Pumping fluids out of or reinjection into the porous media is very popular in engineering applications, such as hydrogeological engineering, environmental protection, biomechanical engineering, etc. These source terms in mass equation of Darcy's model have rarely been discussed when using Lattice Boltzmann Method (LBM). This paper analyzes a simple scheme for simulating pumping or reinjecting water in a confined aquifer. The D3Q7 MRT model was used and an accuracy analysis was conducted by comparing the simulated results of the proposed scheme with Theis's theoretical solutions. In addition, a detailed discussion was carried out for the case that the pumping and reinjection wells are not at the same grid nodes, and a simple implementation scheme is proposed.