The Purple Line light rail project is being asked to “cease and desist” construction near a major water main in Maryland’s Prince George’s County.

The Washington Suburban Sanitary Commission said it has repeatedly told the Maryland Transit Administration that its construction of the Glenridge Rail Storage Yard in Hyattsville threatens a 66-inch water pipe and the state must relocate the pipe around the rail yard.

WSSC, one of the nation’s largest water and wastewater utilities, said the construction work threatens the pipe and water service to homes and businesses in southern Prince George’s County. WSSC maintains 5,573 miles of water mains in Prince George’s and Montgomery counties and provides water to 1.8 million residents.

“I am writing to demand that you cease unauthorized construction work at the Glenridge Rail Storage Yard until further notice,” wrote WSSC General Manager Carla Reid in a letter to MTA administrator Kevin Quinn.

WSSC said the pipe must be relocated around the rail yard because the utility needs immediate and unfettered access to the critical pipe.

“These water mains, especially a water main of this size, they’re under tremendous amounts of pressure, holding millions of gallons of water. So if something were to happen, if this main were to break it could be devastating,” said WSSC spokesman Chuck Brown.

The Maryland Transit Administration says it’s being responsive to the concerns raised by WSSC.

“MTA and our contractor were able to visit the field this morning and confirm with WSSC that we have not constructed anything atop their pipe and we’re working to address their other concerns to keep the Purple Line moving forward,” said MTA director of project delivery and finance Jeff Ensor.

Ensor said MTA is working through details now of helping to find a way to relocate the pipe around the rail yard.