State OKs gas site pollution standards
Changes on new permit for stations
State regulators have finalized new air pollution limits for natural gas compressor equipment and, for the first time, proposed standards to curb air emissions from well pad activities tied to the development of the Marcellus Shale, the Department of Environmental Protection said Thursday.
One change will affect the general permit used for many compressor station engines that push gas from wells into pipelines. The other will require stricter controls on leaks and pollution from wells and storage tanks if developers want to remain exempt from a site-by-site air quality approval process.
Taken together, the state expects the new permit and proposed exemption standards to stem pollution as shale gas well sites and compressor stations multiply.
"The steps we are taking now mean far lower emissions at well sites and more efficient compressor stations, resulting in cleaner air as development, production and transmission take place," DEP Secretary Michael Krancer said.
The new compressor station permit will require a sharp reduction in pollution from the current standard. Allowable levels of smog-forming nitrogen oxides, or "NOx," will be cut 75 percent in the most common, lean-burn compressor engines, and 90 percent for less common, rich-burn engines. Allowable emissions of volatile organic compounds and carbon monoxide will also be reduced by between 87 and 93 percent.
But some of the cuts are not as steep as the ones proposed by the department in the draft permit it circulated in early 2012 and some specific limits for particulate matter and sulfur dioxide were dropped. Those changes were suggested by the industry in public comments submitted to the DEP last year.
DEP spokesman Kevin Sunday said the volatile organic compounds limits were changed to make it possible for companies to meet the engine-specific standards continually while burning the gas they draw from the field.
General permits include standard limits that apply to similar facilities, allowing for a more streamlined approval process than an individual review. DEP said this general permit, called the GP-5, will give operators the ability to install more lower-emission engines at a compressor station because compliance will be measured by actual emissions instead of an assumed permit maximum that was used in the past.
The newly-proposed well site emissions limits are included in a draft revision to the state's list of sources that are exempt from certain air quality permitting requirements. The new standards would be stricter than federal rules released last year for controlling wellhead emissions, the DEP said.
If the changes are approved, shale well sites would qualify for the exemption only if companies monitor for gas leaks at wellheads and storage tanks 60 days after a well is completed and then annually, install strict emissions controls on tanks and meet limits on the amount of NOx and volatile organic compounds released from a well pad each year. Drillers will also be able to elect to apply for an air quality approval for the site instead.
Industry officials said they supported the measures on Thursday and touted the air quality benefits associated with using natural gas.
"The revised GP-5 permit aims to reduce emissions by 75 to 90 percent from compressor stations and will further leverage technologies that continue to reduce our industry's footprint," Marcellus Shale Coalition CEO Kathryn Klaber said. "We are squarely focused on building upon this positive progress and working to ensure that our operations, and the expanded use of natural gas, continue to enhance air quality."
Environmental groups have welcomed the efforts to reduce drilling-related air pollution while arguing that much stronger controls are technically possible and should be required. Efforts to reach the Clean Air Council for comment on Thursday evening were unsuccessful.
Details about both the final compressor engine general permit and the proposed well site emissions controls will be published in the Pennsylvania Bulletin on Saturday.
Contact the writer: llegere@timesshamrock.com