D.C. voters had the chance to hear from six mayoral candidates on Friday night about their stances on environmental issues at a forum arranged by the city’s growing sustainability community and held not far from the Anacostia River.

Topics ranged from the culpability of coal power in the city to the merits of continuing a costly tunnel project that would reduce polluted runoff into the Anacostia and Potomac rivers. Of the candidates that participated, three currently serve on D.C.’s City Council — Councilmembers Jack Evans, Vincent Orange and Tommy Wells. Along with incumbent Mayor Vincent Gray, they came across as the most informed on environmental issues, especially those on which some of them had presented or debated bills.

D.C. Councilmember Muriel Bowser was invited but did not participate in the forum held in an unfinished former factory building that will soon be home to Ideaspace at the Navy Yard.

The event drew some 200 people on an evening when pleasant weather — and plenty of other issues to consider when voting for D.C.’s mayor — may have kept people away.

Ed and Carole Kaminski, who live in Southeast D.C., said they were eager to hear from the candidates on environmental topics on which they’ve kept informed as residents. But they weren’t sure how much those issues would weigh in other voters’ decisions.

“If you came here from other places, you don’t know about the problems,” Ed Kaminski said, noting the water quality issues in the city’s two rivers.

What was missing from the evening’s debate was any mention of the issue that has dominated discussions about the mayoral race: whether incumbent Mayor Gray knew about an illegal shadow campaign that helped raise funds for his last election and could get him indicted in federal court.

Early voting has already begun for D.C.’s April 1 Democratic primary, which functions as somewhat of a general election in the heavily Democratic city.

But D.C. voters are increasingly aware of environmental issues and how the new mayor’s stance on water quality, transportation and renewable energy could impact major decisions facing the city.

Evans, who as been on the council for 23 years, said cleaning up the two rivers will require a mayor who can work with neighboring Virginia and Maryland, which, he noted, is home to 82 percent of the Anacostia River that winds its way into D.C.

“We have to work with Maryland, because we can be as clean as we want and never achieve those goals. Virginia is very difficult. They wanted to do everything they could to pollute the air, because that’s the way they do things in Virginia,” Evans said.

Carlos Allen, a Mount Pleasant property manager and underdog mayoral candidate, chose to address environmental issues through the lens of economic inequality. He said D.C. residents must first have job security because when they are “in survival mode — they’re not going to care about the environment.”

Mayor Gray told the audience that he doesn’t have to say what he would do when it comes to the environment, “I can tell you what I’ve done.”

Gray’s comprehensive Sustainable DC initiative released more than a year ago lays out 143 “green” initiatives to be attained by 2032, including making the Anacostia River swimmable and fishable. Until recently, Gray served as chair of the Chesapeake Bay Program’s Executive Council  and has often touted the city’s leadership in green roofs or in LEED-certified buildings.

Councilman Orange said he would essentially “stay the course” of this sustainability plan for D.C. 

Councilman Wells seemed determined throughout the evening to come across as the most informed and aggressive candidate on environmental issues. He expressed a vision for a “LEED-certified city,” a certification that does not yet exist (though neighborhoods can be certified) but that Wells said describes how he views the District as “a holistic organism.”

“You can’t really compartmentalize these things,” he added.

Wells went on to say that, while he supports building green infrastructure in the city, he does not support changing the city’s consent order with the U.S. EPA to reduce or postpone its $1.6 billion tunnels project that’s currently underway. The huge underground tunnels are designed to store overflow from the city’s combined sewage and stormwater systems until it can be treated at Blue Plains Sewage Treatment Plant.

“We have to do every inch of that tunnel. The idea of delaying it at all and putting more sewage into the river is not what I support,” he said.

(None of the other candidates addressed this issue, and  Wells brought it up of his own volition. The decision will ultimately be made by  DC Water and the EPA.)

A question from the audience brought up another complex river issue in the District that tested the candidates’ knowledge. Brooke DeRenzis, a project director at DC Appleseed and Ward 1 resident, asked whether the candidates would ensure that toxic sediment in the Anacostia River is cleaned up in a timely manner. A newly formed coalition of environmental groups, spearheaded in part by former D.C. mayor Anthony Williams — who co-moderated the forum — is helping to make toxics cleanup a top priority in restoring the Anacostia River.

Evans answered the question by mentioning again that the District cannot clean up the river on its own, while Wells seemed to grasp the issue at greater depth and understand that the question was aimed at a component of the cleanup that falls squarely in D.C.’s lap.

“What you’re asking us to do is that we have to go through the sediment and we have to figure out what the toxics are and then identify who is responsible for getting them there… That’s going to be politically tough and you’ll need someone who’s not beholden to the corporations,” he said.

Later, in response to another question about toxics, Wells said, “We don’t have to wait for Maryland to go after these folks to pay for the cleanup of the river.”

The candidates seemed to mostly agree on a question about whether coal should be prohibited as a source of power in the District, though they differed on the timelines for implementing such a ban. The same was true for a proposed ban on polystyrene that is currently part of a broader bill in the District, which has already implemented a 5-cent plastic bag tax to help reduce pollution to the two rivers and generate funds for their cleanup.

And nearly all of them followed Evans’ lead to take issue with the presence of small plastic water bottles at the forum.

“I’m amazed these are sitting out here,” Evans said, holding up a plastic water bottle, one of many that were set out to keep the candidates hydrated. “Half the landfills in America are filled with these things. You want to get serious about the environment? Take on this industry.”