a) Active gas collection systems. Each owner or operator of an active gas collection system shall install a sampling port and a thermometer, other temperature measuring device, or an access port for temperature measurements at each wellhead and:

1. 1) Measure the gauge pressure in the gas collection header on a monthly basis, as provided in Section 220.240(a)(3) of this Subpart; and
2. 2) Monitor the temperature and nitrogen or oxygen concentration in the landfill gas on a monthly basis, as provided in Section 220.240(a)(5) of this Subpart.

b) Enclosed combustors. Each owner or operator of an enclosed combustor shall calibrate, maintain, and operate according to the manufacturer's specifications, the following equipment:

1. 1) A temperature monitoring device equipped with a continuous recorder and having a minimum accuracy of plus or minus 1 percent of the temperature being measured, expressed in degrees Celsius, or plus or minus 0.5°C, whichever is greater. A temperature monitoring device is not required for boilers or process heaters with design heat input capacity greater than 44 MW.

2. 2) A device that records flow to or bypass of the control device. The owner or operator shall either:

   1. A) Install, calibrate, and maintain a gas flow rate measuring device that shall record the flow to the control device every 15 minutes; or
   2. B) Secure the bypass line valve in the closed position with a car-seal or a lock-and-key type configuration. A visual inspection of the seal or closure mechanism shall be performed at least once every month to ensure that the valve is maintained in the closed position and that the gas flow is not diverted through the bypass line.

c) Open flare. Each owner or operator of an open flare shall install, calibrate, maintain, and operate according to the manufacturer's specifications the following equipment:

1. 1) A heat sensing device, such as an ultraviolet beam sensor or thermocouple, at the pilot light or the flame itself to indicate the continuous presence of a flame.

2. 2) A device that records flow to or bypass of the flare. The owner or operator shall either:

   1. A) Install, calibrate, and maintain a gas flow rate measuring device that shall record the flow to the control device at least every 15 minutes; or
   2. B) Secure the bypass line valve in the closed position with a car-seal or lock-and-key type configuration. A visual inspection of the seal or closure mechanism shall be performed at least once every month to ensure that the valve is maintained in the closed position and that the gas flow is not diverted through the bypass line.