EXHIBIT 21

Name* Incorporation
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State of:

ACTION CONTRACT SERVICES, INC. Delaware
ATNAM, INC. (81.9%) Delaware
BROOKFIELD CORPORATION Ohio
C.A. TURNER CONSTRUCTION COMPANY Delaware
C.A. TURNER MAINTENANCE, INC. Texas
CAMBRIDGE CONSTRUCTION SERVICE CORP. Nevada
CANADIAN ENERGY SERVICES LIMITED British Columbia
CHEMPOWER, INC. Ohio
CONTROLLED POWER LIMITED PARTNERSHIP Illinois
ECO SYSTEMS, INC. Delaware
GIBCA SEPARATION & RECOVERY SYSTEMS, L.L.C. INC. (49%) United Arab Emirates
GLOBAL POWER COMPANY Ohio
H.E. CO. SERVICES, INC. Texas
IDS INTEGRATED DESIGN SERVICES, INC. Texas
INDUSTRA ENGINEERS & CONSULTANTS, INC. British Columbia
INDUSTRA SERVICE CORP. Washington
INDUSTRA SERVICE CORPORATION British Columbia
INDUSTRA THERMAL SERVICE CORP. Washington
INDUSTRA THERMAL SERVICE CORPORATION British Columbia
INDUSTRA, INC. Washington
LAKE CHARLES CONSTRUCTION CORPORATION Louisiana
MIDATLANTIC RECYCLING TECHNOLOGIES, INC. Delaware
MM INDUSTRA LIMITED Nova Scotia
NUCON LTD. Alberta
NUS, INC. Washington
P.W. STEPHENS CONTRACTORS , INC. (81.9%) Missouri
P.W. STEPHENS RESIDENTIAL, INC. (81.9%) California
P.W. STEPHENS SERVICES, INC. (81.9%) Missouri
SEPARATION & RECOVERY SYSTEMS, (PTY) LTD.IMITED (50%) South Africa
SEPARATION AND RECOVERY SYSTEMS LIMITED, LTD. United Kingdom
SEPARATION AND RECOVERY SYSTEMS RECUPERTEC, INC. (50%) British Virgin Islands
SEPARATION AND RECOVERY SYSTEMS, CALIFORNIA INC. U.S. Virgin Islands
SEPARATION AND RECOVERY SYSTEMS, INC. Nevada
SOUTHWICK CORPORATION Ohio
SPECIALTY MANAGEMENT GROUP, INC. Texas
SRS-ECO LTD. (50%) British Virgin Islands
THE TURNER GROUP, INC. Delaware
UNITED ECO SYSTEMS, INC. Delaware
U.S. INDUSTRIAL SERVICES, INC. (81.9%) Delaware

*All subsidiaries are 100% owned, except where otherwise indicated.