San Mateo County residents and eligible boaters can dispose of expired marine flares for free Sunday, Oct. 25, at Pillar Point Harbor in Half Moon Bay.

The appointment-only collection runs from 10 a.m. to 2 p.m. at 1 Johnson Pier, according to a California State Parks announcement. To arrange a drop-off, call 650-372-6200 Monday through Friday or visit the county’s Household Hazardous Waste Program page.

Eligible participants include San Mateo County residents, people whose boats are berthed in the county and county commercial boaters who generate less than 100 kilograms, or about 220 pounds, of hazardous waste monthly.

Participants must provide documentation showing they qualify. State Parks lists proof of residency, boat registration or a slip-fee receipt as examples. Flares will be accepted only during the scheduled collection hours.

Pyrotechnic flares are one option for meeting boating visual-distress-signal requirements. Those requirements vary by vessel and operating waters, according to the U.S. Coast Guard.

Pyrotechnic marine flares generally expire 42 months after manufacture. State Parks estimates that California recreational boaters generate about 174,000 expired flares annually.

The agency says disposal options can be costly and difficult to find, and California has no permanent statewide disposal program. Discarding flares in household trash or waterways can endanger people and the environment.

The Pillar Point collection is part of a series of October events serving Alameda, Marin, San Mateo, Santa Cruz, Orange and Ventura counties, western Contra Costa County and the Port of San Diego.

The collections involve the California State Parks and California Coastal Commission Boating Clean and Green Program and the California Product Stewardship Council.

Participants can also learn about reusable alternatives to pyrotechnic distress signals. Information about disposal and electronic alternatives is available on the state’s marine-flare webpage.

Boaters seeking additional information can contact environmental boating program manager Vivian Matuk at [email protected].