Fig. 4. Breakthrough curve of Br measured in the monitoring well at the low P site up-gradient of the winter sprayfields. The water table was 7 m below the ground surface. Wastewater containing Br was applied in two pulses on Days 1 through 3 and on Days 50 through 52. Bromide was not added to wastewater applied on Day 4 and on Days 14 through 18.