Ballast Water Sampling and Sample Analysis for Compliance Control - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 180

Sampling for Compliance Control with the D-2 Standard

Compliance control with the D-2.1 standard is purely quantitative, thereby ignoring
the types of organisms with the exception of the indicator microbes (D-2.2 standard).
The numbers of viable organisms per size class document (non-)compliance. As the
BWM Convention in Regulation D-2 reads “Ships conducting Ballast Water
Management in accordance with this regulation shall discharge less than 10 viable
organisms per m 3 …” the D-2 standard is clearly understood as a discharge stan-
dard. This indicates that the most appropriate sampling point to proof D-2 standard
compliance has to be installed in the discharge line of the vessels ballast water sys-
tem. This is also recommended in the Guidelines G2, i.e., “samples should be taken
from the discharge line, as near to the point of discharge as practicable, during bal-
last water discharge whenever possible.”
However, in-tank sampling should also be considered as a valid option for D-2
standard compliance control. This is because some vessels, e.g., certain bulk carriers
and tankers, may have upper side wing tanks which are emptied via direct overboard
discharge valves and not by using ballast pumps and pipework (see Fig. 2 ). In such
cases, the Guidelines G2 indicate that in-tank sampling may be an appropriate
approach.

Fig. 2 Ballast water discharge above pier level from the upper wing tanks of a bulk carrier
(Photo: Jure Barovi č , Port of Koper)