Compliance with the TTHM and HAA5 MCLs
Compliance with the TTHM and HAA5 MCLs for Stage 2 DBPR is based on your monitoring results at each monitoring location.
If you monitor once per quarter:
- Compliance is based on the LRAA of monitoring results, calculated quarterly.
- Compliance will be calculated after four quarters of data have been collected and continue after each quarter.
- If you fail to complete four consecutive quarters of monitoring, compliance with the MCL will be calculated based on the average of the available data from the most recent four quarters.
- If you take more than one sample per quarter at a monitoring location, all samples taken in the quarter at that location will be averaged to determine a quarterly average to be used in the LRAA calculation.
- If the LRAA at any location exceeds the MCL, you are in violation.
- Failure to monitor will be treated as a monitoring violation for the entire period covered by a locational running annual average compliance calculation for the Stage 2 MCLs.
If you monitor once per year:
- Compliance is based on the value of the yearly samples at each location.
- Compliance will be calculated beginning with the first compliance sample taken after the compliance date.
- If any sample exceeds the MCL, you are not immediately in violation. You must begin increased monitoring immediately (monitor quarterly at each location).
- If any sample exceeds the MCL and you are on reduced monitoring, you must begin increased monitoring immediately (monitor quarterly at each location).
- Failure to monitor will be treated as a monitoring violation for the entire period covered by a LRAA compliance calculation for the Stage 2 MCLs.
NOTE: Water systems are required to submit their analytical results and the State will calculate compliance for you.