HomeMy WebLinkAbout1.07 Noise study'" YALERUS Noise Study
) October 7, 2010 Phil Vaughan Phil Vaughan Construction Management, Inc. Construction Manager 1038 County Road 323 Rifle, Colorado 81650 HANKARD ENVIRONMENTAL c:: c::::: ~ ---~ ~ A
cou~llcS AND V I &RA l rOtl C O NS ULTING Re: Noise Compliance Analysis for Proposed Valerus Hunter Mesa Gas Compressor Station Dear Mr. Vaughan, This report describes the results of
Hankard Environmental's analysis of noise from the proposed Valerus Hunter Mesa Gas Compressor Station in Garfield County, Colorado. Our analysis demonstrates that noise levels from
the proposed facility will be in compliance with the noise-related provisions of Garfield County Development Review policy 9.07.06 (2) and Colorado Oil and Gas Conservation Commission
Rule 802. A summary of our analysis methods and results is provided first, which is followed by more detailed descriptions of applicable noise regulations, the proposed project, existing
noise levels at the proposed site, and our analysis methods and results. SUMMARY OF RESULTS Valerus Compression Services, LP is proposing to construct a 50 million standard cubic foot
per day natural gas compressor station in Garfield County, Colorado. The major noise-producing equipment associated with the proposed facility includes five Waukesha L7044GSI gas driven
compressor packages and associated Air-X-Changer 156-EH cooler packages. Per Valerus, each of the engine/compressor/cooler packages will be housed in acoustic enclosures consisting of
sound absorbing interior walls, sound-attenuated building ventilation openings, and soundattenuated engine cooling air intake and discharge openings. The engine exhausts will include
substantial silencers. Garfield County's Unified Lalld Use Resolution requires that noise levels from pipelines and associated equipment (i.e. compressor stations) comply with the Colorado
Oil and Gas Conservation Commission's (COGCC) Rule 802 (Aesthetics and Noise COlltrol). The noise limits imposed by Rule 802 are dependent on the time of day that the facility will operate
and on the land use of the adjacent properties. The proposed Valerus Hunter Mesa station will operate 24 hours per day, therefore both daytime and nighttime standards must be met. Adjacent
land use is rural/agricultural. There are no existing residences within at least one mile of the proposed facility. There are two existing compressor stations within 0.3 miles and 0.6
miles of the proposed station as well as several other oil and gas facilities within one-mile. COLORADO • WISCONSIN • MAINE phone: (303) 666{)617 • www.hankardinc.com • fax (303) 600-0282
) ) HANKARD ENVIRONMENTAL c: c:::: ~-==-----=--~~ A <:OUSI Cl ~IlD vlaQ~"O'l C:O fH U 1 Tl tJC Given this, noise from the proposed compressor station must meet the limits for the "Light
Indush'ial" zone, as COGCC Rule 802 states that a facility located in a "remote area with no proximate occupied structure", which is the case here, shall not emit noise levels in excess
of 65 dBA This limit needs to be met at a distance of 350 feet from the noise source or at the nearest property line, whichever is greater. COGCC Rule 802 also stipulates that, if noise
complaints arise from area residents during operation of the compressor station, the Cweighted noise level shall not exceed 65 dBC when measured at a point 25 feet from an occupied structure
(residence) in the direction of the station. Hankard Environmental constructed a three-dimensional computer model of the proposed ' facility that included each significant noise source,
the proposed acoustic enclosures and exhaust silencers, as well as features of the surrounding terrain such as ground type and topography. The model predicts that noise levels from the
proposed Valerus Hunter Mesa Gas Compressor Station will be equal to or less than 53 dBA at a distance of 350 feet in all directions, which is comparable to the existing ambient noise
leveL This is substantially quieter than the applicable limit of 65 dBA It should be noted that existing noise levels around the proposed site already exceed 50 dBA as a result of the
two nearby compressor stations 0.3 and 0.6 miles away. The model also predicts that the C-weighted noise level produced by the facility will not exceed 65 dBC beyond a distance of 700
feet to the north and south of the station or 1,000 feet to the east and west of the station. There are no occupied structures this close to the proposed station (nor is there much potential
for same in the future). Therefore, we conclude that noise levels from the proposed Valerus Hunter Mesa Gas Compressor Station are expected to be fully in compliance with Garfield County
and COGCC noise level limits. Noise Compliance Analysis for Proposed Valems Hunfer Mesa Gas Compressor Station October 7, 2010 Page 2 ) )
) HANKARD ENVIRONMENTAL c:: ..:::: -=---=----=--> :::> A C O UIl CS "'N O VI I~II.I I O !l C: O !lS Ul lt tlG APPLICABLE NOISE REGULATIONS Section 7-815 of Garfield County's Unified
Land Use Resolution (2008, as amended) states that: Any equipment used in construction or operation of a pipeline must comply with the Colorado Oil and Gas Conservation Commission Rules
and Regulations, Section 802, Noise Abatement. 1. For any pipeline construction or operational facility that will have a substantial impact in adjacent areas, additional noise mitigation
may be required. One or more of the following additional noise mitigation measures may be required: a. Acoustically insulated housing or covers enclosing any motor or engine; b. Screening
of the site or noise emitting equipment by fence or landscaping; c. A noise management plan specifying the hours of maximum noise and the type, frequency, and level of noise to be emitted;
and d. Any other noise mitigation measures required by the COGCc. 2. All power sources used in pipeline operations shall have electric motors or muffled internal combustion engines.
The COGCC Rule 802 provides the maximum permissible noise level for different land uses, and for both daytime and nighttime periods. The limits are listed in Table 1, below. The proposed
station will operate 24 hours per day. The proposed station is located within an active gas development area with no known occupied structures within at least one mile in all directions
from the proposed station. Lands adjacent to the proposed station are currently either owned and operated by oil and gas companies, or are being used for agricultural purposes. In this
case, the limits for "Light Industrial" land use are applicable, as COGCC Rule 802 states that a facility located in a "remote area with no proximate occupied structure" shall not emit
noise levels in excess of 65 dBA. The limit must be met at a distance of 350 feet from the noise source or at the nearest property line, whichever is greater. COGCC Rule 802 also stipulates
that, if noise complaints arise from area residents during operation of the compressor station, the C-weighted noise level shall not exceed 65 dBC when measured at a point 25 feet from
an occupied structure (residence) in the direction of the station. TABLE 1 COGCC MAXIMUM PERMISSIBLE NOISE LEVELS -dBA Zone Residential I Ag I Rural Commercial Light Industrial Industrial
Daytime (I), (2) (7:00am to 7:00pm) 55 60 70 80 Nighttime (2) (7:00pm to 7:00am) 50 55 65 75 (I) During the daytime, the noise level can be increased by 10 dBA for 15 minutes in anyone-hour
period (2) Noise level limit decreased by 5 dBA for impulsive type sounds. Noise Complial/ce AI/alysis for Proposed Valems HUllter Mesa Gas Compressor Statioll October 7, 2010 Page 3
) HANKARD ENVIRONMENTAL c::: c:::::: "'IlL ~ ---==--~::> A c:oUS"CI ",~I) VIA~" T ' O " C':Ot-l\UIT ,!j ('. DESCRIPTION OF THE SITE AND PROPOSED GAS COMPRESSOR STATION The proposed Valerus
Hunter Mesa Compressor Station is loca ted on the south side of Interstate 70, in Garfield County, Colorado, as shown in Figure 1. Figure 2 shows the equipment layout, which consists
of five Waukesha L7044GSI gas driven compressor packages and associated Air-X-Changer 156-EH cooler packages. Each of the engine/compressor/cooler packages will be housed in acoustic
enclosures, consisting of sound absorbing interior walls, sound-attenuated building ventilation openings, and sound-attenuated engine cooling air intake and discharge openings. The engine
exhausts will include substantial silencers. Silt Rifle Project Location 0( --"' Figure 1: General Location of Proposed Valerus Hunter Mesa Gas Compressor Station Noise Compliance Analysis
for Proposed Valerlls Hllnter Mesa Gas Compressor Statioll October 7, 2010 Page 4 )
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"ltD VII~~ro()1t (:OtH UH II'l(; I 1:1 I ,, i.~'a::: ~.;:.r~;..:::: " ;" ~-, -j ," ;;:..--.~ -Figure 2: General Equipment Layout for Proposed Valerus Hunter Mesa Gas Compressor Station
(courtesy of Sopris Engineering -Oct 5, 2010) Noise COlllpliance Analysis for Proposed Valems Hunter Mesa Gas COlllpressor Statioll October 7, 2010 PageS
) HANKARD ENVlRONMENTAL c:: ~-= -=-> => A C OUH 1C S " U D V" O ... "O~ C O ~\ ll ( 'I ~I('; EXISTING NOISE LEVELS Ambient sound levels were measured at two locations (M1 and M2) near
the proposed station, as shown in Figure 3. Measurements were conducted using two Larson Davis Model 820 sound level meters, which meet American National Standards Institute (ANSI) Type
1 specifications (accuracy of approximately ±1 dB). The meters were factory-calibrated within the past year and field calibrated prior to the measurements. The sound level meters were
configured to continuously measure the A-weighted, 60-minute average equivalent level (L,q). The microphones were placed on a tripod five feet above the ground, and covered with windscreens.
The measured ambient sound levels are shown in Figure 4, below. Sound levels were very similar at the two locations, and ranged from approximately 46 to 53 dBA. The primary sources of
noise in the area are two existing compressor stations (non-Valerus facilities). Weather conditions during the measurements included winds less than 5 miles per hour (generally), temperatures
between 44 and 74 degrees Fahrenheit, and relative humidity values between 16 and 49 percent. Figure 3: Noise Measurement Locations Noise Complial1ce Allalysis for Proposed Valerus HUllter
Mesa Cas Compressor Station October 7, 2010 Page 6 ) )
) ) ~ ~ < '. , ~ ,0. . 5! 0 '" ('o'9P ... , J4 1) lalla, as ION Figure 4: Measured Ambient Noise Levels Noise Compliance Analysis for Proposed Valems Hllnter Mesa Gas Compressor Statioll
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ACOUSTICAL MODELING HANKARD ENVIRONMENTAL ~---===--=-~ ::> Ac: o UJ! c: s ~~ o ""~"' T ' O " r: O lfS UII' ~'G Noise levels from the proposed compressor station were predicted using
SoundPlan v7.0, which is an internationally recognized three-dimensional acoustical modeling program that utilizes propagation algorithms from ISO 9613-2 (Attellllatioll ofSolllld During
Propagation Outdoors). A three-dimensional rendering of the acoustical model of the proposed compressor station is provided in Figure 5. The noise emission data used in the model for
each major noise-producing piece of equipment is listed in Table 2. The noise emission levels were measured by Hankard Environmental on other projects with identical or similar equipment.
For sources that we have no direct measurement data, supplemental information was used from equipment suppliers. Table 3 lists the sound transmission loss and insertion loss values for
all of the materials and noise-reducing equipment specified for use on this project by Valerus (Noise Solutions Budgetary Proposal 3397.2 Rev 2, September 13, 2010). Figure 5: SoundPlan
Model Rendering Noise COlllplial/ce Analysis for Proposed Valerus HlInter Mesa Gas Compressor Station October 7, 2010 Page 8 )
) ) TABLE 2 Sound Pressure Level (SPL) and Sound Power Level (PWL) In~ut Data -dBA ) HANKARD ENVIRONMENTAL A c~:oUJ/C~ -",-nD -VI-.-'A---II-O=,=< -C.O::"-~::lI:l :l>lt lG Octave Band
Center Frequency (Hertz) Noise Source 31.5 63 125 250 500 1000 2000 4000 Waukesha L7044GSI Un silenced Exhaust, PWL 82 101 123 129 132 127 130 128 Compressor Building Interior Surfaces,
SPL 59 75 83 91 94 95 94 93 Waukesha L7044GSI Un silenced Air Intake, SPL 57 74 84 90 93 94 94 94 AirX 156EH Inlet Un silenced, SPL 54 71 89 86 88 87 85 79 AirX 156EH Outlet Unsilenced,
SPL 55 73 87 85 86 86 84 81 Source: Hankard Environmental measurements and calculations TABLE 3 Insertion Loss and Transmission Loss Data Used in SoundPlan Analysis -dB Octave Band Center
Frequency (Hertz) Noise Source 31.5 63 125 250 500 1000 Zeron 9000 Exhaust Silencer 36 43 44 45 48 53 Compressor Building (ModeI1A1) 11 12 19 29 34 46 Cooler Inlet Silencer 15 15 22
25 28 30 Cooler Outlet Silencer 7 10 15 18 25 25 Engine Intake Air Silencer 15 16 17 20 25 23 Fan Forced Bldg Vent Outlet Hoods 6 6 14 18 25 25 Induced Draft I-St~e Bldg Vent Inlet Hoods
3 3 5 5 10 18 Cooler Inlet Exterior Walls (ModeI1A1) 11 12 19 29 34 46 Cooler Outlet Exterior Walls (ModeI1A1) 11 12 19 29 34 46 Source: Noise Solutions Budgetary Proposal 3397.2 Rev
2, September 13, 2010 Noise Compliallce Allalysis for Proposed Valerus HUllter Mesa Cas Compressor Station October 7, 2010 2000 4000 57 55 46 46 30 30 25 25 24 21 25 25 15 10 46 46 46
46 8000 Overall 108 137 85 101 87 101 72 95 75 93 8000 Rw 53 53 46 39 31 31 25 26 27 25 24 26 10 15 46 39 46 39 Page 9
) RESULTS OF THE NOISE ANALYSIS HANKARD ENVIRONMENTAL c::: c::::: -= --=-----=-' ~-=" COU ll ( ' " " 0 Y I I~"" I O " C; O '/s UI Tl l<C The predicted noise levels from the proposed
Valerus Hunter Mesa Gas Compressor Station are shown in Figures 6 and 7. The results are shown in terms of noise level contours, which are lines drawn over scaled mapping of the proposed
project site indicating how far from the proposed compressor station that noise levels will be less than or equal to the two applicable noise level limits (65 dBA and 65 dBC). Between
the station and the contours, noise levels are predicted to be greater than the level shown. Beyond the contours, noise levels are predicted to be less than the level shown. From Figure
6, it can be seen that our analysis predicts that noise levels from the station will be equal to or less than 53 dBA at a distance of 350 feet in any direction from the station, which
is comparable to the existing ambient noise level. This is substantially lower than the applicable limit of 65 dBA. From Figure 7, it can be seen that our analysis predicts that the
C-weighted noise level produced by the facility will not exceed 65 dBC beyond a distance of 700 feet to the north and south of the station, and approximately 1,000 feet to the east and
west of the station. There are no occupied structures this close to the proposed station (nor is there much potential for same in the future). Note that the 65 dBC limit is only applicable
when there is a complaint from a nearby residence, and does not affect this assessment of compliance. Thus, the C-Weighted contours are provided for informational purposes only. Based
on our analysis, the proposed Hunter Mesa Gas Compressor Station is in compliance with all appHcable Garfield County and COGCC noise regulations. This compliance determination is based
on the implementation of the noise mitigation measures described in Noise Solution's September 13, 2010 Blldgetary Proposal #3397.2 Rev2. Noise Compliance Analysis for Proposed Valems
HIII/ter Mesa Gas Compressor Statioll October 7, 2010 Page 10 )
) ) ) ) HANKARD ENVIRONMENTAL c: co:: --=----.::;.--~ ... ~ A COUlf l Cl ... ~n VIIQA IIO ,. (; OlfS U l ll ~I G Figure 6: Predicted Noise Levels from Valerus Hunter Mesa Compressor
Station (dBA) 100 200 400 "Mt Figure 7: Predicted Noise Levels from Valerus Hunter Mesa Compressor Station (dBC) Noise Compliance Analysis for Proposed Valems Hllnter Mesa Gas Compressor
Sta tioll October 7, 2010 Page 11
HANKARD ENVIRONMENTAL c:: <IIiiC::: -= ~ -~----=-:::> A C O US TI C s .. N D V • • ~ ... " () .. r: o 'n ~ I " II C Thank you for involving us with this project. Please call if you have
any questions. Sincerely, '2J2ei ~ Jeff M. Cerjan Senior Engineer Cc: Mike Hankard, Hankard Environmenlal lnc. Noise COlllpliallce Allalysis for Proposed Valerus HUllter Mesa Cas COlllpressor
Statioll October 7, 2010 Page 12 ) )