House Democrats want to increase environmental spending, including a proposed $672 million boost for the EPA in fiscal 2020 that—if approved—would be the agency’s second-largest budget in its nearly 50-year history.

The draft fiscal 2020 bill unveiled by the House Appropriations panel on EPA and the Interior Department May 14, and slated for markup May 15, would also increase funding for drinking water and wastewater infrastructure and Superfund and brownfields cleanups....