Passing the DNA Test | New Method to Identify Beach Contamination and Source

Nov 20, 2015Fall 2015

Beach closures are declining across Narragansett Bay, a trend that shows pollution-control measures are working. But is more testing needed to ensure beaches are truly safe?

In 2014, beach closures in Rhode Island hit a record low of 52 days, down from a high of 503 days in 2000. This improvement is occurring as the average number of rainy days per summer steadily increases. Rain produces runoff, which carries pollutants—specifically of concern is E. coli—across streets and parking lots, through storm drains, and into waterways and beaches where they can make swimmers sick.

“Anything on the pavement just washes right off every time it rains,” says Amie Parris, beach coordinator for the R.I. Department of Health.

Beach closures harm tourism as well as reduce opportunities for recreation and just cooling off, especially for urban residents seeking to escape the city heat.

Efforts to collect and treat runoff have paid off in the Providence area through a public works project to clean up the stormwater discharge flowing into upper Narragansett Bay. Since 2008, the $467 million combined-sewer-overflow, or CSO, project has diverted billions of gallons of untreated waste and stormwater from the bay and reduced closures at public beaches.

Run by the Narragansett Bay Commission—the sewage treatment agency for 10 Rhode Island cities and towns—the project is funded by the commission’s 350,000 ratepayers. On a smaller scale, new stormwater containment and treatment systems at problematic beaches in Newport and Bristol have also increased swimming days during the summer.

Closures are down at Easton’s Beach and the Atlantic Beach Club after Newport invested $6 million in an ultraviolet disinfection system that cleans runoff from nearby Easton’s Pond.

Closures at Bristol Town Beach went to zero in 2014 after innovative retention and filtration alterations were made to storm drains and a public parking lot.

The steep decline in closures is the result of targeting a single category of pollutants. Current testing in Rhode Island and at beaches across the country targets enterococci, bacteria that show the presence of fecal contamination. Fecal bacteria can afflict beachgoers with dysentery, hepatitis, and respiratory illnesses, among several waterborne health issues.

The test, however, does not reveal the source of the bacteria, such as whether the contamination emanated from leaky septic systems or Canada geese, pets, or farm animals. Identifying the source of pollution, which can be done with DNA-based tests, advances corrective action upstream from the coast and ultimately leads to cleaner beaches.

Environmental groups such as the Natural Resources Defense Council have called for improved testing, a plea that was answered in 2014 when the Environmental Protection Agency (EPA)—which has also established new guidelines that set a more stringent standard for contamination levels—approved the use of the quantitative polymerase chain reaction (QPCR) test.

The new test uses DNA tracking and delivers results in a few hours instead of the current 24-hour wait needed in tests done by the Department of Health (DOH).

According to DOH, this method may also serve as a tool to find and eradicate sources of contamination as they are occurring. The DOH is working to adopt the new EPA test and testing standards, but in the meantime, the existing slower test potentially exposes beachgoers to contaminants as they wait for test results. The delay also keeps people off beaches even after the harmful bacteria may have dissipated.

The DOH oversees the testing and monitoring of Rhode Island’s 69 permitted fresh and saltwater beaches. Testing is done between once and five times per week, with more tests occurring at pollution-prone sites.

In all, some 1,500 to 1,600 tests are performed each year between Memorial Day and Labor Day, a timeframe established by the EPA, which funds the monitoring programs and sets the season to 92 days for permitted beaches across the country.

While the beaches remain open to the public, beachgoers swim at their own risk after Labor Day.

John Torgan, director of Ocean and Coastal Conservation for the Nature Conservancy in Rhode Island, says that Narragansett Bay and Rhode Island’s beaches are significantly cleaner and healthier today than just a few years ago. Upper Narragansett Bay has improved so much in recent years that work is underway to open a public beach at Sabin Point in East Providence.

“That’s something I never thought I’d see in my lifetime,” Torgan says.

Torgan noted that the most critical part of beach monitoring is gathering data. Although he occasionally hears that closures harm a beach’s reputation with tourists, he says the information learned from testing helps find and stop pollution and ultimately keeps the water cleaner and healthier.

In the long term, the state’s natural places and economy see the greatest benefit. Twenty years ago, he says, Rhode Island beaches were much worse off, and testing occurred only once a year at the start of the summer. Today, he says the testing is safe, sensible, and effective.

“We’ve made really dramatic strides in the way we test and report on swimming water quality in Narragansett Bay,” he says. “Let’s recognize the monumental progress we’ve made to reclaim these public waters.”

— Tim Faulkner
     Photographs by John Zupancic

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