What was going on when I was born?

New York City hopes to open part of its new sewage treatment plant on the Upper West Side a year ahead of schedule but to abandon construction of some or all of the rest, reducing the treatment of matter going into the Hudson River. City officials said yesterday that under a revised agreement being negotiated with the Reagan Administration, the first section of the plant could open by June 1986 and remove 25 to 35 percent of the biological matter from the sewage. The plant was originally designed to remove 85 percent. The city is hoping to abandon its plans to build more than the first section to save an estimated $250 million. The plant will serve the West Side of Manhattan. Untreated sewage from this area is now pouring into the river at the rate of 150 million gallons a day. The city says the reduction in treatment would not be enough to harm the river, but some environmental groups said yesterday that they would oppose scaling back the plant.

The nation's unemployment rate remained unchanged at 9.8 percent in August, the Labor Department reported today. The rate is the highest since 1941, and 10,805,000 people are out of work. Although the rate did not rise from the July level, the figures released today leave open the question whether the economy is recovering from its second recession in three years or whether the rate has reached its peak. ''I think it's a relief it did not go up, but it's not entirely good news and we may have a few more increases,'' said Sandra Shaber, an economist with Chase Econometrics, an economic consulting company. ''We could still get to 10 percent.''

A Federal appeals court yesterday upheld the convictions of four former Congressmen who took payoffs from undercover agents in the Justice Department's two-year Abscam investigation. The unanimous ruling in Manhattan by a three-judge panel of the United States Court of Appeals for the Second Circuit was the first by a Federal appellate court involving any of the seven former members of Congress convicted in the investigation into political corruption. Two previous appeals court rulings upheld the convictions of two Philadelphia City Council members and a Federal immigration investigator. 'Jumping at Chance to Take Bribe' In affirming the jury verdicts against the four Congressmen, along with three co-defendants, the panel declared: ''The evidence shows four Congressmen jumping at the chance to take a bribe and discussing investments in their districts as a convenient cover to justify their rendering of purchased legislative services.''

Gen. Carlo Alberto Dalla Chiesa, one of Italy's highest ranking police officials, was assassinated by gunmen tonight in the center of Palermo, Sicily. His wife and a police escort were also slain. General Dalla Chiesa of the Carabinieri, the national police force under military command, had been named to the political post of prefect of Palermo only last May 1. His assignment was to take charge of the fight against the Sicilian Mafia, which has turned Palermo into a major center of the heroin trade with Europe and the United States.

Shimon Peres, the leader of Israel's Labor Party opposition, said today that his party would open a major national debate in Israel over President Reagan's plan for Palestinian self-rule in the occupied West Bank and Gaza Strip. The proposals, angrily rejected on Thursday by the Government of Prime Minister Menachem Begin, are similar to those that the Labor Party has been advocating for some time. Meeting reporters in his office here, Mr. Peres, who has twice lost to Mr. Begin in bids to become Prime Minister, said the Labor Party would put the case before a special session of Parliament next week. He indicated the party would not propose a vote of no-confidence on the issue because there was little likelihood of its winning. He said that the session had been called ''to make the public aware of different reactions to the American declaration.''

Buyers poured into the stock market yesterday and sent the Dow Jones industrial average to its highest level in more than a year. Trading volume on the New York Stock Exchange, fed by buying demand from pension funds, individuals and foreign investors, was the third largest on record at 130.9 million shares. The Dow industrials, extending recent extraordinary gains, rose 15.73 points, to 925.13. At 1 P.M., with the Anxiety about Latin America put the New York price of gold at its highest level in almost a year. Page 33. stock tape running 15 minutes late, the index, the market's most popular average, was ahead almost 24 points.

In actions aimed at guaranteeing voting rights for blacks, the Department of Justice announced today that it would assign Federal observers to monitor Tuesday's primary elections in nine Alabama counties and send special examiners to register black voters in two Georgia counties. The Department said 461 observers would go to Alabama to monitor activities within polling places, allowing the department ''to determine whether minorities are able to vote without interference.'' First Use of Examiners in 7 Years The examiners assigned to Georgia will ''assure that blacks there have reasonable opportunity to vote'' by improving registration procedures, the department's statement said. Examiners were last used seven years ago in Mississippi.

The following article was altered by Israeli military censorship. WITH THE ISRAELI ARMY in the Bekaa Valley, Lebanon, Sept. 2 - The Israeli Army is deployed in significant strength across the width of Lebanon, ready for war or peace. Israeli tanks, long-range artillery and infantry face the Syrian Army along a cease-fire line that begins 15 miles east of Beirut and sweeps for about 45 miles southeast to within a few miles of the Syrian border. Israeli 175-millimeter guns are within shelling distance of Damascus.

The Soviet Union has cut automatic telephone links with Western Europe, citing a reorganization of its internal telephone network and unspecified technical grounds for the move. Official reports from eight West European countries, from Finland in the north to France in the south, said the only way to telephone the Soviet Union was via an operator calling the central Moscow switchboard. On July 15 the Soviet Government abolished direct-dialing from the Soviet Union to the West.

More than 10,000 journalists went on a 24-hour strike today, shutting India's newspapers and broadcasting stations, to protest a proposed law that would authorize the jailing of those who published ''scurrilous'' articles. ''The strike is total,'' said the Indian Federation of Working Journalists, which organized the walkout.

Uganda's Parliament passed a bill that would return to Uganda's Asians the property that was seized by the dictator Idi Amin 10 years ago, Uganda Radio said today. The bill was passed Thursday evening and goes to President Milton Obote for signature.

AROUND THE WORLD; Marcos Plans Visit To U.S. on Sept. 15 SANTA BARBARA, Calif., Sept. 3 (Reuters) - President Ferdinand E. Marcos of the Philippines will make a state visit to the United States, his first in 18 years, starting Sept. 15, the White House announced today. The visit, which was being announced simultaneously in Manila, will include talks with President Reagan on Sept. 16.