Dataset and Code for Estimating Carbonaceous and Nitrogenous Oxygen Demand Partitioning (fN) and DO Sag Analysis in the Potomac River (USEPA 1977)

This Zenodo record provides the data processing workflow, fitted parameters, and analysis code used to estimate the carbonaceous and nitrogenous components of biochemical oxygen demand (BOD) and to evaluate their impact on dissolved oxygen (DO) sag dynamics. The dataset is derived from the U.S. Environmental Protection Agency Potomac River Long-Term BOD Survey (Summer 1977), which includes time-series measurements of carbonaceous BOD (CBOD) and nitrogenous oxygen demand (NOD) at river-channel and wastewater effluent locations. The repository includes: Processed CBOD and NOD time-series datasets used for model fitting Estimated ultimate carbonaceous demand (Lc) and nitrogenous demand (Ln) for each series Computed nitrogenous fraction of oxygen demand, fN=LnLc+Lnf_N = \frac{L_n}{L_c + L_n}fN=Lc+LnLn Code for nonlinear least-squares fitting of Weibull (stretched-exponential) models Statistical analysis scripts (including Mann–Whitney test and effect size estimation) Numerical implementation of a two-stage DO sag model incorporating carbonaceous oxidation and nitrification The objective of this dataset is to support reproducibility of the analysis demonstrating that the nitrogenous fraction of oxygen demand can serve as a quantitative source signature distinguishing wastewater effluents from receiving waters, and to evaluate its implications for dissolved oxygen depletion in rivers. All raw data originate from: U.S. Environmental Protection Agency (USEPA) (1979). Carbonaceous and Nitrogenous Demand Studies of the Potomac Estuary (Summer 1977); EPA 903/9-79-003; Philadelphia, PA. No original raw data are redistributed here; only processed data and derived parameters are included.