March 2, 2010 · 11:11 AM
I trust that our City Council has taken note of the tragedy in Haiti. Of immediate concern to Mercer Islanders should be the high failure rate of wells. To those who have paid attention to seismic effects on wells, this comes as no surprise. Additionally, wells that should happen to survive seismic events are often contaminated or suffer severe drops in the water table, rendering them unusable. Worldwide experience has shown that wells without sufficient redundancy are not a satisfactory solution to emergency water supplies after an earthquake. Surely, an earthquake that would damage or destroy the city’s water supply has a high probability of doing the same to our single little well.
Mercer Island’s City Council solution was to build one well at a cost of over $1 million. Other cities have much broader solutions to such a catastrophe. For example:
The city of Palo Alto, Calif., has drilled wells in the event that earthquakes damage the Hetch Hetchy Aqueducts. They have, however, drilled 16 wells to provide a margin of safety for the inevitable failures. Officials there were shocked that a community like Mercer Island, surrounded by fresh water, would opt for a single well when lake water is available for filtration.
A major earthquake will likely contaminate the lake with sewage. Mobile filtration systems exist that can provide potable water from biologically, chemically or radiologically contaminated water from fresh or saltwater sources. As these systems are mobile (either contained in 40-foot containers or self-propelled), they could be offered as mutual assistance to communities in the area suffering from floods or other disruptions of the drinking supply.
The Council dismissed the above information while decisions were being made prior to drilling our $1 million well.
I pray that my observations are never proved correct, but I fear we have spent a considerable amount of money on a project that will likely not provide water in an emergency.