Question: An issue of Bloomberg Businessweek this year featured software coming from Israel that uses mathematical algorithms to detect and prevent leaks in water pipes, and also repair and plug leaks without digging. Shouldn’t the Honolulu Board of Water Supply look into this to update its system?

Answer: The BWS would look into the possibility of using this new software tool to prevent and detect leaks within its system, said spokeswoman Shawn Nakamoto.

But for now, she said, the agency has been using “a very successful” internal leak detection program since the early 2000s, although it does require digging.

The program regularly evaluates every BWS water main with high-tech equipment that records vibrations produced in a pipeline.

The vibrations are digitally converted into sounds that allow the leak detection team to “listen” for leaks in the system, locate them, then proactively make repairs, Nakamoto explained.

Since 2005 an estimated average of 1.7 million gallons of water a day would have been lost had the leaks not been detected.

“The program has also prolonged the useful life of our assets and helped the BWS determine whether or not to rehabilitate or replace a water main,” Nakamoto said.

She acknowledged that for now, leak repair procedures require digging up a pipeline to determine the repairs needed and to make them as soon as possible.

Leaks vs. Breaks

What about water losses from pipe breaks, and how do they compare with losses from leaks?

While the Leak Detection Team surveys for leaks on mains, service connections, meters, valves, hydrants, etc., underground leaks can go undetected, Nakamoto said.

The BWS is not able to estimate water loss from undetected underground leaks, she said.

But, “Our Leak Detection Team surveys every pipeline in our water system with a goal of two years to complete a survey of the entire system,” she said. “So, while leaks can spring up at any time and can go undetected for a limited time, we have a program in place to minimize water losses.”

For 2014, BWS estimates that the water saved from detecting and repairing various leaks was approximately 326 million gallons.

Regarding water loss from breaks, for 2014 the Board of Water Supply estimates that approximately 586 million gallons — about 1 percent of the 48.7 billion gallons of water the BWS produced last year — was lost.

That’s based on the size of the main break, flow rate and duration.

Nakamoto said the number of main breaks is “on a decreasing trend,” totaling 293 in fiscal year 2014. That compares with nearly 500 in the 1980s and early 1990s, according to a Board of Water Supply graph.

Minimizing both breaks and leaks is a goal of the BWS’ Capital Improvement Program through a Water Master Plan that is being developed, Nakamoto said.

“The Water Master Plan is a comprehensive program that evaluates the entire water system, identifies necessary improvements and balances needs and costs to provide safe, dependable and affordable water,” she said.

Mahalo

To a nice lady. In late March I was at the Waipio Costco, struggling to get a two-pack of juice out of the box. The plastic bottles each weighed more than 5 pounds. I muttered something about those containers being so heavy and hard for older folks to lift. An attractive woman in a turquoise print top standing nearby offered to help and put the containers in a nearby cart. She commented that I was good to go. I had to tell her that it wasn’t my cart — that my husband had taken our cart to the next aisle to get coffee. So this nice lady again hefted up the two apple juice containers and followed me to our cart. I really appreciated her help and hope that I thanked her adequately. She sure has the aloha spirit. — Anuhea, Aiea

Write to “Kokua Line” at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email kokualine@staradvertiser.com.

CORRECTION: The Board of Water Supply estimates  that approximately 586 million galons of water was lost in breaks, about 1 percent of the 48.7 billion gallons of water the BWS produced last year. An earlier version of this story and a story on page A2 of Friday’s paper  said the BWS produced 48.7 million gallons of water last year.