QUESTAR SELECTS ENVIANCE FOR ENVIRONMENTAL, HEALTH AND SAFETY COMPLIANCE MANAGEMENT

SALT LAKE CITY, UT and CARLSBAD, CA - May 26, 2004 - Questar Corp. (NYSE: STR), an integrated natural gas company with a total enterprise value of $4 billion, and Enviance, Inc., the leading provider of Internet-based solutions that streamline the management of complex environmental, health and safety (EH&S) compliance activities, today announced that Questar selected the Enviance System to streamline EH&S management. By using the Enviance System, Questar is supporting its ongoing commitment to the protection of people and the environment.

Questar launched the Enviance System for management of 25 facilities in Utah, Wyoming, Colorado and Arizona. Initially to be used for managing air quality compliance, the company plans to roll out other health, safety, and environmental compliance areas in the weeks ahead. By systematically replacing disparate spreadsheets and databases with a single repository for compliance related data, Questar will bolster its ability to access, manage, analyze and respond to environmental, health and safety data and information.

"Demonstrating compliance with environmental, health and safety regulations may happen at the facility level, but from the perspective of regulators, there is only one Questar. After successfully configuring one system to our exact needs, we were able to replicate it at 24 additional facilities in a matter of weeks," said Scott Bassett, Environmental Coordinator, Questar Regulated Services "Because it is Internet-based, the Enviance System enables seamless communication across departments and throughout the company so we can share best practices in support of our stated commitment to ensure the effective integration of environmental, health and safety management into all the aspects of our business."

"Industry has recognized the need to focus on core competencies and outsource other needs," said Lawrence Goldenhersh, President and CEO, Enviance. "In the realm of EH&S compliance management, rather than wrestling with developing their own software code or creating piecemeal solutions to keep up with evolving and complex regulations and responsibilities, leaders like Questar are turning to Enviance. And with our Internet based, on demand, system we are like our Utility customers: always on and available for use."

About Questar Corp.

Questar is an integrated natural gas company headquartered in Salt Lake City with a total enterprise value of $4 billion. Through subsidiaries, it engages in gas and oil development and production; gas gathering, processing and marketing; interstate gas transmission and storage; retail gas distribution; retail energy services; and information systems and technologies. For more information, visit Questar's Internet site at: http://www.questar.com.

About Enviance

Enviance helps organizations improve their performance and manage the risk associated with ensuring compliance with environmental, health and safety (EH&S) regulations. The first Internet-based system for the collection, distribution, analysis and reporting of EHS data and information, Enviance offers a comprehensive, flexible, standards-based platform for EH&S compliance management. Many leading organizations trust Enviance to help them reduce the time and cost of managing compliance activities, retain organizational memory, and confidently certify compliance. Founded in 1999, privately held Enviance is based in Carlsbad, California. For additional information, visit www.enviance.com; to request a demonstration, e-mail demo@enviance.com.

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