Methodology
Uses the selected basin geometry and active basin count to calculate plan area, surface overflow, detention, weir loading, optional solids loading, and one-unit-out cases. Criteria and geometry are user supplied; this screen does not predict settling/removal or determine code or regulatory compliance.
Basin plan area uses only the selected geometry: length × width, pi × diameter squared / 4, or the entered area.
Surface overflow rate = design flow / active plan area. Volume = active area × side-water depth; detention time = volume / design flow.
Weir loading = design flow / active weir length. One-unit-out calculations use N - 1 identical basins and their remaining weir length.
Solids loading = the entered plant solids mass flow / active plan area. The same plant solids mass flow is distributed across the remaining active area for the one-unit-out case.