EVER SINCE the massive discoveries of oil and gas on Alaska's North Slope nine years ago, a blazing row has been running over the ways to move it south. The oil pipeline is nearly finished and is to got into operation this summer. The gas pipeline is a more complex undertaking. Three routes are in competition; the hearing before the Federal Power Commission went on for six months, and the transcript goes on for 253 volumes. The country took a long step this week toward a decision - the right decision, in our view - when the FPC's administrative law judge, Nahum Litt, recommended the Arctic Gas proposal.

Next, the EPC itself has to make a recommendation to the President and, by December, the President has to make a recommendation to Congress. The stakes are enormous; the gas line is becoming the most heavily lobbied industrial decision of the decade.

The technical and economic factors heavily favor the Arctic Gas route. It chief environmental drawback is the necessity of running it across the Arctic National Wildlife Refuge on Alaska's northern rim. But the pipeline would take less than five square miles of teh refuge's 14,000 square miles, and most of that land would be right-of-way over the buried pipe. The damage to the ecology would not be fatally greater than that inflicted elsewhere by the alternative routes.

The Arctic Gas line also raises legitimate political questions. This country's relationships with Canada - and, for that matter, the Canadian government's relations with its own provinces - are not so certain as they once seemed. Much of the Arctic Gas route would be a partnership with Canadians, also carrying their gas down from the Mackenzie River delta. The project would run into difficult Canadian domestic issues, particularly where Indian land claims are involved. There is also a fear among some Americans that Canada might sometime use the pipeline as a hostage. All you can say there is that nobody can totally guarantee the future, but good faith has to count for something. Americans and Canadians already have vast economic interests in each other's country - and, incidentally, some of the key Canadian oil pipelines cross U.S. territory.

Both of the routes have serious defects. The El Paso Alaska Company proposes to liquefy the gas in southern Alaska and carry it in ships to California. Both the state of Alaska and teh maritime industry support it, and for the same bad reason - jobs. This project is too important to turn into make-work.The El Paso plan would also deliver the gas to the wrong part of the country. The North Central states need the gas, not the Southwest. A lot of the politics of the final decision will revolve around this regional interest. As for the third competitor, a route following the Alcan highway, it was a late comer and, Judge Litt found, the relatively small diameter of its pipe would make it grossly inefficient.

he scale of the project is staggering: more than 400 miles of pipe for either of the overland routes, a fleet of cryogenic tankers for El Paso's. There is a larger message here for citizens and consumers. The cost of the pipeline alone (over $7 billion) will make the Alaskan gas the most expensive domestic gas in the country, as it crosses into the lower 48 states. The moral of the story: As the country reaches farther for its fuel supplies - farther into the Arctic, farther into the seas, deeper into the earth - the price of that fuel will keep rising sharply.