Energy Secretary Abraham Lauds Participation of Arch Coal

LITTLETON, COLO. - March 20, 2002 - Environmental technology and specialty chemical company ADA-ES, a subsidiary of Earth Sciences (OTCBB: ESCI), announced today that Arch Coal, Inc. (NYSE: ACI) has joined its mercury control project team and will provide significant funding to support the development of mercury control technology for coal-fired boilers.

Secretary of Energy Spencer Abraham expressed his commendation for the increased private sector participation in the project. "We are extremely pleased that one of our Nation's largest coal producing companies recognizes the value of this government-industry research program," Abraham said. "Cleaner technology is the future of America's coal industry. President Bush emphasized the importance of advanced technology in his National Energy Policy and more recently in his Clear Skies initiative. The participation of a leading coal company sends an important signal that the coal industry is prepared to commit its resources to ensuring that Americans breathe cleaner, healthier air and enjoy a more energy secure future."

In October 2000, ADA-ES began work on the nation's first full-scale program to test advanced mercury control technologies. The technologies will be used by power generating companies to comply with potential future Environmental Protection Agency regulations for mercury emissions from the nation's coal-fired power plants. In the project, ADA-ES is demonstrating the use of activated carbon to remove mercury from power plant flue gases. This work is being performed in cooperation with the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL).

One of the largest coal producers in the U.S., Arch is committed to continuing efforts to make coal an increasingly clean resource that can be used in a manner that is highly consistent with the nation's environmental objectives. Steven F. Leer, Arch Coal's President and CEO, states: "This project reflects our commitment to finding new ways to burn coal more cleanly, while enabling the nation to make full use of its enormous reserves of coal. We are pleased to be supporting this program and are encouraged about the results obtained to date."

"We welcome Arch Coal's participation on the program team," said Michael Durham, President of ADA-ES. "Thanks to responsible organizations like Arch Coal and our other team members, including power companies and suppliers of key equipment and supplies, the carbon injection technology is rapidly advancing and will provide a reliable means for the clean use of coal. Arch will be a valuable member of the team that brings the key perspective and knowledge base of a coal producer."

Under the DOE/NETL cooperative agreement, ADA-ES is working in partnership with PG&E National Energy Group, Wisconsin Electric, a subsidiary of Wisconsin Electric-Wisconsin Gas, Alabama Power Company, a subsidiary of Southern Company (NYSE:SO), Ontario Power Generation, TVA and EPRI. The DOE will fund $4.5 million of the $6.8 million project while the other participating companies will co-fund the remaining $2.3 million.

During the three-year project, mercury control systems will be installed and tested at four coal-fired power plants. ADA-ES has developed a mercury control system where sorbents are injected into the flue gas and collected by existing particle collection systems. The sorbents will absorb the mercury, resulting in substantial emissions reduction. According to the DOE's National Energy Technology Laboratory, which is spearheading the project, the goal is to develop a cost-effective technology that will allow the electric utility industry to reduce mercury emissions from power plants by up to 70 percent of current levels.

About ADA-ES

Headquartered in Littleton, Colo., ADA-ES is an environmental technology and specialty chemical company that brings 25 years of experience to improve responsible profitability for electric power and industrial companies through proprietary products and systems that mitigate environmental impact while reducing operating costs.

ADA-ES is a subsidiary of Earth Sciences, whose common stock trades on the OTCBB under the symbol ESCI.

About Arch Coal, Inc.

Arch Coal is the nation's second largest coal producer and mines low-sulfur coal exclusively. Through its subsidiary operations in West Virginia, Kentucky, Virginia, Wyoming, Colorado and Utah, Arch provides the fuel for approximately 6 percent of the electricity generated in the United States. One of Arch Coal's highest priorities is to operate safe and environmentally responsible mines.

Arch Coal is traded on the New York Stock Exchange under the ticker symbol ACI. The company's corporate headquarters are located in St. Louis, Missouri.