TAP WATER SAMPLES, LRL, BERKELEY Samples were taken daily at 0900 from east sink tap, room 208, Building 4, after letting water run for at least ten minutes. One liter samples were evaporated to dryness and counted at least 7 hours on 3 mg/cm” end-window GM tubes. Wide error spread ie due to relatively high background on GM counters. Calculations are similar to those employed on rainwater samples. TAP WATER RADIOACTIVITY | Sine . Date of Bample Activity Date of Sample April 5, 1958 76220 May 26, 1958 32710 June 7 8 56214 9 86-20 12 22: 8 13 162 7 10 12 14 15 137 9 hotly 6* 6 2a- 6 18 29713 20 21 23% 9 e@2atg 23 <5 19 20 45213 6? 6 <5 2k 25 8t 7 yat 6 30 <5 2g : 13: 8 16 17 May 50°18 8" 5 | 6 <6 9 i6 12 130 19° 20 22 <6 < a) < <3 <i <u <5 9 <5 10 18t 7 16 5 18. 13 6 12 13 wat 5 Tt 5 17 May 14 15 June 20 30 g= 5 ' lhe 6 25 <6 koZ12 63213 July 2 1 7-5 28 8 7 27- & 3 22 7 T= 5 5 < 8 <5 <6 5 14- 6 <5 4 15 6 10> 6 3 aki 5 <3 Activity 2 19 16 he A\ww an 27 1 2 on | Tz 5 <9 <6 Sampling Program Stopped 6= 5

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