Special microbiology of Legionella?

Would the health department be able to identify this microorganism by performing routine water-screening procedures, such as serial dilutions followed by incubation on EMB or TSA plates?

Standard microbiological media including EMB or TSA will not support the growth of Legionella. Special procedures and media are required for isolation and identification of Legionella. A few health dept microbiology labs do have this capability.