401 KAR 8:420.  Volatile organic chemicals (VOCs).

The system shall collect one set of samples per entry point to the distribution system or representative site of each source for four consecutive quarters at initiation of water system operation.  

A surface water system shall collect one set each year of the three-year compliance period.  

A groundwater system shall collect one set per three-year compliance period. 

If any contaminants exceed the respective detection limit, the system shall sample the contaminants quarterly. A surface water system shall sample the contaminants for a minimum of four consecutive quarters with results less than the maximum contaminant levels (MCLs). With Drinking Water Branch approval, the system shall then sample the contaminants annually during highest historical quarter. 

A groundwater system shall sample the contaminants for a minimum of two consecutive quarters with results less than the MCLs. With Drinking Water Branch approval, the system shall then sample the contaminants annually during highest historical quarter.

A confirmation sample collected within two weeks at the same sampling point as an MCL exceedance may be averaged with the first sample to determine compliance.

Technical Fact Sheet from EPA on VOCs.