Rule Would Limit Oil-Rig Emissions

To reduce air pollution, oil-field drilling operators would have to power their rigs with electricity rather than diesel-fueled engines, under a rule the County Board of Supervisors will consider Tuesday.

The new rule, proposed by the county’s Air Pollution Control District, is aimed at cutting emissions to improve air quality.

The diesel engines emit large amounts of nitrogen oxide, which goes into the formation of ozone, a primary ingredient of smog.

In 1989, the county’s air quality exceeded state ozone standards on 116 days and federal standards on 46 days. If the new rule is implemented, district officials predict, emissions from oil-field drilling would be cut by about 50%.

Under the proposed rule, drilling operators would have one year from the date the rule is adopted to equip their rigs electrically. However, an operator could seek an exemption from the requirement if it can be shown that electricity would not be cost-effective. If granted an exemption, an operator must use a diesel-powered rig that emits acceptable low levels of pollution.

The new procedures would also require companies to obtain drilling-rig operation permits from the Air Pollution Control District, which in the past has not required emission controls or permits for drilling rigs.

The district staff surveyed drilling operations in the past two years and found that, in 1988, 48 new oil wells were drilled in the county and emitted 88 tons of nitrogen oxide.

In 1989, new wells emitted an estimated 118 tons of the substance. The average well took 21 days to drill.

The district’s Keith Duval said an advisory committee participated in the formation of the new rule, and two workshops were held to inform the oil companies about it.

Some concessions were made to the companies, including a provision that allows them to have backup power should electrical power fail.

Duval said he doesn’t expect a fight from the oil companies over the rule. However, he said, if they ignore the rule, they could be subject to a fine amounting to $25,000 a day.