Zach Binger contributed to the watertap-org/watertap repository by improving both cost modeling accuracy and developer documentation. He corrected the default capital cost parameter for ultra-filtration in the costing model, reducing the risk of overestimating project costs and enhancing the reliability of financial projections. Using Python and YAML for data configuration, Zach ensured that changes were traceable and reproducible through precise commit practices. He also enhanced the Technical Reference Documentation, adding Python import paths for unit models and updating terminology to align with current architecture. His work improved onboarding efficiency and reduced integration errors, reflecting careful attention to maintainability and clarity.