Dec 28, 2000

Calgon Carbon’s ISEP is First System Approved for Perchlorate, Nitrate Treatment

Calgon Carbon Corp. received the California Department of Health Services
approval of its ISEP continuous ion exchange system to treat perchlorate and
nitrate for drinking water distribution.

rendering our decision, the Department’s Surface Water Treatment Rule
Committee extensively reviewed ISEP’s performance in pilot work," explained
Richard H. Sakaji, Ph.D., PE, senior sanitation sanitary engineer for the
California Department of Health Services. The committee also noted that, "ISEP
has been successfully applied in nitrate removal applications locally and
outside California. The investigation of the committee concluded that ISEP has
demonstrated its ability to remove perchlorates from source waters to acceptable

Calgon Carbon Corp.)