Denver planners have been gathering with residents to design the city’s first new big green space in more than a decade — 80 acres of park and natural land around Heron Pond near the South Platte River, including a pollinator garden, artwork and nods to working-class history.

But this is industrial wasteland. The 2-foot-deep pond holds toxic sludge laced with lead, arsenic and cadmium. Contaminated stormwater runoff from surrounding work yards worsens the brew.

And even though low-income north Denver residents say they are practically starved for nature in the city, a festering sense of injustice rankles the deal.