Beach Closings: Understanding the Effects of Beach Pollution and Why the Beach is Closed

Examples of Beach Closed Advisories:

Flags crossed - do not swim

Based on advisories released by local health authorities, the beach manager is tasked to put up signs to warn beachgoers. The image on your left means "do not swim". Here are some examples of beach warning signs:

“Beach Closed Again”

“Bacteria Keeps Newport New Beach Closed”

“Warning: Beach Closed to Swimming”

If the bacteria samples are not enough to meet the standards for beach closings, beachgoers are still alerted using this warning sign or something similar to this:

“Warning: Swim at Your Own Risk”

Understanding Beach Closed Advisories and Beach Pollution

Beach pollution has recently been established as a persistent problem often occurring in ocean, bay, and Great Lakes beaches, although its occurrences are not limited to coastal areas. According to the Natural Resources Defense Council ‘s (NRDC) 2009 annual survey, the number of beach closing advisories has reached a total of 18,000, which is considered as the sixth highest-level in their 20 years of the survey.

What are the Causes of Beach Pollution?

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Storm water runoffs flowing into estuaries and lakes are the main causes of beach pollution but the sources of contaminated water carried off during storm seasons have been detected as coming from several areas.

Water runoffs stem from rain downpours or snow melts and their pathway begins from rooftops passing through land areas and canals, filling up sewer systems, which could cause overflows. Run-offs tend to carry contaminated water coming from malfunctioning sewage treatment plants. Rainwater or snow melts containing contaminated sewage water continue to surge forward as it reaches streams and rivers.

The rivers’ currents will flow to its natural direction, up to the points where river and sea water meet, known as estuaries. Contaminated river water combines with the sea, at the same time depositing a large amount of pathogenic bacteria in beach areas. Tides and incoming waves continue to transport the microorganisms even farther into the sea.

What are the Sources of Beach Pollution?

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The following sections describe the different contaminating agents considered as sources of beach pollutants carried-off by storm water:

Urban Water Runoffs

  • Urban sources include rooftops where bird droppings and cat litter are present.
  • Parking lots include oil, grease, and other forms of trash, which are carried by vehicles or adheres to tires during road travels. Recreational and truck trailers coming from long distance travels reportedly unload illicit discharges of their vehicle’s on-board toilet tanks into storm drains during stopovers.
  • Alleyways and streets, littered with fecal material from stray animals like rodents, or other forms of garbage carelessly thrown away by humans.
  • Construction sites, where solvents, paints, scrap metals and iron discards are strewn around the areas.
  • Dry weather runoffs resulting from landscape irrigations. These often carry pesticides and chemical-based fertilizers, or highly chlorinated water drained from residential and commercially installed swimming pools and spas.
  • Car servicing areas where large amounts of water runoffs carry car cleaning waxes, polishes, or chemicals used for car detailing, spray paints, carpet cleaners, and other forms of industrial cleaners and solvents.

These are only some of the factors affecting beach waters, which urban residents can minimize, if not eliminate, to lessen beach pollutants originating from urban areas.

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Boat Wastes

Marinas, which serve as shelters for sea vessels, have reduced circulation of water surrounding the dock areas, and this is where the elevated levels of fecal coli forms have been traced. Under federal laws, boats are required to treat the septic tank discharges of their onboard toilets before they are unloaded, or to pump them out in designated sewage treatment plants.

However, the limited pump-out facilities have been cited as causes for the oversight in several areas. This is despite the fact that the Clean Vessel Acts of 1992 have provisions for federal grant money to be used in building pump-out stations for the very purpose of maintaining sound environmental practices among boaters.

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Independent research studies reveal that the beachgoers are, likewise, contributors of fecal matter and other infectious viruses that lead to beach pollution. Children beach-bathers wearing soiled diapers are carriers of human waste.

Some swimmers take a dip even while afflicted with contagious diseases. Increases of the E.coli and coliform bacteria were noted to have taken place during summer and weekends, when there are corresponding increases in the numbers of beachgoers.

Sources of Beach Pollution (continuation)

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Leaking Sewage Pipes and Malfunctioning Sewage Treatment Plants

  • Aging sewage pipes tend to bust and break, causing leaks. An example cited by the NRDC was demonstrated at the Rancho Santa Margarita in California recently. A ruptured sewer line spilled untreated sewage content into coastal waters, roughly estimated at hundred thousands of gallons, before the sewage was detected as the source of beach pollution affecting several miles of beach stretch.
  • These specific sources include the busted pipes coming from sewage systems of old business establishments and the illegal connections of newer ones. A nationwide survey revealed that out of the 42 treatment plants in use, some dated back as far as 117 years, while the average period that these treatment plants have spanned is thirty-three years. The rapid deterioration and aging of pipes among newer plants was attributed to overload, lapses in maintenance schedules, and lags in implementing rehabilitation remedies.
  • The overwhelmed conditions of sanitary sewer treatment plants of industrial buildings may discharge untreated wastes when the amounts taken in exceed the sewage treatment plant’s capacity. The occurrences of mechanical malfunctioning in these treatment plants has also been established as the reasons for several advisories that led to beach closings.
  • Other reasons for sewage overflows and malfunctioning have been attributed to clogs in sewage lines caused by tree roots and oil clogs. According to studies conducted by the Environmental Protection Agency (EPA), only 26 percent of sewage overflows were caused by storm water, while 74 percent stemmed from sewage treatment plant defects, line breakages, or malfunctions.
  • Owing to the density of the population in an area, some treatment plants tend to bypass the secondary treatment process; hence, releasing wastes that still contain the following examples of bacteria: 85 percent Shigella bacteria, 85-100 percent Salmonella, 50 to 100 percent Entamoeba histolytica, and 90 percent fecal coli form.

According to the EPA, their proposal for Sewage System Operation regulations was shelved during President Bush’s administration but has currently been revived under the administration of President Obama.

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Wildlife and Pet Wastes

Most migratory birds tend to populate near-beach locations, especially in regions where the wetlands and marshes have been altered to human residential areas.

Seagulls, however, have traditionally been considered the number one contributor of animal wastes to beaches.

Add to this beachgoers’ pets, or even those of residents in the surrounding beach areas, whose pets are intentionally brought over to have their excrement discharged near the coasts.

As the tide rises and reaches the inner coasts, the accumulation and assortment of fecal matter is carried by the incoming waves into the beach water.

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Agricultural Discharges and Runoffs

High concentrations of animal wastes, fertilizers, and pesticides were also traced as coming from polluted rivers. Agricultural pollution has been established to have polluted 40 percent of river waters that eventually flow into the sea. The most notable outbreak of toxic microorganisms emanating from animal feedlots occurred in Chesapeake Bay and in the North Carolina regions. This resulted in 205 recorded illnesses and three fatalities.

These are the sources of beach pollution that contribute to the high-levels of bacteria and various pathogenic strains detected in beach waters, resulting in advisories that “the beach is closed”.

What are the Effects of Beach Pollution on Human Health?

Free-living amebic infections

Pathogens are disease-causing bacteria, viruses and protozoa, whose high levels of incurrence are monitored in beach waters. This will be the basis for beach closing advisories, since the environmental cause for concern are the health risks presented to beach goers.

According to the Centers for Disease Control and Prevention (CDCP), infections and illnesses largely acquired from recreational waters, including beaches, have continued to increase in recent decades.


The most common of these illnesses is gastroenteritis or stomach flu, where the stomach and the small intestines are inflamed. This illness is manifested by several symptoms like vomiting, severe stomach ache, nausea, headache, and fever. Children are the most susceptible to this disease, or adults who have weak immune systems. The illness may last for several days but have also been known to cause long-term lingering illness or even death due to dehydration caused by diarrhea and vomiting.

In most cases, the effects of beach pollution like gastroenteritis are not immediately linked to swimming in polluted beach waters because there is usually a delay of several days, or even up to two weeks, before the pathogens manifest their infections.

Mycobacterium balnei (CDC-PHIL -3111) lores

Antibiotic Resistant Staph Bacteria

A related study conducted in 2009, by University of Washington researchers reported a type of infection resistant to antibiotics which they call as “staph bacteria”. This pathogenic strain was found in 10 beaches located along Washington’s West Coast and Puget Sound areas from February to September 2008. Data gathering is still underway to determine the number of people affected by the staph strain.


Climate change is, likewise, a contributing factor for these pathogenic strains to manifest themselves as in the case of a bacterium called Vibrio Cholerae, which causes cholera. This particular effect of beach pollution was largely monitored to surface during extreme weather events. Examples of these cases happened as an aftermath of Hurricane Katrina and in Chesapeake Bay; the affected areas experience climate variations, warmer conditions, and high rates of stream flows.

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Outbreaks of Waterborne Diseases

The CDCP, the EPA, and the Waterborne Disease and Outbreak Surveillance System are working hand-in hand in collecting data about outbreaks related to beach pollution. The most recent report was released in 2008, which disclosed 78 outbreaks of waterborne diseases from January 2005 to December 2006. Data gathered was considered by the CDCP as the highest number of outbreaks as it resulted in 4,412 illnesses, 116 hospitalizations, and 5 deaths in a span of two years. However, these figures were derived from voluntary reporting solicited by the agencies and do not include those that are unreported; hence, it is feared that the numbers could be higher.

Diseases Caused by Beach Pollution Pathogens -1
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Various Bacterial Strains and its Related Diseases

Studies regarding the effects of beach pollution have revealed numerous disease-causing bacterial strains. NRDC’s list of these pathogens and the diseases that have been associated to swimming in polluted beach waters are provided on the images presented on your left. (Kindly click on the image to get a larger view).

Perhaps, at this point, we have provided sufficient information about the in-depth reasons why local authorities give advisories for beach closings..

Reference Materials and Image Credits



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