Virtually every major environmental group in the state is urging Gov. Martin O'Malley to veto a bill that would classify waste-to-energy incinerators as a "Tier 1" renewable resource, on par with wind and solar power, but the governor has yet to commit to either signing or rejecting it. On the surface, it sounds absurd that burning trash would be considered on the same level with truly nonpolluting energy sources, but the question becomes more complicated when considered in the broad context of waste disposal and energy policies. Dumping trash in landfills isn't good for the environment either, proponents of the bill point out.

The reason the governor is having a hard time with this issue is that it's being framed by one side as a question of whether burning trash is what the state had in mind when it set ambitious goals for renewable energy (clearly not) and by the other side as a question of whether it's better for the environment to dump trash in landfills or to convert it into energy (which is complicated). But these are not questions the governor needs to answer in order to make his decision. There are much simpler problems with the bill that are sufficient to justify a veto.

Proponents of the bill argue that increasing the amount of energy produced by incineration would have a net benefit for the environment in terms of greenhouse gas emissions and other pollutants. Although burning trash does release carbon dioxide into the atmosphere, it prevents the release of methane from landfills, and methane is a much more potent greenhouse gas. It also replaces the need to generate electricity from coal or natural gas-fired power plants and extends the life of landfills. Maryland now gets about 2 percent of its electricity from waste-to-energy facilities and diverts about 17 percent of its trash to incinerators.

Environmental groups say we should not be increasing incentives for incineration, which — as they quite correctly point out — is not as clean as true renewables such as wind and solar power. Much of the trash that would be burned could instead be recycled or composted, and the problem of methane emissions from landfills is greatly mitigated by the use of modern landfilling techniques. Moreover, incineration produces other pollutants, the toxic effects of which are unclear.

The governor is being asked to pick a side in this debate, but that isn't necessary. There are sufficient grounds for a veto because the bill would provide incentives not just for new waste-to-energy facilities but also for existing ones. Essentially, the legislation would cause utilities (and thus, effectively, consumers) to subsidize waste-to-energy plants for doing what they're already doing. That benefits no one except the local governments that own the plants.

Here's how it works: Maryland has a goal to get a certain percentage of its total electric load from renewable sources — this year it's 8 percent, escalating to 22 percent by 2022. Tier 1 renewable resources such as wind power must account for 5 percent this year, and Tier 2 (which includes existing waste-to-energy plants but not new ones) must account for 2.5 percent. (The remaining half-percent is for solar power.) Utilities must either procure the specified percentage of their loads from renewable sources or buy "renewable energy credits" to make up the difference. Ultimately, those costs get passed on to electric consumers.

Tier 1 credits cost significantly more than Tier 2 credits, so much so that a Montgomery County-owned incinerator could see its take from the sale of credits increase by more than 50 percent if this bill becomes law. The same would presumably be true of the state's two other incinerators, in Baltimore and Sparrows Point.

At least two other incinerator projects are in the works in Maryland (one of which would be privately owned and operated), and this bill is not the deciding factor in whether they come online. But relatively high prices for Tier 1 renewable credits could make the difference in whether other projects, such as wind farms, get built because they help guarantee investors would get a sufficient return. That's similar to the theory behind Governor O'Malley's failed wind bill this year, which would have forced the Public Service Commission to require that power companies enter into long-term contracts for wind energy. Including incinerators as Tier 1 renewable resources would dilute the value of the credits and, effectively, push energy policy in the opposite direction of the wind bill.

The proponents of the legislation are right to point out the problems with landfills — both in terms of methane emissions and in the sustainability of continuing to store so much trash in them. But this bill is not about landfills, it is about increasing subsidies for an environmentally ambiguous activity that would have occurred anyway, while at the same time reducing the incentives to create other, cleaner power sources. If the governor wants to provide incentives for additional waste-to-energy plants, he should back legislation allowing new incinerators to qualify for Tier 2 credits. But this bill, he should veto.