Litter Controll at Lethbridge Waste & Recycling Centre

This landfill is located in southern Alberta and is in an area that is subjected to frequent windy conditions.  The City has the distinction of being the 2nd most windiest City in Canada.   Because of historical issues with litter problems at the landfill, the City and the site operators have implemented a comprehensive litter management program.  This is a brief summary of that program. 

Prevent Litter From Customer Vehicles

A secure load policy has been implemented and a surcharge is applied for all loads that are not enclosed, covered with a tarp, or firmly secured.  The surcharge rate is $20/load for loads under 1 tonne, or $40/load for loads over 1 tonne.  

Haulers may also be subject to fines for transporting unsecured loads and causing litter along public highways.

Monitoring & Litter Collection

Regular monitoring is conducted and the site operators retrieve litter along roads, ditches, and nearby irrigation canals. Depending on the road, this retrieval occurs daily to weekly. 

Fence lines around the landfill are monitored and litter is retrieved to keep the site clean. 

Litter is collected from private property adjacent to the landfill site and along road ways with access permission from the land owner.  

Illegal Dumping

To prevent illegal dumping, the City offers a large item service to residents, and provides a free Saturday disposal program. The City conducts regular monitoring for illegal dumping and works with enforcement agencies. 

Litter Controls

A combination of techniques are used at the landfill to prevent litter from occurring and to prevent litter from escaping.  

Portable wind screen fences to shelter the working face and catch fences are used downwind to catch any blowing litter.  The working face is kept as small as possible to minimize exposure of waste to wind.  

An 8 meter tall 'primary' entrapment fence is placed at the edge of the landfill operations, and a 12 meter tall 'secondary' entrapment fence is placed downwind (east side) of the landfill. 

The landfill operations are closed when winds exceed limits set out under the Environmental Approval.  Walking floor transfer trailers are prohibited from unloading when wind gust exceed 60 km/hr, and all loads are prohibited when wind gusts exceed 70 km/hr. 

Transfer Station & Baler

To address the issues with collection systems because the landfill is shut down high wind conditions, the City has constructed a transfer station with a baler.  The waste bales are 'wrapped' and when placed at the landfill, they are not a source of blowing litter.  

Other Technologies

The City and the site operators continue to investigate other technologies to add to the existing litter controls.  For example, a trial for application of a spray on mulch alternative daily cover was used.  

Blowing in the Wind

It is quite intuitive to think that things that are lighter will be more prone to be wind blown than heavier objects.  Items less likely to be blown about if they are heavy, such as a large metal object, or that have a high moisture content like food waste, or  that have been compacted as in a compactor truck. 

We also have to think about surface area as well.  For example, a flat sheet of paper has a great surface area that easily becomes wind blown, yet if it is crumpled into a ball, it has a lower surface area and is less easily wind blown.   We are all aware of the problem with plastic bags being blown about.  Plastic bags are not only light and have a large surface area, but wind will blow into an open bag and carry them aloft.  

Studies carried out in the late 70's for the Crowsnest Pincher Creek Regional Landfill showed how far a variety of objects could be blown at different wind speeds.  The study was based on an object dropping about 1.5 M (as it would from an unloading collection vehicle), and that it would be blown away from the working face of the landfill.  

Wind Speed                    Objects

10 - 25 km/hr                    Envelopes, dry paper

25 - 30 km/hr                    Empty plastic bags

30 - 50 km/hr                    Corrugated cardboard sheets, crumpled paper towels

50 - 60 km/hr                    Plastic strips, empty tissue boxes, tightly crumpled paper

60 - 90 km/hr                    Milk cartons, cardboard boxes

over 90 km/hr                   Metal cans

The energy in the wind is cubically proportional to the wind speedThe strength of the wind should never be under estimated.  (E = v3).  If wind speed is doubled, the energy increases by 8 times (2 x 2 x 2 = 8).  Never under estimate the power in the wind.  In strong winds, large objects, as shown here, can be blown out of the active landfill working face.