You might inquire of your street maintenance department. In my town, residents are allowed to rake leaves into the gutter, and the city vacuums them up and makes nice moist compost piles. Yes, there is some other trash mixed in, but it's very minor and can usually be avoided when collecting the material.
That reminds me, my city moved where the piles are and I need to ask where they are this year.
Like Dale, I have applied generous amounts of coffee grounds right to the soil and tilled it in with good results. I also add a lot to my compost bins. To date I haven't seen any negative results.
In my own situation, the big trucks decline dumping chips right onto my farm because the fear lava tubes might be under the surface of my land, something I can't guarantee one way or the other. Historically in my region, heavy equipment has been known to fall through those tubes. Therefore I have chips dumped along the roadway and simply spend the afternoon running back and forth hauling small loads back to where I want them. Yes it takes time and effort, but the reward is a truckload of fresh mulch for the growing areas.
Living rural, I can forage biomass. I simply get permission from the landowner. I can bring home lots of fallen fruits, or if I wish, machete lots of tall grasses to cart home.
I also provide clean, lidded buckets to various local food establishments for collecting any sort of food waste, I pick up 5 days a week. Where I live, I don't need a permit to do this.
I have many people who collect their old newspapers for me. Usually once a month we make a point to meet somewhere, like the local post office or supermarket, to exchange the paper. Many folks also save me their cardboard, paper egg cartons, and such. And a few save me their kitchen waste, which they freeze in plastic bags between deliveries.
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com
We have one local restaurant that puts their preparation scraps in buckets we provide and leaves them out their back door for pick-up 2x a week. That really provides a lot of moisture as well as other goodies to my compost heaps. We've tried to get others to participate but with no luck so far. I *really* wish I could get a reliable supply of coffee grounds, but it seems others have scooped those establishments.
We do have a fair trade coffee importer who sells the coffee sacks for $20 (Canadian). We have to pick up, and it's however many they have at the time we get there which we try to arrange to be about 200, so it takes an open pick up or a trailer. They are a great source of high carbon to balance some of my high nitrogen sources. The veggie scraps are supposedly close to balanced for a decent compost, but they turn to mush if they aren't mixed with something else. Supposedly the sacks are organic, but they have one stitching that is not biodegradable. I've learned to do my best with a stitch ripper and scissors to remove it as an evening or sit-down rest job, so I'm not pulling it out after the fact when it gets caught around things.
As more and more people realize the benefits of home-made compost, there will be more competition for these sorts of things. It is really important not to create stink or attract vermin, as many places are discouraging or banning back-yard composting due to rat issues.