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MERC+GSI – DRAFT Test Plan
14
Table 3. Great Ships Initiative Standard Operating Procedures Relative to Toxicity Testing.
Analytical Methods of Chlorine Determination:
Samples for chlorine analysis will be collected from the discharged water. Twenty ml of
sample will be transferred from the sample collection container into a 30 ml beaker. The samples
will have 200 µl of potassium iodide reagent and 200 µl of acetate buffer reagent added to them.
Samples will be analyzed for total residual chlorine concentration as soon as possible after
having been collected. Analysis will be conducted with a Thermo Orion Model 97-70 Residual
Chlorine Electrode connected to an Orion Model 290A pH/mV/ISE meter.
A 100 mg/L chlorine stock solution will be prepared daily. Analytical standards, ranging
in concentration from 5 to 3000 µg/l, will be prepared in deoxygenated deionized water by
making dilutions of the 100 mg/l chlorine stock. Potassium iodide reagent and acetate buffer are
added to the chlorine containing analytical standards. Chlorine present in the standards/samples
oxidizes iodide to iodine in an acidic solution. The iodine concentration after the reaction is
equal to the chlorine concentration present before the reaction. A calibration curve plotting log of
the chlorine concentration (x-axis) versus the mV response from the Residual Chlorine Electrode
(y-axis) is used to determine total residual chlorine concentrations in the samples.
Quality control sample analysis consists of analyzing duplicate samples and samples
spiked with known amounts of chlorine. Approximately 10% of the samples will be analyzed in
duplicate. This is also true for spiked samples in dechlorinated laboratory water.
Experimental Design and Test Conditions:
Toxicity tests will be conducted on the discharge from all test trials. As required by the
IMO, the discharges will be tested with three freshwater species as described in Section 2.1
(IMO, 2006). Both acute and chronic data will be generated for each test. A dilution series, using
Duluth-Superior Harbor water, will be run for each species.
Test samples will be collected at the time of discharge from the GSI facility. Samples will
be collected by the GSI staff for analysis of both the efficacy of treatment at eliminating
organisms from the ballast water and to investigate residual toxicity at discharge as described
earlier in this document. Test water will be stored in large HDPE containers and held at 4°C in
the dark to retain as much of the initial toxicity as possible. Portions of this sample will be used
each day to serve as the renewal water for the bioassay. Sub-samples of each will also be sent to
a certified chemistry laboratory for analysis of disinfection byproducts. GSI Testing Team will
collect/ship all samples for chemical analysis and manage analytical results but costs of chemical
analysis will be covered by Siemens.
All of the tests will be conducted in temperature-controlled incubators at the University
of Wisconsin-Superior’s Lake Superior Research Institute, which is located less than 6 city
blocks from the testing facility immediately following sample collection.
GSI SOP Code
Test Type
Test Species
Test Endpoint
GSI/SOP/BS/RA/RT/5
Acute
Selenastrum capricornotum
Survival
GSI/SOP/BS/RA/RT/1
Acute
Ceriodaphnia dubia
Survival
GSI/SOP/BS/RA/RT/2
Acute
Pimephales promelas
Survival
GSI/SOP/BS/RA/RT/8
Chronic
Selenastrum capricornotum
Growth
GSI/SOP/BS/RA/RT/6
Chronic
Ceriodaphnia dubia
Reproduction
GSI/SOP/BS/RA/RT/7
Chronic
Pimephales promelas
Growth