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HomeMy WebLinkAbout1.05 Sound, Traffic, Cultural studySound Survey Grand River Gathering LLC High Mesa Compressor Station OA Project No. 012-0732 826 21 ½ Road | Grand Junction, CO 81505 | TEL 970.263.7800 | FAX 970.263.7456 HOOVER & KEITH INC. ACOUSTICS & NOISE CONTROL ENGINEERING TX Office: 11391 Meadowglen, Suite D, Houston, TX 77082 CO Office: 1680 Northwestern Rd, Longmont, CO 80503 CO Phone: 303-834-9455 TX Phone: 281-496-9876 -Page i- Subject: Encana High Mesa Compressor Station (Garfield County, Colorado): Results of a Sound Survey during Operation of the Station Submitted to: Encana Oil & Gas (USA) Inc. Denver, CO 80944 H&K Report No. 2701 Date of Report: March 20, 2012 H&K Job No. 4489 Submitted by: Paul D. Kiteck, P.E., Hoover & Keith Inc. REPORT SUMMARY This report presents the results of a sound survey performed Feb. 22, 2012 at the High Mesa Station (abbreviated as “Station”). The purpose of the sound survey was to quantify the sound levels during Station operation and compare the sound contribution of the Station to the applicable sound level requirement(s). The following table summarizes the measured daytime A- wt. sound levels at the surrounding (“closest”) residences during Station operation. Measured Daytime A-Wt. Sound Levels at the Closest Residences during Station Operation Description of Surrounding Residences and Sound Measurement Location Meas’d A-Wt. Sound Level Near residences located between approx. 4,200 ft. to 5,000 ft. west/NW of Station 45.1 dBA* Near residences along CR 306 located approx. 5,500 feet SW of the Station 37.6 dBA* *Meas’d sound data (A-wt. sound levels) also includes background (ambient) noise (i.e., noise not associated with the Station operation). Consequently, the sound contribution due only to Station is lower than the reported sound levels. The following table summarizes the measured A-wt. sound levels at 350 feet from the Station (i.e., sound measurement position at 350 feet in each cardinal direction of the Station). Measured A-Wt. Sound Levels at 350 ft. in each Cardinal Direction during Station Operation Pos. Description of the Sound Measurement Location Meas’d A-Wt. Sound Level Pos. 1 350 feet NW of the Station site center (i.e., location of compressor units) 65.7 dBA Pos. 2 350 feet NE of the Station site center (i.e., location of compressor units) 64.3 dBA Pos. 3 350 feet SE of the Station site center (i.e., location of compressor units) 60.2 dBA Pos. 4 350 feet SW of the Station site center (i.e., location of compressor units) 51.6 dBA In summary, the results of the sound survey indicate that the Station sound levels are slightly above or below the sound level limits specified in the COGCC “Aesthetic and Noise Control Regulations” for “light industrial” zoned property (i.e., daytime level of 70 dBA and nighttime level of 65 dBA at 350 feet from the Station). This conclusion assumes that the Station is considered to be in a remote location (i.e., there are no reasonably proximate occupied structures). Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page ii- TABLE OF CONTENTS Page 1.0 INTRODUCTION............................................................................................................................ 1 2.0 SITE/FACILITY DESCRIPTION .................................................................................................... 1 3.0 SOUND LEVEL REQUIREMENT(S) ............................................................................................. 1 3.1 Discussion of the COGCC Noise Regulations .............................................................. 1-2 3.2 Discussion of the CO State Noise Regulations ................................................................ 2 4.0 MEASUREMENT LOCATIONS, CONDITIONS AND MEASUREMENT METHODOLOGY ........ 3 4.1 Sound Measurement Positions and Conditions during the Sound Survey ....................... 3 4.2 Data Acquisition and Sound Measurement Equipment ................................................ 3-4 5.0 MEASUREMENT RESULTS, OBSERVATIONS AND FINAL COMMENT .................................. 4 5.1 Measurement Results ....................................................................................................... 4 5.2 Observations and Final Comment .................................................................................... 5 APPENDIX: SITE/FACILITY DRAWINGS, SUMMARY OF THE MEASUREMENT RESULTS AND ANY SUBSEQUENT SOUND DATA CALCULATIONS ................. 6-15 Figure 1: Area Layout around the Station showing Location of Surrounding Residences, Chosen Sound Measurement Positions and other Areas of Interest ............................ 7 Figure 2: Layout showing Station Buildings/Piping/Equipment and the Chosen Sound Measurement Positions around the Station Property .................................................... 8 Table A: Measured A-Wt. Sound Levels and Unweighted O.B. SPLs at all Reported Sound Measurement Positions during Operation of the Station .................................... 9 Table B: Meteorological Conditions during the Site Sound Survey .............................................. 9 COGCC Noise Requirements (Rules and Regulations) ................................................... 10-12 Summary of Typical Metrics for Regulating Environmental Noise and Acoustical Terminology related to the Report ..................................................................................... 13-15 Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 1- 1.0 INTRODUCTION In this report, Hoover & Keith Inc. (“H&K”) presents the results of a sound survey performed on Feb. 22, 2012 during normal operation of the Encana High Mesa Station (abbreviated as “Station” in the report). The purpose of the sound survey was to quantify the sound level attributable to the Station during typical operation of the Station and compare the resulting sound level contribution of the Station to the applicable sound level requirement(s). 2.0 SITE/FACILITY DESCRIPTION Figure 1 (Appendix, p. 7) provides an area layout around the Station showing the surrounding (“closest”) residences along with the chosen sound measurement positions near the surrounding residences and at 350 feet around the Station, noting that the existing topography is not shown on this figure/drawing. The Station is located in Garfield County, Colorado off County Road 300 (“CR-300”), in the area referred to as “High Mesa”. The Station is approximately 3 miles south of Parachute, CO. The land immediately around the Station is primarily utilized as industrial activities (e.g., oil & gas type operations), and assumed to be classified as “light industrial” zoned property, noting that there is a “water plant” located on the North Side of the Station. The closest residences (i.e., “residential/agricultural/rural” zoned properties) are located west, northwest and southwest of the Station at a distance of between 4,200 feet to 5,500 feet from the Station. Figure 2 (Appendix, p. 8) provides a layout of the Station showing the equipment (i.e., location of compressor units) along with the chosen sound measurement positions around the Station property. The Station consist of seven (7) CAT Model 3516 (unenclosed) skid-mounted engine- driven reciprocating compressor units (i.e., Units #1– #7) and one (1) CAT Model 3616 engine- driven reciprocating compressor unit (i.e., Unit #8) that is located inside a building. 3.0 SOUND LEVEL REQUIREMENT(S) AND ACOUSTICAL TERMINOLOGY For the reader’s information, a summary of applicable acoustical terminology in this report and typical metrics used to measure and regulate environmental noise is provided at the end of the report (Appendix, pp. 13–15). 3.1 Discussion of the COGCC Noise Regulations The Colorado Oil and Gas Conservation Committee (“COGCC”) regulate the oil and gas drilling and production industry in the State of Colorado and the mission of the COGCC is to promote the responsible development of Colorado’s oil and gas natural resources. The COGCC has the responsibility for regulating noise from natural gas facilities in Colorado, and Series 800 (i.e., “Aesthetic and Noise Control Regulations”; Section 801 and Section 802) of the COGCC Rules and Regulations address noise requirements (i.e., maximum allowable noise levels) for natural gas gathering facilities, such as the High Mesa Station. The complete noise regulations given in the COGCC Rules and Regulations are provided toward the end of the report (Appendix, pp. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 2- 10–12). The following summarizes our interpretation of the noise requirements of the COGCC as applied to the High Mesa Station:  Where there is no reasonably proximate occupied structure or designated outside activity area and there are no noise complaints from a nearby property owner regarding noise related to oil and gas operations, which appears to be the case with the High Mesa Station, the “light industrial standard” may be applicable. Consequently, the Station noise level should not exceed an A-weighted (“A-wt.”) sound level of 70 dBA (daytime) and 65 dBA (nighttime) at 350 feet from the Station site center (i.e., area of the noise source, which is the area of the compressor equipment/units).  If the property adjacent to the Station property line is zoned “agricultural & rural” and/or there are noise complaints from a nearby property owner or a local governmental designee, the Station noise contribution at 350 feet from the site center should not exceed an A-weighted (“A-wt.”) sound level of 55 dBA (daytime) and 50 dBA (nighttime). 3.2 Discussion of CO State Noise Regulations There are State of Colorado noise-related regulations (i.e., Colorado State Statute 25-12- 102/103) that could be applicable, although in our opinion, the noise regulations of the COGCC are more stringent than the CO State Statute regulations. The noise regulations of the CO State Statute is a maximum A-weighted (A-wt.) sound level due to the operation of the facility at a distance of 25 feet or more from the property line of the applicable land use category, as given in Table 1 below. Zone or Land Use Category 7:00 AM to 7:00 PM (Daytime) 7:00 PM to 7:00 AM (Nighttime) Metric Sound Measurement Location Residential 55 dBA 50 dBA A-wt. sound level 25 feet or more from property line Commercial 60 dBA 55 dBA A-wt. sound level 25 feet or more from property line Light Industrial 70 dBA 65 dBA A-wt. sound level 25 feet or more from property line Industrial 80 dBA 75 dBA A-wt. sound level 25 feet or more from property line Table 1: Summary of the Sound Level Requirements as given in the Colorado State Statute The land adjacent to the east, north and west property line of the Station is zoned A-1 Agricultural Land, and based on our interpretation of the regulations, agricultural land is classified as a “light industrial” land usage. Consequently, if the noise regulations in the State Statute are applicable, the noise radiated at 25 feet from the property line of the Station should not exceed a nighttime A- wt. sound level of 65 dBA (i.e., most stringent requirement). At land that is zoned Residential Rural (i.e., “residential” land usage), if the noise regulations in the State Statute are applicable, noise radiated at 25 feet from the residential property line should not exceed a nighttime A-wt. sound level of 50 dBA (i.e., most stringent requirement). In addition, activity at the Station shall be conducted in a manner so that noise produced is not objectionable due to intermittence, beat frequency or shrillness. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 3- 4.0 MEASUREMENT LOCATIONS, CONDITIONS AND MEASUREMENT METHODOLOGY 4.1 Sound Measurement Positions and Conditions during the Sound Survey Two (2) locations were chosen for measuring the sound level near the surrounding (“closest”) residences around the Station. Other sound measurements were conducted at 350 feet in each cardinal direction from the Station/equipment and at locations around the Station property. The following provides a description of the reported sound measurement positions and the surrounding “closest” residences. Pos. 1: 350 Ft. NW of the Station equipment (i.e., “North Side” of the Station); Pos. 2: 350 Ft. NE of the Station equipment (i.e., “East Side” of the Station); Pos. 3: 350 Ft. SE of the Station equipment (i.e., “South Side” of the Station); Pos. 4: 350 Ft. SW of the Station equipment (i.e., “West Side” of the Station); Pos. 5: West fenceline of the Station/site, at the “alternative” Station entrance gate; Pos. 6: North fenceline of the Station/site, at the “main” Station entrance gate; Pos. 7: South of the Station/site, in line with Unit #5 and Unit #6; Pos. 8: Near the closest residences that are west and northwest (“NW”) of the Station, located between approximately 4,200 and 5,000 feet from the Station acoustic center (i.e., location of the compressor units), noting that residences in this area are not in line-of- sight of the Station due to the existing topography; Pos. 9: Near the closest residences that are southwest (“SW”) of the Station, and these residences are located along CR-306 (i.e., Spring Creek Road), approximately 5,500 feet from the Station; Note that these residences along the East Side of Spring Creek Road are in line-of-sight of the Station. The sound survey was performed by Paul Kiteck of H&K during the daytime of Feb. 22, 2012. During the sound survey, the temperature was approximately 48 to 50o F.; the sky was mostly cloudy and the wind was blowing primarily from the south/SW. The operating conditions of the Station units during the sound survey are summarized on Table A (Appendix, p. 9). 4.2 Data Acquisition and Measurement Equipment At each sound measurement location, the A-wt. sound levels and the unweighted octave-band (“O.B.”) sound pressure levels (“SPLs”) were measured at approximately four (4) feet above ground. The sound measurements were taken during times when the wind was less than five (5) mph, if feasible. The sound measurement system consisted of a Larson-Davis (LD) Model 2900 Real Time Analyzer/SLM (a Type I SLM per ANSI Standard S1.4 & S1.11) with a 1/2-in. LD condenser microphone covered by a windscreen, and the analyzer/SLM was calibrated with a LD Model CA250 microphone calibrator that was calibrated within one (1) year of the testing date. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 4- 5.0 MEASUREMENT RESULTS, OBSERVATIONS AND FINAL COMMENT 5.1 Measurement Results Table A (Appendix, p. 9) shows the measured A-wt. sound levels and the unweighted O.B. SPLs at all sound measurement positions during operation of the Station along with a summary of the operating conditions of the Station equipment/units during the survey. Meteorological conditions that occurred during the sound survey are summarized in Table B (Appendix, p. 9). The following Table 2 summarizes the measured A-wt. sound levels during the sound survey during Station operation, noting that the measured A-wt. sound levels at these “residential” sound measurement positions included significant existing background noise (i.e., Station noise was not the most dominant noise source). Meas. Pos. Description of the Surrounding (Closest) Residences and the Sound Measurement Location Meas’d A-Wt. Sound Level Pos. 8 Near residences located between 4,200 ft. to 5,000 ft. west/NW of the Station 45.1 dBA Pos. 9 Near residences located approximately 5,500 feet SW of the Station 37.6 dBA Table 2: Summary of the Meas’d A-Wt. Sound Levels at the Closest Residences surrounding the Station The following Table 3 summarizes the measured A-wt. sound levels at 350 feet from the Station (i.e., sound measurement position in each cardinal direction from the Station equipment). These sound measurement positions are presumed to represent suitable sound monitor positions for qualifying the sound level around the Station property line in accordance with the COGCC, if applicable. Meas. Pos. Description of the Sound Measurement Location Meas’d A-Wt. Sound Level Pos. 1 350 feet NW of the Station site center (i.e., location of the compressor units) 65.7 dBA Pos. 2 350 feet NE of the Station site center (i.e., location of the compressor units) 64.3 dBA Pos. 3 350 feet SE of the Station site center (i.e., location of the compressor units) 60.2 dBA Pos. 4 350 feet SW of the Station site center (i.e., location of the compressor units) 51.6 dBA Table 3: Summary of the Meas’d A-Wt. Sound Levels at 350 Ft. from the Station Equipment In summary, the results of the sound survey indicate that the Station sound levels are slightly above or below the sound level limits specified in the COGCC “Aesthetic and Noise Control Regulations” for “light industrial” zoned property (i.e., daytime level of 70 dBA and nighttime level of 65 dBA at 350 feet from the Station). This conclusion assumes that the Station is considered to be in a remote location (i.e., there are no reasonably proximate occupied structures). Regarding the Colorado State Statute, the results of the sound survey indicate that the Station sound level is equal to or below the sound level limits specified in the Colorado State Statute for an adjacent industrial use area (i.e., nighttime A-wt. sound level or Leq of 65 dBA) and at surrounding residences (i.e., 50 dBA at 25 feet from the residential property line). Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 5- 5.2 Observations and Final Comment At the residences located west/NW of the Station, noise associated with the Station was not really audible during the sound survey, and the noise of distant vehicle traffic along Interstate 70 was the primary noise contributor to the measured A-wt. sound levels along with the noise associated with another oil/gas facility located relatively close to these residences. At the residences located southwest of the Station (i.e., along Spring Creek Road), which are in line-of- sight of the Station, the noise generated by the Station was audible but not the dominant noise source. The A-wt. sound levels at these residences SW of the Station were primarily a results of the noise of distant traffic along Interstate 70. At the sound measurement positions around the fenceline and property of the Station (i.e., Meas. Pos. 1, 2, 3, 4, 5, 6 & 7), the noise of the Station was the most dominant noise source, which would be expected since the primary equipment at the Station consist of unenclosed skid-mounted engine-driven compressor units. This concludes the results of the sound survey at the High Mesa Station. The measured sound levels around the Station (e.g., sound levels at 350 feet from the Station equipment/units) would be slightly higher than the measured levels if all compressor units were operating although we understand that the operating conditions that occurred during this recent sound survey is typical for this facility. file: ProjWord\Encana\High Mesa Station\Report – Results of a Sound Survey at Encana High Mesa Station.doc Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 6- APPENDIX  FIGURE 1: AREA LAYOUT AROUND THE STATION SHOWING THE SURROUNDING RESIDENCES, OTHER AREAS OF INTEREST AND CHOSEN SOUND MEASUREMENT POSITIONS NEAR THE RESIDENCES AND AT 350 FT. AROUND THE STATION  FIGURE 2: STATION LAYOUT SHOWING BUILDINGS AND EQUIPMENT ALONG WITH CHOSEN SOUND MEASUREMENT POSITIONS AROUND THE STATION PROPERTY  SUMMARY OF THE MEASURED SITE SOUND DATA AND ANY SUBSEQUENT DATA CALCUATIONS  COLORADO OIL & GAS CONSERVATION COMMISSION (COGCC) NOISE REQUIREMENTS  SUMMARY OF TYPICAL METRICS FOR REGULATING ENVIRONMENTAL NOISE AND ACOUSTICAL TERMINOLOGY RELATED TO THE REPORT Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 7- Figure 1: Encana High Mesa Station: Area Layout showing the Surrounding Residences, other Areas of Interest, and the Chosen Sound Measurement Positions near the Residences and at 350 Feet around the Station Site (Existing Topography not Shown). APPROXIMATE SCALE IN FEET 0 1900950 3800 - HOUSE OR MOBILE HOME - NOISE SENSITIVE AREANSA LEGEND - NONRESIDENTIAL BUILDING - MEASUREMENT POSITION N HIGH MESA STATION POS. 8 POS. 9 5500' 5000' 4200' CR 306 (SPRING CREEK RD.) UNDERGROUND PIPELINE WATER PLANT CR 300 (PARACHUTE - UNA RD.) POS. 4 (350' FROM COMPR. UNITS) POS. 1 (350' FROM COMPR. UNITS) POS. 2 (350' FROM COMPR. UNITS) POS. 3 (350' FROM COMPR. UNITS) Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 8- Figure 2: Encana High Mesa Station: Layout showing the Station Equipment/Building and Chosen Sound Measurement Positions around the Station Property. APPROXIMATE SCALE IN FEET 8040 160 LEGEND 0 - MEASUREMENT POSITION NOISE BARRIER NOISE BARRIER 1 2 3 4567 CONTROL BUILDING UNIT #8 IN BLDG. MAIN STATION ENTRANCE GATE FENCELINE POS. 5 POS. 7 100' POS. 6 HIGH MESA STATION PLANT NORTH TRUE NORTH ACCESS ROAD Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 9- Measurement Set Time Sound Pressure Level (SPL) in dB per Octave Band Freq (Hz)A-Wt.Comments & Observations Pos.Description/Location of Test 31.5 63 125 250 500 1000 2000 4000 8000 Level 1 Approx. 350 ft. NW of the 3:30 PM 73 75 70 61 58 60 57 54 58 65.2 Station noise was dominant noise compressor site 3:35 PM 74 75 70 62 60 61 58 56 59 66.3 source, as would be expected. Average SPLs & A-Wt. Sound Level 74 75 70 62 59 61 58 55 59 65.7 2 Approx. 350 ft. NE of the 3:42 PM 73 72 68 61 57 61 57 53 50 64.5 Station noise was dominant noise compressor site 3:45 PM 74 72 68 61 58 60 57 53 50 64.1 source. Average SPLs & A-Wt. Sound Level 74 72 68 61 57 61 57 53 50 64.3 3 Approx. 350 ft. SE of the 3:52 PM 78 75 69 60 52 54 54 46 36 60.3 Station noise was dominant noise compressor site 3:55 PM 76 76 70 60 52 53 53 46 35 60.1 source. Average SPLs & A-Wt. Sound Level 77 75 69 60 52 53 53 46 35 60.2 4 Approx. 350 ft. SW of the 4:00 PM 70 67 59 51 46 44 42 38 36 51.1 Station noise was dominant noise compressor site 4:05 PM 70 67 59 51 46 46 46 40 32 52.3 source, but noticably less station noise Average SPLs & A-Wt. Sound Level 70 67 59 51 46 45 44 39 34 51.6 on this side of station. 5 West fenceline of station,4:10 PM 77 77 78 70 66 64 62 60 55 70.4 Station noise was dominant noise at alternate station entrance 4:12 PM 76 78 78 70 66 63 62 60 55 70.2 source, as would be expected. Average SPLs & A-Wt. Sound Level 77 78 78 70 66 63 62 60 55 70.3 6 North fenceline of station, at 4:15 PM 78 81 76 71 68 67 65 64 73 75.3 Station noise was dominant noise main station entrance gate 4:18 PM 78 81 76 72 68 67 65 65 74 76.0 source. Average SPLs & A-Wt. Sound Level 78 81 76 71 68 67 65 64 74 75.6 7 South Side of station, in line 4:25 PM 86 83 79 74 71 66 65 61 55 73.4 Station noise was dominant noise with Units #5 & #6 4:28 PM 86 83 79 74 71 66 65 61 55 73.4 source but noise of Unit #8 was not Average SPLs & A-Wt. Sound Level 86 83 79 74 71 66 65 61 55 73.4 significant (i.e., unit in a building). 8 Near the closest residences 5:00 PM 60 57 55 45 42 42 34 29 29 46.2 Noise of station not audible; Audible west/NW of station 5:10 PM 62 57 54 42 40 39 33 25 21 44.2 sound sources include distant I-70 Average SPLs & A-Wt. Sound Level 61 57 55 44 41 41 34 27 25 45.1 vehicle traffic; noise of other facilities 9 Near the closest residences 5:30 PM 53 50 44 39 35 32 25 25 23 37.8 Noise of station audible but not domiant; SW/SSW of station 5:50 PM 55 49 45 37 36 32 20 19 20 37.5 Most significant noise was distant I-70 Average SPLs & A-Wt. Sound Level 54 50 45 38 36 32 23 22 22 37.6 vehicle traffic Table A:Encana High Mesa Station: Meas'd A-Wt. Sound Levels and Octave Band ("O.B.") SPLs as Measured on Feb. 22, 2012 during Operation of Unit #1, Unit #2, Unit #5, Unit #6, Unit #7 and Unit #8. Operating Conditions of Station/Units: > Unit #1 (CAT 3516 skid-mounted unit): Engine speed of 1245 rpm; engine torque at 86 to 88%; > Unit #2 (CAT 3516 skid-mounted unit): Engine speed of 1245 rpm; engine torque at 86 to 88%; > Unit #5 (CAT 3516 skid-mounted unit): Engine speed of 1235 rpm; engine torque at 86 to 88%; > Unit #6 (CAT 3516 skid-mounted unit): Engine speed of 1250 rpm; engine torque at 86 to 88%; > Unit #7 (CAT 3516 skid-mounted unit): Engine speed of 1250 rpm; engine torque at 86%; > Unit #8 (CAT 3616 unit in a building): Engine speed of 975 rpm; engine torque at 96%. Measurement Set Temp. R.H. Wind Wind Peak Sky Conditions Pos. Date/Time of Testing (°F) (%) Direction Speed Wind 1 to 9 3:30 PM to 6:00 PM (2/22/12) 48 - 50 50 - 55 South/SW 3 - 6 mph 6 - 8 mph Mostly cloudy Table B:Ecana High Mesa Station: Meteorological Conditions during Sound Survey on Feb. 22, 2012. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 10- COLORADO OIL & GAS CONSERVATION COMMISSION (COGCC) NOISE REQUIREMENTS (800 SERIES OF THE RULES AND REGULATIONS) The COGCC regulates the oil and gas drilling and production industry in the State of Colorado and the mission of the COGCC is to promote the responsible development of Colorado’s oil and gas natural resources. This “responsible development” balances efficient exploration and production of oil and gas with the prevention of waste, protection of mineral owner’s rights, and protection of public health, safety and welfare and the environment. In Colorado, the COGCC has the responsibility for regulating noise from oil and gas facilities. AESTHETIC AND NOISE CONTROL REGULATIONS (Rules related to Noise Regulations and Noise Abatement as of November 30, 2006) 801. INTRODUCTION The rules and regulations in this section are promulgated to control aesthetics and noise impacts during the drilling, completion and operation of oil and gas wells and production facilities. Any Colorado county, home rule or statutory city, town, territorial charter city or city and county may, by application to the Commission, seek a determination that the rules and regulations in this section, or any individual rule or regulation, shall not apply to oil and gas activities occurring within the boundaries, or any part thereof, of any Colorado county, home rule or statutory city, town, territorial charter city or city and county, such determination to be based upon a showing by any Colorado county, home rule or statutory city, town, territorial charter city or city and county that, because of conditions existing therein, the enforcement of these rules and regulations is not necessary within the boundaries of any Colorado county, home rule or statutory city, town, territorial charter city or city and county for the protection of public health, safety and welfare. 802. NOISE ABATEMENT a. The goal of this rule is to identify noise sources related to oil and gas operations that impact surrounding landowners and to implement cost-effective and technically-feasible mitigation measures to bring oil and gas facilities into compliance with the allowable noise levels identified in subsection c. Operators should be aware that noise control is most effectively addressed at the siting and design phase, especially with respect to centralized compression and other downstream “gas facilities” (see definition in the 100 Series of these rules). b. Oil and gas operations at any well site, production facility or gas facility, shall comply with the following maximum permissible noise levels . Operations involving pipeline or gas facility installation or maintenance, the use of a drilling rig, completion rig, workover rig, or stimulation is subject to the maximum permissible noise levels for industrial zones. The type of land use of the surrounding area shall be determined by the Commission in consultation with the local governmental designee taking into consideration any applicable zoning or other local land use designation. c. In the hours between 7:00 a.m. and the next 7:00 p.m. the noise levels permitted below may be increased ten (10) db(A) for a period not to exceed fifteen (15) minutes in any one (1) hour period. The allowable noise level for periodic, impulsive or shrill noises is reduced by five (5) db(A) from the levels shown. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 11- ZONE 7:00 am to next 7:00 pm (Daytime) (Nighttime) 7:00 pm to next 7:00 am Residential/Agricultural/Rural 55 db(A) 50 db(A) Commercial 60 db(A) 55 db(A) Light industrial 70 db(A) 65 db(A) Industrial 80 db(A) 75 db(A) In remote locations, where there is no reasonably proximate occupied structure or designated outside activity area, the light industrial standard may be applicable. Pursuant to Commission inspection or upon receiving a complaint from a nearby property owner or local governmental designee regarding noise related to oil and gas operations, the Commission shall conduct an onsite investigation and take sound measurements as prescribed herein. The following provide guidance for the measurement of sound levels and assignment of points of compliance for oil and gas operations: (1) Sound levels shall be measured at a distance of three hundred and fifty (350) feet from the noise source. At the request of the complainant, the sound level shall also be measured at a point beyond three hundred fifty (350) feet that the complainant believes is more representative of the noise impact. If an oil and gas well site, production facility or gas facility is installed closer than three hundred fifty (350) feet from an existing occupied structure, sound levels shall be measured at a point twenty-five (25) feet from the structure towards the noise source. Noise levels from oil and gas facilities located on surface property owned, leased or otherwise controlled by the operator shall be measured at three hundred and fifty (350) feet or at the property line, whichever is greater. In situations where measurement of noise levels at three hundred and fifty (350) feet is impractical or unrepresentative due to topography, the measurement may be taken at a lesser distance and extrapolated to a 350-foot equivalent using the following formula: db(A)@DISTANCE 2 = db(A)@DISTANCE 1 – 20 x log10(distance 2/distance 1) (2) Sound level meters shall be equipped with wind screens, and readings taken when the wind velocity at the time and place of measurement is not more than five (5) miles per hour. (3) Sound level measurements shall be taken four (4) feet above ground level. (4) Sound levels shall be determined by averaging minute-by-minute measurements made over minimum fifteen (15) minute sample duration if practicable. The sample shall be taken under conditions that are representative of the noise experienced by the complainant (e.g., at night, morning, evening, or during special weather conditions). (5) In all sound level measurements, the existing ambient noise level from all other sources in the encompassing environment at the time and place of such sound level measurement shall be considered to determine the contribution to the sound level by the oil and gas operation(s). Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 12- d. In situations where the complaint or Commission onsite inspection indicates that low frequency noise is a component of the problem, the Commission shall obtain a sound level measurement twenty-five (25) feet from the exterior wall of the residence or occupied structure nearest to the noise source, using a noise meter calibrated to the db(C) scale. If this reading exceeds 65 db(C), the Commission shall require the operator to obtain a low frequency noise impact analysis by a qualified sound expert, including identification of any reasonable control measures available to mitigate such low frequency noise impact. Such study shall be provided to the Commission for consideration and possible action. e. Exhaust from all engines, motors, coolers and other mechanized equipment shall be vented in a direction away from all occupied buildings. f. All facilities within four hundred (400) feet of occupied buildings with engines or motors which are not electrically operated shall be equipped with quiet design mufflers or equivalent. All mufflers shall be properly installed and maintained in proper working order. Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 13- SUMMARY OF TYPICAL METRICS FOR REGULATING ENVIRONMENTAL NOISE AND ACOUSTICAL TERMINOLOGY RELATED TO THE REPORT (1) Decibel (dB): A unit for expressing the relative power level difference between acoustical or electrical signals. It is ten times the common logarithm of the ratio of two related quantities that are proportional to power. When adding dB or dBA values, the values must be added logarithmically. For example, the logarithmic addition of 35 dB plus 35 dB is 38 dB. (2) A-Weighted Sound Level (dBA): The A-wt. sound level is a single-figure sound rating, expressed in decibels (Re 20 µPa), which correlates to the human perception of the loudness of sound. The dBA level is commonly used to measure industrial and environmental noise since it is easy to measure and provides a reasonable indication of the human annoyance value of the noise. The dBA measurement is not a good descriptor of a noise consisting of strong low-frequency components or for a noise with tonal components. The A-weighted curve approximates the response of the average ear at sound levels of 20 to 50 decibels. The following are the relative response of A-weighted filter per octave band frequency, and a graph/curve is provided below that shows a graphical representation of the A-wt. filter response per frequency (in Hz). 31.5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 1,000 Hz 2,000 Hz 4,000 Hz 8,000 Hz 16,000 Hz -39.4 dB -26.2 dB -16.1 dB -8.6 dB -3.2 dB 0 dB +1.2 dB +1.0 dB -1.1 dB -6.6 dB 10 0 -10 -20 -30 -40 -50 16,00080004000200010005002501256331.516 RELATIVE RESPONSE, dB FREQUENCY, Hz C B A A B, C Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 14- (3) C-Weighted Sound Level (dBC): The C-wt. sound level is a single-figure sound rating, expressed in decibels (Re 20 µPa), which correlates to the human perception of the loudness of sound in excess of 85 decibels. The dBC level is commonly used to measure industrial and environmental noise since it is easy to measure and provides a reasonable indication of the overall sound. The difference between C and A-weighted sound levels provides an indication of the amount of lower frequency sound energy. The following are the relative response of C-weighted filter per octave band frequency, and a graph/curve is provided that shows a graphical representation of the C-wt. filter response per frequency (in Hz), and the graph/curve above in Definition (2) shows a graphical representation of the C-wt. filter response per frequency (in Hz). 31.5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 1,000 Hz 2,000 Hz 4,000 Hz 8,000 Hz 16,000 Hz -3.2 dB -1.0 dB -0.2 dB 0 dB 0 dB 0 dB -0.2 dB -0.8 dB -3.0 dB -8.5 dB (4) Background or Ambient Noise: The total noise produced by all other sources of a given environment in the vicinity of a specific source of interest, and includes any Residual Noise. (5) Human Perception of Change in Sound Level  A 3 dB change of sound level is barely perceivable by the human ear  A 5 or 6 dB change of sound level is noticeable  If sound level increases by 10 dB, it appears as if the sound intensity has doubled. (6) Sound Pressure Level (Lp or SPL): Ten times the common logarithm to the base 10 of the ratio of the mean square sound pressure to the square of a reference pressure. Therefore, the sound pressure level is equal to 20 times the common logarithm of the ratio of the sound pressure to a reference pressure (20 micropascals or 0.0002 microbar). (7) Octave Band Sound Pressure Level (SPL): Sound is typically measured in frequency ranges (e.g., high-pitched sound, low-pitched sound, etc.) that provides more meaningful sound data regarding the sound character of the noise. When measuring two noise sources for comparison, it is better to measure the spectrum of each noise, such as in octave band SPL frequency ranges. Then, the relative loudness of two sounds can be compared frequency range by frequency range. As an illustration, 2 noise sources can have the same dBA rating and yet sound completely different. For example, a high-pitched sound at a frequency of 2000 Hz could have the same dBA rating as a much louder low-frequency sound at 50 Hz. (8) Daytime Sound Level (Ld) & Nighttime Sound Level (Ln): Ld is the equivalent A-weighted sound level, in decibels, for a 15 hour time period, between 07:00 to 22:00 Hours (7:00 a.m. to 10:00 p.m.). Ln is the equivalent A-weighted sound level, in decibels, for a 9 hour time period, between 22:00 to 07:00 Hours (10:00 p.m. to 7:00 a.m.). Hoover & Keith Inc. Encana Oil & Gas (USA) – High Mesa Station H&K Job No. 4489 Results of Sound Survey during Operation of the Station H&K Report No. 2701 (Date: 03/20/12) -Page 15- (9) Equivalent Sound Level (Leq): The equivalent sound level (Leq) can be considered an average sound level measured during a period of time, including any fluctuating sound levels during that period. In this report, the Leq is equal to the level of a steady (in time) A-weighted sound level that would be equivalent to the sampled A-weighted sound level on an energy basis for a specified measurement interval. The concept of the measuring Leq has been used broadly to relate individual and community reaction to aircraft and other environmental noises. (10) Day-Night Average Sound Level (Ldn): The Ldn is an energy average of the measured daytime Leq (Ld) and the measured nighttime Leq (Ln) plus 10 dB. The 10-dB adjustment to the Ln is intended to compensate for nighttime sensitivity. As such, the Ldn is not a true measure of the sound level but represents a skewed average that correlates generally with past sound surveys which attempted to relate environmental sound levels with physiological reaction and physiological effects. For a steady sound source that operates continuously over a 24-hour period and controls the environmental sound level, an Ldn is approximately 6.4 dB above the measured Leq. Consequently, an Ldn of 55 dBA corresponds to an Leq of 48.6 dBA. If both the Ld and Ln are measured, then the Ldn is calculated using the following formula: ()  +=+10/1010/ 10dn nd1024 91024 15log10 LLL (11) L-Percent Sound Levels: The L percent levels (e.g., L50, L90 & L10) refer to the A-weighted sound levels that are exceeded for 90, 50 and 10 percent of the time, respectively, during a sound measurement period. For example, the 50-percentile exceeded sound level is designated to as L50 and is sometimes described as the median sound level. The range between the L10 and L90 values usually provides a good indication of the variability of the sound levels during the period of measurement. (12) Sound Level Meter (SLM): An instrument used to measure sound pressure level, sound level, octave-band SPL, or peak sound pressure level, separately or in any combinations thereof. The measured weighted SPL (i.e., A-Wt. Sound Level or dBA) is obtained by the use of a SLM having a standard frequency-filter for attenuating part of the sound spectrum. (13) Sound Power Level (Lw or PWL): Ten times the common logarithm of the ratio of the total acoustic power radiated by a sound source to a reference power. A reference power of a picowatt or 10-12 watt is conventionally used. (14) Tone: A tone is a sound sensation-having pitch, which is a listener’s perception of the frequency (for example, the higher the frequency, the higher the pitch). For a measured sound spectrum, a tone is represented as a “peak” in the spectrum curve. Noise that contains significant tones is considered a tonal type of noise. End of Report Basic Traffic Study Grand River Gathering LLC High Mesa Compressor Station OA Project No. 012-0732 826 21 ½ Road | Grand Junction, CO 81505 | TEL 970.263.7800 | FAX 970.263.7456 826 21½ Road TEL 970.263.7800 Grand Junction, CO 81505 FAX 970.263.7456 www.olssonassociates.com BASIC TRAFFIC STUDY INTRODUCTION & OBJECTIVE This Basic Traffic Analysis summarizes findings of a traffic impact analysis performed for Grand River Gathering LLC (GRG) High Mesa Compressor Station located southeast of the City of Rifle, Colorado. It is expected that the lifespan of the site will be a maximum of 30 years. EXISTING NETWORK The High Mesa Compressor Station is accessed CR 304 and a private road system. CR 304 is a two lane gravel road. TRIP GENERATION/DISTRIBUTION Trip generation is generally determined using rates found in the IT E Trip Generation manual. Rates from this publication are applied to values related to the size of the proposed site to estimate the trips expected to enter and exit the site. In this case, no rates are provided for facilities similar to these. To estimate trips expected for this site, information was gathered regarding the expected traffic based on previous projects similar to this one. The following table summarizes the expected average and maximum trips for each phase discussed previously. Table 1: Trip Generation – HIGH MESA Compressor Station Phase Average Trips/Day Maximum Trips/Day Percent Trucks Total Trips/Phase Phase Duration Operation <1 1 n/a 7665 30 years Reclamation 5 14 14 % 74 14 days Note that the estimated lifespan of the site is expected to be a maximum of 30 years. Current ADT’s and expected trip generation are currently present accommodating GRG’s natural gas production in the area. Traffic Analysis Page 2 AUXILIARY LANE ANALYSIS As defined in the Garfield County Road Inventory Report, CR 304’s Functional Classification is Local as set by Colorado Department of Transportation (CDOT) and the Federal Highway Administration (FHWA). Garfield County does not have traffic volume data available for CR 304. However, the addition of the small amount of traffic generated by the operation of this facility, as set forth in Table 1, does not warrant auxiliary lanes.. RECOMMENDATIONS Based on the expected trip generation rates discussed above, the increase in average daily traffic is not expected to be significant. Based on the results of the analysis, no mitigation is recommended. The additional traffic from the compressor station will not significantly increase the existing low levels of traffic. Based on this analysis, no roadway improvements or turn lanes are anticipated to be required to support this project. Class I Cultural Resources Study Grand River Gathering LLC High Mesa Compressor Station OA Project No. 012-0732 826 21 ½ Road | Grand Junction, CO 81505 | TEL 970.263.7800 | FAX 970.263.7456 FLATTOPS ARCHAEOLOGICAL CONSULTANTS P.O. BOX1893 March 5, 2012 Mr. Lorne Prescott Olsson Associates 826 21 J2 Road Grand Junction, Colorado 81505 CC: Mr. Fred Jarman Garfield County, Building & Planning 108 81h Street, Suite 401 Glenwood Springs, Colorado 81601 CARBONDALE, CO 81623 (970) 379-2846 RE: Letter Report of Fi ndings-Class I Cultural Resources Study for the Encana Oil & Gas (USA) Inc., High Mesa Compressor Station, Parcel #2409-361-00-048, Garfield County, Colorado Dear Mr. Prescott, This letter report of findings serves as documentation for the completion of a Class I Cultural Resources Study of the proposed Encana Oil & Gas (USA) Inc., High M esa Compressor Station (Parcel #2409 -3 61 -00-048) in Garfield County, Colorado. This report satisfies the requirements of the Garfield County Unified Land Use Resolution, Article IV Section 4-502E part 8b: A determination of the effect on significant archaeological, cultural, paleontological, historic re so urces . The project is located in Section 36, Township 7 South, Range 96 West (61 h Principal Meridian). Cultural resource files for Section 36 were reviewed for this study. The proposed project area is located approximately four miles south-southwest of Battlement Mesa, Colorado and is accessed via Garfield County Road 304 and a private road system maintained by Encana. Physiographically, it is located along the southwestern edge of High Mesa at approximately 5,940 feet above sea level. The file search was conducted on March 5, 2012, by reviewing the Colorado Office of Archaeology and Historic Preservation's COMPASS database. Sixteen previous Class Ill cultural resource inventory projects have taken place. in Sect ion 36, T7S, R96W (Table 1); twelve cultural resources have been recorded as a result of these projects (Table 2). Four (5GF1539, 5GF2648, 5GF2653, and SGF3636) of the cultural resources are prehistoric isolated finds. The isolated finds have been f iel d evaluated not eligible for inclusion on the National Register of Historic Places (NRHP}; no further work is recommended. One site (SGF2649) is a prehistoric open camp, and two (SGF2651 and SGF4141) are prehistoric open lithic sites. 5GF2651 is field evaluated not eligible; no further work is recommended. SGF2649 is Kae McDonald Principle Investigator flattopsarchaeo/ogical99@comcast.net field evaluated needs data, and SGF4141 is officially determined needs data; avoidance and protection are recommended for these two sites . The remaining five sites are historic-three of these sites (SGF447, SGF2650, and SGF2652) are habitation sites, another is a trail (SGF392), and one is a ditch (SGF4149.1). SGF2650, SGF2652, and SGF4149.1 are officially determined not eligible for inclusion on the NRHP; no further work is recommended. SGF392 and SGF447 are officially determined needs data; avoidance and protection are recommended for these sites. Based on an examination of the site forms for SGF392, SGF447 , SGF2649, and SGF4141, it was determined that these sites are located outside the proposed project area and will be avoided. Therefore, based on the results of this Class I inventory, Flattops Archaeological Consultants recommends a finding of no historic properties affected. However, should the proposed project location change, or if other cultural resources are discovered or unearthed during ground-disturbing activities, a qualified archaeologist should be notified . If you have questions or concerns, please do not hesitate to contact me at your convenience. ¥:;· ~ Kae~~PA Principal Investigator Table 1: Previous Class Ill Inventories in Section 36, TSS, R96W. SHPOSurvey Project Title Client Company Year Sites ID#/BLM ID# GF .LM.R131 Cultural Resources Inventory Report of Fuel Resources Grand River 1980 SGF447 Proposed Gas Wells H-25-7-96S and D-31-Development Institute 7-95S Company GF.LM.R218 Cultural Resource Inventory of Six Western Slope Grand River 1982 MC.LM.R371 Segments of the Parachute-Debeque 8-Gas Company Institute inch Loop Line occurring on BLM Lands MC.LM.R68 Grant-Norpac C ultural Resource Inventory Grant-Norpac Metcalf 1991 SGF1539 of a 39 Mile Seismic Line Archaeological Consultants GF .LM.R107/ Tom Brown, Inc . High Mesa Access Roads Tom Brown, Metcalf 1997 5GF447 BLM #5498-6 Class Ill Cultural Resource Inventory Inc. Archaeological Con sultants GF.LM .R178/ Cultural Resource Inventory for the High BLM BLM 1998 5GF2648 BLM -GSRA Mesa Wildlife Habitat Improvement 5GF2649 S#1098-20 Project 5GF2650 5GF2651 5GF2652 GF.LM.R277 Tom Brown , Inc. Parachute Federal 31 -22 Tom Brown, Metcalf 1998 Well Pad and Access Road Class Ill In c. Archaeological Cultural Resource Inventory Consultants GF.LM.R213 Class Ill Cultural Resource Inventory Canyon Gas Metcalf 2002 Report for the Proposed Canyon Gas Resources Archaeological Resources Bentley Phase II Gas Pipeline Consultants GF.LM.R255 Class Ill Cultural Resource Inventory for Canyon Gas Metcalf 2003 the Proposed Canyon Gas Resources Resources Archaeologica I South Parachute Gas Pipeline Consultants GF .lM.R339 Class Ill Cultural Resource Inventory for Noble Energy Grand River 2004 Four Well Locations and Related Institute Access/Pipeline Routes GF.LM .R325 Class Ill Cultural Resource Inventory for Williams Grand River 2005 5GF3636 the Proposed South Parachute #22-8 Well Production Institute Location and Related Access (0.75 Mile) RMT GF .LM.R338 Encana Oil and Gas (USA), Inc. Natural Encana Oil and Greystone 2005 5GF2652 Gas Gathering Pipeline to PH -1 Well Class Gas (USA}, Inc. Ill Cultural Resource Inventory GF .lM.R449 Class Ill Cultural Resource Inventory for Encana Oil and Grand River 2006 the Proposed and Alternate Routes of the Gas (USA}, Inc. Institute South Parachute Pipeline Extension GF.lM .R450/ Encana Oil & Gas (USA), Inc. South Encana Oil and Arcadis-2006 5GF2650 BLM -GSFO Parachute Geographic Area , 20 Well Gas (USA}, In c. Greystone locations Class Ill Cultural Resources #14606-3 Inventory, Garfield County , Colorado GF.LM .R451 Class Ill Cultural Resources Inventory of Not Listed Uncompahgre 2008 SGF447 the ETC Canyon South Parachute loop Archaeological SGF4141 Pipeline Consultants 5GF4149.1 GF.LM.NR922/ Class Ill Cultural Resource Inventory for Encana Oil and Grand River 2010 BLM-CRVFO the Proposed High Mesa 16-inch Discharge Gas (USA), Inc. Institute #1111-1 Pipeline on Private Land GF.LM .R488/ Encana PD-31B WPA: A Class Ill Cultural Encana Oi l and Metcalf 2010 5GF447 BLM-CRVFO Resource Inventory of a Well Pad and an Gas (USA}, Inc. Archaeologica I #5411-2 Access Road Consultants Table 2: Cultural Resources located in Section 36, TSS, R96W. Smithsonian Site Type Site National Register Recommendations SHPOSurvey Number Description Eligibility IDNo. SGF392 Historic Escalante-Officially Needs Avoid and Protect GF.LM .R166 Dominguez Trail Data (2006) SGF447 Historic Cow Camp Officially Needs Avoid and Protect GF.LM.R107 Data (2010) GF.LM.R131 GF.LM.R451 GF .LM.R488 SGF1539 Prehistoric Isol ated Find Not Eligible -Field No Further Work MC.LM.R68 GF.LM.R166 SGF2648 Prehistoric Isolated Find Not Eligible -Field No Further Work GF.LM.R178 5GF2649 Prehistoric Open Camp Needs Data -Field Avoid and Protect GF.LM .R178 Historic Isolated Find SGF2650 Historic Habitation Officially Not No Further Work GF.LM.R178 Eligible (2007) GF.LM.R450 SGF2651 Prehistoric Open Lith ic Not Eligibl e -Field No Further Work GF .LM.R178 SGF2652 Historic Habitation Officially Not No Further Work GF.LM.R178 Eligible (2005) GF.LM.R338 SGF2653 Prehistoric Isolated Find Not Eligible -Field No Further Work GF.LM.R178 5GF3636 Prehistoric Isolated Find Not Eligible -Field No Further Work GF.LM.R325 5GF4141 Prehistoric Open Lithic Officially Needs Avoid and Protect GF .LM.R451 Data (2008) SGF4149 .1 Historic Marling Ditch Officially Not No Further Work GF.LM.R451 Eligible (2008)