One of the interesting themes that emerged from last week's Residential Recycling Conference was how the composition of the waste and recycling streams is changing, and how it has the potential to change a great deal more in the future.

Paper has long made up the biggest piece of the pie by far. It still does, but its dominance is shrinking. There's the depressed state of newspapers, with declining advertising revenue translating into significantly fewer news pages. Increasingly, we're viewing and storing information electronically that we used to read from a hard copy. Imagine the volume change just with the changing nature of phone directories, those hugely thick mass of pages that are quickly disappearing in favor of Internet versions.

Then there's the explosion of drink bottle consumption, especially with water. There's the proliferation in the last few years of electronic waste, led by computers, televisions and cell phones. Their bulk and hazardous components present enormous challenges.

Recyclers and waste managers have to adapt as these material types and volumes change, as it means changes in collection, sorting processes, recycling material markets, etc.

But it also means opportunity. And one big area of opportunity is in organics. While we have the potential to recycle much of the traditional materials, recycling of organics such as food and yard waste remains largely untapped compared to what it could be.

And this is where recyclers need to first determine what the financial potential is for organics. Yes, there certainly are costs creating an infrastructure, and organics can be particularly heavy, bulky and present other challenges. But there is great opportunity for revenue. Recyclers need to build a case for that financial value, because that's how they'll get the money to make the necessary investments in equipment, technology and personnel. It can't just be about doing an environmental and social good.

Many people say recycling is stagnating. But great potential growth is there, for the picking.

Allan Gerlat is editor of Waste & Recycling News. Past installments of this column are collected in the Inbox archive.