Are TTHM and HAA5 the only disinfection byproducts?
No. TTHM and HAA5 are measured and regulated in the EPA Disinfectants and Disinfection Byproducts Rules because they function as indicators for DBP occurrence. There are many other known DBPs, as well as yet unidentified DBPs present in disinfected water. TTHM and HAA5 typically occur at higher levels than other known and unknown DBPs. Their presence is representative of the occurrence of many other chlorination DBPs; thus, a reduction in TTHM and HAA5 generally indicates a reduction of DBPs from chlorination.
