Every Monday morning, the water man shows up here at Laverne Abraham's door carrying two five-gallon jugs, enough bottled water to make sure the Abrahams can go another week without taking a sip from Broomfield's plutoniumlined reservoir.

Over the last decade, leakage of radioactive material from the giant, accident-marred Rocky Flats nuclear weapons plant next door to Broomfield has left a plutonium blanket on the botton of the city's 40-acre Grost Western Reservoir.

Now local, state and federal officials have become embroiled in a controversy over who will put up an estimated $30 million to meet the city's demand for a new water supply.

The argument also has become a rallying point for nuclear opponents, who point to Rocky Flats and Great Western as a glowing example of the dangers that can occur from radioactive waste.

According to federal and state investigators, the plutonium that reached Great Western came from unshielded, nuclear-contaminated wastes buried on the Rocky Flat site that seeped to the surface. The Environmental Protection Agency said in a 1975 report that the plutonium bearing wastes from the nuclear plant reached the reservoir through water runoffa down a stream alongside the plant and into the reservoir.

Like nearly everyone in this rapidly growing Denver suburb, Laverne Abraham said she has listened to officials who say the plutonium that has trickled into the city's reservoir from Rocky Flats is harmless - as long as it remains where it is, on the bottom. Other experts say plutonium isn't dangerous unless inhaled into the lungs.

But like most people here she is also aware that plutonium can cause cancer if it is ingested in even the tiniest amounts and that it is one of the most lethal nuclear products.

"They keep saying it isn't dangerous," Abraham said as she shopped for groceries with her 6-year-old daughter, Jennifer. "Well, even if it was, I don't think they'd tell us. We won't drink the water here until we get a new reservoir."

While the Abrahams may go to more extreme lengths than most of the 20,000 residents of Broomfield, they are hardly alone in their uneasiness about radioactive leaks from Rocky Flats.

The nuclear facility has been sharply criticized to several studies for law procedures that allowed radioactive material to escape into the surrounding area. A report issued by Colorado in October, 1975, noted that the original developers of the plant in 1951 misjudged local wind patterns so that the prevailing wind flows from the plant over area now being devel oped or already. In addition, the report said there have been at least two plutonium fires at the plant that released radioactivity into the atmosphere; a 10-year, slow leakage of plutonium from buried drums of radioactive contaminated motor oil, and the tritium incident. The report also said the plant accidentally released plutonium directly in 1974 in a discharge of untreated air.

Several doctors here urge their patients to avoid Broomfield's water. Last fall, 10 Colorado newspapers carried a letter citing Great Western as a reason to vote against nuclear development in Colorado's unsuccessful antinuclear referendum. Federal and private operators of Rocky Flats are facing a $28 million lawsuit from nearby landowners citing plutonium pollution as having made their land worthless for development. And the city had demanded that the Energy Research and Development Administration, which owns the nuclear weapons fabrication facility, purchase a new water supply to replace the tainted one.

Even some supporters of nuclear development here are behind the demand for a new reservoir.

"I think a certain margin of safety has been used up with a new reservoir," said Dr. William Markel, a local physician who voted last fall in favor of continuing nuclear development.

The controversy over Rocky Flats goes beck to 1970 when tests by the Environmental Protection Agency showed long-term plutonium leakage from the plant into Walnut Creek, which feeds the reservoir. A second series of EPA tests three years later showed 40 times the normal amount of plutonium in the sediment at the bottom of the water supply.

Federal experts quickly assured residents that plutonium is considerably heavier than water and will remain safely on the bottom indefintely. Plutonium has a radioactive half life of 24,000 years. Local officials, however, are worried that the current drought will lower the reservoir so far that the bottom could become roiled up easily and pollute the city's water.

In 1973 state health department investigators also discovered that Rocky Flats had unknowingly flushed another radioactive substance tritium, into the city's water supply. Although the tritium level remained well below the danger point, alarmed residents flooded officials with calls. Only in the last month has the state health department reported that tritium levels in the city's water were back to normal.

But the reservoir contamination incidents led to a study of Rocky Flats by a task force appointed by Colorado Gov. Richard D. Lamm and Rep. Timothy E. Wirth. The task force reported in 1975 that further accidents could occur and recommended that the plant be moved from a populated area. The report also suggested that water in Great Western reservoir not be consumed and that a new water supply be found for Broomfield.

In a point-by-point reply to the task force report, ERDA last year dismissed the possibility of moving the plant or building a new reservoir. But the agency promised to study ways of providing alternative water sources to the city if another accident occurs. The reply also noted Rocky Flat's $47 million annual payroll and the contributions of its scientific employees to local activities.

"That was when we blew our stack," said Goerge Di Ciero, Broomfield's city manager. "They had mistakes, accidents and incidents up ther and they were, in effect, telling us we should take it because of their payroll."

While accidents have occurred at other government nuclear bomb facilities in the West such as at Los Alamos, N.M., and Hanford, Wash., Rocky Flats is different. Local communities around the other plants are relatively isolated and are, in effect, federal "company towns," which tend to provide unquestioning support for them. Broomfield, which serves as a bedroom community for Denver to the south and Boulder to the north, has little financial dependence on Rocky Flats.

Di Ciero and the 10-member Broomfield city council fired off telegrams to everyone from then-President Ford on down demanding a new reservoir. Since then, Rocky Flats' former civilian contractor employee, the Dow Chemical Co., has moved and Rockwell International has taken its place, with pledges of more stringent safety measures. Di Ciero and other city officials say they have calmed down but still want a new reservoir.

"We've made our position known," said the city manager. "They seem to be paying attention, but if we don't get what we want we're going to sue everybody in sight."

That discomfort was not eased this month when EPA warned federal housing officials toproceed cautiously in making development loans in the Rocky Flats area. The warning was issued, according to Paul Smith, EPA's Denver regional radiation representative, because of remaining radioactive plutonium contamination in air and water near Rocky Flats.

The contamination comes from dust blowing off areas on the Rocky Flats grounds that show as much as 5,000 times the normal background radiation levels, Smith said. The areas, which were created by seepage from plutonium-contaminated waste buried there years ago, are in the process of being scraped and cleaned, Rockwell officials said.