Millimeter sized wood activated carbon can remove contaminants to concentrations below analytical detection limits, and compared to powder, it requires only about one fourth the amount of carbon between influent and effluent. Wood activated carbon use is a continuous process, and it is a multiple use products based on thermal reactivation. Thermal reactivation enables the carbon to be classified as “green chemistry.” Where the possibility of industrial pollution is relatively high, more activated carbon must be readily available for possible emergencies. It can be kept in fixed vessels between the influent and effluent.