D-2 Discharge Compliance Check

Contents

BWM Convention D-2 limits for treated ballast water: ≤ 10 viable organisms/m³ (≥ 50 µm) and ≤ 10/mL (10–50 µm).

Formula

$$ \begin{array}{l} N_{\geq 50\mu m} \leq 10 \text{ per m}^3 \ N_{10-50\mu m} \leq 10 \text{ per mL} \end{array} $$

Symbol	Meaning	Unit	Source
$≥50 µm$	Zooplankton-sized organisms	per m³	sample + count
$10–50 µm$	Microalgae-sized organisms	per mL	sample + count
$E. coli / Enterococci / V. cholerae$	Indicator microbes	cfu/100 mL	microbiological assay