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MERC STDN Test Plan
3
independent of treatment. Similarly, concentrating natural assemblages of plankton on nets, and
introducing
them into ballast water being pumped into tanks, can often result in significant
handling associated mortality. Given the unpredictable physical and biological conditions found
in all natural waters, IMO G8 MEPC 58/23 ANNEX 4, Part 2, Section 2.3.36 is used by MERC
as the standard for a valid test trial: “If in any test cycle the average discharge results from the
control water is a concentration less than or equal to 10 times the values in regulation D-2.1, the
test cycle is
invalid”. While a goal of MERC is provide independent G8/ETV data on the
performance of ballast water treatment systems, it is ultimately up to an Administration to decide
if the system meets their requirements for Type Approval Certification.
Table 1. Ranges of various physical and biological parameters in ambient water during the testing season
(March/April – October/November) in the Port of Baltimore in comparison to ETV/USCG and IMO G8
recommended challenge conditions. Port of Baltimore data collected by MERC and various academic
and agency studies or monitoring efforts in the general location of the
Cape Washington
(Patapsco River).
†
Generic Protocol for the Verification of Ballast Water Treatment Technologies: Draft v4 2008, US EPA
Environmental Technology Verification (ETV) program under contract to US Coast Guard.
‡
IMO Guidelines for the Approval of Ballast Water Management Systems (G8), October 2008, Annex 4
Resolution MEPC.174(58).
* TSS, POC and DOC (2004-2007) MD DNR Chesapeake Bay Water Quality database:
www.chesapeakebay.net/data_waterquality.aspx. Zooplankton (1998 – 2002) and phytoplankton (2004-
2007) Chesapeake Bay Program: www.chesapeakebay.net/data_plankton.aspx. Bacteria (1998 – present)
Cowell and Huq, University of Maryland; Louis et al. 2003, AEM 69:2773-2785.
For this specific evaluation of the BalPure treatment system, Severn Trent De Nora has
made a special request to MERC to augment intake water to more consistently approach the
initial challenge water conditions described in the G8 guidelines during the test trials. While
MERC does not make any guarantees on the precise conditions of challenge water, humic acid
and Arizona Test Dust (as proposed by ETV and NRL Key West) will be injected inline during
Parameter
Proposed
ETV/USCG
†
Recommended
IMO G8
‡
Historic Ranges*
Port of Baltimore
Temperature (
o
C)
10 - 35
–
4 - 28
Salinity (psu)
0 - 31
Two salinities, >10
psu difference
5 - 15
Total Suspended
Solids (mg/l)
> 15
> 50
1 - 60
Particulate Organic
Carbon (mg/l)
> 1
> 5
0.5 - 6.0
Dissolved Organic
Carbon (mg/l)
> 3
> 5
2 - 10
Zooplankton (> 50
µ
m) / m
3
> 10,000
> 100,000
10,000 - 300,000
Phytoplankton (10 -
50
µ
m) / ml
> 100
> 1,000
500 - 15,000
Heterotrophic
Bacteria cfu / ml
> 1,000
> 10,000
10,000 - 10,000,000