The Urban Mass Transportation Administration (UMTA) has invited the Metro board to seek $31,000 in UMTA money to study what to do with the rock and dirt Metro would take out of a tunnel that UMTA may not let Metro build.

The tunnel in question is the one that would connect Silver Spring with Glenmont by subway. To dig such a tunnel, material would have to be removed from the ground. Such material is called muck.

UMTA wants to do a "muck utilization study," the Metro board was told yesterday, to help it decide what to do with all that muck.

The proposed Glenmont tunnel apparently was regarded as ideal and UMTA asked Metro to apply for a 100 per cent federal grant to study muck. Since it doesn't cost Metro anything, and since everybody wants to get along with UMTA because it has control of federal construction dollars, Metro applied yesterday.

The problem is that another UMTA office, acting under the orders of the big boss. Transportation Secretary Brock Adams, has mandated a study of the Glenmont line to see if a cheaper way to build it can be found. UMTA has left the clear impression with area officials that if money cannot be saved, the line may never be built - at least with federal money.

Does UMTA's desire for a muck study in the Glenmont tunnel mean UMTA definitely is going to build the Glenmont tunnel?

"No," said Joseph Marshall, an UMTA spokesman.

The money, Marshall said, was in the fiscal 1977 budget and had to be obligated by Sept. 30 or be turned back to the Treasury.

"It's strictly a means of getting the money set aside," Marshall said. "If the Glenmont line is not built, we can shift the money somhe Glenmont line is not built, we can shift the money somewhere else."