Monitoring requirements. Use either a biofilter bed temperature monitoring device (or multiple devices) capable of providing a continuous record or an organic monitoring device capable of providing a continuous record. Comply with the requirements in
§ 63.2450(e)(4), the general requirements for monitoring in
§ 63.996, and keep records of temperature or other parameter monitoring results as specified in §
63.998(b) and
(c), as applicable. If you monitor temperature, the operating temperature range must be based on only the temperatures measured during the performance test; these data may not be supplemented by engineering assessments or manufacturer's recommendations as otherwise allowed in
§ 63.999(b)(3)(ii)(A). If you establish the operating range (minimum and maximum temperatures) using data from previous performance tests in accordance with
§ 63.996(c)(6), replacement of the biofilter media with the same type of media is not considered a process change under
§ 63.997(b)(1). You may expand your biofilter bed temperature operating range by conducting a repeat performance test that demonstrates compliance with the 95-percent reduction requirement or outlet concentration limit, as applicable.