**Insert for New Section IX.B .1.c. Immediately**  **following 1.**  **b.**

**IX. B**  **. 1.** 

**c. Definition of gas well**  **Comment:** Several c ommenters mentioned that the proposed definition of “gas well” was unclear due to the term “principal production ” used in describing what the well produces . One commenter requests that the definition of gas well be modified to include each respective state’s definition of gas well. The commenter states that by doing this, the EPA would eliminate any confusion associated with having to apply different criteria (NSPS versus state regulations) for how to define a well

- type in assessing the applicability of the rule. **Response** : In response to comments requesting further clarity in the definition, the EPA has revised the definition . The proposed definition was “ Gas well means an onshore well, the principal production of which at the mouth o f the well is gas. ” In the final rule, in response to the comments we received, the EPA has revised the definition to exclude the term “at the mouth of the well.” EPA’s intent in setting standards for completion of hydraulically fractured gas wells is to require reducedemissions completions for wells where infrastructure is

generally present to get recovered natural gas to market. We believe that the final rule will result in control of hydraulically fractured gas wells drilled in the four formation type s generally accepted as gas

-producing formations: (1) high

permeability gas, (2) shale gas, (3) other tight reservoir rock, or (4) coal seam. We believe that the wording changes made to the definition of “gas well” clarify the intent so that implementing a gencies and industry will not be burdened with complex applicability determinations. With respect to using state gas well definitions, b asing applicability on different definitions from state to state could introduce inconsistencies that are counter to the goal of nationwide regulation. We believe the NSPS, being a national rule, should contain a single definition applicable nationwide. **C omment:**  One commenter states that based on the EPA’s discussion in Section 4 of the Technical Support Document, it appears the EPA’s intent is to require reduced emissions completions only for natural gas wells. The commenter supports that the EPA applied reduced emissions completions only to natural gas wellhead facilities and excluded oil wellhead facilities and other types of gas wells which have little or no VOC emissions. The commenter states that, as shown on page 4

- 13 on Table 4.4 “Nationwide Baseli ne Emissions from UncontrolledOil and Gas Well Completions and Recompletions” of the Technical

Support Document, there are only 134 TPY of VOCs emissions from oil well completions and recompletions for the entire U.S., which is not worth regulating. One c ommenter recommends the following revision: “Gas well means a well, the principal production of which at the mouth of the well is [add: hydrocarbon gas, not CO 2 ]. . .Well means an oil or gas well, a hole drilled for the purpose of producing oil or gas, or a well into which fluids are injected.” One commenter proposes the following revision: “Gas well means a well, [DELETE the principal production of which at the mouth of the well is gas] completed for production of natural gas from one or more gas zones or reservoirs. Such wells contain no completions for the production of crude oil. The commenter also proposes the following revision: Gas well means a well [STRIKETHROUGH: the principal production of which at the mouth of the well is gas.] [ADD TEXT: complete d for production of natural gas from one or more gas zones or reservoirs. Such wells contain no completions for the production of crude oil.]” **Response:** Although some wells drilled in crude oil formations may produce associated gas along with the oil, the EPA does not have sufficient data on VOC emissions during completion of hydraulically fractured oil wells to set standards for theseoperations at this time. As a result, the final rule will not

apply to completion of oil wells.