Hundreds of people flocked to the Maryland Department of the Environment yesterday, but not for the usual reasons.

Instead of applying for permits or responding to pollution violation notices, they were there for a more upbeat reason - to promote and learn about new ways to control pollution washing off city and suburban streets and parking lots.

More than 360 people registered for the department's first-ever "Clean Water Innovations Trade Show." Three dozen exhibitors were on hand to tout everything from green roofs and floating wetlands to the latest in storm-drain retrofits.

State Environment Secretary Robert M. Summers said the expo grew out of a forum on sustainability held by Gov. Martin O'Malley earlier this year. The state is applying new storm-water pollution control regulations on all new construction and redevelopment, and is beginning to require better controls in existing communities as well.

Summers asserted in remarks to the assembled vendors, local officials and others that the state is a leader in sustainable growth, in less-polluting development techniques and the green economy. But he also acknowledged "a lot of challenges going forward," including regulatory and technical hurdles.

The latter point was seconded by Erik Dalski of Highview Creations, which has installed green roofs in New York and Boston and is branching into Maryland and the Washington area now. One of the company's more interesting projects in these parts is a green roof planned for a new barn near Annapolis.

Dalski said there seems to be "a lot of red tape" here governing green infrastructure, and local officials he's met with still seem hesitant to try new things like green roofs.

Summers suggested such red-tape complaints ought to ease under a recent initiative announced by O'Malley to streamline regulations and "fast-track" permitting.

(Barry Chenkin, founder of Aquabarrel, discusses his products at Clean Water Innovations Trade Show at MDE headquarters. Photo by Jay Apperson, MDE's Office of Communications)