March 14, 1982

THE lack of affordable housing on Long Island for moderate-income families has prompted officials in towns in both Nassau and Suffolk Counties to re-evaluate their local zoning and housing codes. At issue in many localities is the creation of special zones for apartment houses as well as the legalization of the now-widespread but prohibited practice of two families sharing a house designed for single-family occupancy. The scarcity of mortgage money as well as high interest rates on available mortgages has forced more middle-income families out of the buyers' market and into the rental market in recent years, making the existing housing shortage more acute, according to Dr. Lee Koppelman of the Nassau-Suffolk Regional Planning Board. Statistics provided by the Regional Planning Board place the average income of a Long Island household at $22,000. Mortgage rates from Long Island banks are now placed at 17 3/4 percent up to 19 percent plus points.

Not long ago a top adviser to President Reagan was outlining the gloomy situation the Administration faced in bolstering the Government of El Salvador. The picture included diminishing chances of a fair election March 28, increasing prospects of a military stalemate with the Salvador insurgents, and growing skepticism about the wisdom of Mr. Reagan's course. Asked what the Administration was doing in light of its pessimistic assessment, the adviser threw up his hands. ''We're reviewing the situation,'' he sighed. ''What does the Government always do? We're reviewing it. What would you do?'' The tone of exasperation seems pervasive these days. A year ago, White House officials recall sourly, Secretary of State Alexander M. Haig Jr. was assuring Mr. Reagan that the war in El Salvador could be ''won'' with some additional American aid. Today the President is being advised that the United States faces a ''long haul'' there - perhaps five or six years. Whether Congress, the people or America's allies can accept a longterm commitment to El Salvador remains an open question, particularly in light of the sputtering attempts last week to launch an information campaign about the threat perceived in Central America. It is also unclear whether the public is prepared to support covert activities there by the Central Intelligence Agency, which was said to have been planning the financing, organizing and supplying of arms for paramilitary operations aimed at disrupting Cuban arms deliveries to El Salvador and elsewhere.

THE fate of the $135 million Hempstead Resource Recovery plant, which has been idle for the last two years, may be decided in the next few months despite the continuing debate about its viability as a solution to Hempstead Town's garbage-disposal problem. Several recent developments involving the plant -where incineration was halted in March 1980 during a contract dispute that pitted town officials against the plant's private owner and operator, Parsons & Whittemore Inc, - have suggested that a framework is emerging in which some issues can be resolved and the facility put back in operation. These include the following: - The consensus of the town advisory comittee on solid waste disposal that the plant should be reopened for another round of emissions tests. It arrived at this conclusion after it was unable to find any alternative methods of dealing with the town's garbage problems.

Often overshadowed by fundamentalism and shunned by church liberals, the mainstream of evangelical Christians has emerged as the most powerful new force in American Protestantism. These evangelicals, mostly moderate in theology and politics, have been growing in numbers for years. But now they are strengthening their own institutions and making deep inroads in the 50-year-old liberal leadership of the major Protestant denominations. The signs of evangelical vitality are seen in the robustness of student movements, in the enthusiasm of lay people and in the clergy, which is well-equipped by education and outlook to bring the historic tenets of the Protestant faith to bear on 20th-century problems. Another sign is a recent decision by the Harvard Divinity School, a pillar of Protestant liberalism, to establish a chair in evangelical studies. Other old-line seminaries are expanding in similar ways. The influence of leading evangelical publications has expanded and a large network of professional, educational and lay groups amplifies the evangelical voice.

TRENTON GOVERNOR KEAN will not formally present his first budget message to the Legislature until tomorrow. However, key elements of the $6.37 billion document were released by his top aides in two briefings last week, and Democrats in both the Senate and Assembly are already howling that homeowners will be gouged on their property taxes so that business taxes can be cut. Objections voiced by the Democrats showed little of the bipartisanship spirit that Mr. Kean appealed for in his inaugural address in January. Their complaints about some of the budget's key philosophical underpinnings -cutting state aid to municipalities to help offset reductions in business taxes and a big $729.4 million deficit -were so intense that the Governor's aides retorted that the budget was ''not written in stone.'' They invited the Democrats to offer alternative plans, but none was immediately forthcoming. After all, the entire budget was not released from the printer until Friday night, and none of the Democrats controlling both houses of the Legislature has studied it in detail.