To overcome obstacles faced by current remediation technologies for contaminated sediments, the present invention provides a new strategy based on in situ control of hydrophobic organic contaminants (HOC) bioavailability. The strategy employs the addition of activated carbon sorbents to sediments. These activated carbon materials sorb HOC contaminants strongly, reduce release of HOCs into water, and reduce HOC uptake by benthic biota, thereby reducing environmental exposure and human health risk to such contaminants. By in situ sorbing the contaminants, the inventive approach reduces environmental exposure and avoids massive material removal while controlling food web transfer of HOCs including polychlorinated biphenyls (PCBs).