As Metro Vancouver prepares to impose fines to stop the dumping of organic food waste in the garbage, officials at the regional district now worry too many residents and businesses will instead use garburators to send the problem down the drain.
As a result, Metro planners are now considering a ban on the installation of new food waste grinders by restaurants and other businesses, and they're mulling how to keep households from using garburators that are already widespread in newer homes.
Using in-sink disposals to grind up food and flush it down the drain is convenient for people and businesses who don't have organic waste pickup service or don't want to use it.
But Fred Nenninger, Metro director of liquid waste policy planning and analysis, said all those food particles increase the load on the region's sewage treatment plants.
More food waste in the sewage fosters more microbe activity and could potentially deplete oxygen in the effluent discharged to the Salish Sea.
Metro estimates 45 per cent of homes in the region now have garburators and there's no food scrap pickup yet at 63 per cent of apartments and condos across the region.
A continued trend towards more food grinding, coupled with expected population increases, could put Metro in violation of its sewage discharge permits from the Iona and Lions Gate plants that are still on primary-only treatment, Nenninger said.
Metro isn't proposing a residential ban on new garburators – it doesn't have the authority to impose one on households.
But Nenninger wants residents to know they're problematic and diversion of organics – either to backyard compost or to green bins – is a much better use of the material as a resource.
It's cheaper, too.
According to a staff report, the cost of processing food waste through the sewage system is $1,800 per tonne, compared to the $70 per tonne tipping fee for separated organic waste.
Food grinders are so far relatively uncommon as a disposal method in restaurants and supermarkets.
But the report warns increased use of them could cause big problems for the Metro treatment plants, as well as municipalities.
One anticipated problem is that a restaurant food grinder that mushes food bits up with fat and oil will make required grease traps much less effective, causing more oil and grease buildup in sewer lines.
Area cities already spend $2 million a year removing built-up grease from sewer pipes to keep them from backing up.
"If you're trying to grind ahead of grease traps you're going to have a real serious problem," Nenninger said.
He noted some commercial food grinding systems may be less problematic than others.
"There may be different options," Nenninger said. "We will work work with the commercial sector to look at the technologies available in determining what might have to be banned and what might be completely appropriate."
B.C. Restaurant and Foodservice Association president Ian Tostenson said he believes most restaurants will "do the right thing" and find ways to make organic food waste diversion work rather than resorting to more use of food grinders.
In a letter to Metro directors, manufacturer InSinkErator Canada argues the use of in-sink disposers significantly reduces garbage going to landfills, cuts the cost and emissions of trucking garbage or organics, and leaves no material sitting around to attract wildlife and vermin.
Organic waste disposal surcharges take effect in July
Haulers who arrive at Metro transfer stations with too much food waste in their garbage loads will be dinged with a surcharge starting in July.
A ban on organic waste disposal has been in place since the start of the year but actual enforcement through fines is now taking effect after a six-month education period.
Inspectors who already watch for loads with other banned recyclables such as electronic waste, cardboard or paper will now add a 50 per cent surcharge to the tipping fee of loads containing more than 25 per cent food material.
That threshold is expected to drive disposal costs up for mainly just the larger generators of food waste, such as supermarkets, restaurants and hotels that don't have an effective food scraps recycling system.
Metro expects to gradually reduce the tolerance threshold in future years so the surcharge hits more loads and spurs greater diversion of organics to green bins.
Although the Metro surcharges don't take effect until July, the regional district has been getting complaints for months from some residents and businesses who believe they've been wrongly charged.
Haulers have in some cases already begun charging customers who don't have organics recycling in place, or have added across-the-board fees to recover expected higher costs due to the Metro surcharges.
"If customers think they have been charged inappropriately, Metro Vancouver advises them to raise their concerns directly with their hauler," according to a Metro report.
It says early results of the organics dumping ban are encouraging – organics diverted were up 50 per cent in the first three months of 2015 compared to a year ago, following a 12 per cent increase to 300,000 tonnes in 2014.
Organics make up an estimated 40 per cent of the region's garbage that goes to landfills or the Burnaby incinerator.