However, Ward contends the treatment plant spill is no simple accident, and accuses them of negligence.

"The sewage treatment staff elected to test something at this facility at the worst possible time," said Ward. "This river is at its annual low flow and the public activity on and around the river is it at its peak during June, July and August. What were they thinking? Could they have waited to perform an obviously dangerous 'test' until after the first rains?"

Ward noted that had they only waited a few months, higher water flows could more easily dispersed any possible spill. In addition, he emphasized that they could have waited until the bulk of vacationers were away from the river.

"This plant has been prone to sewage spills and leaks and the Park Service has let this go unreported and unrepaired," said Ward. "They have blamed previous mis-management on highway construction. Highways in California are constantly under construction, but I do not recall another instance when this construction caused repeated sewage leaks and spills."

"The U.S. Park Service needs to openly demonstrate that this is a responsible, well managed government agency, not an out of control bureaucracy, not an out of control bureaucracy. I respectfully request that you assure that this dangerous plant is investigated, staffed with competent, responsible technicians and managers and, that funds to clean up this beautiful river are made available."

The Mariposa County Department of Health Services, after conducting tests on the river water after being informed of the spill by the Parks Service, closed and placed health advisories on sections of the river.

"We've been testing the water on a daily basis and have found a significantly elevated level of total bacteria and fecal bacteria at the spill site and downstream," said Dr. Charles Mosher, the County Health Officer. "In the ensuing days, the downstream levels began approaching those upstream from the treatment plant, but there still continue to be pockets of bacteria at the spill site."

At press time, they posted the river for no contact with the water for the first mile below the plant, as well as maintaining a health advisory from the Foresta Bridge to Briceburg.

"The river usually cleans itself pretty well and we hope it will clear itself by this weekend," said Mosher. He said that he didn't think that the bacteria would be absorbed into the flesh of trout, but he advised anglers to adequately wash the skin of any fish they catch on the Merced.

Tony Spada, DFG Game Warden, said he didn't observe any dead fish at the site of the spill or downriver, although he is continuing to monitor the situation.

Randy Kelley, Senior DFG fishery biologist, said that the impact of the spill on the river's wild trout fishery depends upon exactly how the spill occurred, as well as its content; he had just become aware of the spill shortly before I contacted him.

"If the spill occurred over a period of time, it probably wouldn't have a significant impact. However, if it went into the river as a big block it could create a problem from a fisheries standpoint," said Kelly.

He also noted that questions about the spill still remain to be answered, such as whether the treatment plant received waste from other areas and whether or not the sewage received any chemical treatment. He also said it could result in a kill of aquatic invertebrates in the area immediately around the spill, although preliminary surveys indicated no fish kill.

A sewage spill like this recent one on the Merced is not expected to have a long term impact like the toxic spill on the Sacramento near Dunsmuir in July 1991 did. The river has an ability to clean itself from primarily organic pollution, in contrast to the more deadly toxic chemical spills.

Nonetheless, to needlessly put anglers, swimmers and other recreational users on the Merced River at health risk for a significant period of time during the river's most popular time of year is inexcusable. The Secretary of the Interior must fully investigate this sewage spill, deal firmly with those who caused it, and come up with a plan to stop similar events like this from taking place in the future.