The results obtained on the experimental plant, together with those obtained on the main plant, where 24 million gallons per day were treated with bleach only, are given in Tables XXVI, XXVII and XXVIII. The two periods given represent the spring flood condition and that immediately preceding it; these are respectively the worst and best water periods. The results in both cases are from samples examined approximately two hours after the application of the chemicals. The cost data were calculated on the current New York prices of bleach and ammonia. TABLE XXVI.--COMPARISON OF HYPOCHLORITE AND CHLORAMINE TREATMENT BACTERIOLOGICAL RESULTS -----+------------------+----------------------+---------------------------- | RAW WATER. | TREATED WITH HYPO- | TREATED WITH HYPOCHLORITE | | CHLORITE ALONE. | AND AMMONIA. +------------+-----+-----------+-----+----+------------+-----+----+---- 1916 | Bacteria | | Bacteria | | | Bacteria | | | | per cubic | | per cubic | | | per cubic | | | |centimeter. | _B. |centimeter.| _B. | |centimeter. | _B. | | +-----+------+coli_+-----+-----+coli_| +------------+coli_| | |Agar | Agar |Index|Agar |Agar |Index| (1)|Agar |Agar |Index| (1)| (2) | 1 | 3 | per | 1 | 3 | per | | 1 | 3 | per | | | day | days | 100 | day |days | 100 | | day | days | 100 | | | at | at | cc. | at | at | cc. | | at | at | cc. | | | 37° | 20° | | 37° | 20° | | | 37° | 20° | | | | C. | C. | | C. | C. | | | C. | C. | | | -----+-----+------+-----+-----+-----+-----+----+-----+------+-----+----+---- Mar. | 44| 238| 35.7| 4 | 12 |<0.14|0.90| 4 | 12 |0.14 |0.22|0.11 15-31| | | | | | | | | | | | April|3,099|14,408|195.5| 32 | 56 | 0.50|1.10| 33 |246 |0.74 |0.25|0.13 1-19 | | | | | | | | | | | | -----+-----+------+-----+-----+-----+-----+----+-----+------+-----+----+---- Legend: (1) Available chlorine parts per million. (2) Ammonia, parts per million. TABLE XXVII _Percentage Reduction_