A MAR to address the water with high content of suspended solid with a case study in the Yellow River flood plain, China

Managed Aquifer Recharge (MAR) system is often adapted to alleviate drawdown cone and increase the water supply. In this study, an Open channel-Underground perforated pipe-Shaft system which included three identical subsystems was designed on the basis of local ditches, and applied at the Yellow River flood plain, Linqing city in North China. Three anti-clogging methods of the filter tank, inclined underground perforated pipe and shaft were adopted to lower the amount of fine suspended particles in source water. The dimensions and materials of each subsystem were tested and then determined by analytical method, numerical method and laboratory physical model experiment. The filter tank bottom area is 4 m2, perforated pipe diameter of 30 cm, length of 200 m made from plastic blind drains wrapped with geo-textile and 20 cm of coarse sand filled around, slope of 1/500, and the shaft depth of 10 m. A pilot project was constructed in the study area covering 5.4 hm2. Field recharge experiment and tracer test were conducted so as to monitor groundwater level and flow rate in perforated pipe. The measurements showed that the total infiltration amount attained from the field recharge experiment was 65,925 m3, which was close to the simulation results by analytical and numerical methods; the average velocity in the perforated pipe between the inlet and the shaft was 150 m/h approximately by both tracer test and theoretical calculation. This MAR project has the advantages of no energy consumption, no land occupation, managed groundwater recharge and water logging control. Therefore, its wider application in the location with similar conditions can be expected in future.