TABLE 1

Repeated Well Counter Measurements of Background Levels and a ¹³⁷Cs Source

Well	Background measurements ¹¹C									¹³⁷Cs measurements
Well		n	Mean	SD	Min	Max	n	Mean	SD	Min	Max
1	63	173	15	138	207	49	28,797	134	28,502	29,080
2	63	178	14	144	210	49	28,537	183	28,187	28,954
3	63	169	13	144	200	49	29,250	134	28,795	29,494
4	63	178	11	153	203	49	29,427	168	28,964	29,751
5	63	181	13	144	206	49	28,638	169	28,073	29,042
Total	315	176	14	138	210	245	28,930	383	28,073	29,751