How do boaters safely discard of expired flares?

Disposal of flares and other pyrotechnic devices need to be disposed properly.
Properly is defined by the community in which they live.  Owners/users of these devices should contact their local sanitation, fire  or refuse collection departments.

Per the Auxiliary Manual, Ch. 11, B.13.d.(11), Auxiliarist's "acceptance of any pyrotechnic for disposal or disposition, from any individual or entity other than Coast Guard, is also not authorized."