Day at the dump

On location at Kiefer Landfill

Civil engineer Keith Goodrich drove Green Days up to the top of Kiefer Landfill for a panoramic view.

Civil engineer Keith Goodrich drove Green Days up to the top of Kiefer Landfill for a panoramic view.

SN&R Photo By Don Button

Next week’s topic: Sacramento’s urban farm stand

I have never been so excited about a heap of trash! The moment Chris Andis, Sacramento County’s Waste Management and Recycling spokesperson, said our local Kiefer Landfill was an ecologically sound resource, I was hooked and ready to go. Here was my mindset: Gulls circling overhead like buzzards over carcasses, that sweet pungent stench, and garbage mounds with swells large enough to rival a mountain range and ominous enough to earn the respect given to the sea from wide-eyed children who toyed with the anticipation of being swallowed alive and never seen again should they accidentally fall in. “What am I missing?” was all I could think.

On location at Kiefer Landfill, we met Keith Goodrich, a senior civil engineer who kindly took us on a tour of the site. “I’ll drive you up the top so you’ve got a good view of the whole place,” he said. That’s exactly what I wanted—the chance to take in the whole enchilada.

We drove through the entrance, where a gentleman in waste screening speaks with each customer to find out what kind of materials they are disposing and directs them to the appropriate place on site. The dump is no longer a one-stop shop—it’s almost a tiny little city.

Keith gives us the rundown. Disposed appliances will be stripped of chlorofluorocarbons and oils and sent to a metal recovery operation with other metal items recovered at the landfill. Tires are removed by contracted vendors to make such products as protective ground cover in climbing gyms and rubberized asphalt—the latest craze among parents in playground surfaces. Broken up concrete slabs are reclaimed and reused in road construction, which reduces the need to buy aggregate materials for constructing roads.

Green and wood waste has the greatest diversity when it comes to reuse. Some is reclaimed by vendors in the county for composting. Another portion is used as biomass to produce energy (super cool), and the remainder is processed onsite and used in place of soil as an alternative daily cover to help maximize the utilization of air space. Or, in other words, to squish the trash with incredible uniformity, which removes air pockets and uses space in the landfill most efficiently.

Everything else is considered mere trash and customers are directed toward the landfill—the final resting spot for as little waste as possible.

Atop the hill, Keith perched the truck for the promised bird’s eye view. I look around a little and finally ask, “Where’s the dump?”

“It’s right there in front of you,” he said. In front of me was what I considered a morsel-sized, highly controlled area of exposed trash—though my thread of disappointment quickly was replaced with intrigue as Keith explained the science of trash. The barren, modestly excavated site began to shape into an advanced scientific design right before my eyes.

The architecture of a landfill divides the site into modules—carefully planned portions of land small enough to manage and regulate properly, but large enough to accommodate waste for several years. Modules are further divided into rows and layers of adjoining cells, each roughly 15 to 18 feet deep. Only one cell is active at a time: the exposed, morsel of trash. The other inactive cells are covered with soil and appear hidden to the novice landfill visitor: me.

At the close of business this day, as every other day, the active cell will be completely covered with a non-permeable tarp, one of the strict regulations required by an exhaustive list of regulatory agencies to prevent external contamination and proliferation of vectors (rodents and other disease-laden creatures).

And while the preparation of a module may not be margaritas at sunset, it’s got its own little flare of scientific sexiness. After the land is excavated, several ecological layers compose a protective system designed to thwart landfill hazards and keep contaminants out of soil and groundwater. A heavy-duty composite liner made of clay or geosynthetic clay is covered by high-density polyethylene (puncture-resistant plastic). A layer of gravel then is laid to provide a substrate where liquid and contaminants from waste collect and are pumped out by a network of perforated pipes called leachate pipes.

Once the waste has been compacted and covered, micro-organism activity results in anaerobic conditions. Bacteria that only function in the absence of oxygen, break down waste and produce the byproduct, methane gas, a major contributor to global warming. Even though the gas is trapped beneath the surface, it has the propensity to explode. But with a little scientific genius, methane gas becomes the golden egg. A high-density polyethylene pipe snakes around the module and functions like a central vacuum system through wells drilled down into the garbage.

These wells collect the steady flow of methane gas and direct it through the central pipe to an energy plant on the property. Inside the plant, five internal-combustion engines large enough to run locomotives have been configured to run on methane gas. Each turns an electrical generator, producing more than 14 megawatts of energy that goes directly to the grid. Keith is eager to point out that this capacity is enough to serve 8,900 households for more than 20 years. Jaw dropping!

When a module has been completely tapped, a final cover is constructed to permanently seal and protect that portion of the landfill. I was so thrilled to learn these eternal resting heaps of waste are then vegetated and provide peaceful foraging habitat for wildlife. It was like a fairytale ending.

Oh, and my very favorite part of the visit was the news that just beyond my view lies 243 acres of Kiefer Landfill Wetland Preserve—home to 20 acres of vernal pools, an ever-decreasing sensitive habitat for a myriad of flora and fauna; and 223 acres of annual grasslands, critical foraging habitat for wildlife. The preserve is part of Kiefer Landfill’s compensation for the loss of habitat required to build out the landfill. In addition, Kiefer Landfill purchases habitat-restoration credits at the Laguna Terrace Vernal Pool Preserve, owned by Rocklin’s very own Wildlands Inc., one of the nation’s first private organizations to establish conservation banks to protect wildlife habitat in perpetuity.