One of the key drivers of cost and GHG emissions is the ion exchange unit within the NCS which uses zeolite to remove nitrogen. The baseline design consists of 3 zeolite regeneration events per year and complete replacement every 3 years. Two alternative design scenarios for the NCS unit were evaluated, including (i) a zeolite replacement only scenario where zeolite is not regenerated and is instead replaced annually, and (ii) an increased zeolite capacity scenario where the zeolite capacity is increased 3-fold and replaced annually. The zeolite replacement only scenario and increased zeolite capacity scenario had negligible impact on per capita cost, while GHG emissions increased by 50.8 kg CO2eq•cap -1 •yr -1 for both scenarios (Figures and). Although the cost and emissions associated with regeneration labor and consumed NaCl (in regenerant solution) is reduced in both scenarios, the increased consumption of zeolite (from annual replacement) incurred equal costs and greater emissions. Therefore, the baseline design using zeolite regeneration would be preferable over these alternative zeolite configuration scenarios as reductions in labor and regeneration consumables do not outweigh the impacts of additional zeolite consumption.