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                                                                    EXHIBIT 99.1


HARDING LAWSON ASSOCIATES                         MACTEC, INC.

Contact: Robert L. Costello                       Contact: Scott E. State, P.E.
         Harding Lawson Associates Group, Inc.             MACTEC, Inc.
         303/293-6100                                      303/273-5038


                              FOR IMMEDIATE RELEASE

                      HARDING LAWSON ASSOCIATES GROUP, INC.
                   AND MACTEC, INC. ANNOUNCE MERGER AGREEMENT

     Harding Lawson Associates Group, Inc., headquartered in Denver, Colorado
(NASDAQ:HRDG) and privately-held MACTEC, Inc., headquartered in Golden,
Colorado, today jointly announced that they have entered into a definitive
Merger Agreement providing for the acquisition by MACTEC of all of the
outstanding shares of Harding Lawson common stock at a price of $11.50 per
share. The Agreement is subject to certain conditions, including obtaining the
approval of the holders of at least the majority of the outstanding shares of
common stock of Harding Lawson.

     The Board of Directors of Harding Lawson has unanimously approved the
Merger Agreement. CIBC World Markets Corp. is acting as financial advisor to
Harding Lawson and has rendered to the Board of Directors of Harding Lawson its
opinion as to the fairness, from a financial point of view, to the holders of
Harding Lawson common stock of the consideration to be received by such holders
in the transaction.

     Robert L. Costello, Jr., Harding Lawson's President and Chief Executive
Officer commented on the merger, "This transaction will allow our stockholders
to receive a substantial premium over recent trading prices of our stock.
Competitive issues related to the consolidation in the engineering services
industry are the key drivers in our decision to pursue this transaction. Our
clients are demanding a higher degree of responsiveness to their technical
services needs. This can be achieved more readily by bringing together a broader
base of technical resources giving our clients an expanded network of high
quality professional and technical consulting talent, and our employees gain
greatly enhanced career opportunities."

     Scott State, MACTEC's Chairman, President and Chief Executive Officer said,
"Harding Lawson represents a cornerstone merger opportunity for MACTEC and
provides the essential platform we need as we build MACTEC into one of the
leading environmental engineering services firms in our industry. The
acquisition will double our annual revenues to nearly $325,000,000 and will
create a company with over 2,000

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employees located in key cities throughout the U.S. MACTEC is currently ranked
number 26 among the nation's largest environmental engineering firms and Harding
Lawson ranks number 28 based on an Engineering News Record industry survey."

     Harding Lawson will be filing with the Securities and Exchange Commission a
Proxy Statement for submission to its shareholders for use in connection with a
Special Meeting of Shareholders that will be scheduled for the purpose of
approving the merger. That Proxy Statement will fully describe the merger and
should be carefully reviewed by Shareholders.

Harding Lawson Associates Group, Inc., headquartered in Denver, Colorado,
provides a broad range of infrastructure engineering, consulting and
construction-related services to private sector industrial and public sector
governmental clients. The company operates through a network of nearly 40
offices nationwide and currently employs over 1200 staff members.

MACTEC, Inc., established in 1975, has evolved into one of the country's leading
environmental professional services organizations providing major project
support and leading-edge technologies. Today it is a provider of environmental
solutions for multiple government and private clients through a network of over
40 offices.


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       March 24, 2000

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