Post-wildfire erosion has become an increasingly severe problem in Washington state due to climate change and associated increase in wildfire occurrence and severity, creating economic and environmental problems in addition to threatening human life. Mulch treatments are commonly used to reduce erosion; however, mulch, especially agricultural straw mulch, can pose environmental concerns related to invasive plants and has shown limited effectiveness as a slope stabilizer. Alternative methods include polyacrylamide (PAM) or novel xanthan gum (XG) treatment. Our preliminary results showed that both additives can reduce erosion without sealing the soil surface completely. However, if the additives are transported into streams over time, water quality problems downstream may arise due to an increase in nitrogen and phosphorus export or increases in dissolved organic carbon concentrations. The downstream water quality effects of PAM and XG dissolution into streamwaters are unknown. Therefore, the primary objective of the proposed research is to evaluate PAM and XG application on wildfire-burnt slopes and explore the effects on downstream water quality. Indoor rainfall simulation experiments will be run to quantify the amount of PAM or XG leached into runoff after multiple wet-dry cycles during different intensity rain events. The runoff samples will be analyzed for water quality. Controlled experiments will be conducted to measure the impacts of PAM and XG on water quality at different concentrations. The results of this study will provide scientifically supported guidance to stakeholders such as forest and watershed managers for the use of PAM or xanthan gum for post-wildfire erosion management.