Reduce-reuse-recycle is a mantra for the times, and one that Dairyland is committed to following as much as possible in our business operating practices. For instance, the coal combustion process used to generate electricity at Dairyland’s Alma generating site creates an ash byproduct. Dairyland has a strong history of recycling the majority of its fly ash annually. In 2020, 100 percent of fly ash was recycled from Alma's John P. Madgett (JPM) station and the (now retired) Genoa Station #3 power plant (G-3).
Benefits of Dairyland’s ash recycling program
For each ton of coal Dairyland burns to produce electricity, approximately 5 percent - 100 pounds - results in an ash byproduct.
- 80 percent of this ash byproduct is referred to as fly ash, a light powdery substance captured in the emission control systems at the power plant;
- 20 percent is bottom ash, a coarse granular material collected at the bottom of the coal furnace;
- Both consist of compounds commonly found in natural clays and limestone, and are the major components of Portland cement;
- Dairyland also markets its fly ash to pipe manufacturers for use in underground piping.
Using coal combustion byproducts to replace the natural clay and limestone in the manufacturing of Portland cement is the most common recycling option used at Dairyland, with benefits for both business and the environment.
- Most concrete today in the Driftless Region is 30 percent fly ash, contributing to stronger, less permeable concrete, at a lower price.
- Fly ash is less than half the price of Portland cement. Consumers save money when building roads, bridges, buildings and other community projects with concrete that contains fly ash.
- By using a recycled product, less virgin clay and limestone are extracted from quarries.
- Fuel costs are lower for the cement manufacturer: Fly ash doesn't need to be “preheated” since it was already heated during the coal combustion process. This correlates with a major air-quality benefit of using fly ash in place of Portland cement.
Dairyland also recycles bottom ash as a substitute for crushed rock or sand in road construction, and as an anti-skid material in lieu of sand or salt on winter roads. This reduces the need to quarry rock for these purposes.
Finally, Dairyland’s ash recycling program lessens the amount of product safely stored in a landfill facility near Alma, Wis.
In the years Dairyland couldn't recycle all of its fly ash, any remaining dry fly ash was conditioned to achieve optimum moisture content in order to prevent dusting. It is then delivered by truck to the landfill storage cell. The ash is carefully compacted to construct a structure that will resist accumulation of additional moisture. In fact, the fly ash itself is somewhat like cement, which adds to the stability of the landfill storage cell.
Building Stronger Roads and Sidewalks
Dairyland has also harvested its own fly ash from the JPM plant (Alma, Wis.) for internal construction projects. Some concrete for the the installation of environmental control equipment at G-3 in the early 2000s was made using recycled JPM fly ash. Another unique application was its use in the construction of two wind turbine projects in southern Minnesota.
Hwy. 35 and Hwy. K near Genoa, and Hwy. 35 to Alma contain the bottom ash, utilized as a “surface coarse” gravel overlay material, which “sparkles” more than standard road overlay. The bottom ash material provides better traction, is very durable and doesn’t break windshields as readily as standard gravel. It also melts ice faster … a real bonus for winter driving.