Backyard composters sometimes refer to the finished product of their labors as “black gold” because of its value as a soil amendment.

Composting on a much broader scale won’t be a gold mine for the county — municipal composting operations rarely turn a profit or reduce short-term waste management costs — but it’s an idea that merits the attention of county commissioners who recently took a composting field trip to Albany, N.Y. While it’s easier and cheaper in the short run to simply dump garbage and cover it with dirt, landfills have many buried costs, financially and environmentally.

With increasing regulatory restraints, locating and operating landfills is more complicated and expensive than in the past. They require extensive site plans, the construction of liners, caps and monitoring wells. Even when they’re full, the potential expenses are by no means finished. Counties have to continue monitoring the sites to guard against future contamination of groundwater and soil, or the accumulation of methane gas.

Here’s another reason it’s important to find alternatives to landfills: Because of the state’s residential and industrial growth, they’re filling up faster than planners had expected. Between 1995 and 1998, the amount of waste generated in the county increased 25 percent, while the population grew only 5 percent.

In its initial waste-management plan drawn up in 1996, the county had projected it would be handling about 100,000 tons of waste by this time. Last year, residents and businesses produced 133,000 tons. Considering that paper and organic materials make up more than 60 percent of that total, a viable composting program could greatly extend the life of existing landfills by cutting down on the amount of refuse going into them. The resulting product also could be sold for agricultural or residential use.

Municipal composting operations have suffered from the belief that they produce unpleasant odors — operated correctly, they don’t — and aren’t cost effective. But the development of high-tech composting systems, such as the Swedish design the commissioners recently examined, has made large-scale composting more practical and efficient.

The county has taken several steps to reduce waste, including working with local industries, setting up recycling centers and encouraging residential composting and mulching. A large-scale composting program holds the promise of providing another way to reduce waste while producing an environmentally sound byproduct.

The start-up costs for a trial operation would be about $100,000, according to County Manager Tim Russell. In a cash-strapped county that has already dipped into its landfill profits to meet budget, that doesn’t sound dirt cheap — or like cheap dirt. But it could be a good longterm investment, with buried benefits instead of buried costs.