Lowering  SRT always ...

Lowering  SRT always  works...but  if  you have  to  nitrify this could  be tricky... in  warm  waters  (like Florida) we  had  to  to  drop it  to below 0.5  days...but  it   was  a  2 sludge  system and  25 dg. C

Chlorinating RAS can work  but also  can  be tricky...I  do  not  remember dosage needed..check WEF  publications

Surface wasting of   MLSS also works and  is   a  standard  design detail  of  many  major  design  firms  like  Brown  & Caldwell