Lucky we live Hawaii! Ocean-water quality throughout our state is probably better than anywhere else in the world. It helps to be in the middle of the Pacific Ocean, away from major industrial sources of pollution. Nevertheless, there are occasional sewage spills, cesspools that impact water quality in some areas, and other sources of pollution that impact the ocean for recreation and other uses. These are concerns of many in Hawaii, including those in the Hawaii Department of Health. Recently, concerns have been raised about bacterial levels at certain beaches around the state.

A national not-for-profit organization recently issued a report about water quality that compared Hawaii to other states. Hawaii was listed as having several beaches where bacterial levels occasionally exceeded established water quality standards.

In Hawaii, unlike most other states, naturally occurring bacteria that are detected in polluted water grow and reproduce in our relatively moist, warm tropical soils. When it rains heavily, these bacteria are flushed out of the soil and carried into canals and streams that empty into the ocean. They are often found in high numbers regardless of the presence of disease-causing bacteria and viruses associated with sewage or animal waste.

To monitor water quality, we rely on “indicator” bacteria that are found in everyone’s intestines. In colder climates where bacteria do not naturally multiply in soils, it usually indicates the possible presence of disease-causing bacteria or viruses from sewage or other human sources of contamination. Unfortunately, it is impractical to test water for the thousands of bacteria and viruses that can cause disease from sewage. In Hawaii, these bacteria show up in large numbers whenever it rains. If there is no sewage spill or source of contamination, these bacteria pose little or no risk to swimmers, surfers or others.

The Department of Health routinely tests water quality at high-use recreational beaches where there is a threat of contamination. If high indicator bacterial counts are found, beach advisories are posted as a precautionary measure. In these situations, the Department of Health conducts follow-up testing on each subsequent work day and may undertake further tests to determine the underlying source for the bacteria if the elevated levels of indicator bacteria persist. Most often, the bacteria levels drop to normal levels within a day.

We have recently used an advanced DNA-based test tool called the PhyloChip, which can detect more than 59,000 bacteria species that are unique to different sources. It can even detect variations within a gene to identify different bacteria strains. On Kauai, a recent study confirmed the high levels of bacteria in several streams on the West side that were not caused by human or animal fecal contamination. Based on this study, we can say there is little or no health risk of sewage or animal waste contamination at a beach.

Today, we use the same EPA-approved indicators that were used more than 40 years ago. Science has advanced but the U.S. Environmental Protection Agency has not kept up. Unfortunately, these advanced monitoring methods are still expensive and not widely available to health departments and other regulatory agencies. We are now working with the EPA to enhance research on the subject and to identify methods to better determine health risks. In the meantime, we will continue to resolve any uncertainties about health risks in favor of protecting public health.

Bruce S. Anderson is the director of the state Department of Health.