NOISE ISSUES WITH THE GAS COMPRESSOR STATIONS AT THE MILLENNIUM PIPELINE
Minisink Compressor Station
Noise Issues
Environmental Condition No. 15
Millennium shall make all reasonable efforts to ensure its predicted noise levels from the Minisink Compressor Station are not exceeded at the nearby noise-sensitive areas (NSA) and file noise surveys showing this with the Secretary no later than 60 days after placing the Minisink Compressor Station in service. If the noise attributable to the operation of the Minisink Compressor Station at full load exceeds the predicted noise level at any nearby NSAs, Millennium shall file a report identifying what modifications it intends to make in order to meet the predicted level within one year of the in-service date. Millennium shall confirm compliance with this requirement by filing a second noise survey with the Secretary no later than 60 days after it installs any additional noise controls.
Millennium Response
Millennium will file a noise survey with the Commission no later than 60 days after placing the Minisink Compressor Station in service. Millennium will use all reasonable efforts to design and construct a station that meets the predicted noise levels. However, if the noise attributable to the operation of the Minisink Compressor Station at full load exceeds the predicted noise level at any nearby NSAs, Millennium shall file a report on what changes it intends to make to meet the level within one year of the in-service date. In the event additional noise controls are installed, Millennium will confirm compliance with this requirement by filing a second noise survey no later than 60 days after it installs the additional noise controls.
60. Citing an article from the World Health Organization (WHO) and various internet articles, Ms. Marner and Ms. Bowers express concern that the EA does not adequately address the extent that noise from the proposed compressor station could result in a range of medical conditions. It is well-known that machinery noise in excess of 85 decibels (dB) can induce hearing loss and other negative health effects. The cited WHO article mentioned noise levels of 105 dBA.
However, such prolonged exposure to high noise levels is primarily an occupational health hazard for workers using industrial machinery. The EA explains that the Commission has adopted a standard of 55 decibels on the A-weighted frequency scale (dBA) at the nearest noise sensitive area (NSA), based on data from the EPA, to protect the public from indoor and outdoor activity interference. EA at 51. The estimated noise levels from the proposed project are predicted to be below 55 dBA, but admittedly are likely to be noticeable. Thus, as recommended in the EA, we will require Millennium to make all reasonable efforts not to exceed its predicted noise levels (see Environmental Condition 11).
61. Mr. English and Mr. Sanzoverino question the methods and results of Millennium's sound measurements referenced in the EA. Millennium's report on Ambient Sound Survey and Noise Impact, summarized in the EA, provides the methodology and data of the sound survey. See Millennium November 1, 2012 application, Accession Number 20121101-5171, Resource Report 9, Appendix 9-B.
Commission staff evaluated Millennium’s protocols and found them to be acceptable. Mr. DePalma and Mr. Martinez ask whether the Commission would accept independent noise analyses. All future noise surveys performed by Millennium and the survey methodology filed by Millennium would be available for public review and comment. Any independent analyses conducted on noise that are filed in this docket will be reviewed and considered by Commission staff.
62. Mr. English requests that the Commission clarify whether the noise from operation of the compressor station would be detectable at the nearest NSA. The EA states that the noticeable noise increase threshold for humans is about 3 dB, with 5 dB as a clearly noticeable increase in noise and that a 10 dB change is perceived as a doubling of sound level. The EA states that the potential increase in noise at the nearest NSA (800 feet away) would be 4.9 dB. EA at 52.
Thus, there may well be a noticeable noise increase at the nearest NSA, especially given the low level of ambient noise in the project area. EA at 52, 54. As previously stated, we require in Environmental Condition 11 that Millennium make all reasonable efforts to ensure its predicted noise levels from the compressor station are not exceeded at the nearby NSAs and further require operational noise surveys to confirm the effectiveness of the noise mitigation measures. In addition, we will add new Environmental Condition 8 to provide landowners with clear and simple directions for identifying and resolving their environmental mitigation problems/concerns during construction and operation of the project.
63. Millennium filed a request that Environmental Condition 11 be revised to require additional mitigation only if noise attributable to operation exceeds 55 dBA, rather than if it exceeds Millennium’s predicted levels. Millennium claims that the requirement as currently structured is not consistent with the Commission’s review of other projects and was not satisfactorily justified.
64. As indicated above, the existing low ambient noise in the project area would make noise produced by the compressor station more noticeable at lower levels than at many other locations. The project design submitted by Millennium and reviewed by staff predicts noise levels below the standard of 55 dBA. Millennium’s comments do not suggest that it will be unable to meet its predicted noise levels or that Millennium considers those levels unachievable. The Commission has previously imposed such a requirement in similar circumstances. Millennium, 140 FERC ¶ 61,045, at P 78, reh’g denied, 141 FERC ¶ 61,198 (2012).
As described in the EA, if Millennium is unable to meet its predicted noise levels and the Hancock Compressor Station is found to produce noise levels closer to 55 dBA at the NSAs, it would represent an effective doubling of the current noise in the area. Thus, we will reject Millennium’s request to modify the condition.
65. Millennium also requests that if the Commission does not modify the language in Environmental Condition 11, the Commission should clarify that the condition does not pre-determine that additional modifications to the Hancock Compressor Station would be required under all circumstances. The Commission clarifies that there is no pre-determined outcome. We will assess whether “reasonable efforts” have been taken and determine the need for any additional mitigation measures after the compressor station has gone into operation and the sound levels attributable to the compressor station have been accurately measured. The situation at each new compressor station is unique, based on site-specific circumstances such as location, proximity to NSAs, geography, land use, and vegetation.
66. Mr. Sanzoverino objects to the one-year time period recommended in the EA for Millennium to file a report identifying the modifications it intends to make to the compressor station to meet its predicted noise levels. Mr. Sanzoverino states that this time frame should be shortened to 30 days to limit the time noise exceeds Millennium’s predicted levels. We believe that a 30 day period is unreasonable. However, based on the Commission’s experience with compressor station noise emissions, we find that six months is a reasonable time frame to allow Millennium to work up to operating at full load, identify the causes of any unpredicted noise, and to propose corrective actions. Environmental Condition 11 to this order reflects this change.
67. Mr. English questions how often blowdown events would occur, how loud they would be at the nearest NSAs, and how effective the silencers, a device to lessen sound impact, would be. Blowdown sound levels are loudest at the beginning of the blowdown event and they decrease as the blowdown pressure decreases. The Noise Impact Analysis provided by Millennium indicates that the initial sound level for a scheduled blowdown, such as would occur during the start-up or shut-down of the facility, would be 51 dBA at the nearest NSA with the use of the silencers. This sound level is below the Commission’s standard of 55 dBA.
68. Millennium filed comments requesting clarification on the definition of “operating at full load,” as used in Environmental Condition 11. Millennium states that “full load” should be limited to 13,600hp of compression, which reflects the maximum amount of compression that Millennium has projected would be required from the station with existing contract demand, rather than the entire nameplate compression of 15,900 hp. Millennium indicates that while the compressor unit may be capable of running at 15,900 hp, operation at that level exceeds the horsepower necessary to meet its contract demand and would result in Millennium’s exceeding the maximum allowable operation pressure of its downstream pipeline. We agree that “full load” should be defined as operation at 13,600 hp, because Millennium has demonstrated that this reflects the most strenuous operating circumstances needed to meet contract demand. Millennium November 15, 2012, supplement to Exhibits G and G-II.
Need for a Buffer Zone or Conservation Easement
As described earlier, Millennium proposes to construct the Hancock Compressor Project on 35.8 acres of property that comprises four parcels. Parcel 1 is a 10.8- acre site owned by Millennium on which it proposes to construct and operate the compressor station and associated pipelines. Millennium purchased Parcels 2, 3, and 4 to the north, totaling 25.0 acres, partly to serve as construction workspace. Since Millennium requires only Parcels 1 and 2 for the permanent operation of the project, it has indicated that it may sell Parcels 3 and 4 in the future after construction and restoration is complete and the project is operational.
In scoping comments several commenters asked that Parcels 3 and 4 be established as a conservation easement or buffer zone. The EA determined that doing so would not further reduce the impact of the proposed Hancock Compressor Project on adjacent property owners beyond the buffer that would be provided by the 10.8 acres of Parcel 1. EA at 36. In their comments on the EA, Mr. Sanzoverino, Mr. DePalma, Ms. Leidersdorff, Mr. English, Ms. Ryan, Mr. Weil, and Miriam continue to express concern over the potential sale of Parcels 3 and 4, and reiterate their requests that Millennium be required to keep the properties as a permanent buffer zone or conservation easement.[1]
With the exception of Mr. English, as noted below, these commenters request that the Commission require Millennium to retain ownership of Parcels 3 and 4 in order to prevent further development on the land, rather than to prevent or minimize noise or other adverse impacts directly associated with the operation of from Millennium’s proposed project. The overriding concern expressed by the majority of these commenters is that the properties will be sold for industrial or commercial use, which they claim will transform a bucolic, rural, mountain environment into a commercial and industrial zone and destroy property values. However, as discussed above, the Commission will not require Millennium to retain the two parcels for the purpose of preventing potential commercialization of the area to the extent the land is not otherwise necessary to be included as part of the certificated project.
As noted in the EA, Millennium determined that a 10-acre site for the Hancock Compressor Station was necessary to provide an adequate buffer to reduce noise and aesthetic impacts to nearby landowners. Specifically, Millennium stated that the minimum sized site for the Hancock Compressor Station site should be “at least 10 acres to reduce potential visual and aesthetic impacts, increase the distance of the station from noise sensitive receptors, and provide a buffer against outside development and future encroachment.”85 Parcel 1 met these requirements. Moreover, the modification Millennium made to the site design during the pre-filing process by relocating the compressor station to the western edge of Parcel 1 further increased the distances to the nearest residents, who reside east and northeast of Parcel 1, and created a large wooded buffer between the compressor station and those neighboring residences. This buffer area will serve to further minimize landowner impacts, such as visual impacts from Hungry Hill Road.
While Parcel 1 by itself acts as a wooded buffer between the compressor station and the nearest residences, Millennium purchased Parcels 2, 3, and 4 “in an effort to eliminate any impacts on the current occupants of the closest residences, create a larger buffer between the station and the remaining residences, and to provide additional workspace for the [p]roject during construction.”86 Millennium will retain Parcel 2 for permanent project operations,87 expanding the permanent buffer created by Parcel 1 by an additional 6.5 acres. In addition, Parcels 3 and 4 not only provide additional workspace construction, but also act as a temporary buffer against the impacts of construction, but also act as a temporary buffer against the impacts of construction. These benefits from the purchase of Parcels 3 and 4 would not be negated by any subsequent sale.
With respect to the question whether a buffer zone is required for the Hancock Compressor Project, Mr. English contends that Parcels 3 and 4 are needed to protect surrounding residents from the impacts of the compressor station or to minimize such impacts. Mr. English is concerned that if the local environment changes as a result of a sale of Parcels 3 and 4, such as from the removal of trees on those parcels, the noise levels in the surrounding area from the operation of the compressor station could increase. He claims that this would result in the creation of additional noise not identified or analyzed in the EA and further adversely affect the rural and recreational nature of the community. Mr. English also questions why Millennium is not required to establish a conservation easement for the Hancock Compressor Station when a conservation easement was established for the Minisink Compressor Station.
The closest residences to the proposed project are located along the opposite side (east side) of Hungry Hill Road, and are 800 feet from the compressor station, to the east and northeast of Parcels 1 and 2.88 The EA found that the only part of the facility that would be visible from these adjacent residences would be the access driveway entrance off of Hungry Hill Road on Parcel 2, and that no part of the compressor station, including the 60-foot-high stack, would be visible.89 The EA concludes that the topography and maintenance of vegetative screening along Hungry Hill Road and at the project site should aid in screening views of the site from points along the roadway and at existing adjacent residences.90 The EA also determines that noise from the operation of the compressor station at the adjacent residences described above, which are the nearest NSA (NSA No. 1), will meet the noise criterion of 55 dBA that the EPA has established to protect the public from indoor and outdoor activity interference.91 Since the trees that provide the visual and noise screening for these neighboring residences are located on Parcels 1 and 2, the conclusions of the EA are based on the topography of Parcels 1 and 2, as well as on the station design and the proposed mitigation at the site during operation of the facility, and do not rely on Millennium’s retention of Parcels 3 and 4.
Thus, the Commission concludes that the impacts on adjacent property owners have been sufficiently minimized without the need for an additional buffer zone on Parcels 3 and 4. In fact, the location of Parcels 3 and 4 relative to the residences nearest to the station would prevent the parcels from having any real value as a buffer to these residences. Parcels 3 and 4 are situated directly north of Parcel 2 on the west side of Hungry Hill Road, and are generally northwest of these residences. Thus, as Parcels 3 and 4 do not lie between the closest residences and the compressor station to the southwest of the residences, they are not positioned to act as a buffer.92
In addition, Parcels 3 and 4 would not act as a buffer to help minimize project impacts on other landowners further from the compressor station site than the adjacent residents. With respect to visual impacts, the only vantage point analyzed in the EA from which the compressor exhaust stack and 6 feet of the compressor building would be visible is Vantage Point No. 2, located 1,800 feet to the southwest of the compressor station. Thus, Parcels 3 and 4 to the north of the compressor station cannot serve as a buffer against visual impacts for Vantage Point No. 2. As there are no visual impacts at the other vantage points, there is no need for Parcels 3 and 4 to buffer visual impacts for those locations. With respect to noise impacts, the next closest residences to the compressor station (NSA No. 2) are 1,400 feet to the southwest of the compressor station, for which Parcels 3 and 4 would also be irrelevant. The next closest residences located to the north or east of the compressor station, after NSA No. 1, are between 2,250 (NSA No. 3) to 3,600 feet (NSA No. 5) from the compressor station. However, they are not expected to perceive a noticeable noise increase from station operations.93 Thus, these residences would receive no benefit from Parcels 3 and 4 being designated a buffer zone.
Mr. English is concerned that if Millennium sells Parcels 3 and 4, and the new owner cuts down the trees on the parcels, “an important part of the vegetative sound barrier will be lost” which could change the predicted noise levels to residents as determined in the EA. Noise from the operation of the compressor station will meet the required noise threshold of 55 dBA at the nearest NSA based on the vegetative buffer of the permanent project site, the project design, and mitigation measures, without consideration of the existence of trees or other vegetation on Parcels 3 and 4. Further, as presumed by the EA, NSAs further from the compressor station than the nearest NSA would experience noise levels less than 55 dBA. Finally, and most important, in the event the vegetation on Parcels 3 or 4 is disturbed or eliminated after any sale of the properties, and noise levels do increase above those predicted, Millennium will still be required to meet the day-night noise level of 55 dBA at the NSAs near the compressor station site, and its other predicted noise levels, using mitigation measures if necessary.94 Environmental Condition 11 requires that Millennium describe to the Commission in its noise survey report the modifications it will make in order to reduce noise levels exceeding the predicted noise level at any nearby NSA.
In response to Mr. English’s query why a conservation easement was appropriate for Millennium’s Minisink Compressor Project, but is not being required or implemented for the Hancock Compressor Project, the Commission clarifies that it did not require Millennium to establish a conservation easement for the Minisink Project. Rather, in response to a request by the Orange County Department of Planning, Millennium was willing to consider reserving 42.5 acres of the project site as a conservation easement. Thus, noting that it generally believes it appropriate for an applicant to purchase additional land surrounding compressor stations to serve as a buffer between residences and compressor stations, the Commission required Millennium only to update the Commission on its efforts to develop a conservation easement.
While located on the same pipeline, the impacts of the Minisink Compressor Project differ from those of the Hancock Compressor Project. Notably, the Minisink Project, unlike the project here, will be more visible to surrounding residents and drivers, and it will require more time for the visual screening plan at Minisink to become recognition of this, Millennium agreed to limit its rights with respect to the recognition of this, Millennium agreed to limit its rights with respect to the 00 feet (NSA No. 5) from the compressor station. However, they are not future use of the land on which the compressor station is located, committing to avoid development on specific portions of the site and to allow farming to continue in certain other areas. However, no formal conservation easement was established95 and the Commission denied the request by the Town of Minisink that Millennium be prohibited from constructing new above-ground structures on the unused portion of the project site or from selling any of the property.96
85. For the reasons discussed above, the Commission finds that it is not necessary to require Millennium to use Parcels 3 and 4 as a buffer zone to protect surrounding landowners from the effects of the project, as the additional land will not provide increased protection beyond that provided by the project design and Parcels 1 and 2, which EA determined adequately minimize potential adverse impacts.
[1] Robert Sanzoverino March 24 and 30, 2013 Comments; Anthony DePalma March 10, 2013 Comments; Cathy Leidersdorff April 1, 2013 Comments; Craig English March 25, 2013 Comments; Jeffrey Weil March 31, 2013 Comments; and Miriam March 21, 2013 Comments. In addition, Mr. DePalma and Miriam contend that Millennium, in stating it was purchasing the three additional properties to create a buffer between the compressor and residences, and then proposing to sell two of the parcels, broke its “promise” to establish a buffer zone, “misled” property owners, and engaged in “bait and switch” and “sleight of hand” tactics. See Anthony DePalma March 10, 2013 comments; Miriam March 21, 2013 Comments.