Arcadis NV — Board/Management Information 2011

May 20, 2011

ARCADIS NV Gustav Mahlerplein 97-103 P.O. Box 7895 1008 AB Amsterdam The Netherlands Tel +31 20 2011 011 www.arcadis.com

PRESS RELEASE

(RE)APPOINTMENTS AT ARCADIS

May 19, 2011 – ARCADIS (EURONEXT: ARCAD), the international design, consulting, engineering and management services company, announced today that during the Annual General Meeting of Shareholders that was held on May 18, 2011 Mr. Gerrit Ybema was reappointed to the Supervisory Board for a period of four years, while Mr. Neil McArthur was appointed to the Executive Board also for a four year term.

For Mr. Gerrit Ybema, who has broad managerial and governmental experience, this will be the last term in an ARCADIS Supervisory Board position, given the 12-year limit the company has on these positions.

Neil McArthur (49), a civil and mechanical engineer with degrees from the University of Glasgow started his career at Shell. In 1990 he obtained his MBA at the INSEAD Business School in Fontainebleau (France), subsequently joining Booz Allan Hamilton, now Booz & Company where, as a member of the Global Executive Committee and Managing Director Europe, he was responsible for the activities in 15 European countries. Furthermore in the role of Senior Vice President, he has worked in international multidisciplinary teams to serve Fortune 500 clients in the global energy, chemicals and utilities markets.

For more information please contact Joost Slooten at +31-20-2011083 or outside office hours at +31-6-2706-1880 or via email joost.slooten@arcadis.com.

About ARCADIS:

ARCADIS is an international company providing consultancy, design, engineering and management services in infrastructure, water, environment and buildings. We enhance mobility, sustainability and quality of life by creating balance in the built and natural environment. ARCADIS develops, designs, implements, maintains and operates projects for companies and governments. With 16,000 employees and EUR 2 billion in revenues, the company has an extensive international network supported by strong local market positions. ARCADIS supports UN-HABITAT with knowledge and expertise to improve the quality of life in rapidly growing cities around the world. Visit us at: www.arcadis.com