Their petition said that four gas-pipeline projects have been built since 2011 and that seven more were planned.
The commission, which oversees water quality and quantity in the basin, has concluded that its rules specifically exempt pipelines from commission review, with limited exceptions. One of those exceptions - involving a state forest - prompted a decision to review two pipelines that have been completed.
The protesters came to Wednesday's meeting hoping to persuade the commissioners - representatives of New Jersey, Pennsylvania, Delaware, New York state, and the federal government - to do more.
After more than 90 minutes of comment, the commissioners concluded their meeting as the protesters continued to chant and sing. Commission Chair Kelly Heffner, a water chief in the Pennsylvania Department of Environmental Protection, then said the board had 30 minutes in which to hear more comment, but the protesters refused.
Heffner later said, "It's a great system that lets people come and provide public input. The fact that they didn't take advantage of the last half-hour was their choice."
Delaware Riverkeeper Maya van Rossum said there was no point in commenting more when "we continue to have a situation where the commission . . . is simply not listening. We're fed up."
In a related action, State Sen. Andrew Dinniman (D., Chester) last month introduced three pipeline-oversight bills.
They would require the Department of Environmental Protection to ensure that residents were notified of proposed projects and to post public documents on its website. The bills, supported by three area Republican senators - John Rafferty Jr., Ted Erickson, and Charles McIlhinney - also would require pipeline operators to replace affected land under agriculture or conservation easements.
See a video from the meeting at www.philly.com/drbcprotest
Contact Sandy Bauers at 215-854-5147 or firstname.lastname@example.org, or follow on Twitter @sbauers. Read her blog, "GreenSpace," at www.philly.com/greenspace.