LAIDLAW ENVIRONMENTAL SERVICES, INC.
EXHIBIT 21

The following list sets forth the subsidiaries of Laidlaw Environmental
Services, Inc. as of September 20, 1997. Parent subsidiary relations are
indicated by indentations. Unless otherwise indicated, 100% of the voting
securities of each subsidiary is owned by the indicated parent of such
subsidiary.

State of
Incorporation
-----------------------

Laidlaw Environmental Services, Inc. Delaware
LES, Inc. Delaware
Laidlaw Environmental Services de Mexico, S.A. de C.V. (90%) Delaware
Laidlaw Environmental Services (Puerto Rico), Inc. Delaware
Laidlaw Environmental Services (Bridgeport), Inc. Delaware
Laidlaw Environmental Services (Deer Park), Inc. Delaware
Laidlaw Environmental Services (Baton Rouge), Inc. Delaware
Laidlaw Environmental Services (Plaquemine), Inc. Delaware
Laidlaw Environmental Services (Custom Transport), Inc. Delaware
Laidlaw Environmental Services (Los Angeles), Inc. California
Laidlaw Environmental Services (Tipton), Inc. Delaware
Laidlaw Environmental Services (Gloucester County), Inc. Delaware
Laidlaw Environmental Services (Deer Trail), Inc. Colorado
Laidlaw Environmental Services (Mt. Pleasant), Inc. Tennessee
Laidlaw Environmental Services (Minneapolis), Inc. Minnesota
Laidlaw Environmental Services (Aragonite), Inc. Delaware
Laidlaw Environmental Services (Sussex), Inc. Delaware
Laidlaw Environmental, Inc. Delaware
Laidlaw Environmental Services (US), Inc. Delaware
Laidlaw Environmental Services (Lone and Grassy Mountain), Inc. Oklahoma
Laidlaw Environmental Services (Tulsa), Inc. Oklahoma
Laidlaw Environmental Services (San Antonio), Inc. Texas
Laidlaw Environmental Services (Wichita), Inc. Kansas
USPCI of Mississippi, Inc. (50%) Mississippi
Laidlaw Environmental Services of Delaware, Inc. Delaware
ECDC Environmental, L.C. (80%) Utah
Laidlaw Environmental Services (Rosemount), Inc. Minnesota
Laidlaw Environmental Services (Sawyer), Inc. Oklahoma
Laidlaw Environmental Services (Tucker), Inc. Georgia
Ninth Street Properties, Inc. Missouri
Laidlaw Environmental Services (San Jose), Inc. California
Chemclear, Inc. of Los Angeles Delaware
USPCI, Inc. of Georgia Delaware
McDuffie County Environmental Facility, Inc. Delaware
East Carbon Development Financial Partners, Inc. Utah
Laidlaw Environmental Services (Imperial Valley), Inc. (50%) California
Laidlaw Environmental Services (Lokern), Inc. (23%) California
Laidlaw Environmental Services (North East), Inc. New Hampshire
Laidlaw Environmental Services (Recovery), Inc. Louisiana

State of
Incorporation
-----------------------

Laidlaw Environmental Services (TES), Inc. Texas
Corsan Trucking, Inc. (25%) Louisiana
Laidlaw Environmental Services (TG), Inc. Delaware
Laidlaw Environmental Services (TOC), Inc. South Carolina
Laidlaw Environmental Services (TS), Inc. Delaware
Laidlaw Environmental Services (Thermal Treatment), Inc. Delaware
Corsan Trucking, Inc. (75%) Louisiana
GSX Chemical Services of Ohio, Inc. Ohio
LEMC, Inc. Delaware
Laidlaw Chemical Services, Inc. Massachusetts
Laidlaw Environmental Services (Altair), Inc. Texas
Laidlaw Environmental Services (FS), Inc. (13%) Delaware
Laidlaw Environmental Services (BDT), Inc. New York
Laidlaw Environmental Services (FS), Inc. (86%) Delaware
Laidlaw Environmental Services (GS), Inc. Tennessee
Laidlaw Environmental Services (Clive), Inc. Oklahoma
Laidlaw Environmental Services (WT), Inc. Ohio
Laidlaw OSCO Holdings, Inc. Delaware
Laidlaw Environmental Services of Nashville, Inc. Tennessee
OSCO Treatment Systems of Mississippi, Inc. (50%) Tennessee
Bryson Industrial Services, Inc. South Carolina
Laidlaw Environmental Services of Bartow, Inc. Florida
Laidlaw Environmental Services of California, Inc. California
Laidlaw Environmental Services (Lokern), Inc. (77%) California
Laidlaw Environmental Services (Imperial Valley), Inc. (50%) California
Laidlaw Environmental Services of Chattanooga, Inc. Tennessee
Laidlaw Environmental Services of Illinois, Inc. Illinois
Laidlaw Environmental Services of South Carolina, Inc. South Carolina
Laidlaw Environmental Services of White Castle, Inc. Colorado
Laidlaw Environmental Services (Canada) Ltd. Canada
Laidlaw Environmental Services Ltd. Ontario
Laidlaw Environmental Services (B.C.) Inc. Canada
I.W.M. Disposal Inc. British Columbia
Laidlaw Environmental Services (Sarnia) Ltd. Ontario
1197296 Ontario Inc. Ontario
Laidlaw Environmental Services (Quebec) Ltd. Quebec
Laidlaw Environmental Services (Mercier) Ltd. Quebec
Les Entreprises D'Incineration Industrielle Tricil Inc. Quebec
Laidlaw Environmental Services (Ryley) Ltd. Alberta
Laidlaw Environmental Services (Atlantic) Limited Nova Scotia
Laidlaw Environmental Services (Guelph), Inc. Ontario