Separating drippy milk cartons and clean paper from garbage can be a tedious task, but it pays big bucks.

The city of Napa handed out $12,500 in prize money Thursday to nine businesses, four schools and two apartment complexes that excel in recycling.

These prizes, which ranged from $250 to $1,500, are nice, but they are dwarfed by the garbage bill savings that accompany them, said Sara Gallegos, the city’s recycling coordinator.

Some businesses have reduced their garbage bills by as much as $24,000 annually by shifting waste from garbage Dumpsters to recycling bins, Gallegos said.

Under the city’s contract with Napa Recycling and Waste Services, recycling is free. Customers only pay for non-recycling containers.

Charter Oak Apartments won $1,500 for running an ambitious recycling program for its 75 tenants on Browns Valley Road.

Manager Becky Weeks handed out 6-gallon recycling containers — provided free by Napa Recycling — to every tenant, while maintenance man Roy Conner makes sure garbage and recycling end up in the proper bins.

“We’ve cut our garbage bill in half,” said Weeks, who attended the awards ceremony Thursday at Downtown Joe’s.

Weeks said she intends to share the $1,500 prize with Charter Oak residents. “I think we’ll plan a nice party and get a jumpy house for the kids,” she said.

The city uses Dumpsters diving to determine its award winners, Gallegos said. The diver: John Fullner, a retired Mare Island Naval Shipyard worker who now works two days a week for the city.

It’s Fullner’s job to assess how much recycling is inappropriately mixed in with garbage and how much garbage is wrongly tossed in with recycling.

“It takes only one person to mess up the apartment complex,” Fullner said. One soupy container of garbage can fatally foul a cart of clean paper, he said.

Most customers are receptive when they hear they can help the planet and reduce their monthly bills, he said.

Fullner “pointed out that we needed to do a better job,” said Leo Helmick of Dan Moore Tax Service, which got a $250 prize. Every desk now has a recycling container, Helmick said.

Shearer Elementary School won $1,000 for an ambitious recycling program that involves training 600 students, some as young as 5 years old, to do the right thing with their lunch and classroom waste.

The school put recycling containers of “all shapes and sizes” throughout campus and got buy-in from the custodial staff, Principal Lisa Miri said.

With the new system in place, “we don’t have an excuse not to recycle,” Miri said.

The city’s contract with Napa Recycling and Waste Services requires the company to provide $10,000 annually for recycling awards. This year’s awards were supplemented by a grant from the California Department of Conservation, Division of Recycling.

Eight businesses in south Napa’s unincorporated area, customers of Napa County Recycling and Waste Services, also received recycling honors — trophies made from recycled glass — but no cash.

Metro Label, a wine label printer near the Napa County Airport, now recycles 85 percent of its waste, cutting its garbage bill by $2,300 per month, said Vikram Lal, company president.

The city’s $1,000 winners were: Napa Town Center, Olive Tree Apartments, Shearer School, Wintun School, First Christian School, Acacia Vineyards, Aldea School and Napa Valley Wine Train.

Winning $500 were: Etude Winery, Trefethen Winery, Villa Corona and Taqueria Rosita. Dan Moore Tax Service and the Napa Infant Program won $250. Charter Oak Apartments won $1,500.

Receiving cash award for the second year in a row were Charter Oak, Aldea School, Taqueria Rosita and Napa Infant Program.

Award recipients in the unincorporated area were: Barrel Ten Quarter Circle, Collotype Labels, di Rosa Preserve, the Doctors Company, Foster’s Wine Estates, Metro Label, Portocork America and Silverado Resort.