Local beaches among top in nation for water quality
Delaware’s beaches ranked first in the U.S. in water quality for the year 2011 in a report issued last week by the Natural Resources Defense Council (NRDC). Out of 30 states ranked, the state had the fewest water quality samples that exceeded national standards, with just 1 percent of samples for designated beach areas exceeding those standards.
Delaware has 50 miles of Delaware Bay coastline, 25 miles of Atlantic Ocean coastline and 115 miles of inland bay shoreline along Rehoboth Bay, Indian River Bay and Little Assawoman Bay.
The state’s marine beachwater monitoring program is administered by the Delaware Department of Natural Resources and Environmental Control (DNREC) and includes roughly weekly sampling of 26 sites along the entire Sussex County coastline. In 2011, the monitoring season extended from May 2 to Sept. 28 and involved between 12 and 38 samples at each location (with sampling rates based on usage and other factors), all taken at knee-deep levels.
The state’s Floatables and Debris Program also has a vessel in the water year-round in all weather conditions, to monitor floating debris, as well as oil spills, harmful algae blooms, sewage treatment discharges, nutrient runoff and industrial discharges.
In 2011, only 1 percent of all individual reported beach monitoring samples exceeded the state’s daily maximum bacterial standard of 104 colonies/100 ml.
Nationally, the portion of monitoring samples exceeding national recommended health standards for designated beach areas (indicating the presence of human or animal waste) remained steady at 8 percent, the same level as in 2010 (up from 7 percent in 2009, 2008, 2007 and 2006).
After Delaware, the states of New Hampshire (1 percent exceedences), North Carolina (3 percent), New Jersey (3 percent), Florida (3 percent) and Virginia (4 percent) had the highest levels of water quality. Louisiana, Ohio, Illinois, Indiana, Connecticut and Wisconsin had the highest percentage of samples exceeding the EPA’s recommended single-sample maximum for designated beach areas among the 30 states in the report.
Southern Delaware beaches get good review
Locally, Bethany Beach, South Bethany, the beaches at the north and south sides of the Indian River Inlet, Delaware Seashore State Park’s Tower Road bayside beach, the Holts Landing beach and beaches at the Maryland-Delaware state line south of Fenwick Island all garnered clean bills of health, with not even a single water sample exceeding standards in all of 2011.
Even for those local beaches where standards were exceeded, they did so just once or twice last year. Delaware Seashore State Park’s Tower Road ocean beach had 5 percent of 21 samples exceeding the standards. The Fenwick Island State Park beach had 3 percent of 32 samples exceeding standards.
Elsewhere in the state, Broadkill Beach had a 10 percent exceedence rate. Prime Hook Beach had a 6 percent exceedence rate. Slaughter Beach had a 5 percent exceedence rate. Closings and advisories were issued twice in 2011 for each of those three beaches.
Overall, the state’s beaches exceeded the standards less often in 2011 than in 2009 and 2010, which saw 2 percent and 3 percent exceedence rates, respectively, when the same list of beaches was compared. The rates in 2007 and 2008 were also 1 percent for those beaches.
Other Sussex County beaches garnering a clean bill of health from sampling in 2011 included 3R’s, the Gordon’s Pond ocean beach, Cape Henlopen, Cape Henlopen State Park at Herring Point, Conquest Road, Deauville Beach, Dewey Beach, Key Box, Lewes’ north and south beaches, and Rehoboth Beach at Queen Street, Rehoboth Avenue and Virginia Avenue.
NRDC considers all reported samples individually (without averaging) when calculating the exceedence rates, including duplicate samples and any samples taken outside the official beach season.
Permanent cautions remain in place for bays
Because of concerns about water quality, there is a permanent caution regarding swimming in Rehoboth Bay, Indian River Bay and Little Assawoman Bay, including Tower Road Bayside in Rehoboth Bay and Holts Landing Beach in Indian River Bay. NRDC does not include the permanent caution in its analysis of closing and advisory days.
According to NRDC, contaminants in the bays come from sources including failing septic systems, farm and lawn fertilizers, wildlife and runoff from poultry operations. In addition, they noted, the sewage treatment plants in Lewes and Rehoboth discharge treated effluent into the Lewes and Rehoboth Canal, which feeds into the bays.
“Poor flushing of the shallow waters in these bays allows pollutants to linger; it takes more than two months for water to move out of the inland bays,” the report stated.
Signs are posted at popular access points around Rehoboth Bay, Indian River Bay and Little Assawoman Bay to warn potential swimmers of the risks associated with swimming in those bodies of water, particularly after a heavy rain.
Much of bacteria at beaches with advisories is from wildlife
Delaware standards for marine beachwater quality are an enterococcus single-sample maximum of 104 cfu/100 ml and a geometric mean standard for the most recent five samples within 30 days of 35 cfu/100 ml.
According to NRDC, DNA analyses used to track the source of bacteria at Slaughter Beach and Prime Hook Beach have shown that nonhuman sources contribute to indicator bacteria counts at those beaches. Monitoring results at those beaches are adjusted downward to account for nonhuman sources at the beaches before the water quality standard is applied, but NRDC uses the unadjusted values in its analysis of exceedances.
For Slaughter Beach, the microbial source tracking study found that 77 percent of fecal bacteria came from wildlife sources, with a 26 percent margin of error. At Prime Hook, microbial source tracking found that 70 percent of fecal bacteria came from wildlife, with a 24 percent margin of error.
State policy is to issue advisories when fecal bacteria counts exceed either the single-sample or geometric mean standard. Circumstances that would trigger an imminent health threat result in a closing rather than an advisory.
Delaware also has a standard for issuing preemptive rainfall advisories. For marine waters, DNREC has determined that 3.5 inches of rainfall within 24 hours or 3 inches within 12 hours may trigger a closing. Preemptive closings are issued in the case of a known sewage spill.
Additionally, DNREC also samples water and/or shellfish for harmful algal bloom species (Karenia brevis and K. papilionacea) and toxins, and issues harmful algal bloom swimming advisories at freshwater beaches. In 2011, Karenia species were quantified along the Mid-Atlantic coastline, and K. papilionacea was found north of Delaware and in the coastal bays of New Jersey.
NRDC proposes tougher standards
NRDC advocates for testing to protect the health of those using the beaches, and the group argued in its 2011 report that tougher standards are needed nationwide.
“In order to protect beachgoers from waterborne illnesses, we need strong policies to identify unsafe beach water quality and to clean up the major sources of beach pollution,” they said. “EPA is revising the safety standards that are designed to protect swimmers from getting sick, but the agency needs to strengthen its proposed standards, which — based on EPA’s estimates of illness risks — would make it acceptable for 1 in 28 swimmers to become ill.”
Rather than just establishing such a standard, NRDC recommended strengthening regulations governing polluted stormwater and runoff, including advocating “green infrastructure”— along the lines of the rain gardens being implemented in South Bethany, as well as rain barrels — that can allow runoff to be naturally absorbed and filtered, or used for other purposes, rather than going directly into local waterways.
“In addition, because polluted runoff is the biggest known source of pollution that causes swimming advisories or beach closings, EPA needs to reform the national requirements that govern sources of polluted stormwater,” they said, “and the states and EPA need to rigorously enforce existing requirements to ensure that runoff is controlled using innovative solutions known as green infrastructure that enable communities to naturally absorb or use runoff before it causes problems.”
Nationally, NRDC said, “The 2011 results confirm that our nation’s beaches continue to experience significant water pollution that puts swimmers and local economies at risk.”
The EPA has estimated that up to 3.5 million people become ill from contact with raw sewage from sanitary sewer overflows each year. The Centers for Disease Control and Prevention has also concluded that the incidence of infections associated with recreational water use has steadily increased over the past several decades.
“EPA must revise the level of acceptable risk so that it is protective of public health,” NRDC argued. “To do so, the latest and best scientific evidence needs to be utilized to determine appropriate water contamination ‘cut points,’ above which the public is subject to unacceptable additional health risks, on the order of 1 in 100 instead of 1 in 28. The criteria also must adequately address non-gastrointestinal illnesses, such as rash and ear infections.”
NRDC noted that poor beach water quality can negatively impact local economies, particularly if advisories or closures keep swimmers out of the water and away from beach communities. It also pointed out that climate change would be likely to make water quality conditions worse, increasing rainfall, flooding, sewer overflows and populations of pathogens that can cause illness and potentially life-threatening disease.
To view the NRDC report on Delaware’s beaches for 2011, visit http://www.nrdc.org/water/oceans/ttw/de.asp online. The full national report can be seen online at their Website at http://www.nrdc.org/water/oceans/ttw/.