Environmental Impact Assessment (EIA) is needed for development projects that may have negative
impacts on people and environment. A screening procedure plays a crucial role in determining whether
an EIA is required for a particular proposal. Misjudging the EIA requirement results in the unnecessary
EIA being undertaken and causes mental anguish to the people who are in trouble because carrying out
the EIA takes a long time. This article presents a case study of coastal protection by detached breakwaters
in Nakhon Si Thammarat province, Thailand, where an initial environmental examination found no
significant environmental impact and the EIA was deemed unnecessary by coastal communities. After an
engineering design of the detached breakwaters had been completed, the people, whose houses and
properties were at risk of sinking into the sea, had to wait one more year for the EIA to be completed. The
willingness to pay (WTP) of the people affected to bypass the EIA was measured by a single-bounded
dichotomous choice approach. Their mental pain caused by waiting for the detached breakwaters was
equated to aggregated WTP which was about US$ 724,160. Such a large WTP from the poor coastal
dwellers sends an urgent message that the categorical screening in Thailand’s EIA legislation may need
some adjustments.