Mass transport across densely packed surfactant covered oil-water interfaces in microemulsions plays a key role in numerous applications, such as separations, reactions, drug delivery, and detoxification. We use coarse-grained molecular dynamics simulations to investigate solute transport in model systems containing flat hexadecane-water interfaces covered by monolayers of non-ionic surfactants. To elucidate the role of the monolayer microstructure in the solute transport, we perform a detailed analysis of structure, size, and life-time of short-lived pores formed between surfactants within a monolayer. We demonstrate that the pore statistics is consistent with predictions of percolation theory and apply this theory to identify the characteristic length-scale of the monolayer microstructure. The obtained pore structures are sensitive to minute changes of surfactant configurations occurring on the picosecond time-scale. To reduce this sensitivity, the pores are averaged over short time intervals. The optimal duration of these time intervals is estimated from analysis of dynamics of pores with diameters comparable to or exceeding the characteristic percolation length-scale. The developed approach allows us to filter out transient events of the pore dynamics and to focus on events leading to substantial changes of the monolayer microstructure. Once the dynamics of the monolayer microstructure is resolved, we investigate its correlations with the dynamics of the solute motion and assess possible cooperative effects between the solute transport and such processes as creation, destruction, fission, and fusion of pores within the monolayer.