Inside a McGill composting facility
Ever wonder what the inside of an industrial composting facility looks like?
A drive-by won’t reveal much about what goes on behind the gate at a McGill facility. An entry sign, some naturalized areas, vegetated berms and, maybe, a roof line or two is the most common vista — and that’s quite intentional.
We want to be as unobtrusive as possible, blending in with the neighborhood.
But behind this woodsy facade is a modern, industrial-scale compost manufacturing plant utilizing a scientifically-advanced process and computer control. But they’re not identical. Each one reflects the locale, applicable regulations and our own design and process evolution. Each new facility is a bit more advanced than the one before.
Look inside a McGill composting facility
Peek inside our existing plants to see some of our most recent design and technology upgrades:
This photo shows the indoor off-loading area at McGill’s Glenville facility near the city of Cork in Ireland. The “pit” is actually an extension of the blending area floor. At older facilities, off-loading is not under roof. But at all facilities, feedstocks are off-loaded into indoor concrete bunkers.
High-moisture materials are dropped onto a bed of very dry amendment or compost to absorb free liquid. Some dry amendments (the woody fraction of yard waste, shredded pallets, etc.) may be stored on a small, outdoor pad until needed for blending.
Tractor-trailer rigs are pressure washed after off-loading to eliminate odors and minimize track-out. The concrete apron is sloped so wash water drains into the pit for use in the composting process. Non-toxic detergents and cleaners keep our microbes safe.
The way we blend isn’t really innovative. Tried and true would be more accurate. We have used mechanical mixers and conveyor systems, but they were never as efficient, reliable or flexible as good old bucket blending, which is now the method of choice at all facilities. The pictured blending area is also at our facility in Glenville, Ireland.
Encapsulated bay processing
Residuals and by-products, blended to prescribed ratios based on available feedstocks, are placed inside concrete-encapsulated bays designed with a special floor to accommodate our aeration system. Sensors are placed and the doors closed, totally encapsulating the admixture.
The composting mass is not touched again until the computer tells us the process is complete. Some facilities have metal doors (like McGill-Glenville, pictured in top photo on this page); others use a geotextile.
The translucent panels on the roof of this bay at the Merry Oaks plant protect the composting process from weather influences, seal the bay for air extraction/biofiltration, and improve visibility for workers.
Aeration system and biofilter
At McGill-Glenville, the aeration system is located in the attic space above the bay, giving each bay a concrete “roof.” For bays with translucent panels as a roof, system components are outside, along the back wall.
Aeration delivers oxygen to the microbial populations responsible for biodegradation and removes the heat generated by their feeding activity, maintaining temperatures within the specific range required for happy microbes. Air is pushed up and through the composting mass, while extraction fans pull air off the pile and away from work zones within the building. Process air is piped to a biofilter.
The time:temperature ratio of our process mimics pasteurization, even though no external heat is applied. It’s all provided by the feeding activity of the microbial populations responsible for biodegradation. Pictured in the control room at McGill-Glenville are Jim McGill (left) and Niall Carroll.
After curing and screening, our compost is ready for market as an EPA Exceptional Quality (EQ) product. Sold under the SoilBuilder brand, this compost is also used as the base ingredient in the formulation of a number of McGill specialty soil products. It is tested monthly in accordance with the U.S. Composting Council’s Seal of Testing Assurance (STA) program.Visit our compost products website