Skip to main content

This tanker truck is carrying corn syrup in Decatur, Ill.Seth Perlman/The Associated Press

Take a minute to savour that piece of chocolate. Before reaching your lips, it may have travelled a long journey, from the trees where cocoa is grown to a manufacturing plant, to a distribution centre, then to a grocery store and finally to you.

Ontario-based Prokleen Washing Services knows all about the journeys of food. The company, which has 50 employees, cleans 7,000-gallon cargo tanks that carry food across North America. On a given day, a tank might come in that recently carried syrup. Another might have carried flour, chocolate or barley.

For health reasons, it's crucial the trailers are cleaned properly. But environmental issues inevitably crop up during the process. That's why Prokleen recently revamped its operations to better clean tanks, be kind to the environment and save money, too.

It pays to do the right thing. The changes are saving Prokleen $675,000 a year.

The company's green transformation began when its two Ontario plants - one in Oakville and another in Concord - underwent pollution prevention assessments, funded partly by subsidies arranged through the non-profit Ontario Centre for Environmental Technology Advancement. The assessments were carried out by environmental consulting firm Enviro-Stewards Inc., which made suggestions for greening Prokleen.

Before the changes, both Prokleen plants faced the same environmental - and financial - problem. Trailers are supposed to arrive at the cleaning company empty, but sometimes there is a bit, or much more than a bit, of food left in the tanks. In the past, food waste was sent down the drain. But that was pricey.

Here's why: Sending food residue into waterways can be an environmental hazard, says Enviro-Stewards' president, Bruce Taylor.

If sugar is dumped into a river, Mr. Taylor says, "natural bacteria is going to eat that. However, as they do, they're going to use the oxygen from the river, and there is only 10 milligrams per litre of oxygen in a river to start with. So if I put more than 10 milligrams per litre of [sugar]in there, there is no oxygen left for the fish to breathe."

That's why water with organic waste is sent to water treatment plants, where organic waste is removed. It costs governmental regions money to clean the water, so they set limits on how much food waste companies can send to the sewer. Companies that exceed those limits are charged. Prokleen's Concord plant faced a whopping $18,000-a-month surcharge.

Thanks to Enviro-Stewards, Prokleen installed two new systems in its plants. Now the typically small amounts of food waste that wash off during a cleaning session are sent to a tank and treated before being released into the sewer.

Each Prokleen plant also has been equipped with a system to store larger quantities of leftover food waste. One container stores sugars, another contains oils and a third, flours. Prokleen then tries to sell the collected waste. Finding buyers isn't hard, says Prokleen general manager John Corrigan. "Pig farmers use it to fatten their pigs," he says. Other buyers mix it into fertilizers, he adds.

Concord's food waste diversion system cost less than $10,000, but it saves the plant $69,000 a year. The Oakville plant sees even higher savings, $82,000 a year. "With pollution prevention, a lot of it is not necessarily very difficult," Enviro-Stewards' Mr. Taylor says. Small steps can bring big results.

Savings also came from boosting Prokleen's water efficiency. Prokleen cleans 13,000 cargo tanks a year. That takes a lot of water, especially because each tank is rinsed several times.

Prokleen is about to launch a pilot project in which water from the final rinse, which is basically clean, will be captured and reused in the first rinse of another trailer. Reusing final rinses reduces Prokleen's water consumption by about 12,400 tonnes per year, which could save the company nearly $25,000 a year.

Prokleen's plants have separate areas for washing tanks that carried chemicals. Previously, chemical waste from the trailers went into the same storage container as soap, sludge and wastewater. Because chemicals were mixed together, it was very expensive to dispose of, Mr. Corrigan says.

Thanks to Enviro-Stewards, Prokleen now separates chemicals into storage tanks. This not only makes for cheaper disposal - the system saves the company about $80,000 a year - it also allows Prokleen to search for opportunities to divert chemicals from disposal altogether. For example, asphalt collected in the Oakville plant is returned to the manufacturer. The asphalt recapturing system cost $2,500 and saves Prokleen $11,250 a year.

As part of its services, Prokleen washes small fittings of the cargo tanks that carry chemicals. In the past, staff in Oakville soaked the parts in a bucket of solvent. Now the plant has a double sink, which lets staff reuse solvent for about a week. The $500 sink cuts the amount of solvent the company needs to buy, which not only benefits the environment but saves Prokleen $4,000 a year.

Becoming eco-friendly improved Prokleen's bottom line. That's why Prokleen's Mr. Corrigan strongly encourages other small businesses to find ways to green their operations. "You don't have to be a chemist or an engineer to be able to carry out these projects," he says. "The help is out there. You've just got to ask for it."

Interact with The Globe