E. COLI BACTERIA AT BOARD OF WATER SUPPLY (BWS)

KALAUAO WELLS PUMP #5

Water is safe to drink. The public was never in any danger.

HONOLULU – Follow-up tests at BWS Kalauao Wells pump 5 were found to be negative for E. coli bacteria.

What should I do?

There is nothing you need to do. Your water continues to be safe to drink. This notice is a public announcement required by Federal and State drinking water regulations.

What happened?

On December 07, 2024, the Board of Water Supply (BWS) issued a news release notifying the public that a raw, pre-chlorination water sample collected on December 05, 2024 from BWS Kalauao Wells pump 5 tested positive on December 06, 2024 for E. coli bacteria. As required by the Ground Water Rule, on December 06, 2024, five (5) additional raw, pre-chlorination samples were immediately collected from Kalauao Wells pump 5 to follow-up on the initial E. coli detection. The following day, on December 07, 2024, those five raw, pre-chlorination samples from Kalauao Wells pump 5 were all found to be negative for E. coli bacteria. As required by Federal and State regulations, BWS is providing this second public notice to report these five negative E. coli results from the five follow-up samples taken from Kalauao Wells pump 5. The tap water remains safe to drink because the pre-chlorination, raw water from this source is disinfected with chlorine before it goes to any consumers. For this reason, no further action is required by customers. Water from Kalauao Wells pump 5 serves the area from ‘Aiea to Kahala.

According to the Environmental Protection Agency (EPA), the Ground Water Rule is a regulatory process aimed to reduce the potential risk of illness caused by microbial contamination in ground water. Under the Rule, utilities must test the ground water sources when E. coli bacteria are detected in any sample collected from the water system. If E. coli bacteria are found in the ground water source, the Rule requires the public to be notified. While an E. coli detection is not a rule violation, the Rule requires that the public be notified of the findings nevertheless.

Background

On December 04, 2024, BWS detected E. coli bacteria in a water sample collected on December 03, 2024, from a routine sampling site on Ala Mahamoe Street. On December 05, 2024, in accordance with the Ground Water Rule, BWS staff collected a repeat sample from the original sampling site and from other sites on Ala Mahamoe Street, and additionally from all sources and all pumps at all stations that were serving water to Ala Mahamoe Street. Kalauao Wells and Punanani Wells are the sources serving water to Ala Mahamoe Street. Of all the samples collected, only Kalauao Wells pump 5 was found to be E. coli positive on the following day, December 06, 2024. The repeat samples from Ala Mahamoe Street and all other samples collected on December 05, 2024, from all other pumps at all other sources were all found to be E. coli negative on the following day, December 06, 2024.

With this result and as required by the Ground Water Rule, on December 06, 2024, the BWS immediately collected five (5) additional raw, pre-chlorination resamples from Kalauao Wells pump 5. After collecting these five resamples, Kalauao Wells pump 5 was immediately shut down as a precaution, until results were known. E. coli testing requires at least 18 hours to complete. The five additional raw, pre-chlorination samples collected were all found to be negative for E. coli bacteria on December 07, 2024. As required under the federal Ground Water Rule, BWS is providing this second public notice of these negative findings.

E. coli bacteria can exist in tropical, sub-tropical, and temperate soil and may persist in the soil for many years. E. coli is a fecal indicator and a microbe whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause short- term health effects, such as diarrhea, headaches, or other symptoms. They may pose a special health risk for infants, young children, some of the elderly, and people with severely compromised immune systems.

The BWS has notified the State Department of Health (DOH) of these follow-up negative test results and is informing the public as required by Federal and State drinking water regulations.

During the times when Kalauao Wells pump 5 is operating, chlorine is being added to the water before it reaches customers. Other water samples collected from Ala Mahamoe Street taken on December 03 and 05, 2024 had chlorine present and all tested negative for E. coli bacteria. Other samples taken in the area served by Kalauao Wells and Punanani Wells were collected on December 03, 2024, from Kalihi Kai Fire Station, Soto Mission, and Central Fire Station, and were collected also on December 05 from Pizza Hut on N. Kuakini Street, Kalihi Kai Fire Station, Honolulu Bus Maintenance Facility, Lagoon Chinese Restaurant, Central Pacific Bank Mapunapuna, Moanalua Golf Course, Salt Lake Elementary School, O’ahu Veterans Center, Extra Space Storage on Lawehana Street, and Kilauea District Park, all also had chlorine present and all tested negative for E. coli bacteria. For this reason, the public was not at risk of E. coli exposure.

What is being done?

The BWS, in consultation with DOH, investigated whether the presence of E. coli bacteria at Kalauao Wells pump 5 could be confirmed and found that it could not. All five (5) resamples taken on December 06, 2024, before chlorination at Kalauao Wells pump 5 were found on December 07, 2024 to be negative for E. coli bacteria. Upon reporting these uniformly negative E. coli results to DOH, BWS received approval from DOH to resume Kalauao Wells pump 5 operations.

For more information, please contact the BWS Water Quality Division at (808)748-5080 or (808) 748-5855 or the EPA Safe Drinking Water Hotline at 1(800) 426-4791.