Patricia, Here are some ways to keep bears away from septic tank lids: *Secure the lid: Use bolts, screws, or other locks to keep the lid secure and prevent easy access. Make sure the riser is in good shape so the fastener is firmly in place. *Cover the lid. I know you already did this. Maybe a more aggressive "lid cover" option is up for a try. Use temporary, movable objects to cover the lid, such as mulch, pea gravel, removable bricks, or river rock. You can also camouflage the lid with artificial landscape rocks, potted plants, or half wine barrels filled with flowers. *Use a bear-resistant lid: Some lids are designed to be resistant to bears. Colorado Parks and Wildlife suggest some bear deterrents in this article: https://cpw.state.co.us/Documents/Education/LivingWithWildlife/BearDeterrents.pdf I hope you are successful in your "bear-b-gone" effort.