MAKING BANKS and S&Ls safer is a crucial responsibility now before Congress, as urgent as any it faces. The House voted this week to give federal regulators the power to raise deposit insurance premiums as high as necessary to fund the insurance system adequately. The legislation is likely to shoot rapidly through the Senate. But by itself it's not a solution. Extremely high premiums could kill banks that might otherwise survive.

There are two routes to the goal that Congress is pursuing. One leads through reform of the deposit insurance system, and that -- understandably -- is where most of the attention is focused at the moment. It was the bankruptcy of the S&L deposit insurance system that has thrown the gigantic costs of the cleanup directly onto the taxpayers, and nobody wants to see that disaster repeated in the banks' insurance fund.

But there's another possibility -- to raise the requirements for banks' and S&Ls' capital and to improve the enforcement of those requirements. That gets at the same dangers in another and perhaps better way. It was because the regulators let those failing S&Ls run without any capital that their losses wiped out the federal deposit insurance cushion.

The defect in the present system is that it does not discriminate between well-run banks and those that take big risks with the depositors' money. Congress is considering a number of ingenious proposals to ensure that federal deposit insurance will work like private insurance, raising the premiums in proportion to risk.

But risk is already recognized in the rules for capital -- the amount of their own money that the owners of a bank or an S&L are required to keep invested in the business. Risk-based capital requirements will begin to go into effect at the end of this year, setting a relatively low requirement of capital for each dollar invested in very safe loans and progressively higher amounts for the less certain kinds of lending. There's now a growing consensus in favor of raising these requirements. As Alan Greenspan, the chairman of the Federal Reserve Board, pointed out last week, that will require the people who run banks to meet the test of the private financial markets as well as government regulation. Banks that are run badly or that take high risks are going to have trouble raising capital.

Reform of deposit insurance is going to be necessary, but it's not sufficient. The most substantial protection of the public and its money lies in ensuring that banks always run with a lot of their stockholders' money at stake.