Exhibit

Exhibit 21.1

QUANTA SERVICES, INC.

SUBSIDIARIES LIST

The following is a list of the significant subsidiaries of Quanta Services, Inc. showing the place of incorporation or organization and the names under which each subsidiary does business. The names of certain subsidiaries may be omitted if such subsidiaries, considered as a single subsidiary, would not constitute a significant subsidiary.



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
1 Diamond, LLC Cutting Technology - 1 Diamond, LLC	Delaware
1Diamond AS	Norway
618232 Alberta Ltd.	Alberta
8246408 Canada Inc. G-TEK G-Vac	Quebec
Advanced Electric Systems, LLC Advanced Utility Testing & Maintenance, LLC Utility Testing & Maintenance, LLC	Delaware
Alexander Publications, LLC	California
Allteck GP Ltd.	British Columbia
Allteck Limited Partnership	British Columbia
Apprenticeship Programs, Inc.	Idaho
Arcanum Chemicals, LLC	Delaware
Arnett & Burgess Oil Field Construction Limited	Alberta
Arnett & Burgess Pipeliners (Rockies) LLC	Delaware
Arnett & Burgess Pipeliners Ltd.	Alberta
B&N Clearing and Environmental, LLC	Delaware
Banister Pipelines Constructors GP Ltd.	British Columbia
Banister Pipelines Limited Partnership	British Columbia
Brent Woodward, Inc.	Oregon
Brink Constructors, Inc. Brink Constructors, Inc. A Corporation Of South Dakota	South Dakota
Canadian Utility Construction Corp.	Canada
Catalyst Changers Inc.	Alberta
Cat-Spec, Ltd. Cat Spec Limited, LP Cat Spec, Ltd CAT SPEC, Ltd. Cat Spec, Ltd. L.P. Cat Spec, Ltd., LP Cat Spec., Ltd. LP CAT-Spec Limited Partnership Cat-Spec Ltd, LP CAT-SPEC, Limited Partnership CAT-SPEC, Limited Partnership (Regd Name) CAT SPEC, Ltd. (Part Name) Cat-Spec, Ltd (A Domestic limited Partnership) Cat-Spec, Ltd. Limited Partnership Cat-Spec, Ltd., L.P. Cat-Spec, Ltd., LP (Used in VA By: Cat-Spec, Ltd.)	Texas



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Citadel Industrial Services, Ltd. Citadel Industrial Services, L.P. Citadel Industrial Services, Ltd. Limited Partnership Citadel Industrial Services, Ltd., L.P.	Texas
Coe Drilling Pty Ltd.	Australia
Conam Construction Co.	Texas
Consolidated Power Projects Australia Pty Ltd	Australia
Conti Communications, Inc.	Delaware
Crux Subsurface Canada Ltd.	British Columbia
Crux Subsurface, Inc.	Delaware
Dacon Corporation	Delaware
Dashiell Corporation (f/k/a Dashiell, LLC) Dashiell (DE) Corporation (Dashiell Corporation) Dashiell Corporation DBA Dashiell (DE) Corporation Dacon Corporation	Delaware
Digco Utility Construction, L.P. Digco Utility Construction Limited Partnership	Delaware
DNR Pressure Welding Ltd.	Alberta
Dorado Specialty Services, Ltd. Dorado Specialty Services, L.P. Dorado Specialty Services, Ltd. L.P. Dorado Specialty Services, Ltd. Limited Partnership Dorado Specialty Services. Ltd., L.P.	Texas
EHV Power ULC	British Columbia
Elite Fabrication, Ltd. Elite Fabrication, LP	Texas
Elite Piping & Civil, Ltd. Elite Piping & Civil Limited Partnership Elite Piping & Civil Ltd, L.P. ELITE PIPING & CIVIL, L.P. Elite Piping & Civil, Limited Partnership Elite Piping & Civil, Lp Elite Piping & Civil, Ltd. Limited Partnership Elite Piping & Civil, Ltd., L.P. Elite Piping and Civil, L.P.	Texas
Elite Turnaround Specialists, Ltd. Elite Turnaround Specialists Limited Partnership Elite Turnaround Specialists Limited Lp Elite Turnaround Specialists Limited Partnership Elite Turnaround Specialists Ltd. L.P. Elite Turnaround Specialists, L.p. Elite Turnaround Specialists, Limited Partnership ELITE TURNAROUND SPECIALISTS, LTD Elite Turnaround Specialists, Ltd, Lp Elite Turnaround Specialists, Ltd. Limited Partnership Elite Turnaround Specialists, Ltd., LP	Texas
Energy Consulting Group, LLC	Delaware
Enscope Pty Ltd	Australia
FIC GP, LLC (f/k/a First Infrastructure Capital GP, LLC)	Delaware
Field Personnel Services, LLC	Delaware
First Infrastructure Capital Advisors, LLC	Delaware
First Infrastructure Capital GP, L.P.	Delaware
Five Points Construction Co.	Texas



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Grid Creative, Inc.	Idaho
Grid Manufacturing Corporation	Idaho
Grid Training Corporation Northwest Lineman Center Northwest Lineman College	Idaho
H.L. Chapman Pipeline Construction, Inc.	Delaware
Haverfield International Incorporated Haverfield Aviation Haverfield Aviation, Inc.	Delaware
Heritage Midstream, LLC	Delaware
Infraestructura ETP de Mexico, S. de R.L. de C.V	Mexico
InfraSource Construction, LLC (f/k/a Infrasource Underground Construction, LLC) Infrasource Iowa Underground, LLC InfraSources Construction, LLC IUC ILLINOIS, LLC IUC Nebraska, LLC QS Mats Trans Tech Electric	Delaware
InfraSource Field Services, LLC	Delaware
InfraSource Services, LLC	Delaware
Integracion Tecnologica del Peru, SAC	Peru
Intermountain Electric, Inc. Grand Electric Inc. IM Electric, Inc. Ime Electric Intermountain Electric, Inc. which will do business in California as: Colorado IM Electric Intermountain Electric, Inc., A Corporation of Colorado	Colorado
IonEarth, LLC	Michigan
Irby Construction Company Irby Construction Company, Inc. Legend Foundation Services Marathon Construction Services	Mississippi
Island Mechanical Corporation	Hawaii
J.C.R. Construction Co., Inc. J.C.R. Utility Construction Co.	New Hampshire
J.W. Didado Electric, LLC	Delaware
JBT Electric, LLC	Texas
Lazy Q Ranch, LLC DE Lazy Q Ranch, LLC (De) Lazy Q Ranch, LLC	Delaware
Lazy Q Training Center, LLC The Lazy Q Lineman School	Delaware
Lex Engineering Ltd.	British Columbia
Lindsey Electric, L.P.	Texas
M. G. Dyess, Inc.	Mississippi
M. J. Electric, LLC Great Lakes Line Builders Iron Mountain M.J. Electric, LLC M. J. Electric, LLC - Iron Mountain M. J. Electric, LLC DBA M. J. Electric Iron Mountain, LLC M. J. ELECTRIC, LLC IRON MOUNTAIN M.J. Electric, LLC DBA M.J. Electric Iron Mountain M.J. Electric, LLC Iron Mountain	Delaware



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Manuel Bros., Inc.	Delaware
Mears Canada Corp.	Nova Scotia
Mears Equipment Services, LLC Infrasource Of Pa, LLC QPS Global Services	Delaware
Mears Group Pty Ltd	Australia
Mears Group, Inc. De Mears Group De Mears Group, Inc. Enscope Ranger Directional	Delaware
Mears Installation, LLC	Delaware
Mearsmex S. de R.L. de C.V.	Mexico
Mejia Personnel Services, LLC	Texas
Microline Technology Corporation	Michigan
Mid America Energy Services, Inc. (f/k/a Tom Allen Construction Company) TA Construction Tom Allen Construction Company Inc. Tom Allen Construction Company of Delaware	Delaware
MTS Quanta, LLC Mercer Technical Services MTS Field Services MTS Field Services (Richmond Co)	Texas
NACAP Niugini Ltd.	Papua New Guinea
Nacap PNG Limited	Papua New Guinea
Nacap Pty Ltd. (f/k/a Nacap Australia Pty Ltd.)	Australia
NLC CA., Inc.	Idaho
NLC FL., Inc. Northwest Lineman Center	Idaho
NLC ID., Inc. Northwest Lineman College	Idaho
NLC TX., Inc. Northwest Lineman Center Northwest Lineman Training Center Northwest Lineman Training Center, Inc.	Idaho
North Houston Pole Line, L.P. North Houston Pole Line Limited Partnership QUANTA FOUNDATION SERVICES	Texas
Northern Powerline Constructors, Inc. Chatham Electric	Alaska
NorthStar Energy Services, Inc. (f/k/a CAN-FER Utility Services, LLC) NC Northstar Energy Services, Inc Quanta Underground Services Quanta Underground Services (Culpeper Co) Quanta Underground Services (Spotsylvania Co) Quanta Underground Services, Inc.	North Carolina
Northstar Energy Solutions, LLC	Delaware
Nova Constructors LLC	Japan
Nova Constructors LTD	United Kingdom
Nova Equipment Leasing, LLC	Washington



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Nova Group, Inc. NGI Construction NGI Construction, Inc. NGI Construction, Inc. (FN) Nova Group, Inc Nova Group, Inc (CA) Nova Group, Inc. DBA NGI Construction	California
Nova NextGen Solutions, LLC	Delaware
NPC Energy Services LLC	Alaska
O. J. Pipelines Canada Corporation O.J. Pipelines Canada O.J. Industrial Maintenance	New Brunswick
O. J. Pipelines Canada Limited Partnership	Alberta
One Call Locators Canada Ltd.	Canada
PAR Electrical Contractors, Inc. Computapole Didado Utility Company, Inc. J.W. Didado Electric J.W. Didado Electric, Inc. Longfellow Drilling Riggin & Diggin Line Construction Seaward Seaward Corp Seaward Corporation	Missouri
Par Internacional, S. de R.L. de C.V.	Mexico
Performance Energy Services Guyana, Ltd. (f/k/a Quanta International Holdings III, Ltd.)	British Virgin Islands
Performance Energy Services, L.L.C.	Louisiana
Phasor Engineering Inc.	Alberta
Phoenix North Constructors Inc. (f/k/a DiFazio North Constructors, Inc)	British Columbia
Phoenix Power Group, Inc.	Delaware
Potelco, Inc. Potelco, Incorporated	Washington
Power Delivery Program, Inc.	Idaho
Price Gregory International, Inc.	Delaware
Price Gregory Services, LLC	Delaware
Probst Electric, Inc. Probst Construction, Inc. Advanced Electric Systems Utility Fleet Services	Utah
QEPC Power Solutions, LLC	Delaware
QES GP, LLC	Delaware
QP Energy Services, LLC (f/k/a Quanta-Potelco Electrical Utilities, LLC)	Delaware
QPS Engineering LTD. Quanta Inspection Services Quanta Resource Development	Alberta
QPS Engineering, LLC QPS Engineering PLLC QPS Environmental QPS Global QPS Global Services QPS Global Services (Richmond Ci) QPSE	Delaware



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
QSI Engineering, Inc. (f/k/a Empire Geo-Services, Inc.)	Delaware
QSI Finance (Australia) Pty Ltd.	Australia
QSI Finance (Cayman) Pvt. Ltd.	Cayman Islands
QSI Finance Canada ULC	British Columbia
QSI Finance GP (US) LLC	Delaware
QSI Finance I (Singapore) Pte. Ltd.	Singapore
QSI Finance I (US), LP	Delaware
QSI Finance II (Australia) Pty Ltd.	Australia
QSI Finance II (Lux) S.à r.l	Luxembourg
QSI Finance II (Singapore) Pte. Ltd.	Singapore
QSI Finance III (Canada) ULC	British Columbia
QSI Finance III (Lux) SARL	Luxemburg
QSI Finance IV (Canada) ULC	British Columbia
QSI Finance IX (Canada) Limited Partnership	British Columbia
QSI Finance V (US), L.P.	Delaware
QSI Finance VI (Canada) ULC	British Columbia
QSI Finance VII (Canada) Limited Partnership	British Columbia
QSI Finance VIII (Canada) ULC	British Columbia
QSI Finance X (Canada) ULC	British Columbia
QSI, Inc.	Delaware
QSN Lux Holdings I SCSp	Luxembourg
QSN Lux Holdings II SCSp	Luxembourg
QSN Lux Holdings III SCSp	Luxembourg
QSN Lux Holdings IV SCSp	Luxembourg
QTSL, LLC	Delaware
Quanta APL GP II Ltd.	British Columbia
Quanta Asset Management LLC	Delaware
Quanta Associates, L.P.	Texas
Quanta Aviation Services, LLC	Delaware
Quanta Canada GP ULC	British Columbia
Quanta Canada Holdings III Limited Partnership	British Columbia
Quanta Canada Holdings LP	Alberta
Quanta Canada III GP Ltd.	British Columbia
Quanta Capital GP, LLC	Delaware
Quanta Capital LP, L.P.	Delaware
Quanta Capital Solutions, Inc.	Delaware
Quanta Cares	Texas
Quanta Electric Power Construction Management, Inc.	Nebraska
Quanta Electric Power Construction, LLC QEPC	Delaware
Quanta Electric Power Services West, LLC	Delaware
Quanta Electric Power Services, LLC	Delaware
Quanta Energized Innovations Ltd.	British Columbia
Quanta Energized Services of Canada Ltd.	British Columbia
Quanta Energized Services U.S., LLC	Delaware
Quanta Energy Services, LLC	Delaware



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Quanta Equipment Company, LLC	Delaware
Quanta Government Solutions, Inc.	Delaware
Quanta Holdings I (Netherlands), B.V.	Netherlands
Quanta Holdings II (Netherlands), B.V.	Netherlands
Quanta Infraestructura de Chile SpA	Chile
Quanta Infrastructure Services, LLC	Delaware
Quanta Infrastructure Services, S. de R.L. de C.V.	Mexico
Quanta Inline Devices, LLC	Texas
Quanta Insurance Company, Inc.	Texas
Quanta International Holdings (US) LLC	Delaware
Quanta International Holdings II, Ltd.	British Virgin Islands
Quanta International Holdings, Ltd.	British Virgin Islands
Quanta International Limited	British Virgin Islands
Quanta Kingsvale LP Ltd.	British Columbia
Quanta Lines Pty Ltd. (f/k/a N.J. Construction Pty Ltd.)	Australia
Quanta Maine Services, LLC	Delaware
Quanta Middle East, LLC	Qatar
Quanta Pipeline Services, Inc. QPS Flint Construction QPS Flint Tank Services QPS Professional Services Quanta Environmental Solutions Quanta EPC Services Quanta Tank Services	Delaware
Quanta Power Australia Pty Ltd	Australia
Quanta Power Generation, Inc.	Delaware
Quanta Power Solutions India Private Limited	India
Quanta Power, Inc.	Delaware
Quanta Services Africa (PTY) Ltd.	South Africa
Quanta Services Australia Pty Ltd.	Australia
Quanta Services Chile SpA	Chile
Quanta Services Colombia S.A.S.	Colombia
Quanta Services Costa Rica, Ltda.	Costa Rica
Quanta Services Guatemala, Ltda.	Guatemala
Quanta Services International Holdings II LP	British Columbia
Quanta Services International Holdings LP	Alberta
Quanta Services Management Partnership, L.P.	Texas
Quanta Services Netherlands B.V.	Netherlands
Quanta Services of Canada Ltd.	British Columbia
Quanta Services Panama, S. de R.L.	Panama
Quanta Services Peru S.A.C.	Peru
Quanta Services Puerto Rico, LLC	Puerto Rico
Quanta Subsurface Canada, Ltd.	British Columbia
Quanta Subsurface, LLC	Delaware
Quanta Technology Canada ULC	British Columbia
Quanta Technology UK Ltd.	United Kingdom
Quanta Technology, LLC Delaware Quanta Technology, LLC	Delaware



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Quanta Tecnología do Brasil Ltda.	Brazil
Quanta Telecommunication Services, LLC Quanta Telecom Quanta Telecom Services Quanta Telecommunication Services Quanta Telecommunications Services, LLC	Delaware
Quanta Utility Engineering Services, Inc. (f/k/a Utilimap Corporation) Utility Line Management Services, Inc.	Missouri
Quanta Utility Installation Company, Inc.	Delaware
Quanta Utility Operation, LLC	Delaware
Quanta West, LLC (f/k/a Quanta Services West, LLC)	Delaware
Quantecua Cia. Ltda.	Ecuador
R. R. Cassidy, Inc.	Louisiana
Realtime Engineers, Inc. (f/k/a Infrasource Engineers, Inc.) Infrasource Engineering Company, PC	Delaware
Realtime Utility Engineers, Inc. (f/k/a Infrasource Engineering Company)	Wisconsin
Redes Andinas de Comunicaciones S.R.L.	Peru
RMS Holdings, LLC RMS Holdings, LLC (Delaware) RMS Welding Systems Rms Welding Systems LLC RMS Welding Systems LLC RMS Welding Systems, LLC Rms Welding, LLC	Delaware
Road Bore Corporation	Hawaii
Service Electric Company (f/k/a Dillard Smith Construction Company) P.D.G. Electric Service EC (DE), Inc. Service Electric Company (DE) Service Electric Company of Delaware Service Electric Company, Inc.	Delaware
Servicios de Infraestructura del Peru S.A.C.	Peru
Servicios Par Electric, S. de R.L. de C.V.	Mexico
Southwest Trenching Company, Inc.	Texas
Specialty Tank Services, Ltd. Specialty Tank Services Limited Partnership Specialty Tank Services, L.P. Specialty Tank Services, Limited Partnership Specialty Tank Services, LP Specialty Tank Services, Ltd. (LP) Specialty Tank Services, Ltd. Limited Partnership Specialty Tank Services, Ltd. LP Specialty Tank Services, Ltd., L.P. Specialty Tank Services, Ltd., LP Texas Specialty Tank Services, Ltd. LP	Texas
Stronghold General, LLC	Texas
Stronghold Holdings (BVI) Limited	British Virgin Islands



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Stronghold Inspection, Ltd. Stronghold Inspection Limited Partnership Stronghold Inspection Ltd, L.P. Stronghold Inspection, L.P. Stronghold Inspection, Limited Partnership Stronghold Inspection, Lp Stronghold Inspection, Ltd. Limited Partnership Stronghold Inspection, Ltd., L.P.	Texas
Stronghold Specialty General, LLC	Texas
Stronghold Specialty, Ltd. Stronghold Specialty, Ltd. Limited Partnership	Texas
Stronghold Tower Group, Ltd. Stronghold Tower Group, LP Stronghold Tower Group, Ltd, LP Stronghold Tower Group, Ltd., LP	Texas
Stronghold VI, LLC	U.S. Virgin Islands
Stronghold, Ltd. Stronghold Management Holdings, LP Stronghold, Limited Partnership Stronghold, Ltd. Limited Partnership	Texas
Subterra Damage Prevention Specialists Ltd.	Canada
Summit Line Construction, Inc. Summit Line Construction	Utah
Sumter Utilities, Inc.	Delaware
T. G. Mercer Consulting Services, Inc.	Texas
TC Infrastructure Services Ltd.	British Columbia
The Aspen Utility Company, LLC The Aspen Utility Company, LLC	Texas
The ComTran Group, Inc.	Georgia
The Hallen Construction Co., Inc.	New York
The Ryan Company, Inc. Ryan Company, Inc. of Massachusetts Ryan Company, Inc.(The) Ryan Company, Inc., The The Massachusetts Ryan Company, Inc. The Ryan Company Inc Of Massachusetts The Ryan Company Inc of Massachusetts The Ryan Company Incorporated of Massachusetts The Ryan Company Incorporated Of Massachusetts The Ryan Company Of Massachusetts, Inc. The Ryan Company of Massachusetts The Ryan Company of Massachusetts (FN) The Ryan Company of Massachusetts, Inc. The Ryan Company, Inc. (Massachusetts) The Ryan Company, Inc. of Massachusetts The Ryan Company, Incorporated Electrical Contractors	Massachusetts
TurnKey Automation, Ltd. TurnKey Automation Limited Partnership TurnKey Automation, Limited Partnership Turnkey Automation, Ltd. L.P. TurnKey Automation, Ltd. Limited Partnership Turnkey Automation, Ltd. LP. TurnKey Automation, Ltd., Limited Partnership TurnKey I&E, Ltd.	Texas
Underground Construction Co., Inc. Delaware Underground Construction Co. Ucc - Underground Construction Co. UCC Underground Construction Co., Inc. Underground Construction Co., Inc. (Delaware)	Delaware



Subsidiary Name and Names Under Which Subsidiary Does Business	Jurisdiction of Incorporation or Formation
Underground Electric Construction Company, LLC	Delaware
Utility Training Services Corporation	Idaho
Valard Construction Australia Pty Ltd	Australia
Valard Construction (Ontario) Ltd.	Ontario
Valard Construction (Quebec) Inc.	Quebec
Valard Construction 2008 Ltd.	Alberta
Valard Construction LP	Alberta
Valard Construction, LLC Valard	Delaware
Valard Equipment (AB) Ltd.	British Columbia
Valard Equipment GP Ltd.	Alberta
Valard Equipment Limited Partnership	Alberta
Valard Geomatics (Ontario) Ltd.	Ontario
Valard Geomatics BC, Ltd. (f/k/a Valard Land Surveying Ltd.)	British Columbia
Valard Geomatics Ltd.	Alberta
Valard Mechanical Ltd.	British Columbia
Valard Norway AS	Norway
VALARD Polska sp. Z o.o.	Poland
Valard Sweden AB	Sweden
Valard Zagreb d. o. o.	Croatia
Winco, Inc. Winco Powerline Services Winco Powerline Services Inc. Winco Powerline Services, Inc. Winco, Inc. an Oregon Based Corporation Winco, Inc. D/B/A Winco Powerline Services Winco, Inc. DBA Winco Services Inc. Winco, Inc. which will do business in California as: Winco Helicopters	Oregon