The Dirt On Soil: It's Tough To Get Rid Of

DISPOSING of earth used to be literally dirt cheap. Now it's a bigger part of construction costs.

Here's the problem: We're digging up too much dirt and it's becoming expensive to truck it away.

In the last decade, the population in King County has been growing at a double-digit rate. And to the familiar litany of traffic, housing costs and other pitfalls of growth, you can add the rising cost of soil disposal.

For developers and home builders, removing earth dug up for construction projects has always been part of the job. But in the recent economic boom, it's become a bigger headache for an industry running out of room to build.

"The cost of removing dirt 20 years ago used to be just a small line item," said John Cochenour, president of Lexington Fine Homes, a builder of luxury houses on the Eastside. "Today it has grown to a cost of some substance. It's not unusual to spend thousands of dollars just to export dirt compared to spending nothing back then."

These costs are passed on to customers, and are a factor contributing to the steep increases in construction costs.

A little lesson in homebuilding: To lay a stable and level foundation, the top layer of soil, usually about three feet, has to be removed. It's called "duff" and consists of sod and topsoil, materials that are relatively soft. Builders favor the substance underneath, a harder, more compact soil, often called structural fill.

In the past, builders could take the duff and spread it around the lot, which was generally large and flat. The excess soil was either disposed of in dump sites, farmlands or given to homeowners needing fill.

"Excess soil decades ago was quite valuable because we were filling all of the wetlands," said Rob Harrison, an associate professor of soil chemistry at the University of Washington. "Seattle when first found was an island, and it was filled. But now we recognize the wetlands as extremely valuable."

As land becomes a dwindling commodity in the county, so have the dirt-removing options.

"We're running out of ground quickly," Cochenour said. "Areas that might have been marginal to build on a few decades ago . . . today we're saying, `Yeah, all right, we'll build on it.' "

Development on steep slopes and hills, which requires more soil removal to level the foundation, is becoming more common.

In addition, lot sizes have become smaller, meaning there is less room to spread around dirt that has been dug up.

"We're building on 5,000-square-foot lots, that's barely enough room to put a house on, let alone spread dirt," Cochenour said.

New environmental laws intended to prevent landslides and detect hazardous waste also have made it harder to give dirt to homeowners.

"It used to be that when anyone had a low spot in their yard, you could talk to them and they'd say, `Sure, bring it over,' " said Mike Echelbarger, president of EchelbargerProperties in Lynnwood. "Today the homeowner and builder can run into serious problems by moving dirt without getting approval from the government.'

Harrison, the UW professor, agreed.

"We can't really just drop soil off anymore," he said. "People need to obtain permits. If I were to fill a large area of lawn, I would be destabilizing the soil underneath, and that whole thing could give way and slide off and maybe slide off into my neighbor's yard."

So what's a person to do with all this dirt?

Basically there are only two choices, both of which require substantial trucking fees. Take it to a landfill, an expensive option because of the distances and the limited amount of soil accepted. Or, haul it to a soil recycler, a business that has been growing rapidly. About 280 tons of soil will be removed from a typical sloped or smaller-sized lot. Trucking fees average around $1,400. If taking soil to a commercial recycler, tack on an additional $600.

Landfills that take topsoil are few and far between. King County landfills no longer accept dirt, said Carsten Thomsen, a county solid-waste specialist. The few private landfills that do accept it charge between $80 and $100 a ton.

Three years ago, Pacific Topsoils, one of the largest recyclers and providers of soil in Western Washington had four sites. It now operates 14 sites with a staff of 300 in King, Kitsap, Pierce and Snohomish counties.

Depending on soil quality, Pacific Topsoils charges up to $15 a cubic yard to recycle construction dirt. The firm recycles about 2 million cubic yards of material a year, including soil, bark and concrete.

"We're not making out like bandits," said Jim Lindsay, property developer manager of Pacific Topsoils. "What we do is a fairly labor-intensive and expensive process."

From sifting out dirt and wood particles to adding organic content, Lindsay explained, there are at least a half a dozen steps involved before the dirt can be resold to the public as legitimate topsoil.

"It's not just dirt," he said. "There's about 25 varieties of topsoil we produce, and they all require a lot of work."

Lindsay said developers and homebuilders should be happy to have businesses like his around.

"Without us, the only alternative is dumping it in a landfill, and they're about five times as expensive," he said. "Not only are we cheaper, we're doing the environment a favor."

Cochenour, who recently spent $25,000 removing dirt from a subdivision in Newcastle, might take issue with the cheaper part.

"But, it's just one of those hurdles you have to pass if you want to stay in business," he said.