Interesting Facts about the Halton Waste Management Site’s Construction

September 2012 marks the 20^th anniversary of the Halton Waste Management Site.  We’re celebrating with a community open house on Saturday, September 29, 2012!  While many residents are coming out to see our landfill equipment in action, most will likely be surprised to learn how our landfill was constructed to help protect the environment.

In 1991 and 1992, state of the art ideas and best practices were incorporated into the careful design and construction of the Halton Waste Management Site.

The site’s buildings were all designed to blend into the rural landscape by resembling barns and farm-style outbuildings. The metal roofs of the three largest buildings were designed to collect rain or snow melt. A 50,000 litre grey water storage tank was installed on site to keep this free source of water ready for use on the Site for washing of equipment or watering of plants and trees.

The main roads on the site were paved in 1992 with asphalt that contained rubber particles from over 35,000 shredded scrap tires.  That original 4 km of road is still in fairly great shape today after 20 years of service, half of which receives heavy truck traffic six days a week. In the weight of garbage alone, that’s over 1.8-million tonnes of road pounding abuse, and counting! The rubber particles mixed into the asphalt built some permanent flexibility into the roadway surface that has paid off in longer life.

The hydraulic trap

The landfill liner system was designed with an innovative hydraulic trap design that is  state-of-the-art. The lowest part of the clay liner is constructed so that it sits in the ground as though it was sunk just below the natural level of the local water table. This makes it so that the groundwater applies upward pressure on the liner’s bottom at all times. Because of this unique concept, if the clay liner holding all of the garbage were to form a crack or crevice, clean ground water would leak into the landfill (like fresh sea water filling into an empty boat hull) before any dirty water (called leachate) could ever leak out. This keeps the environment clean and free from contamination.  In 20 years of operation, we have never had a leak!

Besides being nearly at the geographical centre of Halton Region, the natural properties of the site were also desirable because of what lies beneath. It is not an accident that a re-mouldable “blue clay” is in great supply right at the same location where it is needed. The core of the landfill liner is watertight because it is made of this particular type of clay that is highly impermeable (meaning not much can get through it).

The so-called ‘blue clay’ is not actually blue in colour, but when it is compared to typical reddish-orange coloured clay it has a tone that appears more bluish-gray to the eye. The amount of liquid that can pass through this Plasticine-like material is very small, especially when it is kneaded together in thin layers and built up to one final thick layer.

The clay layer is just one of many layers that make up the landfill liner.

When we expand the landfill footprint in stages, we dig down through the more ordinary reddish coloured clay, stockpiling it for later use as daily, interim and final waste cover, just to find this special blue clay to make our landfill liners from.

If you want to know more about how the different sections of the landfill liner are constructed, check out our video about Landfill Construction.

We’re very proud of the Halton Waste Management Site and its many features that help protect our air, water and soil.  We can’t wait to tell you more at our 20^th anniversary celebration!