E-21 Construction, LLC (E-21), is a privately-owned construction and environmental engineering firm with experience in buried utility construction, stormwater control, earthwork construction, demolition, and site preparation.

Since 1991 our firm has been bringing decades of construction and engineering experience to our customers projects.

About Our Company

E-21 is a fully-insured corporation that provides services to the top 500 corporations, financial institutions, major contractors and governmental agencies at all levels.

As a professional company, and as individuals, we strive to provide excellence in our service to our clients. To us, our occupation and our service are personal as well as professional.

Our Key Team Personnel

Sergius Hanson, P.E., P.G.


Founder of E-21 Construction, LLC

Paul Gottler, P.G.

Environmental Assessments

22 Years at E-21 Construction, LLC

Mike Smith

Construction Operations Manager

13 Years at E-21 Construction, LLC

Mat Wargo

Construction Field Supervisor

12 Years at E-21 Construction, LLC

Our Customers

We have a wide range of services. E-21 personnel has been involved in over 2,000 projects, for all types of clients, including a heavy emphasis at aerospace facilities.

Government - All Levels

US Air Force, Buckley AFB
US Air Force, Cheyenne Mountain AFB
US Air Force, Schriever AFB
US Forest Service
US Bureau of Land Management
US Department of Agriculture
Colorado Department of Health
Colorado Division of Oil and Public Safety
Counties of Adams, Denver, Jefferson and Weld
Cities of Aurora, Denver, Englewood, Glenwood Springs
Arapahoe-Douglas Mental Health
Aurora, Denver, and Littleton Public Schools

Industrial and Aerospace

Lockheed Martin Space Systems
US Air Force, Buckley Aerospace Data Facility
Ball Aerospace
MillerCoors Brewery
Excel Energy
Waste Management of North America
Shamrock Foods
Rocky Mountain Bottling Company
Sun Edison
Tri-State Generation and Transmission Assoc.


Amoco Oil Co.
Valero Energy Company
K&G Stores, Inc.
Circle K
7 Eleven
Gilco, Inc.
Trammel Crowe Development
Jon Cook Properties
Phil Long Ford

Construction - General Contractors

Hensel Phelps Construction Co.
W. E. O’Neil Construction
J. E. Dunn Construction
G. H. Phipps Construction Co.
BAB Builders
Jordy Construction
LVI Services, Inc.
Argus Contracting
Sturgeon Electric Company, Inc.
Apollo Mechanical Contractors


Bank of Colorado
First Bank
Citibank Financial
Vectra Bank
Equitable Real Estate
Bank One Commercial
General Electric Capital Corp.
Republic National Bank
ZJ Investments
Allied Realty