Local and international consultants monitored the construction
by site visits with approximately 2 weeks intervals; a full day journey
from the central office in Bangkok including air, land and sea
transport. In March 2006, about half way through the construction
phase, it was identified that the contractor had mixed soil into the
gravel filter medium, especially in the vertical flow units – maybe
to facilitate the planting of flowers on top of the gravel filter, maybe
to reduce material transportation costs. The contractor was immediately
asked to remove the media in the gravel filters, cleanse the
gravel and re-install the gravel as outlined in the design drawings
and technical specifications. Subsequently, the frequency of
monitoring the construction was increased. The wastewater management
system was put into operation on the 14th of October
2006 (Fig. 4). The total cost of the system accounted to 28 million
Thai baht (approximately $700,000 USD in 2006).