The state Health Department reiterated yesterday that Oahu’s drinking water is safe despite the presence of tiny amounts of chromium-6, a toxic chemical.

Eleven samples taken from Oahu pumping stations within the last month showed levels of chromium-6 ranging from 0.32 to 4 parts per billion.

The U.S. Environmental Protection Agency sets a standard of 100 parts per billion or less of all varieties of chromium in drinking water. There are several different types of chromium, and the EPA is determining what the appropriate maximum contaminant level should be specifically for chromium-6.

The Honolulu Board of Water Supply tested for chromium-6 following a report last month by the Washington, D.C.-based nonprofit Environmental Working Group. The nonprofit tested water in 35 cities, including Honolulu, and found 2 ppb of chromium-6 in a single sample at a residence at Wilhelmina Rise.

The sample was the second-highest level found among the 35 samples. The highest was 12.9 ppb in Norman, Okla.

The Board of Water Supply found the highest level of chromium-6 in Waipahu and the lowest in Wahiawa.

"You don’t want any chromium-6 in the water because there’s always a risk of cancer, but it’s understanding that at very low levels the risk of getting any kind of illness is very low," said interim Health Director Neal Palafox. "The water by present science is very safe."

California has a goal of 0.06 ppb for chromium-6 in drinking water.

The chromium-6 is most likely derived from naturally occurring volcanic soils, according to Gary Gill, DOH deputy director for environmental health. "Levels are far below any EPA action levels at this point," Gill said. "The goal for any contaminant should almost always be zero — that’s a goal, that’s not a health standard."

Total chromium levels among the Oahu sites tested ranged from 0 to 4.8 ppb.

"To have citizens and people concerned about anything that’s unsafe in the water is always good and should raise red flags," Palafox said. "The other part of the responsibility is to help people interpret what it means."

The state will test water from all 100 pumping stations islandwide over the next year, as well as neighbor island water stations, to form a statewide database. Testing costs $100 per sample, or $10,000 for all stations on Oahu.

The latest results are posted online at www.boardofwatersupply.com or www.hawaii.gov/health.

Local water companies, such as Menehune Water Co., say they have not seen any substantial increase in sales following the release of the environmental group’s report in December.

However, companies have posted water test results for chromium on websites to assure consumers and vendors of quality standards.

"We haven’t seen a huge spike," said Joseph Hartzman, Menehune’s director of sales and marketing. "We did get calls asking if our water is chromium-free. So maybe people just don’t take it serious."