Worked on the watertap repository to enhance the reliability and clarity of the costing module, focusing on both documentation and unit consistency. Applied technical writing and Sphinx skills to standardize formatting, correct typos, and add references, resulting in clearer guidance for costing methods. Updated the electricity_cost unit from a fixed USD value to a flexible base_currency, ensuring consistency across modeling and tests for dye desalination flowsheets. Adjusted the Python-based test suite to reflect these changes, improving cost calculation reliability. These updates support better cross-system reconciliation, reduce error risk, and streamline onboarding for engineers working with unit conversion and costing.