Monitoring frequencies for ammonia

Where ammonia limits are toxicity-based, permits will require the permittee to monitor ammonia at a frequency of three times per week. At any time during the term of a permit, where the permittee has completed 12 consecutive reporting periods subject to toxicity based ammonia limits where the highest daily maximum concentration did not exceed 1.5 times the toxicity based MAL and there were not exceedances of the monthly average or daily maximum limits for ammonia, the permittee may request a reduction of the ammonia monitoring frequency to one time per week. If WET test failures attributable to ammonia are experienced at any time during the term of a permit, or there are exceedances of the monthly average limit or daily maximum limit for ammonia, the ammonia monitoring frequency must be continued at or be returned to three times per week. If there are no WET test failures attributable to ammonia and no exceedances of either the monthly average limit or the daily maximum limit for ammonia following a reduction of the monitoring frequency for toxicity-based ammonia limits to one time per week, the reduced 23 ammonia monitoring frequency may be continued in the ensuing permit cycle. This paragraph does not apply to ammonia monitoring required to be performed concurrently with WET testing.