February 4, 2002

Dear Mr. Alcamo,

In reference to a document cited on the COPA web site dated November 16, 2001 from Tetra Tech EM, Inc. called "Data Evaluation Summary of 2001 Split Sample Analytical Results", I object to the EPA's explanation for data differences (see attached).

First, no data, nor explanation are given for the split sample sent by PSARA for the Bennett's Dump sample for MW-6I. What happened to this sample? Second, the data presented for samples taken at Lemon Lane Landfill on August 9 and 16, and September 27, 2001 for LL-PXD, LL-LF6-8", and LL-PZD have extreme differences between analyses for portions of samples from the same volume sent to two separate laboratories. EPA's contractor has attributed the discrepancy between results from the two laboratories to normal variation in the analytical method. I must defend EPA's analytical methods as far more reliable than claimed by your contractor. To produce results that differ by more than 1,400% (as for sample LL-PXD) cannot be casually explained as normal method variation. More seriously, it can imply that data used for cleanup decisions and health assessments could also be in error by such magnitudes. A sample, cited as 50 ppm and meeting the cleanup goal, may actually have more than 700 ppm when left on site. Water analyses meeting a 0.3 ppb goal may actually have far more dangerous levels of contaminants when released into Sargent's Pond or Clear Creek.

EPA's SW-846 Method 8082, (or any other EPA method for PCB analysis used for waste sites) should not produce such differences except when the methods are applied incorrectly. I have reviewed Method 8082 and must suggest that other serious laboratory errors are more likely the cause, rather than those suggested by your contractors. If the EPA verifies that the data presented here are correct, and maintains that the method was correctly carried out, then it brings into serious question these data and all others for the Bloomington sites (and all other sites using these methods). This indicates that results presented to date can all have had extreme errors and that decisions on health risk assessments and cleanup levels all could have errors of this magnitude.

I request that you investigate this matter and provide a complete explanation of the source of the problem and its resolution, including a plan to provide better oversight on data gathering procedures for these sites. If EPA's methods are at fault, other data for these sites (and most other analyses for PCBs) could involve errors of this magnitude. In that case, we must begin to examine all other data for the Bloomington project to determine if EPA has used erroneous analyses or data in its decision-making.

I raise this issue because the EPA has been the victim of laboratory misdeeds in the past and that data used for the Bloomington investigations and cleanups has continued to raise data quality questions. I am attaching a copy of my examination of other EPA reports containing similar data quality questions that I believe your office should address. These six pages indicate only some of the ongoing questions that need attention in order to restore confidence in your work here in Bloomington.