‘Dual redundant’ deep well water systems needed
During the monthly Water Board meeting of the Department of Water Supply on Aug. 22, I made a recommendation to make our North Kona deep well water systems “dual redundant.” Let me explain what this means, but first a short background.
North Kona’s water supply comes from 10 deep wells located mauka of the Mamalahoa Highway and water is pumped to the surface from depths of about 800 to 1,800 feet. Everyone should know by now that North Kona is under Water Restriction Notice since January requiring customers to reduce their consumption by 25 percent. This restriction notice is due to the breakdown of the pumps on four and now five of the 10 deep wells.
Just like any other mechanical equipment, it’s a given that pumps will breakdown. Some will have relatively long operational life while some will break down sooner than expected. Many factors contribute to their breakdown but mostly are caused by material failures due to stresses from prolonged or continuous operation. Whether they have short or long operational life, all pumps will breakdown eventually. The irony of the situation is that the North Kona’s deep well pumps seem to be breaking down all at the same time.
So what do I mean by “dual redundant” system? It means that each of our deep wells should have a primary and secondary wells that are used to service a single storage tank. In case of break down, the secondary well will kick in while the primary is being repaired, or vice versa. The result should be transparent with little or no noticeable effect to the customers. The cost of adding a secondary well onto the existing single deep well systems could be relatively high due to additional pumps and related components but it should pay for itself and worth the investment in the long run.
Due to its unique geographic features, North Kona area will always rely on deep wells for its water supply. I urge the community to support this recommendation and the county to implement it.
Nestorio Domingo
Hawaii County Water Board Member
Kailua-Kona