While many legislators and most reporters have been singing the blues about how uneventful the 1985 General Assembly session is, nearly all private industry lobbyists have been humming "Pennies From Heaven."

A sudden rush of legislation affecting a number of Maryland special interests is turning the 1985 session into what promises to be the most lucrative 90 days in state history for the band of lobbyists that flock to the annual gravy train.

Compared with last year, when much of the legislature's attention was on public policy issues such as the budget and state employe pensions -- issues that lined no one's pocket -- the assembly this year is faced with an array of purely economic questions that are fattening wallets throughout Annapolis.

Take the phosphate ban, for example. The legislation that would prohibit most uses of detergents containing phosphates has been dubbed "the lobbyists full employment act of 1985." And for good reason.

More than a half dozen lobbyists representing detergent manufacturers, chemical companies, and soap associations are working that one bill. Their billable hours took a quantum leap when the legislation passed the state Senate by a surprisingly healthy margin.

Other issues dear to the lobbyists' hearts include:

* A proposal to build a coal-slurry pipeline across Maryland, which pits two groups with deep pockets against each other -- the electric utilities and the railroads. The utilities' sudden decision to press for the legislation midway through the session started hearts a-thumping throughout the state capital.

* The governor's health care package, which brought out lobbyists for every group imaginable connected with the medical care industry. Not only was the Maryland Hospital Association well-represented, but some of its individual member hospitals even recruited lobbyists of their own.

* A plan by Gov. Harry Hughes to give Citicorp a leg up on interstate banking, in exchange for taking over the former Fairchild plant in Hagerstown and creating 1,000 new jobs. That late entry suddenly made it an interesting session for banking industry lobbyists.

"This has been my busiest session," said Franklin Goldstein, who counts railroads, Procter and Gamble and Citicorp among his clients. "My wife is complaining more because I'm staying overnight more."

"I didn't think I'd ever do better than last year," added Goldstein, who made about $175,000 for three months work during 1984, placing him "a poor third" among state lobbyists in terms of total income.

Bruce Bereano, who last year topped all lobbyists by making almost $250,000, expects to do even better this year. His 39 clients take up five pages in the lobbyists directory put out by the state Ethics Commission, and includes everything from health care providers to tobacco interests, from Rosecroft Raceway to the Progress Club.

"Incompetence elevated to an art form," sniffed one of Bereano's rivals in the trade who does not think much of such wholesale lobbying.

One factor that is boosting many incomes this year is a new trend toward industries hiring multiple lobbyists to work the same issue.

"It seems like when an issue gets in trouble, clients are hiring additional lobbyists," said one Senate committee chairman.

Thus, Procter and Gamble hired Goldstein and Ira Cooke about two weeks ago, even though the soap and detergent association was already well-represented.

Despite that, not everyone is having a banner year. Consider poor James Doyle Jr. He got shut out of coal slurry because he represents both Pepco and the Western Maryland Railway, two industries fighting tooth and nail on that issue.

"I've been kind of neutered by conflicts," Doyle said.

For years Annapolis' leading lobbyist, Doyle predicts that he will have an "average" year in 1985. Lest we feel too sorry for Doyle, an average year means more than $200,000.

As Bereano said: "It's been a very enjoyable, productive session."