Air Enforcement: Arkansas Department of Energy & Environment - Division of Environmental Quality and Searcy Natural Gas Compressor Station Operator Enter into Consent Administrative Order

The Arkansas Department of Energy & Environment – Division of Environmental Quality (“DEQ”) and Natural Gas Pipeline Company of America, LLC (“NGPL”) entered into a March 1st Consent Administrative Order (“CAO”) addressing alleged violations of an air permit. See LIS No. 22-017.

The CAO provides that Natural Gas Pipeline owns and operates a natural gas compressor station (“Station”) in Searcy, Arkansas.

The CAO references two air permits to which the Station operates and/or operated.

The Station is stated to have conducted emissions testing at the 5,000 HP Worthington ML-14, 2-stroke lean-burn Compressor Engine (SN-08) on March 16, 2020. The Station sent an email on March 17, 2020, to DEQ stating that SN-08 had exceeded the Carbon Monoxide (“CO”) emission rate limit during the test. It therefore submitted an Upset Condition Report. The Upset Condition Report indicated that during the emissions test the average emission rate for CO recorded at SN-08 was 30.8 lbs/hr.

This is alleged to violate Specific Condition 5 of an air permit.

A retest is stated to have been conducted on March 18, 2020, for which test results were submitted. The test report is stated to have indicated that SN-08 exceeded the permitted emission rate limit during the test. The test results from the failed test were included in the emissions test report.

DEQ is stated to have informed Natural Gas Pipeline in a letter dated May 1, 2020, that after review of the emissions test results submitted on April 13, 2020, SN-08 was in compliance with the permitted CO emission rate limit at the time of testing on March 18, 2020.

A DEQ compliance inspection was conducted on February 2, 2021, of the Station. The inspection is stated to have covered the reporting period of August 2019 through December 2020.

The Station is stated to have failed to conduct emissions testing for CO on the remaining eight engines at the Facility after SN-08 exceeded the permitted CO emission rate limit on March 16, 2020.

Such alleged failure is stated to violate Plantwide Condition 8 of Permit R6 and Permit R7.

The Station successfully passed the emissions testing required for SN-01, SN-03, SN-04, SN-09 and the retesting of SN-08 in March 2020.

Natural Gas Pipeline submitted a response to a March 17, 2021, DEQ query noting the following information:

1. Regarding the compliance issues listed in Paragraph 7 above, Respondent stated that "during the stack test on March 16, 2020, SN-08 failed the stack test on CO. The test results are to be extrapolated to correlate with 100% of the permitted capacity to demonstrate compliance with PWC 8. The extrapolated CO results were 30.8 lb/hr, which was over the permitted limit of 30 lb/hr CO. SN-08 was shut-down and repaired. SN-08 was retested on March 18, 2020, and passed. NGPL contacted ADEQ upon receipt of preliminary test results from SN-08 that indicated an exceedance of CO emissions and an Upset Condition Reporting Form was submitted on March 17, 2020. A deviation was reported in the Semi-Annual Monitoring Report and Annual Compliance Certification for the associated reporting period. Submittal of the upset notification and inclusion of the permit deviation complies with General Provision 8 of the Title V Operating Permit."
2. Regarding the compliance issues listed in Paragraph 11 above, Respondent stated that "Units SN-01 through SN-07 are 3,080 HP Cooper Bessemer GMWH compressor engines, SN-08 is a 5,000 HP Worthington ML-14 compressor engine, and SN-09 is a 9,063 HP Cooper Bessemer 16W330 Compressor Engine. The five-year emissions testing in March 2020 was conducted on units SN-01, SN-03, SN-04 (representative of all Cooper Bessemer GMWH units), SN-08 (ML-14) and SN-09 (16W330)." Because SN-08 is the only engine of its kind and the CO results for the GWMH units (SN-01, SN-03, SN-04) and Cooper Bessemer 16W330 (SN-09) were within permitted limits, Respondent stated that they reasonably believed that testing was not required on any additional units and that they respectfully disagree with the Division's allegation that NGPL failed to comply with the requirement of the permit to test other nonidentical units because of the test failure on SN-08.

During an October 19, 2020, meeting, Natural Gas Pipeline indicated that it would prepare an application for a Title V permit modification. Further, it requested that DEQ clarify the applicability of the requirement to retest all eight units. Natural Gas Pipeline requested a written notification of DEQ’s decision regarding additional testing of the remaining four units.

DEQ received a permit modification application from Natural Gas Pipeline on October 28, 2021, to modify Plantwide Condition 8. Additional verbiage was also requested.

Natural Gas Pipeline neither admits nor denies the factual and legal allegations contained in the CAO.

A civil penalty of $2,100 is assessed.

A copy of the CAO can be downloaded here.