the test before placing the organisms in the test solutions. The organisms were not fed during the 

 48-h test period. Mortality in the control and storage control solutions may have been caused by 

 the lack of food during the test period. The three porewater solutions, although filtered through a 

 1 10-um-mesh screen, may have contained fine particulate matter which could have provided a 

 temporary food source for the organisms, thus reducing mortality. 



Table 3. Mortality data for the Ceriodaphnia dubia acute toxicity tests of selected porevvaters of Reach 15. 

 Mortality in the control mussels was hiaher than 10 % (as indicated bv the asterisk, *) making this test invalid. 



3.1.2. Ceriodaphnia dubia Survival / Reproduction Assay 

 Porewater for the C. dubia survival / reproduction assay was depleted after six days. No adult 

 mortality was recorded in control, storage control or Sylvan Slough porewater solutions, but one 

 adult death occurred in each of the ALCOA and Campbell's Slough solutions. Adult death was 

 recorded on Day 4 of the experiment for ALCOA, and on Day 7 for Campbell's Slough. 

 Differences between observed mortality in the storage control and porewater solutions, and in the 

 control solutions were not significantly different (Fisher's Exact Test, p < 0.05). Therefore, it 

 was concluded that the porewaters were not acutely toxic. 



A total of 146, 188, 143, 24, and 127 young were produced by adults in the control, storage 



