Animal consumers contribute to fluxes and ambient pools of key nutrients through excretion and egestion, influencing stream biogeochemical processes. Aggregations of consumers can create hotspots of nutrient cycling due to high areal rates of biological activity. Freshwater gastropods have the potential to influence ecological processes due to their high abundance and role as primary consumers, yet few studies have attempted to quantify their contributions to nutrient cycling in streams. To understand the role of freshwater snails in nutrient cycling, we conducted excretion assays with Elimia boykiniana, a Pleurocerid occurring in high densities in Ichawaynochaway Creek, GA, USA. We incubated individual snails in 15 mL of filtered stream water for one hour, after which we filtered and analyzed water for ammonium and soluble reactive phosphorus. We quantified egestion rates using the mass of egestion pellets that we filtered out of the sample at the end of the trial, and hourly rates of ammonium and phosphorus excretion by taking the difference of snail treatment and the average of control (no snail) treatment concentrations. We determined mass-specific excretion and egestion rates using a length-mass regression curve developed for E. boykiniana, and calculated areal rates using densities from 10 surveyed shoal reaches on Ichawaynochaway Creek. Excretion and egestion rates varied with individual size, and areal rates varied across sites with position in the watershed. Our results shed light into the functional role of an endemic pleurocerid in a low-gradient, coastal plain stream, illustrating the ecological significance of an under-studied group of freshwater organisms.