Impacts of reduced domestic water use on stream water quality in suburban watersheds

Septic systems in suburban watersheds significantly contribute to nitrogen (N) pollution, affecting water quality and aquatic ecosystem health in local and downstream waterbodies. This study explores how reduced domestic water use impacts the movement and retention of nitrate (NO3-) in local streams by modifying septic system discharge. By implementing a scenario analysis with an ecohydrological model, Regional Hydro-Ecological Simulator System (RHESSys), in the Baisman Run, Baltimore, Maryland, we assessed the effects of varying septic water usage on N cycling and hydrological processes. Results indicate that reducing septic water use by 50% could decrease mean NO3- concentrations, assuming unchanged water distribution practices like lawn irrigation. This suggests that managing groundwater extraction and septic system use could enhance water quality, calling for further research to establish effective residential water usage guidelines.