Following the earlier announcement today regarding the sale of carbon credits by Biógas, ARCADIS (NASDAQ: ARCAF, EURONEXT: ARCAD) announces that the Company expects that, based on current information, the expected effect of this transaction on ARCADIS will be more than € 3 million. This effect will be spread over 2006 and 2007, based on the contractual delivery terms for the carbon credits.

ARCADIS is an international company providing consultancy, engineering and management services in infrastructure, environment and facilities, to enhance mobility, sustainability and quality of life. ARCADIS develops, designs, implements, maintains and operates projects for companies and governments. With more than 10,000 employees and over €1 billion in gross revenue, the company has an extensive international network that is supported by strong local market positions.

Except for historical information contained herein, the statements in this release are forward-looking statements that are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.  Forward-looking statements involve known and unknown risks and uncertainties that may cause the company's actual results in future periods to differ materially from forecasted results. Those risks include, among others, risks associated with possible changes in environmental legislation and risks with regard to the Company's ability to acquire and execute projects.  These are other risks are described in ARCADIS' filings with the Securities and Exchange Commission over the last 12 months, copies of which will be available from the SEC or may be obtained upon request from the Company.