A researcher's second test of beach water and nearshore seaweed found more clues of what he saw the first time he looked: hints of sewage.

Peter Barile suspects the sources could include mini sewer plants along the barrier island and deep injection wells that contaminate ground water.

"Based on this data, the whole barrier island system appears to be hemorrhaging sewage nitrogen, whether it's septic tanks, deep wells or package plants," said Barile, a researcher at Harbor Branch Oceanographic Institution in Fort Pierce.

Sebastian Inlet chapter of the Surfrider Foundation, which paid for Barile's tests, posted his latest results on its Web site this week.

Brevard County health and environmental officials have denied any sewage problem along the barrier island. They cite weekly bacterial tests that yield levels well below the threshold for public swimming advisories.

Swimmers exposed to bacteria from sewage can suffer ear, nose, throat and skin infections and gastrointestinal illness.

Barile's tests have spurred the county to spend up to $35,000 to hire an expert to review his results and determine whether there's a health or environmental threat from sewage at the beaches. The county expects to hire someone next month to do the work.

"We're looking for someone who is well known in the field and totally objective," said Conrad White, director of Brevard's Natural Resources Management Office.

Part of Barile's analysis included a stable nitrogen isotope test of the seaweed he and Surfrider members gathered on offshore rocks. The results from the June 1 test found similar high ratios of two nitrogen isotopes --which Barile says spell sewage -- that he found in mid March.

He measured the ratio of a heavy nitrogen isotope, N-15, to a lighter one, N-14, in the plants. The higher the ratio of the heavier to the lighter isotope, the greater the chance the nitrogen passed though a human digestive tract, Barile said.

"The higher it gets the more indicative it is of a human-based nitrogen source," he said.

While a natural "background" level would yield ratios close to zero, Barile found ratios of the two isotopes from 8:1 at Satellite Beach and nearly 12:1 at Cocoa Beach Pier. He said anything above a 5:1 ratio is more than likely to be from humans.

Barile also found four of the seven beaches he tested had thresholds of nutrients in the water above what is known to cause harmful agae blooms. Cocoa Beach Pier and Indialantic Boardwalk were the worst.

Barile will meet with county staff next month to present his results.

The county has deep injection wells on Merritt Island and in the South Beaches area. Assistant County Administrator Steve Peffer said those wells don't leak waste water.

"We don't think we're having a problem," Peffer said. "We certainly don't think they are potential sources of out in the ocean."

But Barile suspects sewage nitrogen could be leaching through the aquifer's sandy soils to the surf zone.

The city of Melbourne also has a 2,500 foot deep injection well for treated wastewater on the mainland.

Melbourne Utilities Director Bob Klaproth defended the well in a letter to the editor that ran June 4 in Florida Today.

"There is no data to suggest that the injection well is affecting ocean water along the beaches," Klaproth wrote.

The U.S. Environmental Protection Agency is considering allowing continued use of deep injection wells that leak into the aquifer in South Florida, as long as those wells pose no threat to drinking water supplies.

While heavy rains can flush excess nutrients from land into the surf during the rainy season, Barile said his tests were taken before onset of the wettest months, and therefore prove a strong link between ground water seepage and high nutrients into the surf.

"We're not getting the stormwater, the rainfall, and what might be surface water effects," he said.

Barile said he also doubts whether recent cold water upwelling, which boost nutrients, can account for the high nitrogen isotope ratios he found.