The Ocean State’s beaches were the fourth worst in the nation last year in terms of meeting national health standards for beach pollution, according to a national report released yesterday by a New York environmental watchdog agency.

But those numbers may be misleading, say state officials: Rhode Island does have bacteria problems at some of its beaches — particularly those at the north end of Narragansett Bay — but the high result is largely due to heavy rainfall and extensive testing programs and stricter standards for beach closures than many states employ.

The report, issued by the National Resource Defense Council, noted that closures due to pollution in Rhode Island more than tripled from 2005 to 2006.

Tests showed that 14 percent of all water samples tested at Rhode Island beaches exceeded federal standards, trailing only Ohio, Indiana, and Illinois as the nation’s worst figure. The state endured 351 beach closure days last summer, according to the Department of Health. Ernest Julian is chief of the Department of Health’s Office of Food Protection, which monitors pollution levels at state beaches.

He said that the increase from 2005 to 2006 is almost exclusively tied to dramatically higher rainfall levels, which wash pollutants that lie on roadways and on people’s lawns directly into the water, and also cause septic systems to overflow. At the same time, the inadequate Providence sewer system dumps millions of gallons of sewage into the Bay during heavy rain events.

With rainfall fairly low this year, the closures are back down again. There have been 68 closure days so far, a rate consistent with other low rainfall years.

But local environmental advocates say that rainfall cannot be used as a scapegoat for beach closures. Rain happens everywhere, and Rhode Island’s problems are directly connected to its poor sewage infrastructure.

“Beach closings in 2006 were up dramatically from 2005,” said Matt Auten, an advocate for Environment Rhode Island. “While the frequency and intensity of rainfall directly impacts how often our beaches are closed, the underlying problem is pollution, whether it is sewage or contaminated runoff. The best step Rhode Island can take to tackle beach closings is to tackle our pollution problems by funding upgrades to our sewer systems and treatment plants and stopping polluted runoff.”

Julian said he was surprised to see Rhode Island rank as one of the highest risk states. But he said that while Rhode Island certainly does have bacteria problems, he believes it is listed so highly because its intensive testing approach is different from many other states: once the state detects high bacteria levels at a beach, it dramatically increases the frequency of testing, leading to a spike in failed tests.

“One of the reasons that we’re so high is that we sample the problem beaches at a much higher frequency than the good beaches,” Julian said.

The report agrees that many of the problems last year were due to heavy rainfall, and that the state is taking steps to identify the root causes of pollution. It also makes note of the intensive testing program as a cause of high results.

Among the worst beaches last year were Warwick’s Conimicut Point Beach and Gorton Pond, Newport’s Easton’s Beach, the beach at Atlantic Beach Club in Middletown, and town beaches in Warren, Bristol, and Barrington.

Nationally, 2006 was the worst year for beach closures in the 17 years the organization has tracked closure statistics.

But despite the national record, 2006 was not the worst year for Rhode Island beaches. That dubious honor goes to 2003, when 459 closure days were recorded, and high-profile fish and clam kills took place in Greenwich Bay.

The years of 2003 and 2006 had highly similar rainfall levels, but Julian said that the difference in closures shows the improvement that has been made in water quality in only a few years, the result of sewer construction projects in Warwick and sealing broken sewage lines in Warren and Middletown that were leaking filth into the water.

In Warwick, roughly 4,000 homes were sewered from 2003 to 2006 as part of a $150-million project to tie in much of the city. The result so far has been a dramatic reduction in bacteria buildup and subsequent beach closures.

“That seems to have had a major impact,” Julian said.

In other areas, simpler fixes were needed.

Warren Town Beach was one of the state’s most-closed beaches in both 2003 and 2006, both times the result of leaky sewer pipes in the area. After snaking robotic cameras up sewer lines following bad seasons both years, cracks were found, and in 2004 and again this summer, the bacteria numbers were down.

And there is hope that the largest single root cause of Bay pollution, sewage overflow from Providence, can be neutralized. Next fall, Providence will complete the first phase of its Combined Sewage Overflow tunnel, which should capture the millions of gallons of rainwater and sewage that currently overflow the metropolitan sewer system during heavy rains.

dbarbari@projo.com