The question about CPS/APS and interpreters continues to come up.
CPS and APS are required to bring their own interpreters. Here is the department of family services guidance: http://www.dfps.state.tx.us/handbooks/CPS/Files/CPS_pg_1200.asp#CPS_1251
As a caveat - I would suggest using your judgement if you have a student who has special interpreting needs, such as a student with very low language skills or one who has only recently come the US. CPS and APS still need to bring an interpreter, but you may want to consider having a staff member who truly understands the student’s communication best be involved to help with communication.