Development of a percolating sand trap for urban drainage

Development of a percolating sand trap for urban drainage was attempted in this project.
Sand traps in University Teknologi Petronas campus were chosen for the initial observation.
From the observation, most of the sand traps were trapping sand and water. Some become
mosquito breeding ground. Larvae were found in the water retained by sand traps. Several
tests were conducted in this project on soils particle size, laboratory permeability test,
percolation test on field and percolation test with different water table. The result of the
experiment indicated that the mining sand has 0.02 cm/s hydraulic conductivity. Loamy
sand from Seri Iskandar area has 0.000 158cm/s hydraulic conductivity and sandy loam from
UTP new academic building area has 0.000103 cm/s hydraulic conductivity. A prototype ·
sand trap used for field percolation test for each location was able to percolate retained water
within three days. ·From the results, different sizes of opening from the trap do not affect
much to the percolation rate. The percolation rate was affected by soil moisture content and
level of water table. Water of recharge or rainfall percolate through opening below prototype
was cause to the underground soil moisture content and water table increase. This
percolation reduces with lower hydraulic gradient during water table increased. An
improvement in design of the percolating sand trap has to modify to fulfill the site condition
of high water table area. It is necessary to determine site water table level and hydraulic
conductivity before application of percolating sand trap. The procedure appears promising
for field use following prototype using appropriate boundary and initial conditions and field
testing.