JACK HERRITY, who doubles as self-appointed Grand Warden of Lorton Reformatory when he's not doing Fairfax County business, had better watch out: he's got rivals in the prison- bashing department. Rep. Stan Parris is another Northern Virginia Republican with one eye on the next campaign for governor and one eye on the District of Columbia's inmate facility at Lorton. Along with Republican Sen. Paul Trible, Mr. Parris wants Congress and the White House to step in and take over the minute details of running Lorton -- from what to build where under which conditions to what to do with any prisoners left over. And all this from a congressman who says, "I voted for home rule."

Mr. Parris says the bill that he and Sen. Trible are proposing would specifically block the city's plans to build a new 400-inmate facility at Lorton. It also would contain provisions aimed at forcing the city to accelerate its selection of a site for a new prison. In addition, the legislation would call for the Justice Department to resume its agreement to imprison some of the city's inmates -- but would cancel any such agreement if the city did not submit to Congress a list of sites in the District for temporary prisons 10 days after enactment of this legislation.

There are a few more do's and don'ts for the city government. One provision would prohibit the District from increasing the number of inmates at any of Lorton's eight facilities above a set capacity. The bill would state, too, that the District would not be able to use early release or early parole of violent offenders to alleviate prison crowding.

About the only thing not yet specified in the Parris-Trible prison directive is what the city should serve Lorton's inmates for breakfast, lunch and dinner. This, presumably, will be covered in a substitute provision.

It is not that the District is running Lorton smoothly or that its plans for additional prison facilities in the District are proceeding in any orderly or even visible fashion. For that matter, the city government itself is reviewing a blistering report, submitted to its corrections department and other city officials, that says the department suffers from "chronic managerial ineptitude, political interference and official inaction." But if Mr. Parris, Mr. Trible or anybody else has problems with the city's corrections department, the place to go is City Hall -- where an elected mayor and council are responsible, if not always responsive.

The Justice Department has met with Mayor Barry to negotiate arrangements to alleviate prison overcrowding, and even Mr. Herrity has met with the mayor to discuss their differences on Lor- ton. This is the way it should be. There is no reason whatever for Congress to move clumsily and inapropriately into the affairs of the District's prison.