Environment Report: Food Waste Bins Face Black Fly Summer

Written By MacKenzie Elmer, Voice of San Diego, June 12, 2023

Republished per content sharing policy

After a rainy winter and with a wetter, warmer El Niño series of seasons ahead, San Diego is about to slip into the heat of summer –  ingredients for an invasion of black flies.

Now add the new black fly buffet that is rows of green bins filled with lawn clippings and rotting food. Green bin organic waste recycling is San Diego’s solution to a state requirement that cities divert food from landfills in the name of climate change.

Whether San Diegans are correctly using these bins – or at all – will influence this potential plague. At my own apartment complex, I’m the only one that uses the green bin. And every time I opened it, my face was met with a swarm of flying things.

I am not alone.

Nextdoor is riddled with other San Diegans struggling with the brand-new stink. Al from South Park wrote that he is “SO DONE with this composting crap.” He posted that alongside a video of his dirty bin.

Jeff in University Heights wrote that he has used his bin for two weeks and closely followed directions. But, “the flies buzzing all over the green bin are disgusting. Multiply that by how many households? Then the hot summer? How do you keep the flies away?”

Seth from Clairemont wrote that he’ll use it for yard waste and veggies.

“I’m very on the fence about how much other stuff I’ll put in there especially with summer coming up. It’s not been an ideal experience so far,” he wrote.

But I was also not using my bin correctly.

Up Your Green Bin Game

Composting experts recommend keeping green bin waste content at a ratio of 2:1 green material to brown material. So every few layers of food waste should be topped with a layer of brown material like leaf litter, paper bags or newspaper.

Brown material is hard to come by as an apartment dweller. I shop at Sprouts which exclusively provided paper bags (my coveted brown layer for my green bin) until the company recently switched to plastic.

My respite from green bin anxiety came only when our biweekly landscaper filled it with leaf clippings. I could dive in and save some to use for green bin layering – but who has the time, patience or forethought to be dumpster diving for gold star compost behavior?

Mallika Sen with Solana Center for Environmental Innovation stressed that layering is key.

“It’s just a barrier, a light blanket, and then the fly can’t reach or smell (the food waste) … and it moves on to find better breeding ground,” Sen said.

Sen’s compost routine is gold star. She keeps vegetable scraps, rice and scratches in her on-counter compost caddy. But meat and bones go in the refrigerator or freezer until the day before green bin collection when she transfers all of her waste into a rolled-up brown paper bag – so flies can’t get at the waste – and tosses it in her bin.

Another method is to keep food waste in a five-gallon bucket with a screw-top, called a gamma seal, which keeps odors and flies at bay. Sen says you can purchase Bokashi bran – a mix of bacteria and yeast that breaks down food with fewer odors – and sprinkle it over each layer of food waste.

Here’s my way, and it’s not perfect but it’s the best I’ve figured out on the cheap side: I keep food waste – meats, bones, canned tomatoes, veggie peels, all of it – in a thick plastic grocery bag in my freezer. It squishes up enough that I have room in my small apartment freezer for other stuff.

I empty that bag in the green bin when it’s untenable in my freezer. Then I nab a paper bag, cardboard pizza top or other paper from the community recycling bin to cover the food.

So far, fewer flies are swarming my face. I’ll keep you posted.

Written By MacKenzie Elmer