Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping film by quantifying the transport effectiveness of capillary rivulets in comparison to a flat, thin film. A laboratory constructed fissure comprised of a limestone slab and a glass plate was used to quantify the mass of calcium ions transferred from the rock to the film during the passage of seeping water as either a film or capillary rivulet. While film flow extracted 170% more calcium ion mass than the capillary rivulets, when normalized by the wetted area, the capillary rivulet extracted 300% more calcium ions than the film flow. As mass flux, capillary rivulets exhibit greater potential for solute transfer across the rock-liquid interface than film flow.