0.1 |jg/g. Washington had a high MDL for tin (20 |jg/g) however due to the method of 
calculating the MDL for this compound the RL (0.2 pg/g ) was lower than the MDL and 
close to the recommended detection level of 0.1 pg/g. 
California and Oregon met all the DQOs for the average deviation for all 
sediment metals, deviations for the individual metals, and for precision. California had a 
low accuracy for silver while Oregon had a low accuracy for tin. Washington met the 
precision and the matrix spike recovery DQOs for all metals. However, the average 
deviation for the 15 metals in Washington was 29.8%, exceeding the DQO of an 
average of 20% for metals. Failure to meet this DQO was due to the high deviance 
(>90%) for arsenic, selenium, and tin, and values for these metals should be interpreted 
cautiously for samples from Washington. 
2.5.3 Organics in Sediments 
The recommended MDLs (Table A7-2 in U.S. EPA, 2001) are 10 ng/g for PAHs 
and 1 ng/g for PCBs, DDTs, and chlorinated pesticides. All three states met the MDL 
requirements for all the organic compounds with the exception of toxaphene in 
California which had a MDL of 10 ng/g. With the exception of PCBs for one of two 
standards used by Washington, all three states met the DQOs for recovery from matrix 
spikes and for precision for all the organic compounds. 
In terms of accuracy, California met the DQOs that the average deviation for all 
PCBs was within ±30% of the average value within the standard reference material as 
well as that 70% of the individual PCB congeners were measured within ±35% of the 
true values. Washington failed to meet the recommended average deviation from 
reference materials of <30% for PCBs. The major factor driving this failure was PCB 
congener 105 which had a percent deviation of 192%. When all the PCB congeners are 
considered, 83% of the individual congeners were within ±35% of true values. Oregon 
accuracy for PCBs was not as high as the other two states, with an average difference 
between the reported PCB values and the certified values of 115% or 71% if PCB 170 is 
excluded. Only three of the 19 PCB congeners were within ±35% of true value in the 
standards even though recoveries were high in the matrix spikes. In analyzing the 
sediment PCB data, the Oregon data should be interpreted cautiously as should the 
PCB 105 data from Washington. 
Both California and Oregon met the accuracy DQOs for sediment DDTs, though 
Oregon had poor accuracy with 2,4'-DDE. In Washington, all three of the DDTs 
measured in the standard reference material exceeded the value in the standard by 
>50%. In analyzing the sediment DDT data, the Washington values should be 
interpreted cautiously 
The standard reference materials used by the three states did not contain most 
of the non-DDT pesticides, so that it was necessary to use the recoveries in the matrix 
spikes as a measure of accuracy. In California, all the recoveries from the spiked matrix 
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