Doing battle with contamination? Peel Region just completed a study on gravity locks you need to read!

In Peel Region, gravity locks were installed on a few Front End Loading (FEL) bins at Multi Residential (MR) buildings where the buildings did not use chutes for recycling as a means to control contamination and improve material quality.

Okay, so what do gravity locks have to do with contamination?

Gravity locks deter MR residents from placing large contaminants in the bins. Bagged materials, both garbage bags and small grocery bags, make up a significant part of the contamination category in Peel Region’s program.

The goal was to prevent residents from lifting lids and dropping in the bagged materials. The hope was that the locked lids would redirect residents to use the openings on the front face of the bin which were sized to receive only accepted materials, thus lowering contamination levels.

Wait, so what is a gravity lock?

Peel Staff  answers that question in this guided video walk through.

Reducing contamination levels

In Peel, the average contamination level in recycling in FEL containers is 33%, compared to MR cart-based recycling which is 27%. The added weight of contaminated material increases costs for the collection of recycling material and makes recovering and marketing quality material more difficult.

Gravity locks eliminate the need for building superintendents to unlock the bins for collection and to relock them after collection. The mechanism automatically unlatches when the container is tipped during the collection process and re-latches once the bin is returned to the ground. The gravity lock can still be unlocked by superintendents to gain access, if needed, by using a padlock and key. This makes it more convenient for superintendents to comply with the Region of Peel’s Waste Collection By-Law, which requires front-end recycling containers to be locked the between collections.

This project

The Region targeted 11 MR buildings having a total of 17 FEL bins, to study the impact of gravity locks on reducing contamination. The goal was to see if the savings in collection and processing merited installing the gravity locks on all 382 MR buildings that do not have chutes and use FEL bins to collect recycling.

Pairing gravity locks with education as well as by-law enforcement is key

The project also examined if reducing the amount of litter left on the ground around FEL recycling bins would encourage superintendents to keep the bins locked. When residents could not open the lids, they would often drop the items on the ground beside the bin, leaving them for superintendents to deal with.  This often deterred superintendents from locking their FEL recycling bins.

Therefore, another critical aspect of this project was to make residents and building staff aware of the problem and proper set out expectations, aiming to correct this issue and increase superintendent participation.

The total reduction in contamination: 34.75% down to 29.00%!

The table below shows the gravity lock pre and post audit results as displayed in weights and percentage.

The audit results were further supported by the visual inspections completed after the gravity lock installation; the recycling material appeared less contaminated. Furthermore, the initial site inspections within the first few weeks indicated that the superintendents were working well with the gravity locks. In the baseline inspections, 71% of the FEL containers were not locked prior between collections.  Once the gravity locks were installed only 12% of bins were found unlocked.

In Peel Region, the projected full-scale implementation cost for 382 bins is $296,951.00  and the payback period would take approximately 16 years based on collection cost savings alone.

For many more insightful findings, please view Peel’s report: Gravity Locks Contamination Abatement Study for Front-End Recycling Containers used at Multi Residential Building Sites. If you’re interested in more tech reviews and video blogs on the subject, please reach out to Jessica Landry with your requests.