MONSON, Calif. — Laura Garcia was halfway through the breakfast dishes when the spigot went dry. The small white tank beneath the sink that purified her undrinkable water had run out. Still, as annoying as that was, it was an improvement over the days before Ms. Garcia got her water filter, when she had to do her dishes using water from five-gallon containers she bought at a local store.

Ms. Garcia’s well water, like that of her neighbors, is laced with excessive nitrates, a pollutant associated with agriculture, septic systems and some soils. Five years ago, this small community of 49 homes near the southern end of the Central Valley took its place on California’s priority list of places in need of clean tap water.

Today the community is still stuck on that list, with no federal help in sight.

Monson’s situation has parallels in places around the country, large and small, seeking federal funds under the Safe Drinking Water Act. The Environmental Protection Agency distributes these funds to state agencies that are supposed to identify problems and underwrite solutions. By the E.P.A.’s calculations, no state has been as inept in distributing the money as California.

The state’s most recent priority list contained 4,925 applications. Some have been on the list for a dozen years. Some have been abandoned by the original applicants. Some are getting the federal funds quickly; others are in limbo. Of $1.5 billion in federal money sent to California and cycled through a revolving fund, $455 million lay fallow earlier this year while the priority list grew.