THE ACOUSTIC GROUP PTY LTD CONSULTING ACOUSTICAL & VIBRATION ENGINEERS

Transcription

1 THE ACOUSTIC GROUP PTY LTD CONSULTING ACOUSTICAL & VIBRATION ENGINEERS ACOUSTIC ASSESSMENT PROPOSED GROUNDWATER CLEANUP PROJECT R3:NSC Prepared for: Orica Australia Beauchamp Road MATRAVILLE NSW FRED STREET, LILYFIELD, 2040, NSW, AUSTRALIA ph: (612) fx: (612) A.B.N

2 Acoustical Assessment Proposed Groundwater Cleanup Project CONTENTS Page No 1 Introduction 1 2 Noise Assessment Criteria 2 3 Construction Noise Impact GTP Additional Infrastructure Additional Extraction Wells in the PCA DNAPL Extraction Wells and DNAPL Pipeline Treated Water Pipeline Construction Traffic 9 4 GTP Noise Design Goals 10 5 Operational Noise for the BCG Project 12 6 Conclusion 13 APPENDICES A: Site Location B: Proposed Development C: Plant Items 9 th November, 2004

3 Acoustical Assessment Proposed Groundwater Cleanup Project Page 1 of 15 1 INTRODUCTION The purpose of this report is to present the results and findings of an acoustical assessment of noise emission from the proposed Botany Groundwater Cleanup (BGC) Project. It is proposed to construct and operate a groundwater treatment plant (GTP) to treat contaminated groundwater under the Botany Industrial Park and adjacent lands. The GTP site is shown in Appendix A. An Environmental Impact Statement is being prepared for the proposed construction and operation of the GTP and associated infrastructure with this acoustical report forming part of the EIS prepared by URS Australia Pty Ltd. It is proposed that the GTP will consist of a single treatment system involving groundwater feed storage, air strippers, off-gas oxidation and treatment (refer to Appendix B). Adjacent to the plant will be feed storage and treated water tanks and tanks for the temporary storage of recovered EDC. The BGC Project also includes extraction wells, piping to transfer the extracted water to the GTP and piping for the distribution of treated water and discharge of waste streams. Some aspects of this infrastructure, including the primary and secondary pipeline and extraction wells on Foreshore Road, are complete at the time of writing. The focus of this assessment is the GTP on the BIP. Consideration has also been given to the construction noise associated with the additional infrastructure which is yet to be built for the BGC Project. Operational noise impacts associated with all facets of the BGC Project have been assessed. The Director s requirements from DIPNR identify that the EIS must assess the predicted noise impact resulting from all noise sources during construction and operation, including road traffic noise. The noise assessment must be undertaken in accordance with the EPA s Industrial Noise Policy document and the Environmental Criteria for Road Traffic Noise document.

4 Acoustical Assessment Proposed Groundwater Cleanup Project Page 2 of 15 The Director s requirements nominate that in relation to construction noise, there must be consideration of the construction site noise guidelines from the EPA s Environmental Noise Control Manual and that potential impacts resulting from vibration generated during any drilling activities must be considered. The Botany Industrial Park premise operates under licenced conditions issued by the New South Wales Environment Protection Authority (now Department of Environment and Conservation). Licence conditions pertaining to noise govern the cumulative noise impact from the subject site and are part of the Botany Industrial Park Noise Reduction Program that has governed the control and reduction of noise from existing operations. 2 NOISE ASSESSMENT CRITERIA Noise is normally measured using the decibel (db) which is a logarithmic measure of a variation in air pressure (sound waves). Community noise is normally measured using an A weighted scale - noted as db(a). The A weighting is considered to approximate the frequency response of the human ear. For continuous noise emission from a subject site any increase in background (average minimum) noise levels of more than 5 db(a) is generally taken to be unacceptable. Due to the size and nature of the Botany Industrial Park, the GTP will be Scheduled under the Protection of the Environment Operations Act and falls under the jurisdiction of the NSW Department of Environment and Conservation (including the EPA).

5 Acoustical Assessment Proposed Groundwater Cleanup Project Page 3 of 15 The proposed project involves the creation of a new GTP on the Botany Industrial Park and associated pump and piping infrastructure. With respect to noise, any plant on the BIP is governed by the stringent noise emission criterion set down by the NSW EPA. The EPA noise emission limit for an L eq sound level contribution from the plant not exceeding 35 db(a) at night, results in a sound level contribution significantly less than the existing ambient background level around the perimeter of the Botany Industrial Park site. There are no specific operational noise criteria for off site infrastructure and such items are not near residential premises. Orica has chosen to require such noise to be consistent with BIP noise assessment procedures. The off site infrastructure is considered as part of the plant noise design criteria. The provision of a noise goal applicable to the subject plant which is noticeably less than both the ambient background level at residential boundaries and the amenity goal that is obtained from the INP, automatically realises full compliance with the EPA s Industrial Noise Policy document as nominated in the Director s requirements. As such standard noise assessment procedures with respect to the measurement of existing ambient sound levels is not required for this project as the design goal that has been specified by the NSW Environment Protection Authority renders the conduct of such measurements of no assistance. In addition to compliance with external noise emission limits, the Botany Industrial Site Noise Policy also identifies that the noise level in working areas not governed by speech communication or annoyance shall not exceed 85 db(a) so as to address the company s occupational noise goals. The specifications in relation to individual plant items provided for our assessment indicate that at the present time, the specification for various items is to achieve a noise level no greater than 82 db(a) at 1 metre, which in turn nominates various acoustic controls required for existing equipment.

6 Acoustical Assessment Proposed Groundwater Cleanup Project Page 4 of 15 The design of the GTP is currently in terms of a general concept and generic plant items have been determined for the purpose of this acoustic assessment. Primarily, working backwards from the permitted noise emission levels at residential boundaries results in the specification of an effective sound power level for the subject plant so as to achieve compliance with the noise goal. This sound power level in turn determines the effective noise control for individual plant items, of which the most significant noise emission sources are associated with the two air stripper blower (part of the off gas oxidation package). The EPA s Environmental Criteria for Road Traffic Noise document considers noise goals associated with various types of developments or road classifications. Access into and egress from the site is via the main (number 3) gate on Denison Street, which is not directly opposite residential premises. Denison Street is a designated heavy vehicle transport route in the subject area, particularly to Port Botany, and carries a significant volume of traffic not associated with the Botany Industrial Park site. The minimal number of truck movements associated with the subject plant result in an insignificant increase in terms of the existing road traffic noise levels and as a consequence would readily satisfy the EPA recommended criteria set out in their ECRTN document. The construction noise criteria set out in the Environmental Noise Control Manual (Chapter 171) nominates a series of noise goals at residential receivers dependent upon the period of construction. For a construction period of 4 weeks and under, the target is for an L 10 level measured over a period of not less than 15 minutes when the construction site is in operation and must not exceed the background level by more than 20 db(a). Where the construction period of greater than 4 weeks and not exceeding 26 weeks, the noise target becomes background +10 db(a). Where the construction period is greater than 26 weeks, there is no specification in the guidelines and it is assumed that the normal concept of background +5 db(a) would apply.

7 Acoustical Assessment Proposed Groundwater Cleanup Project Page 5 of 15 The off site infrastructure occurs in different areas for a short period of time and could be considered in terms of the background + 20 db(a) goal. However, considering such works as part of the overall construction of the project would see the use of the background + 5 db(a) target. The EPA has indicated in their Noise Guide for Local Government that the Construction Noise Guideline is under review. Whilst the noise control guideline is specified in terms of an L 10 (average maximum) descriptor, the EPA some 5 years ago (with the introduction of the INP and ECRTN) altered their acoustic design goals to be assessed in terms of an L eq level and it is envisaged that any condition pertaining to construction would be addressed in terms of an L eq requirement. 3 CONSTRUCTION NOISE IMPACT 3.1 GTP Activities associated with the construction phases are described in detail in the EIS. The construction techniques are relatively conventional and follow the following logical steps: Earthworks The site is currently used for parking tanker trailers and trucks. This area is raised and sealed with a two layer coat bitumen coating (2 coat seal). At this stage it is expected that new site area will reduce the existing parking area by approximately one metre and create a one level platform for most of the facilities required for the GTP. Site Drainage - Site drainage lines will be laid to carry stormwater via a first flush system into the established site storm water system. Concrete Work - the concrete work identified to date for the site are: First flush pit(s), Site drainage pits, Equipment slabs, Tank slabs and bund walls, Infill slabs (areas between equipment slabs), Roads and pathways Structural Steelwork - steelwork identified to date will be fabricated off-site for: Pipe rack, Stripper structure, Awning over part of the water processing equipment

8 Acoustical Assessment Proposed Groundwater Cleanup Project Page 6 of 15 Buildings - A control room and amenities building as well as an electrical switch room will be constructed on site to service the plant. Equipment and Plant Installation - Tank construction/erection, equipment installation, electrical, and pipe work will run concurrently. In accordance with EPA requirements construction work is normally limited to Monday to Friday 7am to 6pm, and Saturday from 7am to 1pm if required. Botany site has continuing work for existing plant maintenance and individual equipment overhauls that from previous monitoring of construction activities is found to be masked by general plant and traffic noise and clearly complied with EPA construction noise limits. The project will generally only use common sized equipment i.e. welders, small mobile cranes, forklifts etc. for general work. Loading and unloading of equipment and steel erection is likely to be carried out with a 35 to 50 tonne crane(s) with an occasional large crane brought in for heavy lifts. The nature of the construction of the plant involves regular tradespeople and general provision of buildings pipework installation of pumps, electrical cabling etc. Between 15 and 115 persons will be working on the plant over the construction period. Due to the location of the plant from the residential boundary there is a significant degree of distance attenuation which for normal construction activities would result in noise site boundary levels similar to existing day time background levels. In accordance with EPA requirements, cleaning of pipes during the short commissioning phase would be carried out during daytime only and noise levels from these activities would be less than background + 5 db(a) at residential boundaries. It is not envisaged that the proposed GTP will require piling. Therefore vibration is not an issue.

9 Acoustical Assessment Proposed Groundwater Cleanup Project Page 7 of Additional Infrastructure The following infrastructure is to be constructed for operation of the BGC project: Installation of additional extraction wells in the PCA Installation of DNAPL wells Construction of the DNAPL pipeline Cleaning and relining an existing pipeline that runs from the BIP to Bunnerong Canal and creating an outlet at this point for the discharge of excess treated water. This infrastructure was not installed at the time of writing and is likely to be constructed in advance of works on the GTP site. Construction of this additional infrastructure would occur during standard hours as discussed in section 3.1 above. Installation of the additional wells and the DNAPL pipeline are planned to occur over the period from November 2004 to May Works on the treated water pipeline are planned to occur over an approximately 4 month period from January to April A description of the construction works associated with this infrastructure is provided in the EIS Additional Extraction Wells in the PCA The key noise generating activity for installation of the PCA extraction wells would be drilling rigs. Two rigs would be used, with access to Southlands from McPherson Street. The rigs would be mounted on the back of 10 tonne trucks. Operation of these rigs would result in a maximum sound level for each rig of 84 db(a) at 4 metres.

10 Acoustical Assessment Proposed Groundwater Cleanup Project Page 8 of 15 Monitoring of drilling conducted in earlier stages of this project revealed that there will be no perceptible vibration, either adjacent to the rig or at sensitive receptors. The additional wells to be installed in the PCA are located in an industrial zone approximately 30 metres from commercial and industrial businesses on the southern side of McPherson Street and 400 metres from the nearest residential receivers off Botany Road in a south westerly direction The operation of two drilling rigs simultaneously would realise a sound level contribution less than 43 db(a) and clearly satisfy the background + 5 db(a) goal DNAPL Extraction Wells and DNAPL Pipeline The installation of the DNAPL extraction wells would involve similar activities to the PCA wells, with access via Gate No. 3 and the internal BIP road network. Construction of the DNAPL pipeline would involve minor clearing and excavation, concrete preparation, welding, fastening and other metal works, and sealing / painting. Minor equipment deliveries would be required. Other construction equipment would include cranes, excavators, welders, and forklift trucks. There are no sensitive receptors in close proximity to the DNAPL wells to be installed on the western boundary of BIP. Installation of these wells and the minor works required for the installation of the DNAPL pipeline would generate a sound level contribution less than 48 db(a) at the nearest residence in Denison Street for operations near the plant and a sound level contribution less than 42 db(a) at the nearest residence in Spring Street for activities at the northern end of line 6.

11 Acoustical Assessment Proposed Groundwater Cleanup Project Page 9 of Treated Water Pipeline The existing pipeline to be refurbished for the discharge of treated water is underground from the BIP to Bunnerong Canal. Access at a number of locations would be required for temporary works associated with the relining process. A diffuser would be installed at the discharge point in the Canal, for equal distribution of the discharge into the Canal. The access points are located in an industrial setting. The works at each access location would take approximately 2 weeks and involve the use of an excavator and a truck mounted compressor. These works would not result in construction noise being audible at residential premises. 3.3 Construction Traffic Additional traffic generated during the construction phase has been examined by URS as contained in the EIS. In comparison to existing traffic movements on the BIP Site the small number of movements associated with construction (up to 6 trucks per day) should be virtually imperceptible and have no significant impact. Traffic associated with the additional infrastructure is minimal and would only occur at particular sites outside the BIP for a short duration. Drilling rigs would enter the relevant site by truck and remain until the full number of wells had been installed (with only minor movements required as the wells were installed in progression). Construction of the DNAPL pipeline and the relining of the existing pipeline for water discharge to Bunnerong Canal would involve a minor number of work vehicles. Accordingly in terms of noise impact, vehicles associated with the construction phase should have negligible impact.

12 Acoustical Assessment Proposed Groundwater Cleanup Project Page 10 of 15 4 GTP NOISE DESIGN GOALS In accordance with the Botany Industrial Park Noise Reduction Program, the design goal for the subject GTP at residential boundaries is not greater than 35 db(a). Regular noise monitoring around the Botany Industrial Park has identified reference locations that are used for assessment purposes. Denison Street would be the nearest residential boundary to the proposed GTP with reference location 10 (just south of the intersection with Grace Campbell Crescent) considered to be the nearest residential location. At the EIS Stage the selection of equipment is not fully known and this assessment considers the effective sound power level to obtain compliance with the nominated criteria. The prevailing weather conditions at night are a still (neutral) conditions or a light NW wind. Temperature inversions are very rare at the site but may be associated with a light easterly wind or draft that would reduce noise levels along Denison Street. Working backwards from the residential boundaries would realise an effective sound power level of 98 db(a) for the GTP at reference location 10 under neutral conditions. This effective sound power level has been derived by use of the computer modelling program ENM, an average noise source height of 2.5 metres above ground level and typical ambient background level recorded at night for reference location 10. Under a light NW wind the enhancement due to the wind would require the effective sound power level to be reduced to 96 db(a) relative to reference location 9. Under a 4 m/s SW wind (towards location 14) the effective sound power required to maintain compliance with the design goal becomes 103 db(a) relative to location 14 but 97 db(a) relative to reference locations 10 and 11. The following table identifies the effective sound power level required for the proposed GTP relative to the BIP reference monitoring locations (these locations are identified in Appendix A).

13 Acoustical Assessment Proposed Groundwater Cleanup Project Page 11 of 15 Reference Effective Sound Power Level db(a) Location Neutral light NW SW (4 m/s) a Holloway Brighton From the above table it can be seen that an effective sound power level of 96 db(a) would apply for the proposed GTP with respect to the residential area south of the No 3 gate, whilst an effective design sound power level of 103 db(a) would apply to the residential area north of the intersection of Smith and Denison Streets. Based on the information provided in the above table, Orica has specified that the effective sound power level of the GTP must not exceed 96 db(a) with respect to reference location 10. A schedule of plant items is shown in Appendix C and indicates only 16 noise producing items. The majority of the plant items are small pumps that have a noise level significantly less than the occupational limit of 82 db(a) at 1 metre. From other plants one can utilise a nominal sound power of 75 db(a) per small pump/motor which would realise a cumulative sound power of 86.5 db(a). The two Air Stripper blowers in the Off Gas Oxidation Package are considered to each have a sound power level in excess of 120 db(a). Enclosing such units to achieve the occupational noise limit would require masonry construction with attenuated air inlets and outlets. Specifying an external sound power level of 90 db(a) for each of these sources would result in compliance with the overall effective design sound power levels.

14 Acoustical Assessment Proposed Groundwater Cleanup Project Page 12 of 15 The detail of specific noise control measures for the three major plant items is not available at the present point in time and would become available during the construction phase of the project. Accordingly the design phase of the project must utilise the noise emission goals derived above. This procedure for such plants has been applied for other plants on the BIP site. Typically before operation of the plant is permitted by the EPA (DEC) a detailed acoustic assessment is provided setting out all noise emission sources, noise data and specific controls incorporated into the development to achieve compliance with the EIS noise targets. Testing during installation and commissioning phase is standard practice on the BIP site with any non-compliance required to be rectified before the plant can be placed into operation. 5 OPERATIONAL NOISE FOR THE BGC PROJECT Operation of the pumps in the wells in the median strip of Foreshore Rd, southlands and along the western boundary of the BIP, the primary and secondary pipelines, the treated water discharge line to Bunnerong Canal and pipes throughout the BIP for pumping treated water are not expected to result in audible noise at any residential receivers. The untreated water is pumped from the bottom of each well by a submersible pump into the main delivery line to the plant. Each pump has sufficient capacity to pump the water from its own well back to the plant. There are no additional pumps in the untreated water supply line until on the plant. There are no wells in proximity to residential premises. The delivery line is fully sealed and is anticipated to generate a sound level contribution at the top of each well less than 45 db(a) at 1 metre, resulting in a sound level contribution significantly less than night time ambient background levels.

15 Acoustical Assessment Proposed Groundwater Cleanup Project Page 13 of 15 The treated water discharge line is supplied by the treated water distribution pump located on the plant. The line is to be buried and pass through the industrial area to Bunnerong Canal. No appreciable noise impact will arise from the treated water discharge line. 6 CONCLUSION An acoustical assessment of the proposed GTP Plant to be located on the former Silicates site at the BIP has been carried out in accordance with the requirements of the BIP Site Noise Reduction Program. The allowable noise emission for the new plant has been set at a Leq level of 35 db(a) at any residential boundary as directed by the overall site policy and EPA criteria. The design of the plant is at a preliminary stage using generic equipment with no specific noise emission levels available. From the design criteria at the residential boundary the effective sound power level of the plant has been derived by use of the ENM program. Such a sound power level is achievable but will required noise control measures to the three main plant items. Noise associated with the operation of the off site infrastructure will result in sound level contributions at residential properties significantly below the night time ambient background levels. As the design goal for the GTP is significantly less than the ambient background level (both day and night) any compliance testing, which would be a normal condition of approval from the EPA, would require near-field measurements with calculations to determine the resultant sound level contribution at residential boundaries. In accordance with the BIP site noise policy and EPA requirements it will be necessary for the contractor to provide evidence to the EPA that noise emission requirements have been satisfied and meet the targets set out in this assessment.

16 Acoustical Assessment Proposed Groundwater Cleanup Project Page 14 of 15 The location of the proposed plant is well away from the BIP site boundaries and as construction activities are limited to daytime only, construction noise is not envisaged to create an acoustical impact. The Director General s requirements nominated consideration of vibration during construction piling operations. Whilst not anticipated to be required, any piles are to be installed by rotary drilling and not hammer piling. As such, there is not expected to be any vibration impact at residential boundaries during such operations. Construction of the additional infrastructure off the BIP site is not in proximity to residential premises and will only occur during the daytime period there is not envisaged to be any acoustical impact of such construction works for residential receptors. Traffic arising from the construction and operational phase of the project have been addressed by the traffic engineers and result in a negligible traffic increase on Denison Street such that there would be no perceptible increase in existing road traffic noise at residential properties near the BIP site. An acoustical assessment of the proposed Botany Groundwater Cleanup Project has been undertaken in accordance with the BIP Noise Reduction Program. The GTP and off site infrastructure will achieve noise emission levels in accordance with the EPA noise limits specified for new plants on the BIP. Noise from construction activities on and off the BIP site will comply with the EPA Construction Noise Guideline criteria at all residential receivers.

17 Acoustical Assessment Proposed Groundwater Cleanup Project Appendix A APPENDIX A: Site Location Holloway 15 14a Brighton Proposed Plant 9 8

18 Acoustical Assessment Proposed Groundwater Cleanup Project Appendix B APPENDIX B: Proposed Ground Water Treatment Plant

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20 Acoustical Assessment Proposed Groundwater Cleanup Project Appendix C APPENDIX C: Equipment List and Noise Levels EQUIP. NO. EQUIPMENT NAME TYPE NOISE LEVEL Pressure Vessels V3680 Backlog EDC Isotainer Modified ISO Tank Container Type IM01 No Noise V-4101 Feed Tank Vent Absorber Activated Carbon Absorber No Noise Tanks T4101 Feed Tank Cone roof / bottom cone up /API 650 No Noise T9110 Treated Water Tank Flat roof / AWWA D103 No Noise T3650 Hydorchloric Acid Tank Cone roof / sloping bottom / sump/ BS4994 No Noise T3651 Hydrochloric Acid Lute Pot Rectangular sump tank c/w grating. No Noise T6125 Caustic Day Tank Cone roof / sloping bottom/ BS4994 No Noise S5101A/B - S5120A/B Towers/Columns Air Stripper - (x40) Low profile trayed boxes, 6 trays No Noise Pumps P4101 Air Stripper Feed Pump Centrifugal / single seal /ANSI B73.1 < 80dB (A) at 1 m P5101 Stripped Water Pump Centrifugal / single seal /ANSI B73.1 < 80dB (A) at 1 m P9110 Treated Water Pump Centrifugal / single seal /ANSI B73.1 < 82dB (A) at 1 m P4102 Hydrochloric Acid Dosing Pump Metering Pump c/w pressure valve (PVC), < 80dB (A) at 1 m diaphragm pressure relief valve (PVC) and pulsation dampener (PVC / Viton). VSD controller 'by others'. P3680 Backlog EDC Dosing Pump API.675 Metering Pump c/w Ex D fixed speed < 80dB (A) at 1 m motor, pressure valve (316SS), diaphragm pressure relief valve (316SS) and pulsation dampener (316SS / Viton). P3701 Common 1 First Flush Sump Cent/Cantilever/single seal /ANSI B73.1 < 80dB (A) at 1 m Pump P3650 Common Hydrochloric Acid Magdrive Centrifugal Pump / ANSI B73.1 < 80dB (A) at 1 m Pump P3702 HCl Tank Sump Pump Air Diaphragm Pump < 80dB (A) at 1 m P3703 Feed Tank Sump Pump Air Diaphragm Pump < 80dB (A) at 1 m P7120 Stripped Water Treatment Sump Pump Air Diaphragm Pump P6125A/B Caustic Dosing Pump (x2) Pumps skid mounted. Includes one (1) standby pump. Z6101 Off Gas Oxidation Package Off Gas Oxidation - Vendor Package including two (2) Air Stripper Blowers (C5101A/B) Z7101 Stripped Water Treatment Stripped Water Treatment - Vendor Package Package Miscellaneous Equipment < 80dB (A) at 1 m < 80dB (A) at 1 m <90 db(a) sound power level < 80dB (A) at 1 m EDC Tank Container Trailer Tri Drop Deck Trailer No Noise F5111 Auxillary Air Filter Box type air filter No Noise Plant Air Compressor Package Skid mounted screw type air compressor with air receiver package < 80dB (A) at 1 m