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Underground Injection Control Branch Guidance No~ ~wyg://35Pottp: //ww w.e pa.gov/reg5oh2o/u i Gr5_O5. htm ATTACHMENT8 RADIOACTIVE TRACER SURVEYS FOR DEMONSTRATING PART 2 OF MI A. Basis Acceptance of the test as a means for demonstrating part 2 of MI is limited to those wells where t is no aquifer between [he injection zone and the base of the lowermost USDW and where there is significant water quality difference between individual USDWs. The basis of the test is [hat flow will follow the well bore upward if the cement seal is poor at anc above the base of the casing for open-hole completions or above the uppermost perforation for perforated completions. If the cement at the top of the injection interval is sound and there is no movement upwazd along the casing at that point, it is assumed that there is no alternate conduit which might allow injected liquids to reach the well bore at a shallower depth and then travel ups through either an uncemented or ineffectively cemented well bore. The analyst is primarily conce with identifying the uppermost depth at which tracer material can be seen to be moving within an then exiting the well bore. B. Advantages and Disadvantages Informational Advantages Relative to other Demonstrations ~ None Informational Disadvantages Relative to Other Demonstrations ~ None Operational Advantages Relative to other Demonstrations ~ Can be run with the well injecting Operational Disadvantages Relative [o Other Demonstrations ~ Only valid for part 2 when there are no aquifers between the base of the casing and the bast the lowermost USDW and no significant differences between quality of the USDWs ~ Cannot be used to determine interformational flow where the tracer material cannot be introduced iota the flow stream outside the casing C. Equipment and Forms These are identical to those described for the RTS in A[tachtnettt 3. D. Procedures for Running the Radioactive Tracer Survey (RTS)as a Demonstration of Par of MI The demonstration of mechanical integrity requires that [he packer be seated or the tubing be removed from the well. Three different test methods are usually employed at each instance of testing: 1) slug tracking, 2) 26 of 34 528/99 1:09 PM