The little creek off the Chesapeake Bay is showing its sad signs of spring. Pondweeds are popping up in the shallows close to shore, lonely clusters of life in the barren mud.

Folks around this area have seen the same thing for a decade and a half. "The grass lasts a few weeks, but it all dies off as soon as the water warms up," said an old-timer.

It's been that way since 1972 when, mysteriously, practically every strand of submerged aquatic grass in the Severn River keeled over dead. The story was similar up and down the Bay and its tributaries, particularly in waters close to Baltimore and Washington. The grasses, which once covered square miles of shallow bottom, disappeared and in most places never came back.

It's a big loss. Grass means health in a waterway, but it can't grow in murky water. It needs sunlight. The grasses poking up in the little creek here already are coated with brown slime. If you rinse them off, they are as green as emeralds. They look healthy then, but they're doomed.

And without grass, much of what makes the Chesapeake the richest estuary in North America is doomed. The grass harbors crabs, minnows, tiny shellfish, baby rockfish, grass shrimp and a thousand small things at the bottom of the food chain that feed the creatures at the top. The grass creates oxygen and filters silt, stabilizes muddy bottom and slows erosion by buffering the shore.

Why are the grasses gone?

Three years ago, the U.S. Environmental Protection Agency completed a $27 million dollar study that identified the Chesapeake Bay's single worst problem as excessive nutrients. The study found too much nitrogen and phosphorus flowing into the Bay about equally from two major sources -- runoff from the land, mostly excess fertilizer from farm fields, and effluent from sewage treatment plants.

The nutrients have become so abundant that instead of fostering growth in submerged aquatic plants, they feed a much lower life form -- algae -- that bloom in profusion as soon as the water warms and block light from getting to rooted plants. The short-lived algae rob the Bay of oxygen as they decay.

Two and a half years ago, during a meeting at George Mason University, Maryland, Virginia, Pennsylvania, the District of Columbia and the federal government agreed to work together to fix the Bay. A top priority was nutrient control.

There was an initial surge of interest in pushing farmers to use better land management practices, less fertilizer and more timely fertilizing techniques. Today, officials continue to badger farmers to do a better job.

But rarely is heard a discouraging word about sewage treatment plants, the half of the nutrient mess that government itself created and that government alone can fix.

Has government in Maryland, the leader in the drive to save the Bay, done anything concrete yet to reduce phosphorus and nitrogen loadings from its sewage treatment plants?

"Clearly not," said Chris D'Elia, nutrient expert with the Chesapeake Biological Laboratory in Solomons, Md. "The system just doesn't work that fast. The bigger question is, 'Is the planning going fast enough?' And the answer again is no, probably not."

Sewage plants are spewing as much nitrogen and phosphorus into the Bay as ever, D'Elia said, but he is encouraged that plans for upgrading Maryland plants continue, albeit in fits and starts.

Pete Tinsley, program administrator for Maryland's Water Management Administration, defended state policies. He said there has been a 20 percent reduction in phosphorus loadings from major sewer plants since 1983, although nitrogen input continues to increase. And Tinsley said plans to remove nitrogen from major Patuxent River plants are advancing.

The good news is that there is hope for a new, cheaper method of nitrogen and phosphorus removal being developed by the chairman of environmental engineering sciences at Virginia Polytechnic Institute.

The technique, according to Dr. Clifford Randall, who is testing it in Norfolk and soon will put it in place on the York River, is a fairly simple biological method perfected in South Africa, where it is in operation in 29 plants. It enables sewage plants to remove 90 percent of phosphorus and 70 percent of nitrogen at a lower cost than is spent now to remove phosphorus alone.

Maybe Randall has the answer, or a big part of it. A lot of experts think so. It is clear that Washington's Blue Plains, the biggest sewage treatment plant in the Bay region, dramatically improved the character of the Potomac when it implemented phosphorus removal a decade ago. The Potomac today is alive with submerged grasses, and the fishing has not been better in years. Imagine if Blue Plains removed nitrogen, as well.

New technology to remove more nutrients evidently is here, and it's time, for sure, for states and the federal government to stop pointing fingers at farmers and start pointing fingers at themselves. Time is short. There's a big Bay to clean up.