved post-closure plan must be kept
at a location which was predesignated in the post-closure plan.
(Note: In the final rule there is a typographical error,
referring to ง264. 188(b)(3) instead of ง264.118(b)(3).)
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Owners or operators of permitted surface impoundments and
waste piles not designed in'accordance with specified design
standards, and tanks without secondary containment, must prepare
contingent closure and post-closure plans.
Owners or operators of waste piles, surface impoundments, and
tanks not otherwise required to prepare contingent closure and
post-closure plans must revise the closure plan within 60 days
of the determination that the unit must be closed as a landfill
(or within 30 days, if the determination is made at closure) and
prepare a post-closure plan within 90 days.
Contents of Closure Plan (งง264.112(b) and 265.112(b))
The closure plan must include a description of steps for
performing closure of each hazardous waste management unit, as
well as final closure of the facility.
The plan must include an estimate of the maximum inventory
ever on-site over the active life of the facility and a detailed
description of methods to be used for removing, transporting,
treating, storing, or disposing of all hazardous wastes. The
description must identify the types of off-site hazardous waste
management units to be used, if applicable.
The plan must describe steps for removing or decontaminating
all hazardous wastes, contaminated soils, and contaminated
equipment and structures.
The plan must include a detailed description of other
activities necessary during the closure period to ensure that
all partial closures and final closure satisfy the closure
performance standards, including, but not limited to,
ground-water monitoring, leachate collection, and run-on and
run-off control.
The plan must include a schedule for all partial closures and
final closure.
The closure plan may need to include the expected year of
closure. (See Section 4.D.)
Description of Removal or Decontamination of Facility Structures and
Soils in Closure Plan (งง264.112(b)(4) and 265.112(b)(4)).
The plan must describe, in detail, procedures for the removal
or decontamination of all hazardous waste residues and
contaminated containment system components, structures and
soils, in addition to decontamination of equipment at partial
and final closure.
The closure plan must include, at least, a description of:
Procedures for cleaning equipment and removing contaminated
soils;
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Methods for sampling and testing surrounding soils; and
Criteria for determining the extent of decontamination
required to satisfy the closure performance standard.
D. Requirements to Estimate the Expected Year of Closure
(งง264.112(b)(7) and 265.112(b)(7).
The closure plan must include the expected year of closure for
the following facilities:
Permitted facilities that use trust funds and which are
expected to close prior to the permit expiration.
Interim status facilities that use trust funds and whose
remaining operating life is less than 20 years.
Interim status facilities that do not have approved closure
plans.
E. Contents of Post-Closure Plan (งง264.118(b) and 265.118(c))
The post-closure plan must explicitly address the post-closure
care activities for each hazardous waste disposal unit.
The post-closure plan must contain a description of the
planned monitoring and maintenance activities and frequency at
which these activities will occur, to ensure the integrity of
the containment systems.
The post-closure plan must include the name, address, and
phone number of the person or office to contact during the
post-closure care period.
F. Amendments to Closure and Post-Closure Plans (งง264.112(c),
264.118(d), 265.112(c), and 265.118(d)).
To amend the closure or post-closure plan, an owner or
operator of a permitted facility must submit a written request
to modify the permit in accordance with the Parts 270 and 124
requirements.
For an interim status facility with an approved plan, the
owner or operator must submit a request to the Regional
Administrator to modify the plans. If the amendment to the plan
is a major modification according to the criteria in งง270.41
and 270.42, then the modifications to the plan must be made and
approved in accordance with the public involvement procedures in
งง265.112(d)(4) or 265.118(f).
An owner or operator may amend the closure plans any time
prior to the notification of partial or final closure of the
facility. Post-closure plans may be amended any time during the
active life or during the post-closure care period.
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An owner or operator must amend the closure or post-closure
plans iฃ:
Changes in operating plans or facility design affect the
plans;
Events occur during partial or final closure which require
modification of the plans; or
There is a change in the expected year of closure, if the
expected year of closure is required in the plan. (See
Section 4.D.)
Owners or operators of permitted facilities must submit a
written request to modify the permit:
Within 60 days prior to a planned change in the facility
design or operations,
Within 60 days after an unexpected event has occurred which
affects a plan, or
Within 30 days after an unexpected event, if the unexpected
event occurs during partial or final closure.
Owners or operators of interim status facilities with approved
plans must submit a written request for approval of the changes
in the plans in accordance with the deadlines identified above.
Owners or operators of interim status facilities without
approved plans must revise the plans in accordance with the
above deadlines but need not submit the revisions.
The Regional Administrator may request modifications to
closure or post-closure plans. Modified plans for permitted
facilities and interim status facilities with approved plans,
must be submitted within 60 days of the Regional Administrator's
request, or within 30 days of request if the change in facility
conditions occurs during partial or final closure.
Notification of Partial or Final Closure (งง264.112(d) and
265.112(d))
Owners or operators of permitted facilities or interim status
facilities with approved closure plans must notify the Regional
Administrator in writing at least 60 days prior the the expected
date of closure of each disposal unit, or final closure of a
facility with a disposal unit. Owners or operators must provide
at least 45 days notice for final closure of a facility with
only treatment or storage tanks, container storage, or
incinerator units to be closed.
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For interim status facilities without approved plans, an owner
or operator must submit plans for review at least 180 days prior
to the expected date of closure of the first disposal unit
after October 29, 1986, or final closure if it involves such a
unit, whichever is earlier. Plans must be submitted 45 days
prior to final closure for facilities with only tanks, container
storage, or incinerator units to be closed.
The expected date of closure is within 30 days after receiving
the known final volume of hazardous wastes at a hazardous waste
management unit, or within one year of receipt of the most
recent volume of hazardous waste, if there is a reasonable
likelihood the unit will receive more hazardous waste.
Extensions to the expected date of closure may be granted by
the Regional Administrator if the owner or operator demonstrates
that:
The unit or facility has the capacity to receive additional
hazardous wastes, and
The owner or operator has taken, and will continue to take,
all steps to prevent threats to human health and the
environment, including compliance with all applicable
permit and interim status requirements.
H. Removal of Hazardous Wastes and Decontamination or Dismantling of
Equipment (งง264.112(e) and 265.112(e)).
The owner or operator may remove hazardous waste and
decontaminate or dismantle equipment at any time before or
after notification of partial or final closure, provided that it
is in accordance with the approved closure plan.
5. TIME ALLOWED FOR CLOSURE (งง264.113 and 265.113)
A. All hazardous wastes must be removed or disposed of on-site within
90 days after receipt of the final volume of hazardous waste. A
unit or facility must be closed within 180 days after receiving the
final volume of hazardous wastes. These deadlines may be extended
if:
Activities will, of necessity, take longer than the specified
times; or
The unit or facility has the capacity to receive additional
hazardous wastes, and
There is a reasonable likelihood that the unit or facility
will recommence operations within one year, and
Closure of the unit or facility would be incompatible with the
continued operation of the site, and
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The owner or operator complies with all applicable permit
requirements or interim status requirements for obtaining
extensions to the closure schedules.
B. Requests for extensions to the 90- or 180-day periods must be made
at least 30 days prior to the expiration of those periods.
6. DISPOSAL OR DECONTAMINATION OF EQUIPMENT, STRUCTURES, AND SOILS
(งง264.114 and 265.114)
A. At partial and final closure, contaminated soils, equipment, and
structures must be removed or decontaminated.
B. If the owner or operator removes any hazardous wastes or hazardous
constituents, he may become a generator of hazardous waste and
become subject to additional regulations in Part 262 of this Chapter.
7. CERTIFICATION OF CLOSURE (งง264.115 and 265.115)
A. Certification of closure must be signed by an independent (rather
than an in-house) registered professional engineer, and by the owner
or operator.
B. Certifications must be submitted for partial closure of each
disposal unit and for final closure of a facility.
C. Deadlines for submitting certifications of closure are:
Within 60 days of completion of closure for each disposal unit.
Within 60 days of completion of final closure of a facility.
D. All certifications must be submitted by registered mail.
E. Documentation supporting certification must be furnished to the
Regional Administrator upon request until the Regional Administrator
releases the owner or operator from the financial assurance
requirements for closure.
8. SURVEY PLAT (งง264.116 and 265.116)
A survey plat indicating the location and dimensions of disposal
units with respect to permanent benchmarks must be submitted to the
local land authority and to the Regional Administrator no later than
the certification of closure (which is within 60 days of closure)
for each disposal unit.
The plat must be prepared by a professional land surveyor.
The plat filed with the local land authority must contain a note
stating that the owner or operator must restrict disturbance of the
unit.
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A.
B.
C.
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POST-CLOSURE CARE AND USE OF PROPERTY (งง264.117 and 265.117)
A. The 30-year post-closure care period begins upon closure of each
hazardous waste disposal unit.
B. The Regional Administrator may extend or reduce the post-closure
care period based on cause any time prior to partial closure of a
disposal unit or final closure of facility, or any time during the
post-closure period.
C. Changes in the length of the post-closure care period must be in
accordance with the permit modification procedures in Parts 124 and
270. For interim status facilities, such a change must be in
accordance with modification procedures in ง265.118(g).
D. Security may be required after closure if hazardous wastes may
remain exposed, or if access may pose a hazard to human health.
E. Post-closure use of property must never disturb the integrity of the
unit unless it is necessary to the property's use and will not pose
any threats to human health or the environment, or is necessary to
prevent such a threat.
POST-CLOSURE NOTICES (งง264.119 and 265.119)
A. A record of the type, location, and quantity of hazardous wastes
being disposed of must be submitted to the local land authority and
to the Regional Administrator no later than 60 days after
certification of closure of each disposal unit. For hazardous
wastes disposed of before January 12, 1981, the owner or operator
must identify the type, location, and quantity of wastes to the best
of his knowledge based on available information.
B. A notice in the deed to property on which a disposal facility is
located must be recorded within 60 days of certification of closure
of the first and last hazardous waste disposal unit. The notation
must state that the land has been used to dispose of hazardous
waste, its use is restricted under the Subpart G regulations, and a
survey plat has been filed with the local land authority.
C. The owner or operator must submit a certification to the Regional
Administrator that he has recorded the required notation in the
property deed, and include a copy of the document in which the
notation has been placed, within 60 days of closure of the first and
last disposal unit.
D. Removal of hazardous wastes or hazardous waste residues after
closure is not allowed unless:
For permitted facilities, modifications are made to the
post-closure permit in accordance with the permit modification
requirements in Parts 124 and 270.
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For interim status facilities, modifications are made to the
approved post-closure plan in accordance with the requirements
in ง265.118(g).
E. The Regional Administrator may approve a request to remove the
notation on the deed or add a notation indicating that all wastes
have been removed.
11. CERTIFICATION OF COMPLETION OF POST-CLOSURE CARE (งง264.120 and
265.120)
A. Completion of the post-closure care period for each unit must be
certified by the owner or operator and by an independent registered
professional engineer. This certification must indicate that all
activities have been performed in accordance with the approved
post-closure plan.
B. Certification must be submitted no later than 60 days after
completion of the post-closure care period for each disposal unit.
C. Certifications must be submitted by registered mail.
D. Documentation supporting certification must be furnished to the
Regional Administrator upon request until the owner or operator is
released from the financial assurance requirements for post-closure.
12. COST ESTIMATES FOR CLOSURE AND POST-CLOSURE CARE (งง264.142(a),
264.144(a), 265.142(a), and 265.144(a))
A. The owner or operator must have a detailed written estimate of the
costs of closure and post-closure care.
B. The closure and post-closure cost estimates must be based on hiring a
third-party to conduct the activities. For example, if on-site
treatment will be used at closure, the estimates must include the
cost of a third-party conducting these activities.
C. A third-party is "a party who is neither a parent nor a subsidiary
of the owner or operator."
D. The costs of on-site disposal may be used if the owner or operator
can demonstrate that on-site capacity will exist at all times over
the life of the facility.
E. The closure cost estimate must reflect the most expensive costs of
final closure in a facility's active life.
F. The closure cost estimate may not include any credits for salvage
value of hazardous wastes, facility structures or equipment, land, or
other assets associated with the facility at the time of closure, or .
incorporate a zero cost for hazardous wastes that might have economic
value.
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13. ANNIVERSARY DATE FOR UPDATING COST ESTIMATES FOR INFLATION
(งง264.142(b) and (c), 264.144(b) and (c), 265.142(b)
and (c), and 265.144(b) and (c))
A. Closure and post-closure cost estimates must be updated annually
during the active life of the facility within 60 days prior to the
anniversary date of establishment of the financial instrument, or
within 30 days after the end of a firm's fiscal year and before
submission of updated financial information for owners and operators
using the financial test or corporate guarantee.
B. Cost, estimates must be updated for inflation by recalculating the
maximum costs of closure or post-closure in current dollars, or
applying the most recent annual Implicit Price Deflator for Gross
National Product to the most recent cost estimates.
14. REVISIONS TO THE COST ESTIMATES (งง264.142(c), 264.144(c), 265.142(c),
and 265.144(c)
A. Closure and post-closure cost estimates must be revised when facility
operations change, if the change increases the costs of closure or
post-closure care.
B. Cost estimates must be revised no later than 30 days after the
Regional Administrator has approved the request to modify the
approved closure or post-closure plan, or (for interim status
facilities without approved plans) no later than 30 days after a
revision has been made to the closure or post-closure plan.
15. COST ESTIMATES FOR OWNERS OR OPERATORS USING THE FINANCIAL
TEST OR CORPORATE GUARANTEE MUST INCLUDE UIC COST ESTIMATES
FOR CLASS I WELLS (งง264.143(f)(I)(i)(B) and (D), and
(f)(1)(ii)(B) and (D), 264.145(f)(l)(i)(B) and (D), and
(f)(l)(ii)(B) and (D), 265.143(e)(I)(i)(B) and (D), and
(e)(l)(ii)(B) and (D), and 265.145(e)(l)(i)(B) and (D), and
(e)(l)(ii)(B) and (D))
A. Firms using the financial test or the corporate guarantee for
financial assurance for both RCRA facilities and their UIC facilities
must include the estimated costs associated with their UIC facilities
in the financial test for the RCRA facilities.
16. WRITTEN STATEMENT BY REGIONAL ADMINISTRATOR OF REASONS
FOR REFUSING TO APPROVE OR REASONS FOR MODIFYING THE CLOSURE
OR POST-CLOSURE PLAN (งง265.112(d)(4) and 265.118(f)).
A. The Regional Administrator must provide the owner or operator a
detailed detailed written statement of reasons for refusing to
approve, or reasons for modifying, a closure or post-closure plan.
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CONTENTS OF PART B: GENERAL REQUIREMENTS (งง270.14(b)(14), (15),
and (16))
A. Part B applications must include documentation that notices in the
deed have been filed only if hazardous waste disposal units have been
closed prior to submission of the application.
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PERMITTING HAZARDOUS WASTE
LAND DISPOSAL FACILITIES
TEXT OF CLOSURE SPEECH
JAMES T. BACHMAIER
LAND DISPOSAL BRANCH
WASTE MANAGEMENT DIVISION
OFFICE OF SOLID WASTE
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Closure Options Available Under RCRA
I. Landfill Closure
Cover System to Minimize Migration
Post-closure Care
Ground-water Monitoring
II. Clean Closure
Remove or Decontaminate Wastes and Soil
No Cover System or Post-Closure Care
No Restrictions on Future Land Use
III. Alternative Closure
Remove or Decontaminate Most Wastes and Soil
Design Cover Appropriate to Residual Risk
Perform Confirmation Monitoring
Some Post-Closure Care, on a Case-by-Case Basis
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Status of RCRA Closure Options
as of Febraury 1, 1987
I. Landfill Closure
Final Regulation
- Part 264.310 and Part 265.310
II. Clean Closure of Surface Impoundments
- Final Regulation under Part 264.228
Conforming Changes to Part 265.228
To Be Promulgated in February, 1987
III. Alternative Closure
Proposed Regulation Expected To Be
Published in February, 1987; Final
Regulation in May, 1988
Applies to Landfills, Surface Impoundments, and
Waste Piles
Permitted and Interim Status Units
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Closure Guidance Available or Under
Development February, 1987
Landfill Closure
Closure of Hazardous Waste Surface
Impoundments (SW-873), 1982
Evaluating Cover Systems for Solid and
Hazardous Waste (SW-867), 1982
Hazardous Waste Surface Impoundments (Draft Technical
Operating Manual)
Draft Permit Writer's Guidance Manual for
Hazardous Waste Land Treatment, Storage, and
Disposal Facilities, Volume 2
Final Draft Permit Applicant's Guidance Manual
for Hazardous Waste Land Treatment, Storage,
and Disposal Facilities
Clean Closure of Surface Impoundments
Surface Impoundment Clean Closure Guidance
Manual (Document To Be Available by
September, 1987)
Guidance Document for Cleanup of Surface
Impoundment Sites, 1986 (OSWER Policy
Directive No. 9380.0-6)
Alternative Closure
Work on Guidance Manual Is Beginning
Document To Be Available by July, 1988
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I. INTRODUCTION
I would like to discuss the three closure options that are
or will be available under RCRA for permitted facilities and
interim status units. The three options are the following:
1. Landfill closure - which requires a cover
system designed to minimize infiltration
over the long term; ground water monitoring
during the post-closure period; and inspec-
tion and maintenance of the cover system;
2. Clean Closure or Storage Unit Closure - where
wastes are removed or decontaminated; liners,
soils, and any other contaminated materials
are removed or decontaminated; no post-closure
is required; no restrictions are placed on
the future use of the closed site; no cover
system is necessary.
3. Alternative Closure - which is a "hybrid"
option - which may involve elements of the
other two closure options, but is being
developed to allow as much flexibility as
possible in closing a unit, and still assur-
ing that the overall goal of protection of
human health and the environment is achieved.
Closure under this option may involve
removal of most wastes and contaminated soils,
but possibly not to the level required for clean
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closure; it may involve construction of a
cover system, but the cover may not necessarily
be the 4-Part cover that is generally required
for Landfill Closure; it may involve some post-
closure maintenance and monitoring, but may not
necessarily be for 30 years.
II. STATUS OF THE REGULATIONS FOR THE 3 CLOSURE OPTIONS
1. Landfill Closure
Regulations are final and enforceable;
Found at Part 264.310 and Part 265.310.
2. Clean Closure
Under Part 264, regulations are final and
enforceable - Found at Part 264.228;
Under Part 265, we are about to promulgate
final regulations that conform Part 265.228
to Part 264.228;
Regulations are through the Red Border review
and have received 0MB clearance. They should
be signed by the Administrator and will be in
the Federal Register in mid-February;
They will become effective 180 days from date
of publication, which should be mid-August,
1987 .
3. Alternative Closure
Regulations will be proposed at the same time
that the Final Part 265 conforming changes
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(Clean Closure Regs.) are promulgated - in mid-
February;
These are proposed regulations for Part 264
and 265, and will apply to landfills, surface
impoundments, and waste piles;
There will be a 60-day comment period, which
should close in mid-April;
We expect to have a public meeting to take oral
comments in early April. It will probably be
held in Washington;
We expect to promulgate a final regulation by
May, 1988.
III. STATUS.OF GUIDANCE
1. Landfill
Closure of Hazardous Waste Surface Impoundments,
1982 (SW-873);
Evaluating Cover Systems for Solid and Hazardous
Waste, 1982 (SW-867);
Permit Writers' Guidance Manual for Hazardous Waste
Land Treatment, Storage, and Disposal Facilities;
Permit Applicants' Guidance Manual for Hazardous
Waste Land Treatment, Storage, and Disposal
Facili ties.
2. Clean Closure
Draft Guidance Manual for Clean Closure of
Surface Impoundments is under development;
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Will be available for review by Regional EPA
Office staff in February, 1987;
Final guidance will be available to the public
in September, 1987.
3. Alternative Closure
Work is just starting on guidance;
We will have a draft that will be available for
Regional Office review by mid-July;
- We expect to have a final guidance document
available to the public by July, 1988
IV. SURFACE IMPOUNDMENT CLEAN CLOSURE
I would now like to discuss, in a bit more detail, the Surface
Impoundment Closure Option - or what we refer to as the Clean
Closure Option; Again, completing closure under this option means
that no cover system or post-closure care is necessary and no long-
term ground-water monitoring is required. To satisfy the Agency
that clean closure has been completed, the owner or operator of a
storage unit, such as an interim status surface impoundment, must
demonstrate that there is no possible threat to human health or
the environment, due to exposure to any residual contaminants left
at the site. To achieve this standard of performance, the wastes,
any waste residues, liners, or soils that may be contaminated, must
be removed and managed as a hazardous waste, - and adequate sampling
and monitoring of the soil and ground water, and possibly surface
water and air must be completed prior to closure to ensure that any
residual contamination is below the level of environmental concern,
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given fairly conservative, worst-case exposure assumptions.
The process for establishing what these residual contaminant
levels are, and for determining whether they are met at any given
site, will be detailed in the Clean Closure Guidance Manual that I
had referred to earlier. To repeat, this manual will be available
for regional reviews in February, and will be complete by September,
1987. I will briefly outline the process that we are recommending
in this guidance:
First, the owner or operator must identify the
hazardous constituents of concern. He should
assume that the universe of contaminants is
Appendix VIII, but may go beyond Appendix VIII,
if there is reason to suspect other hazardous
materials such as asbestos are present at the site;
In order to identify the hazardous constituents,
the owner or operator should sample the waste
and perform an Appendix VIII analysis of the
waste; this waste analysis information, along
with historical records of waste management at
the site, will allow identification of chemical
constituents of concern;
We are not requiring a full Appendix VIII waste
analysis - but we are strongly recommending that
it be performed, since we don't believe that
facility records will be complete or can, in all
cases, be relied upon - due to chemical reactions
and transformation products that may be present
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- 6 -
that were not in the waste, but may be of
concern at the time of closure;
The owner or operator should also desire this
information to assure that he has made an
accurate estimation of the amount of soil
removal necessary to complete Clean Closure;
It will also serve as a stronger basis for
narrowing the list of chemical constituents for
further environmental sampling - ground water,
soil, surface water, surface sediments, etc. -
that he will be required to perform to complete
Clean Closure.
Next - Once the chemical constituents have been
identified, it will be necessary to set target
levels for each chemical, in the soil and in
the ground water, and possibly in the surface
water and sediments.
These targets levels are the levels of residualr
contamination that may remain in the soil or ground
water that are not of any further concern or threat
to human health or the environment. They are the
concentration levels that will answer the question -
How clean is clean?
They will be based on EPA-approval health-based
standards. These standards are known as Refe-
rence Doses or Risk-Specific Doses;
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- 7 -
Reference Doses or RFD's are Agency-approved
limits for non-carcinogenic effects - stated in
mg/kg/day;
And Risk-specific Doses - or RSD's are Agency-
approved limits for carcinogenic effects - stated
in mg/kg/day, and associated with a specific
level of risk. We are proposing to use 10~6 for
Class A & B carcinogens and 10"^ for Class C's.
The classes are based on the weight of scien-
tific evidence as to the chemical's carcino-
genic effects;
We will use standard exposure assumptions for
each route of exposure - ingestion of drinking
water, direct contact with soil, inhalation,
etc. - For example, we assume the 70 kg adult
consumes 2 liters of water per day; and inhales
20 m^ of air per day, etc.
The guidance manual will present preliminary
target levels for each Appendix VIII constituent
based on these standard exposure assumptions and
the corresponding health-based standards - (RFD's
or RSD's);
The preliminary target levels will be used
uniformly at all sites that are attempting to
achieve clean closure. They should be used by
the owner/operator in estimating the extent and
266
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- 8 -
amount of soil removal that may ultimately be
required;
The preliminary target levels may be modified
at any individual site, and final or ultimate
target levels set, based on;
unique mixtures of chemicals present;
ability to sample and analyze for certain
chemicals in certain media;
level of background contamination present
at any site;
The process for using the preliminary target
levels to set final target levels will be
explained in the guidance manual.
Once the constituents are identified and the
target levels set, the waste and waste residues,
the liner, and any contaminated soils must be
removed, and managed as a hazardous waste.
When enough soil excavation has been completed,
it will be necessary to take soil and ground
water samples, analyze them for the chemical
constituents of concern, and compare the results
with the final target levels;
If target levels are met for each chemical,
clean closure has been completed. If not,
additional excavation may be necessary;
It is recommended that the owner or operator
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- 9 -
attempting to complete clean closure re-evaluate
his decision at various points in the waste
removal and soil excavation process. It may not
be possible to estimate accurately the level of
contamination in the soil until the wastes and
the liner are removed. Therefore, preliminary
estimates of the amount of soil removal may
prove to be inaccurate.
It is very important that waste constituents
be identified early in this process, and accu-
rate target levels determined to prevent the
situation where clean closure becomes
infeasible, due to the amount of soil that
must be removed, and the owner or operator must
modify the closure plan to possibly close the
facility as a landfill.
To re-emphasize, the standard of performance to
be achieved to complete Clean Closure is compre-
hensive and is based on fairly conservative
assumptions. We feel that this is necessary
to justify not requiring a cover system and no
post-closure care requirements.
V. ALTERNATIVE CLOSURE OPTION
- We also feel that many impoundments may not be
able to meet the strict clean closure standards,
but nevertheless, could be closed in such a
268
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- 10 -
manner that human health and the environment are
protected without installing the 4-part cover
system described in guidance, and without the
full 30 year post-closure care requirements.
For this reason, we are proposing the Alternative Closure
option, as I previously mentioned, to allow more flexibility and
to allow consideration of site specific factors - so that a closure
approach can be designed uniquely for a site, as long as the general
closure performance standard is met.
The alternative closure option may involve leaving certain
residual levels of contaminants in the soil above what would be
allowable under clean closure, provided that the owner or operator
could demonstrate that these contaminants would never migrate to
the water table. To prevent direct contact at the surface, possibly
a soil cover could be installed and maintained. Ground water moni-
toring for a certain period of time following closure may be
necessary to verify that any predictions of migration are valid;
(such predictions may be made through modeling unsaturated zone
flow and chemical or physical attenuation).
The proposed alternative closure regulation has only recently
been published, the comment period is still open, and the decision
process that the Agency and owner or operator must go through is
still not well defined at this point. The proposal provides numerous
options that the Agency is considering for implementing the
Alternative Closure option.
I strongly encourage each of you to consider the proposal rule
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- 11 -
carefully, and provide meaningful comments. We are aware that
flexibility is needed in assuring protection of human health and
the environment and closing each interim status unit in a reasonable
manner, and will make every effort to promulgate an effective
Alternative Closure Option in as timely a manner as possible.
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VULNERABLE HYDROGEOLOGY GUIDANCE
Glen Galen
U.S. Environmental Protection Agency
271
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Criteria for Identifying Areas of Vulnerable
Hydrogeology under the Resource Conservation
and Recovery Act
An Overview of the Guidance Manual for
Hazardous Waste Land Treatment, Storage,
and Disposal Facilities
Introduction
This presentation will provide a brief overview of EPA's
guidance manual entitled Criteria for Identifying Areas of
Vulnerable Hydrogeology under the Resource Conservation and
Recovery Act, which presents a technical method for determining
ground-water vulnerability at hazardous waste surface
impoundments, waste piles, and landfills.
First, the guidance manual will be briefly summarized,
highlighting some of the information and describing how EPA
might use the vulnerable hydrogeology criteria. The presentation
will providein some detailsome examples of ground-water
characterization that I hope will illustrate how the
vulnerability definition and its method of analysis using flow
nets can be used to understand the interaction of waste
management units with the hydrogeologic environment.
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CRITERIA FOR IDENTIFYING AREAS OF VULNERABLE
HYDROGEOLOGY UNDER THE RESOURCE CONSERVATION
AND RECOVERY ACT
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AN OVERVIEW OF THE GUIDANCE MANUAL FOR
HAZARDOUS WASTE LAND TREATMENT, STORAGE,
AND DISPOSAL FACILITIES
M
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Overview of the Guidance Criteria and its Purpose
The first section of the manual provides background on the
development of the document and discusses how the vulnerable
hydrogeology criteria might be used.
The guidance manual was pr pared in response to requirements of
the Resource Conservation and Recovery Act as amended by the
Hazardous and Solid Waste Amendments of 1984. Specifically,
under section 3004(o)(7), EPA is required to publish guidance
criteria identifying areas of vulnerable hydrogeology and to
promulgate regulations that specify criteria for the acceptable
location of new and existing hazardous waste management
facilities. This guidance manual responds to the first
requirement; EPA is now drafting regulations to respond to the
second requirement which we expect to propose in 1987.
Although the Hazardous and Solid Waste Amendments require the
guidance criteria to be published, the amendments do not
stipulate how the document is to be used. At this time, there
is no statutory or regulatory citation requiring implementation
of the criteria in and of themselves. The guidance document
should not be construed as siting policy.
EPA, however, is investigating how consideration of the
hydrogeologic vulnerability of a facility's location can be
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HAZARDOUS AND SOLID WASTE AMENDMENTS OF 1984
SECTION 3004(o)(7) REQUIRES EPA TO:
PUBLISH GUIDANCE CRITERIA IDENTIFYING AREAS OF VULNERABLE
HYDROGEOLOGY.
- PUBLISHED IN JULY, 1986
PROMULGATE REGULATIONS THAT SPECIFY CRITERIA FOR THE ACCEPTABLE
LOCATION OF NEW AND EXISTING HAZARDOUS WASTE FACILITIES.
- PROPOSED REGULATIONS, SEPTEMBER, 1987
- FINAL REGULATIONS, SEPTEMBER, 1988
31
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incorporated into RCRA permitting decisions and future
regulations.
Currently, the technical guidance for Identifying Areas of
vulnerable Hydrogeology provides RCRA permit writers with a
standardized, uniform technical method for determining the
adequacy of the permit applicant's site characterization,
evaluating the applicant's plans to monitor ground-water at the
site, determining the adequacy of hydrogeologic data submitted
in permit applications, and identifying RCRA facilities located
in areas of vulnerable hydrogeology and prioritizing sites for
further attention. In this presentation examples will be used
to illustrate these ideas.
This method can be used to assess compliance with several
regulatory standards related to a facility's location. As
presented in recent EPA guidance entitled: Permit Writers'
Guidance Manual for Hazardous Waste Land Storage and Disposal
Facililties--Phase I--Criteria for Location Acceptability and
Existing Applicable Regulations (available from NTIS, PB 86-125
580), site characterization and the ability to monitor are
prerequisites for permitting a facility. As I will show later
in this presentation, the TOT method can be used to objectively
assess compliance with these standards.
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PROVIDES RCRA PERMIT WRITERS WITH A STANDARDIZED,
UNIFORM TECHNICAL METHOD FOR:
DETERMINING ADEQUACY OF THE SITE CHARACTERIZATION.
EVALUATING GROUND WATER MONITORING AT THE SITE.
DETERMINING ADEQUACY OF HYDROGEOLOGIC DATA
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IDENTIFYING RCRA FACILITIES LOCATED IN AREAS OF
VULNERABLE HYDROGEOLOGY.
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THE FOUR CRITERIA
THAT ARE USED IN DETERMINING LOCATION
ACCEPTABILITY:
1. ABILITY TO CHARACTERIZE THE SITE
2. SITE NOT A HIGH HAZARD/UNSTABLE TERRAIN
3. ABILITY TO MONITOR AT A LOCATION
4. NO DANGER TO FEDERALLY-PROTECTED LANDS
PERMIT WRITERS' GUIDANCE MANUAL FOR HAZARDOUS WASTE LAND
STORAGE AND DISPOSAL FACILITIES-PHASE l-CRITERIA FOR
LOCATION ACCEPTABILITY AND EXISTING APPLICABLE REGULATIONS
(AVAILABLE FROM NTIS, ORDER NUMBER: PB86-125580)
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As described in Section 2 of the manual, EPA considers areas of
vulnerable hydrogeology to be those in which the predominant
natural hydrogeologic conditions are conducive to the subsurface
migration of contaminants in a way that may adversely affect
drinking-water sources, sensitive ecological systems, or nearby
residents. The method used to determine the vulnerability of
hydrology is based on the objective of identifying natural
conditions that minimize the potential for exposure. It does
not predict the rate of migration for a specific constituent.
EPA is concerned that ground-water contamination, and any
resulting human and environmental exposure, can occur as a
result of the failure of engineered barriers and the absence of
operational controls and oversight at hazardous waste Land
Disposal facilites. Once such contamination occurs, it can be
both difficult and costly to clean up.
In developing the ground-water vulnerability Guidance, EPA
determined that the definition should respond to three major
pathways for potential exposure to contaminated ground-water.
First, there is the well-recognized water well pathway, in which
an aquifer contaminated by hazardous waste leachate is used to
supply water for residential, commercial, agricultural, or
industrial uses. Second, exposure can occur when contaminated
ground-water discharges to surface waters, thereby endangering
both the surface-water ecosystem and water users downstream.
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EXPOSURE PATHWAYS
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Ground Water as an
Industrial or Commercial
Water Supply
Ground Water as a
Supply for Residence
or Agriculture
Ground Water Discharge
to Surface Water
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The third pathway is called the basement seepage pathway. Human
exposure can occur when contaminated ground-water seeps into
residences through walls or utility line apertures or by flowing
overground. When these structures are permanently or seasonally
affected by a shallow saturated zone that can be contaminated by
releases from a waste management unit, the potential for
contamination via the basement seepage pathway exists. Seepage
of contaminants into basements is an important pathway that is
often overlooked. It was the major exposure pathway at Love B5
Canal and it may be a major pathway in other areas that receive
municipal drinking water drawn from areas not affected by the
waste management facility.
The integrated method that EPA has developed to identify B6
vulnerable hydrogeology requires the calculation of the Time of
Travel (referred to as "TOT") of ground-water along at least a
100-foot flow line originating at the base of the hazardous
waste management unit. A greater distance should be used if the
100-foot segment does not represent an appropriate "sample" of
the site. We feel that the 100-foot interval corresponds to an
area open to ready investigation by the owner/operator without
needing off-site access. This calculation requires data on
hydraulic conductivity (also often called permeability), the
hydraulic gradient, and the effective porosity of sediments (or
gravity drainable porosity of rock). This method is not
applicable to geologic settings in which Darcy's Law is not
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WEST-EAST CROSS SECTION
LOVE CANAL
Seasonal high water table
B5
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Hazardous Waste Unit
Selected Flow Line
Ground Water Table
Non-vulnerable Hydrogeology:
TOT., oo > 100 years for disposal facilities.
TOTioo > Tlme required for corrective action at
treatment or storage facility.
a
283
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applicable, such as areas of turbulent flow through large
fractures or subterranean channels.
Using the TOT calculation, ground-water at a site is
characterized as non-vulnerable to contamination from land based
hazardous waste management activities by its natural
hydrogeologic conditions if these ground-water flow conditions
are characteristic of aquitards. The guidance states that
TOTioo values on the order of 100 years or greater as
characteristic of non-vulnerable settings for disposal units.
These conditions define non-vulnerable hydrogeologies for RCRA
hazardous waste land disposal facilities only. For those land
storage or treatment facilities such as treatment impounements
or waste piles where it is certain that wastes will be removed
at closure (i.e., clean closure), the vulnerability of the
ground-water is related to the time that would be necessary to
correct a problem in the event that design and operating
controls in place at the facility failed. The objective of the
TOT calculation should be to determine whether contamination
could migrate beyond a limited this distance in less time than
is needed to effectively recognize and respond to a release
through successful implementation of a corrective action plan.
In developing the time-of-travel criteria, EPA analyzed exposure
potential and health risk using actual facility performance data
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and theoretical modeling. These are described in detail in
Appendix D.
During this analysis, EPA assessed the frequency distribution of
TOT among well-studied aquifers. Out of 67 case studies EPA
found that only 4 percent of the case studies have a TOT^qq
that equals 100 years.
EPA also estimated the number of land-based Treatment, Storage,
and Disposal Facilities (TSDFS) that are located in areas of
vulnerable hydrogeology. By assessing both facility-specific
and flow regime classification data, EPA found that the majority
(approximately 70 percent) of the 171 Treatment, Storage, and
Disposal Facilities studied are located in areas of vulnerable
hydrogeology.
Section 4 of the guidance provides a description of situations
where special engineering modifications, such as slurry walls
and grout curtains, might be used to increase TOT in areas that
predominantly satisfy the overall aquitard concept, and Section
5 provides a list of abstracts of supporting technical documents
and references.
Supplementing the guidance manual are four important technical
references that are included as appendices. Appendix A
describes how to determine hydraulic conductivity, hydraulic
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APPENDICES
A. TECHNICAL METHODS FOR EVALUATING HYDROGEOLOGIC PARAMETERS.
B. GROUND-WATER FLOW NET/FLOW LINE CONSTRUCTION AND ANALYSIS.
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C. TECHNICAL METHODS FOR CALCULATING TIME OF TRAVEL (TOT)
IN THE UNSATURATED ZONE.
D. DEVELOPMENT OF VULNERABILITY CRITERIA BASED ON RISK
ASSESSMENTS AND THEORETICAL MODELING.
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gradient, and effective porosity. Appendix B describes how to
construct ground-water flow nets to understand flow patterns at
hazardous waste facilities. Constructing flow nets for a site
and using the vulnerable hydrogeology calculation can provide a
tool for ensuring that a location is properly characterized and
the ground-water at the site can be properly monitored.
Appendix C describes how TOT can be estimated for the
unsaturated zone in areas with arid or semi-arid climates where
thick unsaturated zones are common. Appendix D describes EPA's
technical analyses performed in developing the TOT criteria.
Hydrogeologic Parameters Required for TOT Analysis
The TOT calculations provide an estimate of ground-water flow
velocities at a site. This characterization of the flow field
is based on Darcy's Law, and requires data on three
hydrogeologic parameters:
1. hydraulic conductivity measurements of the porous media that
characterize representative conditions for each aquifer or
aquitard.
2. effective porosity of each lithology or soil type.
3. hydraulic gradientsboth horizontal and vertical.
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HYDROGEOLOGIC PARAMETERS REQUIRED FOR TOT ANALYSIS
HYDRAULIC CONDUCTIVITY - CHARACTERIZE EACH AQUIFER/AQUITARD
EFFECTIVE POROSITY
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HYDRAULIC GRADIENTS ฆ HORIZONTAL AND VERTICAL
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The preferred methods for determining each parameter are
described in Appendix A of the Guidance Document.
HYDRAULIC CONDUCTIVITY
Hydraulic Conductivity values used in the analysis are extremely
important because the values strongly affect the calculated flow
velocity.
Field methods should be used for determining hydraulic
conductivities because results obtained from these methods are
more closely representative of in-situ conductivities of the
materials tested. These methods are described in Appendix A of
the document and EPA method 9100. Generally, laboratory methods
underestimate hydraulic conductivity.
EFFECTIVE POROSITY
The effective porosity of porous media is used to convert the
volume flux calculated by Darcy's law into an estimate of actual
fluid velocities within pore spaces. In Section 3 the document
provides default values for effective porosity, although lab or
field data may be used.
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HYDRAULIC CONDUCTIVITY
FIELD METHODS ARE PREFERRED, AS DESCRIBED IN
APPENDIX A AND EPA METHOD 9100.
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LAB TESTS USUALLY UNDERESTIMATE HYDRAULIC
CONDUCTIVITY.
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EFFECTIVE POROSITY
DEFAULT VALUES ARE PROVIDED IN SECTION 3
FIELD TESTS APPROPRIATE ONLY FOR UNCONFINED CONDITIONS
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HYDRAULIC GRADIENT
The hydraulic gradient used in the TOT calculation is provided
by the flow net construction. Both the flow lines and the
gradient are based on the distribution of hydraulic head as
delineated by piezometer measurements and the water table. The
hydraulic head values may vary at a site because of seasonal or
daily influences such as river stages or tides and by the type
of unit (for example, an impoundment versus a lined waste
pile). Head values used for flow net construction should be
selected to represent maximum hydraulic gradients that exist at
a site. This provides a "worst case" TOT analysis that prevents
underestimating the ground-water flow velocities.
TIME OF TRAVEL CALCULATION
Now for the Time of Travel analysis. This analysis provides a
measure of the ability of the natural hydrogeologic setting to
minimize the potential for exposure to releases, based on the
hydrogeologic parameters just described. The TOT^qq is best
analyzed by construction of a flow net. The flow net solves
Darcy's law for the paths of flow and the flux of ground-water
in the area of investigation.
For this demonstration, there is a flow net with a water table
and piezometer data. Equipotential lines are based on the water
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HYDRAULIC GRADIENT
CHARACTERIZE TEMPORAL VARIATIONS OF HEAD VALUES AT A SITE
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SELECT VALUES WHICH REPRESENT THE MAXIMUM HYDRAULIC GRADIENT AT A SITE
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VARIATION IN HYDRAULIC HEAD
DUE TO UNIT-TYPE
Surface Impoundment ^
^7\ Fi^d
y 1i S n
f. , Cover
Landfill _ "Y f
/ A-A-- \
X Waste >
Waste Pile (without liner)
Where hi = initial head and 1-j = initial point for flow line
294
-------
3E
W
=
_ 150
4
*3
ro
vฃ>
cn
^ 145\
\ซ = -ป40
o\
-------
table position and interpolation of piezometer values. Notice
the values for A1 and A2. These closely spaced piezometers
illustrate that decreasing head with depth characterizes
recharge areas. Inversely, head is greater at depth in
discharge areas, as shown by Wells A4 through A6.
With this flow net, we can TOT^qq over a 100-foot flow line
can be calculated. The variables in the equation are hydraulic
gradient, hydraulic conductivity, and effective porosity. The
hydraulic gradient can be graphically determined for a segment
of the flow line by measuring the change in head (between
equipotential contours) divided by the distance (between the
contours).
Hydraulic conductivity must be measured for each formation.
Effective porosity is either measured or estimated for each
formation. (Section 3 of the guidance manual has estimates
based on soil type.)
TOT along the flow line is the sum of TOT for each segment of
the flow line. The average linear velocity of flow for each
segment is found by dividing the Darcy Flux by the effective
porosity.
The Darcy flux is calculated by multiplying the conductivity by
the gradient.
296
-------
V L, L2
totioo= y
V V
1 2
where l = length of flow line segment
v r AVERAGE LINEAR VELOCITY
IL, + Lg .... = 100 FEET
v =
ru
where k = hydraulic conductivity
i = HYDRAULIC GRADIENT
ne = EFFECTIVE POROSITY
297
-------
The time for travel along the flow path is the sum of the time
of travel for each segment of the flow path, until the end of
the 100 foot flow line is reached. If this 100-foot interval is
not thought to be representative of site conditions, a larger
interval can be used, with the results prorated. For this
example, if hydraulic conductivity equals 1 x 10 ^ M/S,
hydraulic gradient equals 0.2 and effective porosity equals 0.1,
TOTioo equals 47 years.
Evaluation of Site Characterization
Flow net construction can be used to evaluate the
characterization of a site. The construction of flow nets for
the TOT analysis requires integration of hydrogeologic data into
a reasonable interpretation of the ground-water flow regime.
The requirements for flow net construction may reveal any
inconsistencies or gaps in data provided for the site
characterization. Flow net analysis may also provide an
objective measure of the accuracy and completeness of the site
characterization. In a sense a flow net is an analytical
"model" of a site. Any hypothesis can be verified by asking
certain additional questions.
To check site characterization, additional piezometers may be
installed and head data collected. The new data can be compared
with interpolated head values from the flow net. If the new
298
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FLOW NETS AS AN OBJECTIVE MEASURE OF
SITE CHARACTERIZATION
INTEGRATION OF HYDROGEOLOGIC DATA INTO A REASONABLE INTERPRETATION
OF THE GROUNDWATER FLOW-REGIME
INCONSISTENCIES AND GAPS IN DATA ARE REVEALED
CHARACTERIZATION CAN BE TESTED BY INSTALLATION OF ADDITIONAL PIEZOMETERS
El
-------
data are not consistent with the flow net, the site has not been
adequately characterized. The following example illustrates
this concept.
This cross section is taken from the site characterization
submitted in a permit application for a proposed landfill. The
watf.. table has been delineated by the applicant by connecting
the static water level in all wells except S-8. The water level
in S-8 is labeled as a perched water table above the silt. Flow
net construction and a general knowledge of the area where the
site is located allows the completeness and accuracy of the
characterization to be evaluated.
The site is located on the floodplain of a major river in the
Upper Coastal Plain of the Southeastern United States. Standing
water is present in the drainage ditches adjacent to wells S-8
and M-6. Considering the floodplain setting and humid climate,
these water levels may be interpreted as outcrops of the water
table, which would lie just beneath the ground surface at most
of the site. The "so-called" perched water table, as shown in
well S-8, would be highly unlikely in such a setting, especially
where the underlying low permeability sediments are
discontinuous. As shown on the cross-section, by positioning
the water table just below the surface as indicated by the water
in the ditches, the head values of the piezometers can be
roughly contoured. These contours show that head decreases with
300
-------
CROSS SECTION SUBMITTED IN PART B APPLICATION
West
h = 107
Water Level In Well
Water Table
Flow lines
Depth ol Screen
Equlpotential lines
E2
-------
ALTERNATIVE INTERPRETATION: RECHARGE AREA
SHALLOW WATER TABLE
E3
-------
depth, which is characteristic of a recharge area. Ground-water
flow in this area is mainly downward with some lateral flow to
the east (which is the direction of the river). This flow net
shows a reasonable distribution of head values and flow patterns
across the site, which fit the observations and both the local
and regional setting.
An objective evaluation of differing interpretations of site
data can be obtained by collecting additional data--by
installing additional piezometers. For example, if a piezometer
is located as shown (the verification well on the right), the
observed head may be compared with the interpolated head from
the flow net. If the applicant's cross section is correct, the
new piezometer would be dry. However, if the new flow net is
correct, a static water level of 122 feet would be observed in
the well. If the new data conflicts with both flow nets, the
site has not been adequately characterized, and further data
collection is necessary. In this way, the accuracy of a site's
characterization can be evaluated. In the same manner, the flow
net allows you to assess whether background and down gradient
monitoring wells have been properly placed to encounter ambient
conditions and possible contamination.
Below are described a few situations where flow nets can be used
to understand the interaction of land-based units and the
hydrogeologic environment.
303
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Example 1: Surface Impoundment with Inward Gradient
The first example deals with the design and operation of a
storage or treatment surface impoundment that intersects the
ground-water table. Flow net analysis will be used to show
effective design and operation under saturated soil conditions.
By actively controlling the hydraulic head over an area (such as
by pumping), we can change the natural hydraulic gradient can be
changed and cause both equipotential and flow lines to conform
to a new gradient.
In the case of a surface impoundment, the head in the area under
the impoundment is a function of the depth of liquid standing in
the impoundment. By changing the level of liquid standing in an
impoundment, the head and the gradient in the area can be
manipulated. By pumping we can actively lower the level of
liquid in the impoundment to below the ground-water table.
Water will flow from the surrounding area into the surface
impoundment.
The level of liquid in the impoundment and the water table will
attempt to equilibrate, but active pumping to control the level
in the impoundment and low permeability of the surrounding soils
preserve the inward gradient. In other words, a non-vulnerable
site can be used to prevent migration over a finite period of
304
-------
FLOW NET: SURFACE IMPOUNDMENT WITH
INWARD GRADIENT
ACTIVE CONTROL OF HYDRAULIC HEAD IN IMPOUNDMENT
INDUCES INWARD GRADIENT
u>
o
en
F1
-------
time by ensuring an inward gradient condition during the life of
the unit.
The EPA Interim Status Surface Impoundment Retrofitting Variance
Guidance Manual states that this design, if properly
implemented, meets the "no migration" standard of Section
3005(j)(4).
This design is effective at eliminating migration only for a F2
treatment or storage impoundment where all waste is removed upon
closure. If an impoundment of this design is closed as a
landfill, with waste left in place, the inward gradient would
not be actively maintained and ground-water would flow through
the impoundment, resulting in constituent migration.
The second example, considers an area where a Marine Clay G1
aquitard overlies a sand aquifer. TOT^qq for the undisturbed
area is calculated to be 1,940 years.
Using a frequent landfill design, as shown in this figure, the G2
excavation limit of the unit is above the water table. This is
required by many State regulations
At the end of the active life of the landfill, it is covered G3
with a clay cap having a hydraulic conductivity of 1 x 10 ^
centimeters per second. Over time, the ground-water table
306
-------
CLOSURE OF SURFACE IMPOUNDMENT AS A
LANDFILL
INWARD GRADIENT IS NOT ACTIVELY MAINTAINED
GROUND WATER FLOWS INTO AND OUT OF THE UNIT,
PROMOTING CONSTITUENT MIGRATION
F2
-------
-------
CONVENTIONAL LANDFILL DESIGN
DURING OPERATION, THE LIMIT OF THE WASTE IS
MAINTAINED ABOVE THE GROUND WATER TABLE
135
130
125
120
Aquitard
G2
-------
TOT100: CONVENTIONAL LANDFILL DESIGN
DURING POST-CLOSURE PERIOD, WATER TABLE MOUNDS
AND HYDRAULIC HEAD INCREASES
GRADIENT (i) = 0.625
Marine Clay
K = 1 x 10"9cm/s
CO
O
Sand
K = 1 x 10*ฎ cm/s
G3
-------
equilibrates and a mounded water table is formed mimicking the
convex shape of the cap. TOT^qq ca^culate^ taking into
consideration the increased gradient caused by the elevation in
head [ground-water mound], along the same flow line. It equals
1,550 years. Although the increase in head has affected TOT, it
is only a relatively minor amount.
If other pathways of exposure are considered, problems may be G4
found. A flow net drawn after the ground-water has equilibrated
shows a change in the flow regime. In areas at the edges of the
landfill, the water table intersects the surface, and toe
seepage occurs allowing surface water contamination and possibly
basement seepage. Drawing the flow net makes this exposure
pathway obvious.
Can toe seepage and the exposure it might cause be avoided? An G5
innovative solution to preventing toe seepage is to maintain the
upper limit of the waste below the water table. Popular
intuition has been that you're asking for trouble if you put
waste where it will become saturated with water. However, look
at whether this is really true in non-vulnerable settings.
Flow-net analysis and TOT^qq can be used to investigate this G-6
design option. The flow net shows that the water table no longer
intersects the ground surface near the edges of the unit,
thereby effectively eliminating toe seepage.
311
-------
TOE SEEPAGE ALONG FLANK OF LANDFILL
G4
-------
G5
-------
TOT100: ALTERNATIVE DESIGN
h = 135
h = 130
UPPER LIMIT OF WASTE MANAGEMENT AREA IS BELOW
WATER TABLE
Water table does not intersect
the ground surface in the area
of the facility.
Aquifer
Sand
K = 1 x 10"ฎcm/s
G6
-------
Using the flow net to calculate TOT^qq shows that it would
take approximately 1,900 years to travel the 100-foot distance.
TOT is not greatly affected by putting the unit in the saturated
zone because of the magnitude of the hydraulic conductivity.
These examples help illustrate how TOT^qq and flow net
analysis can be used to effectively model different situations
that influence the design of disposal units. A further
discussion of this topic is found in Appendix D (2.4) of the
Guidance.
The document is available from the National Technical
Information Service, [generally known as NTIS.] The order
number for the entire document is PB-86-224-946 (Cost: $60.00).
315
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CRITERIA FOR IDENTIFYING AREAS OF
VULNERABLE HYDROGEOLOGY
AVAILABLE FROM THE NATIONAL TECHNICAL
INFORMATION SERVICE
PHONE NUMBER: (703) 487-4650
ORDER NUMBER: PB-86-224-946
HI
-------
GUIDANCE ON ALTERNATIVE CONCENTRATION LIMITS
Vernon Myers
U.S. Environmental Protection Agency
317
-------
GENERAL RCRA ACL POLICY
-------
BACKGROUND
ACLs ARE PART OF THE RCRA GROUND-
WATER PROTECTION PROCESS THAT
APPLIES TO ALL REGULATED UNITS.
-------
ALTERNATE CONCENTRATION I. f M [ T (ACL) GUIDANCE DOCUMENT
o TECHNICAL PART OK C II I I) A N C E DOCUMENT HAS C f R C II I, A T K I) WIDELY IN DRAFT FORM,
REV IS TONS HAVE BEEN MADE IN RESPONSE To THE COMMENTS RECEIVED
o RECENT POLICY DECISIONS HAVE PROVIDED IMPORTANT P ROC RAM IMPLEMENTATION GUIDANCE
o POLICY WAS DEVELOPED TO CLOSELY TRACK PROVISIONS OF CERCLA REAUTHORIZATION
o
GUIDANCE DOCUMENT CONTAINING IMPLEMENTATION POLICY AND TECHNICAL IHSCUSSION
WILL RE NOTICED IN FEDERAL REGISTER AS "INTERIM FINAL." PUBLIC COMMENT
PERIOD WILL BE 60 DAYS
-------
GENERAL RCRA ACL POLICY
ACLs WILL NOT ALLOW FURTHER DEGRADATION OF THE
GROUND-WATER
ALL OFF-SITE CONTAMINATION MUST BE CLEANED UP, UNLESS
THE UNIT PERFORMS SOURCE CONTROL, AND:
1. ACQUIFER RECEIVING THE CONTAMINANTS IS NATURALLY
NON-POTABLE (HIGHLY SALINE)
OR
2. AQUIFER IS NOT USED AND CONTAMINANTS ARE DILUTING
INTO A NEARBY SURFACE WATER BODY AT ACCEPTABLE
LEVELS
A FACILITY'S PROPERTY BOUNDARY* MAY NOT BE EXTENDED TO
PREVENT OR DELAY THE START-UP OF A CORRECTIVE ACTION
PROGRAM.
PROPERTY BOUNDARY AS DEFINED IN INITIAL PERMIT APPLICATION
-------
ACL POLICY IMPLICATIONS
PLUMES CANNOT GROW LARGER
GO
ro
FUTURE RELEASES OF POLLUTANTS TO THE GROUND WATER
ABOVE DRINKABLE/ENVIRONMENTAL LEVELS WILL TRIGGER
CORRECTIVE ACTION
MAJOR SOURCE CONTROL AND CORRECTIVE ACTION
PROGRAMS WILL BE IMPLEMENTED AT MOST RCRA SITES
WHICH HAVE CONTAMINANT RELEASES TO THE GROUND WATER
-------
EFFECTS OF ACL POLICY ON
CURRENT REGULATIONS
ANALYSIS OF CORRECTIVE ACTION AND CLOSURE REGULATIONS
WILL OCCUR IN FY 87
DEVELOPMENT OF CORRECTIVE ACTION REGULATIONS FOR
SWMUs WILL EVALUATE:
- TECHNOLOGICAL FEASIBILITY
- SOURCE CONTROL
- CHANGES NEEDED TO SUBPART F CORRECTIVE ACTION
REGULATIONS
ASSESSMENT OF CLOSURE REGULATIONS WILL LOOK AT:
- LONG TERM PROTECTION OF HUMAN HEALTH AND THE
ENVIRONMENT (I.E., WHAT TO DO WITH ACLs ABOVE A
HEALTH OR ENVIRONMENTAL LEVEL?).
MAY NEED MORE STRINGENT SET OF GROUND-WATER
STANDARDS FOR CLOSING UNITS THAN FOR OPERATING
UNITS.
-------
ACL POLICY AND CLOSURE
OPERATING FACILITIES COULD MEET HEALTH AND
ENVIRONMENTAL PROTECTIVE LEVELS AT THE POINT OF EXPOSURE.
HOWEVER, FACILITIES THAT CLOSE WOULD HAVE TO MEET HEALTH
AND ENVIRONMENTAL PROTECTIVE LEVELS AT THE POINT OF
COMPLIANCE BEFORE THEY COULD CEASE POST-CLOSURE CARE
ฃ FOR GROUND-WATER CONTAMINATION
DURING OPERATION OF A RCRA FACILITY, AN ACL BASED ON
NATURAL ATTENUATION MAY BE APPROPRIATE SINCE THE
OWNER MAINTAINS A CONTINUING PRESENCE AT THE SITE
AFTER THE POST CLOSURE CARE PERIOD, A MORE STRINGENT
GROUND-WATER STANDARD IS NEEDED SINCE THE OWNER HAS
NO FURTHER RCRA OBLIGATIONS FOR MANAGING THE FACILITY
-------
ACLs ARE SITE-SPECIFIC
THE GROUND-WATER PROTECTION STANDARD (ACL) IS
ESTABLISHED FOR GROUND-WATER MONITORED:
- AT WASTE MANAGEMENT UNIT BOUNDARY
- IN THE UPPERMOST AQUIFER
AN ACL ENTAILS A FINDING THAT THE SPECIFIED
CONCENTRATION AT THE UNIT BOUNDARY WILL RESULT IN AN
ACCEPTABLE LEVEL AT THE POINT OF EXPOSURE
THE ACL IS INCORPORATED INTO THE FACILITY PERMIT
(PUBLIC SCRUTINY)
-------
ACLs ARE BASED ON
SITE-SPECIFIC FACTORS
(1) CONTAMINANT CHARACTERISTICS;
(2) FACILITY AND AREA HYDROGEOLOGY;
(3) CURRENT AND FUTURE USES OF THE LOCAL GROUND AND
SURFACE WATERS; AND
(4) HEALTH AND ENVIRONMENTAL EFFECTS OF CONTAMINANT
EXPOSURE:
WATER QUALITY CRITERIA
AGENCY REVIEWED DOSE LEVELS
-------
GENERALIZED RCRA ACL SITE
DEFINITIONS
REGULATED
UNIT
CONTAMINANT
PLUME
POINT OF
COMPLIANCE
POINT OF
EXPOSURE
FACILITY BOUNDARY
REGULATED unit-the area
WHERE THE HAZARDOUS WASTES
ARE KEPT (LANDFILL. SURFACE
IMPOUNDMENT).
POINT OF COMPLIANCE - THE
POINT ON THE DOWNGRADIENT
SIDE OF THE UNIT WHERE THE
GROUND WATER PROTECTION
STANDARD IS MET. THE ACL
IS SET HERE.
POINT OF EXPOSURE 1POE) -
POINT AT WHICH POTENTIAL
EXPOSURE TO CONTAMINANTS IS
ASSUMED. LOCATION IS SITE
SPECIFIC. HEALTH/ENVIRONMENTAL
BASED LEVEL IS MET HERE.
FACILITY BOUNDARY-THE
PROPERTY BOUNDARY OF THE
FACILITY.
CONTAMINANT PLUME-THE
VOLUME OF GROUND-WATER
THAT CONTAINS THE LEAKING
POLLUTANTS.
-------
THREE BASIC ACL SCENARIOS
1) UNITS (NEW OR OLD) WITH NO CONTAMINATION
ro
oo
2) UNITS WITH EXISTING CONTAMINATION CONFINED TO THE SITE
3) UNITS WITH EXISTING CONTAMINATION THAT EXTENDS OFF-SITE
-------
SCENARIO 1
REGULATED
UNIT
POINT OF
COMPLIANCE
FACILITY BOUNDARY
DEFINITION
- NO CURRENT GROUND WATER
contamination
POLICY
- ACL. IF APPLIED FOR.
WOULD BE SET AT HEALTH/
ENVIRONMENTAL STANDARD
RESULT
NO CONTAMINATION ABOVE
A DRINKABLE/ENVIRONMENTALLY
SAFE LEVEL
-------
SCENARIO 2
REGULATED
UNIT
r
ATTENUATION
CONTAMINANT
PLUME
POINT OF
COMPLIANCE
POINT OF
EXPOSURE
FACILITY BOUNDARY
DEFINITION
- EXISTING ON SITE CONTAMINATION
POLICY
- POE WOULD NOT BE SET PAST
THE FARTHEST EDGE OF THE PLUME
- NATURAL MECHANISMS OF
ATTENUATION (DEGRADATION.
DISPERSION) COULD BE RELIED
ON ONLY WITHIN THE PLUME
(IN ESTABLISHING ACL)
- UNIT MUST STOP FURTHER RELEASES
TO THE GROUND-WATER ABOVE THE ACL
RESULT
- PLUME COULD NOT GROW
- FURTHER GROUND-WATER
CONTAMINATION PREVENTED
-------
SCENARIO 3A
REGULATED
UNIT
oo
CO
-m ATTENUATION
POINT OF
COMPLIANCE
POINT OF
EXPOSURE
FACILITY BOUNDARY
DEFINITION
- EXISTING OFF-SITE CONTAMINATION
POLICY
- POE WOULD NOT BE SET PAST THE
FACILITY BOUNDARY
- NATURAL MECHANISMS OF
ATTENUATION COULD ONLY BE
RELIED ON WITHIN THE ON-SITE
PORTION OF THE PLUME
- UNIT MUST DO SOME SOURCE CONTROL
TO STOP FURTHER RELEASES TO THE
GROUND WATER ABOVE THE ACL
RESULT
- ALL OFF-SITE CONTAMINATION
CLEANED UP
- FURTHER GROUND-WATER
CONTAMINATION PREVENTED
-------
SCENARIO 3B
DEFINITION
- EXISTING OFF SITE CONTAMINATION
- SURFACE WATER BODY NEAR
- NO GROUND-WATER USE
POLICY
- POE WOULD NOT BE SET PAST THE
FACILITY BOUNDARY
- BETWEEN THE UNIT AND THE FACILITY
BOUNDARY. NATURAL MECHANISMS OF
ATTENUATION MAY BE TAKEN INTO ACCOUNT
- UNIT MUST STOP FURTHER RELEASES
TO THE GROUND-WATER ABOVE THE ACL
- TEMPORARY GROUND WATER USE CONTROLS ARE
NEEDED BETWEEN POE AND SURFACE WATER
RESULT
- OFF-SITE PORTION OF THE PLUME IS ALLOWED
TO DILUTE SAFELY INTO THE WATER BODY
- FUTURE CONTAMINANT RELEASES WOULD
NOT LEAVE FACILITY PROPERTY
-------
SCENARIO 3C
REGULATED
UNIT
ATTENUATION
CONTAMINANT
PLUME
POINT OF
COMPLIANCE
POINT OF
EXPOSURE
FACILITY BOUNDARY
DEFINITION
- EXISTING OFF-SITE CONTAMINATION
- UPPERMOST AQUIFER IS NON-POTABLE
(HIGHLY SALINE)
POLICY
- POE WOULD NOT BE SET PAST THE
FACILITY BOUNDARY
- WITHIN THE PLUME. NATURAL
MECHANISMS OF ATTENUATION
MAY BE TAKEN INTO ACCOUNT
- UNIT MUST STOP FURTHER RELEASES
TO THE GROUND-WATER ABOVE THE ACL
RESULT
- PLUME COULD NOT GROW
- FURTHER GROUND-WATER
CONTAMINATION PREVENTED
-------
334
-------
LAND DISPOSAL
Steve
U.S. Environmental
RESTRICTIONS
Weil
Protection Agency
335
-------
EPA's LAND DISPOSAL RESTRICTIONS PROGRAM
I. STATUTORY REQUIREMENTS
A. PROHIBITION ON LAND DISPOSAL AND "NO MIGRATION"
B. TREATMENT STANDARDS
C. EFFECTIVE DATES AND EXTENSIONS
1. Solvents and Dioxins - November 8, 1986
2. "California List" - July 8, 1987
3. Schedule for Other Wastes - August 8, 1988 - May 8, 1990
4. National Capacity Extensions
5. Case-by-Case Extension
6. Disposal Requirements During Extension
D. UNDERGROUND INJECTION
E. STORAGE
II. SOLVENTS & DIOXINS - THE NOVEMBER 8^h RULE
A. THE JANUARY 14, 1986 PROPOSAL AND SCREENING LEVELS
B. THE NOVEMBER 8th RULE
1. Framework - How We Set Treatment Standards
2. Other Aspects - Petitions, Variances, Effective
Dates
3. Treatment Standards
4. Effective Dates
III. THE "CALIFORNIA LIST" PROPOSED RULE
A. STATUTORY REQUIREMENTS
B. EPA's PROPOSAL
1. Concentration Levels
2. Treatment Standards
3. Effective Dates
IV. FIRST THIRD ACTIVITIES
336
-------
PETITIONS AND VARIANCES
A. Case-by-Case Extensions
1. Binding Contractual Committment
2. Alternative Capacity Not Reasonably Available
B. Treatability Variances
C. No Migration Variances
1. Allows Disposal of Waste Not Meeting the Treatment
Standards
2. Statutory Standards - "No Migration of Hazardous
Constituents for as Long as the Waste Remains Hazardous.
3. How is "No Migration Evaluated?"
337
-------
338
-------
hazardous waste treatment or storage in
CHESTER OSZMAN
INCINERATION/STORAGE PAT SECTION
PERMITS S. STATE PROGRAMS DIVISION
OFFICE OF SOLID WASTE
US ENVIRONMENTAL PROTECTION AGENCY
202-382-4499
339
-------
SUMMARY OF RULE
On July 14, 1986, EPA amended the regulations under the
Resource Conservation and Recovery Act for tank systems that
accumulate, store, or treat hazardous waste (51 Federal Register
25422, July 14, 1986). These rules establish technical standards
and operating procedures for small guantitv generators, less than
90-day accumulation, interim status, and permitted hazardous
waste tank systems.
Two procedural aspects of the reaulation will need to be
carefully addressed. First, certain portions of the July 14 rule
were promulgated pursuant to pre-HSWA authority, while other
portions were promulaated pursuant to provisions added by HSWA.
This ".'two authority'.' oromulaation is ootentially confusing in
reaulating different types of faclities in authorized and un-
authorized States.
HSWA-PROVISIONS
- INTERIM STATUS REQUIREMENTS APPLICABLE TO TANK SYSTEMS
OWNED AND OPERATED BY SMALL QUANTITY GENERATORS
(Section 3001(d));
- LEAK DETECTION REQUIREMENTS FOR ALL NEW UNDERGROUND TANK
SYSTEMS (Section 3004(o)(4)); and
- TECHNICAL AND PERMITTING STANDARDS FOR UNDERGROUND TANKS
THAT CANNOT BE ENTERED FOR INSPECTION (Section 3004(w)).
340
-------
PRE-HSWA PROVISIONS
- ALL SECTIONS OF THE JULY 14 TANK RULE WHEN APPLIED TO:
A) ABOVEGROUND
B) ONGROUND
C) INGROUND
D) UNDERGROUND (THOSE THAT CAN BE
ENTERED FOR INSPECTION)
The other procedural aspect of the recrulation that might be
confusing is the concept of existing and new tank systems beina
defined by the July 14, 1986 promulaation date. This is different
than the established system for defining existing and new systems
for purposes of determining eligibility for interim status.
Given the above, I will begin the summary of the new tank
rule. The owners and operators ('.'o/o'.") are subject to the followina
procedures and reauirements (under 40 CFR Parts 264 and 265).
I. INTERIM STATUS AND PERMITTED TANK SYSTEMS
[Effective in all unauthorized States and in all States
regulating new underaround tank systems or underaround
tank systems that cannot be entered for inspection.]
Existing Tank Systems
"Existing tank system"; or "existing component" means a tank
system that was handling hazardous waste or for which installation
had commenced on or prior to 7/14/86. This definition should
341
-------
not be confused with the definitions in ง260.10 for '.'existing
facility'.' or '.'existing portion'.' which are used to determine
eligibility for interim status. For example, an existinq interim
status facility could have a new tank system, and as such, the
the facility must comoly with the (new) more strinaent requirements
for desiqninq and installing new tank systems under Subpart J.
Table A-l provides a visual flow representation of the followincr
requirements relatinq to existing tank systems.
- Existing tank systems that do not have secondary containment
meetinq the new requirements must undergo an assessment that
attests to the system's integrity by 1/12/88. The assessment:
a) must be reviewed and certified by an independent, qualified,
registered professional engineer;
b) must determine that the system is adequately designed, has
sufficient structural strenqth and is compatible with stored
or treated waste;
c) must consider corrosion protection measures;
d) for newly listed wastes, must be conducted within 12 months
after the date the waste becomes hazardous; and
e) results in discoverv of leak or other unfit condition the
o/o must comply with ง265.196.
- Until secondary containment is installed, nonenterable under-
ground tank systems, interim status other-than-nonenterable tank
systems, and all ancillary equipment nust underao integrity testing
at least anually. Integrity tests for permitted other-than-
nonenterable-tank systems will be conducted according to owner
and operatorls schedule contained in the permit.
- Integrity assessments must be maintained at the facility.
- Secondary containment must be provided ner the schedule in
งง264.193(a) & 265.193(a) and must be designed, using minimum
standards (งง264.193(b)-(f) or 265.193 (b)-(f)), to detect and
contain any release. (Tanks used to store or treat h.w. without
free liquids and placed inside buildings with impermeable
floors and tanks that serve as part of a secondary containment
system are exempt).
342
-------
An owner or operator may be granted a variance from the secondary
containment requirements if the RA finds that the design or
operation of the tank system, toqether with its location charac-
teristics will prevent the migration of h.w. into the ground
water or surface water, or that, in the event of a release, no
substantial present or potential hazard will be posed to human
health and the environment. To be aranted a variance:
a) o/o must notify of intent to submit demonstration for variance
24 months prior to date secondary containment is due;
b) o/o must supply the complete demonstration within 6 months of
notification; and
c) for interim status facilities, RA must notify public, allow
30 day comment period, make hearing available, and approve
or disapprove the request within 90 davs from receipt of the
demonstration.
General operating requirements must be met reaardinq compati-
bility, spills, and overflows.
Daily inspections required for overfill/spill control eauipment,
above qround portions of systems, data aathered from monitoring
and leak-detection eauipment, and construction materials
surrounding tank.
Proper operation of cathodic system must be.confirmed; within
six months of installation initiallv, annually thereafter.
Sources of impressed current inspected and/or tested bimonthly.
Owners and operators must follow procedures for respondino to
spills or leaks from the tank svstems that release hazardous
waste or constituents to the environment. Includes notificaiton
of leaks and certification of repair.
At closure of the tank systems o/o must remove contaminated
materials from the tank area, or if such removal is not possible,
the owner/operator must follow closure & nost-closure care
requirements for landfills.
Owners/operators must observe special reauirements for ignitable,
reactive, or incompatible waste.
In addition to performinq waste analysis required by ง265.13,
o/o must perform additional waste analysis and trial tests when
an interim status tank system is used to treat or store a
hazardous waste that is different than waste previously treated
chemically or stored, or a substantially different chemical
treatment process is used.
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New Tank Systems
A '.'new tank system'.' or "new tank comoonent" means a tank
system or component for which installation commenced after 7/14/86.
This definition should not be confused with the definition in
ง260.10 of a '.'new facility", which is used to determine eliqibility
for interim status. Table A-2 provides a visual flow representation
of the following requirements relatina to new tank systems.
- For new tank systems, o/o must obtain, and submit to the RA at
the time of submission of Part B information, an assessment of
tank system inteqrity and acceptability for storina and treating
h.w., and must include an analysis by a corrosion expert.
The corrosion expert must assess the corrosion potential and
the type & degree of corrosion protection that may be needed
for new metal tank systems (or any external metal component of
the tank system) in contact with soil or water.
- New tank systems must be desianed to provide proper foundation
for structural suoport, nroper anchoraae to nrevent flotation,
protection aaainst frost heaves, and protection from vehicular
traffic passing over underaround comnonents.
- Installation of new tank systems and system components must be
inspected by a aualified soecialist or engineer. Certifications
must be on file.
- New tank systems or components olaced underaround must be back-
filled with a noncorrosive, porous, homooeneous substance.
- Secondary containment that meet the requirements of งง264.193
(b)-(f) and 265.193(b)-(f) must be provided for all new tank
systems prior to beina put into service.
- An owner or operator may be aranted a variance from the secondary
containment requirements if the RA finds that the desiqn or
operation of the tank system, toqether with its location charac-
teristics will prevent the migration of h.w. into the around
water or surface water, or that, in the event of a release, no
substantial present or potential hazard will be posed to human
health and the environment. To be qranted a variance:
a) o/o must notify of intent to submit demonstration 30 days
prior to entering into contract to install new tank system;
b) o/o must supply the complete demonstration within 6 months of
notification? and
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c) for interim status facilities, RA must notify public, allow
30 day comment period, make hearing available, and approve
or disapprove the request within 90 days from receipt of the
demonstration.
Until secondary containment is installed, nonenterable under-
ground tank systems, interim status other-than-nonenterable-tank
systems, and all ancillary equipment must underao inteqrity
testing at least anually. Integrity tests for permitted other-
than-nonenterable-tank systems will be conducted accordina to
owner and operator's schedule contained within the permit.
Integrity and corrosion protection assessments must be maintained
at the facility.
General operatina reauirements must be met reaarding compati-
bility, spills, and overflows.
Daily inspections reauired for overfill/spill control equipment,
above ground portions of systems, data qathered from monitoring
and leak-detection equipment, and construction materials
surrounding tank.
Proper operation of cathodic system must be confirmed: within
six months of installation initially, annually thereafter.
Sources of impressed current inspected and/or tested bimonthly.
Owners and operators must follow procedures for responding to
spills or leaks from the tank svstems that release hazardous
waste or constituents to the environment. Includes notificaiton
of leaks and certification of repair.
At closure of the tank systems o/o must remove contaminated
materials from the tank area, or if such removal is not possible,
the owner/ooerator must follow closure & post-closure care
requirements for landfills.
Owners/operators must observe special requirements for ignitable,
reactive, or incompatible waste.
In addition to performinq waste analysis required by ง265.13,
o/o must perform additional waste analysis and trial tests when
an interim status tank system is used to treat or store a hazardous
waste that is different than waste previously treated chemically
or stored, or a substantially different chemical treatment
process is used.
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II. LESS THAN 90 DAY ACCUMULATION TANK SYSTEMS
[Effective in all unauthorized States and in all States
regulating new underground tanks or underaround tanks that
cannot be entered for inspection.]
Generators may accumulate hazardous waste less than 90 days
provided:
1) complies with Part 265 Subparts C, D, & J (except งง265.197(c)
& 265.200) and ง265.16. Need not comply with Part 265
Subparts G & H (as required in ง265.197) except must comply
with งง265.111 & ง265.114;
2) date of startina accumulation is marked & visible for insDectionr
3) labeled '."hazardous waste';.
Note: 262.34(b) offers 30 day extension to be qranted by RA.
III. SMALL QUANTITY GENERATORS (100 < kilos/month < 1000)
[Effective in all States]
Generators may accumulate hazardous waste for 180 days (or
270 days if TSD is > 200 miles away), provided:
1) total amount accumulated is less than 6000 kilos;
2) complies with Part 265 Subpart C, ง265.201 and special
requirements for contingencies at ง262.34(d)(5);
3) date of starting accumulation is marked & visible for
inspection;
4) labeled "hazardous waste'.'
Note: oenerators who accumulate more then 6000 kilos or for more
than 180 days (or 270 davs), except for 30 day extensions aranted
by RA, must comply with revised Parts 264, 265, and 270.
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TjftBLE A-l. SCHEDULE PCJR IMPLEMENTATION ACTIVITIES FOR EXISTING TANK SYSThMS
[Existing systems - installation commenced on or before 7/14/86]
ACTIVITY
DURATION
1/1987 1/88 1/89 1/90 1/91 1/92 1/93 1/94 1/95 1/96-
-1/2001 7/01
1. If no secondary containment:
a. initial assessment.
b. all nonenterable underground
and interim status other
than nonenterable tanks
and all ancillary eq.,
c. permitted other than
nonenterable tanks.
2. Integrity and corrosion
oo assessments kept on f ile.
3. Secondary containment
retrofit tequicements:
a. treat or store dioxin,
b. tank systems of
documentable age,
c. tank system of un-
documentable age but
facility greater than
7 years old,
d. tank system of undocu-
mentable age but facility
less than 7 years old,
annual integrity tests due
* until containment in place *
* integrity tests conducted according to schedule in permit >
ongoing >
*
(max)
* which ever is Later, 1/89 or when tank reaches 15 yts old *
which ever is later, 1/89 or
* when facility reaches 15 yrs old
(max)
_*
* within 8 yrs after 1/87-
(max)
*
e. tank systems that store or
treat material that first
become hazaodous after 1/87
date material becomes
laz js ef< e r ! x>r ' cc "-'nmt- -etneeded min. of 2 yrs. and max. of 15 yrs.
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TABLE A-l. SCHEDULE t\)R IMPLEMENTATION ACFIVITLKS tXDR EXISTING TANK SYSTEMS (cont. )
(Existing systems - installation commenced on or before 7/14/86]
DURATION
ACTIVITY
1/1987 1/88 1/89 1/90 1/91 1/92 1/93' 1/94 1/95 1/96
1/2001 7/01
4. Variances requests from
secondary containment
and leak detection:
a. notification of intent to
demonstrate for a variance
24 months before secondary (max-7/99)
containment is due, * for the present universe of facilities *
b. demonstration due
complete (due 180 days
<ฃ> after notice,
-pป
oo
c. for interim status TSUs
(max-1/2000)
for the present universe of facilities
RA must (jrant/deny in
(max-3/2000)
90 days,
* for the present universe of facilities
d. tank systems that store or
treat material that first
becomes hazardous after 1/87,
or for future new tank
systems. * ongoing
>
5. General operating, inspection
closure & special handling
requirements.
* ongoing
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For additional information, see the "Technical Resource Document for the
Storage and Treatment of Hazardous Waste in Tank Systems, December 1986.
Available from NTIS, PB-87-134 391. $36.95 (703) 487-4650.
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