On May 17, a Trump administration-created group called Freedom 250 held a prayer and celebration event on the National Mall. Generators used at the event leaked more than 30 gallons of fuel into underground cisterns that collect rainwater to irrigate the Mall's grass.

Four cisterns — holding up to 250,000 gallons each — sit beneath the National Mall. Cleanup crews and environmental remediation vehicles were spotted on the Mall days later.

The responsibility for what happens on the National Mall during a permitted event falls squarely on the permit holder.

National Park Service guidelines are clear: commercial liability insurance is required for events of this size, and the permit holder is typically held liable for environmental cleanup after a spill. It is currently unclear whether Freedom 250 or its event organizer, Event Strategies Inc., will be held responsible for the cleanup costs — or whether taxpayers will foot the bill instead.

The National Mall belongs to the American people. A fuel spill of this magnitude — on top of the damage already being done by a packed calendar of high-traffic events — threatens the health of the grass and grounds that millions of visitors enjoy every year.

We're calling on the National Park Service to hold Freedom 250 and Event Strategies Inc. fully liable for the cleanup costs and ensure this never happens again.