Rains have no doubt brought relief to Bengaluru. However there was a flip-side to it at the Varthur lake. The lake has begun foaming once again. Toxic foam was spilling over to the Whitefield Main Road and commuters had a tough time negotiating traffic on Saturday and Sunday.To make matters worse was the unbearable stench emanating from the lake. The residents say that that the situation is so bad that the froth had reached a mall and a hospital.