Three-quarters of a ton of natural gas leaked into the air from a Robeson County compressor station, a state investigation has found. And the compressor station, owned by Piedmont Natural Gas, has legally operated without a permit because it qualified as a low-level polluter under rules passed last year by the state Environmental Management Commission.
According to the investigation conducted by the Division of Air Quality’s Fayetteville office, Alan Henderson of Piedmont Natural Gas supervisor of compression reported that an emergency shutdown occurred in the early morning of Nov. 22 after a mechanical failure allowed natural gas to leak into the air. The company estimated that 1,500 pounds of natural gas was released during the 50 minutes before the leak was contained. The leaking pipe was 2 inches in diameter.
State regulators determined Piedmont Natural Gas had not violated any state or federal rule over which the Division of Air Quality has enforcement authority.
State environmental officials launched the investigation after Ryan Emanuel, a Robeson County native and member of the area’s Lumbee tribe, complained. Emanuel is now an asociate professor specializing in hydrology and environmental science at NC State University.
Emanuel is an outspoken opponent of the proposed Atlantic Coast Pipeline, which will route through Robeson County.
The rules passed by the EMC last year allow certain facilities to apply to NC Department of Environmental Quality for an exemption from securing an air quality permit. Based on their emissions levels, more than 1,110 facilities qualified to apply for what is called a “rescission.” Piedmont Natural Gas applied for, and received, an exemption for its compressor station in Prospect.
Facilities that emit less than five tons per year of each specified pollutant and less than 10 tons per year in total are exempt from permitting, as long as they meet all eligibility requirements. The facilities still must comply with air quality rules.
Facilities that are not exempt and that between 5 tons and 25 tons per year and meet other eligibility requirements in the rule are eligible for registration instead of obtaining a permit.The facilities also still must comply with air quality rules.
As Policy Watch reported last fall, the exemptions can create pockets of small polluters that, in aggregate, can emit amounts approaching that of a large facility.
This also creates environmental justice issues in neighborhoods where small, exempt facilities congregate: East Durham, for example, and Robeson County, whose per capita income ranks 99th of the state’s 100 counties. A third of households in the census tracts near the compressor station live below the federal poverty threshold, according to a Policy Watch analysis of federal data.
NC DEQ finances and business costs played a role in the EMC rule’s passage. The changes save businesses an estimated $771,950 per year in permit fees and associated costs, according to DEQ figures.
Although the Division of Air Quality could lose about $280,850 per year in revenue from permit fees currently paid by small facilities, but will no longer have the administrative costs associated with writing and renewing permits for most small sources.