Attendees of the annual 4/20 pot celebration left behind almost 15,000 pounds of trash at the Golden Gate Park.

The cleanup crew began work at 6 a.m. and did not leave until 10 p.m.

“Not exactly a leave no trace moment out there,” commented Phil Ginsburg, San Francisco Recreation and Park Department manager.

The crews picked up “countless bottles of Shasta soda, beer cans, Fruit Loops boxes and butts.” Last year, the workers picked up more than 17,000 pounds of trash.

Board of Supervisors President London Breed said no one sponsors the event. Despite this, the city sends out city workers to clean up the mess, costing the taxpayers tens of thousands of dollars. KQED reports:

The unsanctioned event costs the city between $80,000 and $100,000 per year because additional help has to be requested from city agencies to ensure safety, control heavy traffic and collect trash. Crews have cleaned up more than 5 tons of trash in previous years, Breed said. City officials are hoping for some help with the trash this year.

More than 15,000 lbs of trash and cost of $50,000 for #420 cleanup at #GoldenGatePark per #SF Rec+Park GM. pic.twitter.com/PacGQqPdOA — Stephanie Chuang (@StephChuang) April 21, 2016

New video: light shows how much more trash there is on #HippieHill after #420. Sharon Meadow below pretty clean. pic.twitter.com/RJou49TtKs — Stephanie Chuang (@StephChuang) April 21, 2016

Things may change next year after people vote on the marijuana legalization initiative in November.