By Michael Howden
We do have a choice of what sort of water our families drink: stream water with some organic matter in it, which can be cleaned and otherwise processed by our water treatment plants; or ground water highly contaminated by numerous agricultural chemicals – such as DBCP, TCP and EDP – as well as potential nitrates, which we trust will be decontaminated by charcoal filtration.
There are unknown costs of running minimum 72-hour pump tests to determine the sustainable yield for the Hamakuapoko wells, tests for a complete battery of contaminants, as well as Department of Water Supply staff to monitor these tests.
If new contaminants are found, what would be the cost of additional treatment? For example, high nitrate levels will not respond to the granular-activated carbon filtration used for DBCP and, in fact, will clog such filters rendering them ineffective in taking DBCP out of the system.
The Hamakuapoko wells are described as backup wells. Yet if they are not used on a regular basis there will be bacterial buildup in the filtration system, which raises another set of water quality issues.
Further, the sustainable yield of the aquifer is, according to figures given by the state Commission on Water Resource Management, somewhat inflated due to the present diversion of stream water into the aquifer. If this source is diminished, what will be the effects on these wells?
I don’t understand why we don’t use the water we already have rights to, not simply under the largely ignored Public Trust Doctrine, but by the relatively unknown and often forgotten Memorandum of Understanding by the County of Maui and Hawaiian Commercial & Sugar/East Maui Irrigation.
Maui County has the rights of withdrawal from the Wailoa Ditch of 3 to 4 million gallons per day more than we are presently taking. Under certain circumstances, the county has the right to withdraw up to 16 gpd, though the plant at Kamaole Weir, even with continual upgrades through the years, still cannot process near that amount. But the county can easily treat an additional 2 million gpd more than we are presently using (on average).
What is the sense of putting a severely contaminated well online even as an emergency backup? The cost of running such a well whose production figures are still estimates, in an aquifer the potential of which (for withdrawal) is still in question – a well whose very use brings a divisive tenor to all community discussions on its use – is very high.
Rather than facing higher and higher costs due to pumping Hamakuapoko’s water to the surface and then to Kamaole Weir, along with the increasing costs of filtration, how can it possibly be worthwhile even to run the Hamakuapoko well when we already have substantial access to the surface waters arriving at the Kamaole Weir?
Even if we eventually had to build a second treatment plant at Kamaole Weir (or further along the ditch system), would not this make more sense than dependence upon the waters of the Hamakuapoko wells?
* Michael Howden is past chairman of the Maui County Board of Water Supply. He lives in Makawao.