Thousands of wells along Sri Lanka's coast remain
unusable because of contamination caused by the Asian tsunami 17 months ago, a
government official said, as international monitors urged new measures to tackle
the problem.
S.R.J.R. Senanayake, an official at the state-run Water Supply Management
Board, acknowledged Tuesday that a project to restore wells affected by the
10-meter (33-foot) high waves has so far failed.
"Initially, we thought that by flushing those wells, salinity could be pumped
out," he told The Associated Press. "But it was not successful and salinity
continues to prevail and people can't drink that water."
Some 40,000 wells _ usually hand dug and relatively shallow _ were destroyed
or contaminated by the tsunami.
A 14-member international research team from the United States, Sri Lanka and
Denmark found during investigations from February to September 2005 that the
waves had affected coastal drinking water sources in several ways.
First, the tsunami itself, which reached up to 1.5 kilometers (0.9 miles)
inland, poured sea water, along with other contaminants, directly into the open
wells, rendering those that were not destroyed unusable.
Efforts to restore wells by pumping out sea water were sometimes apparently
counterproductive, as excessive pumping may have allowed more sea water to enter
the aquifer from below, the researchers wrote in a paper published in the
American Geophysical Union journal Water Resources Research.
Second, in addition to direct contamination of wells, large quantities of sea
water penetrated from the flooded surface of the land through porous layers
below and into the aquifer, they said.
As a solution, Senanayake said the board had decided to provide pipe-borne
water to all the affected areas.
The researchers, led by Prof. Tissa Illangasekare of the Center for
Experimental Study of Subsurface Environmental Processes, located at the
Colorado School of Mines, said that around the world, devastating floods can
also be caused by storm surges, hurricanes or cyclones, and rising sea levels.
They urged hydrologists to participate in the formation of emergency plans
that could greatly reduce human suffering.
The December 26, 2004, tsunami killed more than 31,000 people and affected 1
million others in Sri Lanka, a tropical island of 19 million people off India's
southern coast.
