Mathematical Modeling of COVID-19 Outbreak Dynamics (ARA Werdhölzli, Autumn 2020) Compared to Telecommunication Network Thresholds and 25% Lineage Displacement Dynamics Dr Theodor Heutschi System Dynamics & Network Analysis Research Group | www.heutschi.com Date: July 2026 ABSTRACT In this working paper, we investigate the identification of critical phase transitions (tipping points) in biological-epidemiological systems using passive, unbiased wastewater measurements from the ARA Werdhölzli wastewater treatment plant (autumn 2020). Conventional individual test data suffer from systematic selection and testing capacity biases (ascertainment bias). We demonstrate that the wastewater viral load (SARS-N1/N2) provides an ideal, aggregated signal for determining the exact tipping point of the outbreak dynamics using derivative analysis (Ruck j(t)) and System Dynamics. At the end of October 2020, the system tipped from linear to highly exponential growth at a measured concentration of C = 39.2 ng/L (normalised gene copies). We calculate the cumulative prevalence at this tipping point to be exactly 0.43% of the total population in the catchment area (~2,050 cumulative cases out of 470,000 inhabitants), which corresponds to an effective reproduction number of Reff ≈ 1.8 to 2.2. Furthermore, we extend the modelling to include the displacement dynamics of new viral variants: as soon as the signal share of a new mutant exceeds the critical threshold of 25 per cent, the logistic substitution curve reaches its maximum surge, after which complete dominance (> 80 per cent) becomes mathematically deterministic. Finally, we compare this epidemiological outbreak threshold (< 0.5 per cent) and the 25 per cent substitution threshold with the empirically determined critical mass in mobile networks (25 per cent–27 per cent market penetration) and highlight the fundamental systemic similarities and differences.