Requirements for Existing Non-Emergency Spark Ignition 4SLB and 4SRB

Stationary RICE >500 HP Located at Area Sources of HAP

(a) Owners and operators of existing non-emergency spark ignition four-stroke lean burn (4SLB) and 

four-stroke rich burn (4SRB) stationary RICE >500 HP located at area sources of HAP meeting any of 

the criteria in paragraphs (a)(1) through (3) must meet identical requirements to those currently specified 

for existing non-emergency spark ignition 4SLB and 4SRB stationary RICE ≤500 HP located at area 

sources of HAP (i.e., the management practices in items 7 and 9 in Table 2d to subpart ZZZZ and the 

operation and maintenance requirements in §63.6625(e), (h), and (j)).

(1) Stationary RICE located in an offshore area that is beyond the line of ordinary low water along that 

portion of the coast of the United States that is in direct contact with the open seas and beyond the line 

marking the seaward limit of inland waters.

(2) Stationary RICE located on a pipeline segment that meets both of the criteria in paragraphs (a)(2)(i) 

and (ii).

(i) A pipeline segment with 10 or fewer buildings intended for human occupancy within 220 yards (200 

meters) on either side of the centerline of any continuous 1-mile (1.6 kilometers) length of pipeline.

Each separate dwelling unit in a multiple dwelling unit building is counted as a separate building 

intended for human occupancy.

(ii) The pipeline segment does not lie within 100 yards (91 meters) of either a building or a small, welldefined outside area (such as a playground, recreation area, outdoor theater, or other place of public 

assembly) that is occupied by 20 or more persons on at least 5 days a week for 10 weeks in any 12-

month period. The days and weeks need not be consecutive. The building or area is considered occupied 

for a full day if it is occupied for any portion of the day. 

(iii) For purposes of this paragraph (2), the term pipeline segment means all parts of those physical 

facilities through which gas moves in transportation, including but not limited to pipe, valves, and other 

appurtenance attached to pipe, compressor units, metering stations, regulator stations, delivery stations, 

holders, and fabricated assemblies. Stationary RICE located within 50 yards (46 m) of the pipeline 

segment providing power for equipment on a pipeline segment are part of the pipeline segment. 

Transportation of gas means the gathering, transmission, or distribution of gas by pipeline, or the storage 

of gas. A building is intended for human occupancy if its primary use is for a purpose involving the 

presence of humans.

(3) Stationary RICE that are not located on pipelines and that have 5 or fewer buildings intended for 

human occupancy within a 0.25 mile radius around the engine.

(b) Owners and operators of existing non-emergency spark ignition 4SLB and 4SRB stationary RICE 

>500 HP located at area sources of HAP meeting the criteria in paragraph (a) must evaluate the status of 

their stationary RICE every 12 months. If the stationary RICE no longer meets the criteria in paragraph 

(a), the owner or operator must comply with the requirements specified in paragraph (c) within one year.

(c) Owners and operators of existing non-emergency spark ignition 4SLB and 4SRB stationary RICE 

>500 HP located at area sources of HAP that do not meet the criteria in paragraph (a) must meet the 

requirements of this paragraph (c). 
(1) Install a catalyst to reduce emissions of HAP.

(2) Meet the requirements of paragraph (i) or (ii):

(i) Continuously monitor the catalyst inlet temperature and maintain the temperature between the 

specified range in subpart ZZZZ, or 

(ii) Equip the engine with automated shutdown so that the catalyst inlet temperature does not exceed the 

specified maximum temperature of the range in subpart ZZZZ.

(3) Conduct an initial test, and subsequent annual tests, to show the catalyst reduces emissions as 

specified in paragraphs (c)(3)(i) and (ii). The initial test must consist of three test runs. Each subsequent 

annual test must consist of one test run. Each test run must be of at least 15 minute duration, except that 

each test run with CTM-034 must consist of one measurement cycle as defined by the method and 

include at least 2 minutes of test data phase measurement.

(i) For 4SLB stationary RICE, CO emissions must be reduced by 93 percent or more, or limited to 47 

ppmvd at 15% O2.

(ii) For 4SRB stationary RICE, CO must be reduced by 75 percent or more, or alternatively, THC must 

be reduced by 30 percent or more.

(4) The CO and O2 testing required in paragraph (c)(3) can be conducted using EPA Conditional Test 

Method 034 or the methods already specified in subpart ZZZZ. The THC testing required in paragraph 

(c)(3) can be conducted using EPA Method 25A. 

(5) If any of the tests required in paragraph (c)(3) show that the emissions exceed the levels specified in 

paragraph (c)(3), the stationary RICE must be shut down as soon as safely possible and appropriate 

corrective action must be taken (e.g., repairs, the catalyst cleaned or replaced). The stationary RICE 

must be retested within 7 days of being restarted and the emissions must meet the levels specified in 

paragraph (c)(3). If the retest shows that the emissions continue to exceed the specified levels, the 

stationary RICE must again be shut down as soon as safely possible, and the engine may not operate, 

except for purposes of start-up and testing, until the owner/operator demonstrates through testing that 

the emissions do not exceed the levels specified in paragraph (c)(3). 

(6) Failure to meet any of the requirements of paragraphs (c)(1), (c)(2), and (c)(5) is a violation of 

subpart ZZZZ. Failure to conduct an initial test and subsequent annual tests, as specified in paragraph 

(c)(3), is a violation of subpart ZZZZ.