The City of Vancouver -- and all of us citizens -- have a liability to overcome in our pursuit to be the world's Greenest City.
Each year we send nearly a half-million tonnes of mixed garbage to our City-owned landfill in Delta, a practice that produces the potent GHG methane.
To address this vulnerability, the City installed pipes to capture the gas in 1991. The captured gas was "flared" -- burned in an open flame -- so that it emitted CO2 rather than CH4. Then in 2002 the City signed a 20 year agreement with Maxim Power to use the captured gas to produce electricity. The City receives revenues of $200 - 300 thousand per year to offset the cost of maintaining the system. The captured gas produces enough energy each year to power 6,000 homes. (see the
2009 Vancouver Landfill Annual Report and this
Solid Waste page from the City's Sustainability website.)
The bad news is the gas that escapes.
Two reports this week call for a policy of
methane prevention, rather than end-of-pipe approaches.
The Environmental Commissioner of Ontario's
Annual Greenhouse Gas Progress Report slammed the landfill-gas-to-energy concept in an interview, saying that "landfills are inherently leaky" and that the "process of using landfills as digesters is faulty."
Also
in the news this week is a report released by North Carolina State University that points to contradictory policies that encourage landfilling of biodegradable materials that break down
before the gas capture systems are in place.
Twenty years into effort to control the emission of methane from the Vancouver landfill, we still have no way to measure the amount of gas that escapes. Furthermore, the City report admits that fully one-third of the gas that is captured is not put to "beneficial use" to produce electricity, but simply flared.
In his report looking at the full spectrum of GHG emissions, Gord Miller advised his province:
"Given methane's significantly higher short term global warming potential, the prevention of fugitive methane emissions from landfills should become a near-term priority."In January 2010, a
report by the Sierra Club called for a shift to methane prevention -- and also pointed to other harmful pollutants in landfill gas.
Zero Waste Vancouver will be pitching in to help the City get more folks composting in their backyards this summer....