This caused problems with dirt and
floatables at the pumping station and the risk of raw wastewater
reaching street level during heavy rain events. The influent
proved more concentrated than expected causing highBODloading
rates at the treatment system. In addition, new and un-controlled
connections resulting from ‘pirating’ and the rapid reconstruction
and return of tourists after the tsunami created higher flow
rates than the designed capacity. Despite the request for rectification
during the construction phase, some soil remained in the gravel filter. Moreover, during the run-in of the system it
was identified that the contractor had made a wrong packing of
the filter gravel and that soil was located in the middle of the
gravel layers in all three vertical flow constructed wetland cells.
This observation with a remark of the increased risk of clogging
was reported by the local expert to the municipality and donor
for them to decide on actions to be taken, herein whether and
how to activate the safeguards. The identified problems would
not seriously impact the system if solutions were implemented
quickly and effectively. However, nobody reacted upon the warnings.