March 1, 1981

WASHINGTON FOUR times she proposed, only to be left at the altar. But now, after her fifth proposal in as many years, the new man in the White House has accepted, pledging: ''I will.'' All this has to do with Representative Millicent Fenwick's perenially popular proposal to scuttle the so-called ''tax on marriage,'' the tax provisions that discriminate against millions of married couples when both husband and wife have earned incomes. A prime example offered by Mrs. Fenwick is that of the husband with a modest income of $10,000 whose wife, to help make ends meet, gets a similar $10,000 job. Their income doubles, but their income-tax bill quadruples.

EXCEPT for the chilly weather, it seemed like a Fourth of July parade. The Weber High School band, decked out in red, white and black, struck up the tune ''God Bless America'' as the color guard of the First National Bank of Chicago stood rigidly at attention. But the crowd that gathered last week in a parking lot on a commercial strip on this city's northwest side had come for a new kind of patriotic celebration - a salute to free enterprise. Polk Brothers, a furniture chain based here, had invited the crowd to witness the unveiling of a billboard reading ''Let's Rebuild, America in the 80's.'' That message will appear on 200 similar billboards that Polk will set up across the country as part of a drive by the Chamber of Commerce of the United States to garner grass-roots support for President Reagan's economic plan.

Governor Carey today offered a package of 22 bills to reduce state regulation of business, including a proposal to aid the development of electronic branch banking in the state. The bills also seek to eliminate duplicative regulations, reduce the number of environmental permits required of businesses and deregulate parts of the state's trucking and bus industries. They were designed, Mr. Carey said, ''to stimulate economic development and foster renewed entrepreneurial spirit.'' Richard J. Roth, spokesman for the Senate Republican majority leader, Warren M. Anderson of Binghamton, said he could not assess the proposals' chances of passage until he had studied them. But he added, ''The concept of deregulation is certainly one that Senate Republicans can accept and that we've been trying to do in various ways.''

PORT WASHINGTON POTENTIALLY dangerous concentrations of methane gas have been found in homes near the North Hempstead Town landfill here, and while the discovery has left homeowners worrying that methane explosions could set their homes on fire whenever it rains, town officials have proposed a long-term solution that would allow the landfill to be phased out. That proposal - a $50 million garbage-recycling plant constructed by the Power Authority of New York - would not solve the immediate problem of the methane. But town officials are counting on 40 special vents that they began drilling at the edge of the landfill last week to reduce levels of the odorless gas found in homes nearby. As local fire marshals and county health inspectors continued their daily checks for methane, officials began a detailed review of the recycling-plant proposal. The basic plan raised questions about the reliability of the technology involved and the timing of the announcement, which caught assemblymen and area officials by surprise.

KILLINGLY FROM the magnificent New England country estates of Pomfret to Killingly's century-old brick Town Hall, evidence abounds of the wealth and style that the textile industry brought to northeastern Connecticut in the 1800's. But for most of this century, since the textile companies moved south and a 1955 flood destroyed much of the remaining industry, the 10 towns from Canterbury to Thompson have been an economic backwater. While there are signs that the economic pace is now quickening, the area remains vulnerable. ''We've been faced with high unemployment, low income, and a low education level in the area'' since the textile industry collapsed before World War II, said Thomas Dwyer, Town Manager of Killingly. The economic statistics are grim for the Danielson area, which comprises the towns of Thompson, Putnam, Killingly, Sterling, Plainfield, Canterbury, Brooklyn, Pomfret, Eastford and Woodstock. Manufacturing employment accounts for 48 percent of the jobs, as against 30 percent for the state as a whole, and is concentrated in low-wage rubber, plastics, and textile factories.