Honestly, the best way to stop rust streaks is to keep the bottom of the bin from sitting in moisture on the concrete. Rust needs water, bare metal, and time. If you cut off one of those, you stop most of the staining.
Start by checking the bottom of the bin. If paint is chipped or rust is already starting, sand it lightly, wipe it clean, and hit it with a rust-inhibiting primer plus a couple of coats of enamel or a spray made for outdoor metal. Pay special attention to welds, rivets, and the rim where the bin meets the ground. A rubberized coating or truck-bed liner on the bottom can also help, but let it cure fully before the bin goes back outside.
Then get the bin off direct contact with the sidewalk. A plastic drip tray, boot tray, or shallow concrete-safe pan under each bin catches the nasty liquid that leaks out. If your bins have to stay on the sidewalk, put them on a rack or small platform with rubber feet so air can move underneath. Don’t use a bare metal pan, because it will just rust too and make the problem worse.
Use liners religiously. A sturdy bag keeps wet trash, food juice, and pet waste from soaking the bin’s inner bottom. Add a little baking soda or kitty litter to absorb odors and moisture. Empty and rinse the bin on a regular schedule, but do it in a yard, alley, or wash bay, not on the sidewalk where the runoff can soak into concrete. Dry the bin in the sun, upside down if possible, before you put a new liner in.
If the sidewalk already has rust stains, prevention is only half the battle. Seal your concrete with a breathable masonry sealer after cleaning, because sealed concrete gives rust less chance to soak in. Clean up small leaks immediately. For already stained spots, try a dedicated concrete rust remover or a poultice with oxalic acid, following the label carefully.
Finally, think about the bin itself. Plastic or galvanized bins with intact coatings are easier to maintain than old painted steel. If your city-issued bin is the problem, ask for a replacement or repair. And make sure water isn’t pooling around the storage spot. Fix low spots or poor drainage. If the bin sits in a puddle, rust streaks will keep coming back no matter what you paint on it.