2. Water 2.1 Sr?° in Tap Water - New York City New York City tap water has been analyzed since August 195). Until the end of November 1956, the sampling period lasted about two weeks during which time an average of 50 liters was collected (3-4 liters per day). Since December 1956, the collections are made over a period of a month and the total volume is about 100 liters. The strontium 90 content in pyc/liter is shown in Table 7 for collections made in 1958, Data for collections carried out before 1958 have been presented in HASL-l2 ent2tled "Environmental Contamination from Weapon Tests", Figure 7. Data for all samples analyzed are presented graphically in The error term depicts one standard deviation due to the error in counting. ~ 535