When A Day at the Beach Turns Nasty
The Hawaiian rain slips through the soil, drips from the lush green leaves and flushes the earth clean. A big rain makes torrents of water rush through numerous streams, brown and foamy as it sweeps through our gulches. It is a beautiful sight to watch, but does this occasional flooding put us in danger when we swim and surf in the beaches where the rivers flow into the sea?
Most of the popular beaches in Eastern Hawai`i are river mouths like Hakalau, Papaikou Mill, and Kolekole. Most of these beaches clear out when the weather is bad and the rivers are strong and muddy, but one beach, Honoli`i, about 3 miles north of Hilo and a very popular surf spot, actually gets more crowded when the rain thunders down.
The storms bring large swells to the beach, where many surfers convene to ride the big waves. Samples taken by the Department of Health, Clean Water Branch, in the most popular surfing spot on the beach, show that in times like these, measurements of Clostridium perfringens and Enterococcus can be up to four times the standard for Hawai`i’s near-shore waters.
Clostridium perfringens and Enterococcus are two bacteria used to measure whether the water is hazardous to human health. Most of the time when these bacteria are present, they indicate a high level of human sewage in the water. More than just indicating the presence of sewage, these bacteria can also cause disease. These diseases aren’t lethal, but they do have some effects, the most common one being diarrhea.
The samples were taken from the ocean, a good 100 yards from the river mouth, showing how the river can affect the whole beach, and spread through the entire surfing area. Out of 43 samples taken from January 4, 1999 to November 1, 1999, sixteen samples violated the Enterococcus standard for water safety. Notes accompanying the samples stated that there had been a large rainfall on the days of the sampling, or that the water was turbid and muddy.
We cannot trust the state to close the beaches whenever the water samples show a lot of bacteria. Instead, the Department of Health says it closes beaches either when a large sewage spill has occurred, spilling millions of gallons of sewage into the river, or when the results of water samples taken every day for a week show consistently high levels of bacteria. But normally by then, the muddy water is washed out. Honoli`i has never been closed because of bad water.
Usually, the water is very good, its bacteria is low, and there is no reason for caution. But when the rain has been pouring and pouring down into the rivers and washing out all the soil, it is a good idea not to swim or surf in the beaches where the rivers empty their waters out.
— Emma Yuen
Volume 10, Number 8 February 2000