hertfordshire noise study ve isft versiond · the furnace/boiler process area will therefore have a...

NOISE STUDY

HERTFORDSHIRE ENERGY FROM WASTE PLANT

Hertfordshire County Council

EMPLOYER: Veolia Environmental Services (UK) Plc Veolia House 154A Pentonville Road London N1 9PE

Copy No Rev.D Date: 20th January 2011

ISFT submission

Hertfordshire Noise study VE ISFT VersionD.doc - 2-

Contents

1 Subject ......................................................................................................................................................................... 3 2 Presentation of the installations ................................................................................................................................... 3 3 Noise specifications ..................................................................................................................................................... 4 4 Acoustic simulation of the site .................................................................................................................................... 5

4.1. Presentation of the simulation ............................................................................................................................. 5 4.2. Hypothesis .......................................................................................................................................................... 5 The tipping hall and the efw bunker ................................................................................................................................. 5 Mpt storage area ............................................................................................................................................................... 7 Mpt process area ............................................................................................................................................................... 7 Furnace/boiler hall ............................................................................................................................................................ 8 Air Cooled Condensers (ACC) ......................................................................................................................................... 9 Air drycoolers ................................................................................................................................................................... 9 Chimneys ........................................................................................................................................................................ 10 Vehicle movement inside the plant ................................................................................................................................. 10 4.3. Results ............................................................................................................................................................... 11

5 Conclusions ............................................................................................................................................................... 13


1 SUBJECT This report concerns the estimated noise impact of a residual waste treatment plant in Hertfordshire (UK).This plant will be composed of the Mechanical Pre-Treatment (MPT) and the Energy from Waste (EfW) process. The goal is to:

• Estimate the acoustic impact of the EfW at three different noise receptors next to the site. • Recommend mitigations measures (if required) and assist in technical design of the facility.

This study will only consider the operational noise from the EfW facility including the traffic inside the EfW plant. External traffic will then not be considered in this study.

2 PRESENTATION OF THE INSTALLATIONS

Indicative layout that does not include the definitive plant design.

Flue Gas Treatment Area underneath PV cells cladding

EfW process area underneath basic steel cladding

Air Cooled Condenser underneath mesh cladding

Administrative building and bottom ash hall

Site entrance

Tipping hall and EfW bunker underneath polycarbonate cladding

MPT storage area

MPT process area underneath textile roof

Chimneys


3 NOISE SPECIFICATIONS The objective of this study is to inform about the noise impact of the proposed EfW plant at three different locations by day and by night: location 1, 2 and 3 detailed below. This study has been carried out in compliance with the British Standards BS4142.

Receptor Reference to the ISFT

documents Description Daytime LA90

dB(A) Background Noise level

Night time LA90 dB(A)

Background Noise level

Daytime LA10

dB(A) Background Noise level

1 LT2 Southfield

School 49.2 45.7 59.7

2 No receptor has been identified at this location in the WYG noise study. ST5 receptor has been used for

the comparison with the background noise

See map above for the

accurate position used

for this study

58 52.2 66.6

3 ST7/ST8 Pooleys Lane/

Parsonage Road

49.1 41.5 46.8

The data mentioned in the table above are based on White Yound Green report.

Receptor 1

Receptor 2

Receptor 3


4 ACOUSTIC SIMULATION OF THE SITE

4.1. PRESENTATION OF THE SIMULATION In order to perform the acoustic simulation of the site, the following input data have been considered in the acoustic model:

� The geometry of the ground with its altitude contour lines � The complete site (building, obstacles, landscaping, etc.) � The future noise sources: air inlets and outlets, equipments, etc. � The acoustic receptors on the site boundaries.

This study has been carried out on the basis of the similar studies using the following software: IMMI software, powered by Wölfel company.

NB: These photomontages are indicative and do not show the definitive plant arrangement that has been used for the noise study.

4.2. HYPOTHESIS

The study is composed of various acoustical analysis applied to the key plant parts in term of noise emission. These segregated analyses have allowed reaching the whole plant noise emission. This study will only consider the operational noise from the EfW facility including the traffic inside the EfW plant. External traffic will then not be considered in this study. The tipping hall and the efw bunker The tipping hall is the area at the plant entrance where the trucks can tip in the MPT and in the EfW bunker. It is cladded by the roof composed of polycarbonate. The EfW bunker is composed of concrete material and covers the area from the waste pit until the furnace hopper. Architectural hypotheses:

• Tipping hall walls and roof: single coated cladding and translucent roof cladding in polycarbonate (Danpalon Cristal Softlite 16mm)

• Door: single coated steel door (transmission loss 15 to 20 dB). The tipping hall door can be considered opened during the daily period and closed during the night.

• Bunker walls: Concrete walls 20cm Noise sources:


The hypotheses are based on the acoustic pressure level related to the various operations carried out in this area: Loading noise of the hopper:

Global level (A) hopper loading: 88 dB(A) Loading time of the hopper (max. noise): 3 s

Stacking noise:

It is caused by the operation of the travelling crane which mixes and accumulates the refuses. This work is generally made between two hopper loading operations. Global level (A) stacking: 86 dB(A)

Noise of truck unloading: It corresponds to the waste tipping operation in addition to truck engine noise and its tractor drive kit. Global level (A) truck unloading : 91.5 dB(A) Unloading time of 1 truck: 90s

Truck noise: Several trucks may be present at the same time in the hall (unloading, idling or haulage of trucks). Global level (A) manoeuvring: 80 dB(A) Average time for truck manoeuvring: 60s Global level (A) parking: 77 dB(A) Average time for truck parking: 60s

Hypothesis summary:

Noise pressure levels on day period:

Noise pressure levels on night period


Installation of parallel baffle silencers of type 200-100 length 1500 on the primary air combustion fan. Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz

Sound attenuation 5 11 25 45 49 50 37 25 Result: Sound pressure level in the tipping hall: Lp 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lp 81 80 80 81 81 78 73 71 89 Mpt storage area The MPT storage area is composed of concrete walls and a roof cladding. The incoming waste throughput is stored in this area before to be sorted in the MPT hall. This building houses loading engines and shredders. Architectural hypotheses:

• Walls: concrete wall 20cm • Roof: double coated cladding with acoustic absorption α w>0.5 • Ventilation at roof level fitted with acoustical grids

Noise sources: The main noise emitters in this area are the MPT shredders feeding the MPT trommel by day time. These 3 shredders create a noise pressure of 90dB (A) at 1 meter and will work 12 hours a day. Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Double coated cladding for the roof 15 20 21 24 25 17 13 13

Sound attenuation spectrum of the Acoustical grid: Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz

Acosutical grids 3 3 4 9 14 17 13 13 Sound pressure level in the MPT bunker hall: Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 100 92 90 88 86 81 75 67 90.5 The MPT storage area will therefore have a maximum acoustic power Lw of 91dB (A): Mpt process area The MPT process area is a concrete building divided in two floors and with a roof cladding. The incoming waste throughput is stored in this area before to be sorted in the MPT hall. This building houses the Baling equipments and the sorting equipments whose each emission has been considered in the study. Architectural hypotheses:

• Walls: concrete wall 20cm • Roof: double coated cladding with acoustic absorption α w>0.5 • Ventilation at roof level fitted with acoustical grids


Noise sources: The main noise emitters in this area are the following equipments:

• Trommel screen: 88dB(A) at 1m • Overbands: 85dB(A) at 1m • Eddy current Separator: 85dB(A) at 1m • Vibrating conveyors: 85dB(A) at 1m • Plastic sorter: 85dB(A) at 1m • Paper disc screen: 85dB(A) at 1m • Air classifier for paper: 85dB(A) at 1m • Air compressors: 92dB(A) at 1m • Dust collection and Filter system: 85dB(A) at 1m • Conveyor belts: 85dB(A) at 1m • Ballers: 85dB(A) at 1m

Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Double coated cladding for the roof 15 20 21 24 25 17 13 13

Sound attenuation spectrum of the Acoustical grid: Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz

Acosutical grids 3 3 4 9 14 17 13 13 Sound pressure level in the MPT process hall: Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 83 81 81 83 83 78 73 71 88 The MPT process area will therefore have a maximum acoustic power Lw of 88dB (A): Furnace/boiler hall Architectural hypotheses:

• Wall : double coated cladding and concrete walls • Roof : basic steel roof cladding • Doors : single coated steel door • Ventilation at roof level fitted with acoustical grids

Noise sources: The main noise emitters in this area are the turbine, the air compressors and the exhausting fans.

• The compressors will be housed in a full concrete structure with a single-coated steel door. This room is fitted with simple acoustic grids for the ventilation.

Lp 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lp 99 92 83 81 76 73 73 71 84

• The turbine will be housed in a full concrete structure. The room access door will have an attenuation of 35dB(A) maintained closed. Ventilation fitted with acoustical grids will be provided. The turbine acoustic pressure at 1m is 86dB(A). Therefore the acoustic pressure outside the building will be around 75dB(A).


• The exhausting fans acoustic pressures at 1.5m are the following.

Lp 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lp (1.5m) 84 84 85 78 80 75 72 64 84 Finally the Furnace/Boiler hall will be fitted with the following mitigation systems: Installation of parallel baffle silencers of type 200-100 length 1000 on the secondary air combustion fan. Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz

Sound attenuation 3 8 16 27 37 37 26 16 2 parallel baffle silencers of type 200-100 length 1500 mm will be installed at the exhaust fan end, with a transmission loss as follows: Sound attenuation 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz

Sound attenuation 9 19 43 50 50 50 50 43 The silencers will have to be installed with at least 1 meter between each silencer. Sound pressure level in the Furnace/Boiler hall: Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 83 81 81 83 83 78 73 71 89 The Furnace/Boiler process area will therefore have a maximum acoustic power Lw of 89dB (A): Air Cooled Condensers (ACC) The ACC is located in external conditions given it is covered by a 50% porosity mesh whose acoustics attenuations have been considered as negligible. Noise pressure level: 53dB(A) at 25,4m Radiation of the pipe in by-pass mode Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 87 83 82 81 96 90 84 82 98 Air drycoolers The power level of Air drycoolers (16 fans) is as follows: Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 97 101 99 96 92 89 84 75 98


Chimneys Stack top power level (taking the silencers above mentioned into consideration) : Lw 63 Hz 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz 8 kHz Global dB(A)

Lw 108 98 70 60 58 53 50 52 84.9 Vehicle movement inside the plant The following hypothesis have been taken: Truck traffic in daily period: 15 vehicles per hour at 50 km/h.


4.3. RESULTS The table below shows the noise levels including the background noise values: Results for the daily period:

Day period (LA90)

Receptors Background noise level Plant noise level Exceedance

1 49,2 dB 47,9 dB NO

2 58 dB 46.1 dB NO

3 49,1 dB 41.9 dB NO

Day period (LA10)


1 59,7 dB 59,5 dB NO

2 66,6 dB 57,5 dB NO

3 52,5 dB 48,0 dB NO

Results for the night period:

Night period (LA90)


1 45,7 dB 47.6 dB Acceptable (1.9dB)

2 52,2 dB 45,7 dB NO

3 41,5 dB 41.5 dB NO

Noise levels are considered as acceptable when they are are more than 10dB below the background noise level. The Likelihood of Complaints for these noise levels are unlikely. (See White Yound Green report included in the Hertfordshire ISDS tender document: Technical Appendix Volume 6 / Noise Baseline Report / Date June 2009)


The contribution of each source at every reception point is given by the following table

Receptor 1 Receptor 2 Receptor 3

Day Night LA90 LA10 Distance

(m) LAeq

Distance

(m) LAeq

Distance

(m) LAeq

Trucks X X X 60 59,1 76 57,1 260 46,4

MPT Pit X X 210 33.8 275 31,5 400 28,2

MPT hall X X 250 28,7 265 28,2 350 25,7

MPT grids X X 210 27.6 275 25.22 400 22

EFW bunker and

tipping hall

X X X

162 33,8 232 30,7 400 26,0

EFW hall grids X 220 37.8 240 37 300 35

Bottom ash hall X X X 155 19.2 196 17.2 196 11.5

Bottom ash hall

grids

X X X

155 41.8 196 39.76 196 34.2

ACC X X X 150 37,6 175 36,2 325 30,9

ACC bypass duct X X X X 190 41,4 220 40,2 350 36,1

Dry coolers X X X 155 43,4 196 41,4 375 35,7

GTA room X X X 190 15,4 225 14,0 325 10,8

GTA room grids X 190 35 225 33.5 325 30.4

Compressed Air

room

X X X

250 11,0 290 9,8 300 9,5

Chimneys X X X 220 30,0 240 29,2 300 27,3

Exhausting fans X X X 240 39,9 255 39,4 290 38,3

The preponderant noise sources are the trucks, the air coolers and ACC bypass duct that operates occasionally and can be compared to then LA10 noise background.


5 CONCLUSIONS This study shows that the acoustic treatment selected and the civil works design for the Hertfordshire EfW plant allow reaching acceptable noise level at the 3 noise receptors of the New Barnfield site: between 0 and 1.9dB above the background noise. These treatments are the following :

- Installation of simple acoustic grids for the ventilation of the waste bunker hall and the compressor room.

- Installation of double acoustic grids for the ventilation of the furnace-boiler hall. - Installation of parallel baffle silencers for the ventilation of the turbine hall - Installation of a double-coated cladding for the parts such as the MPT roof or Boiler hall walls.

- Installation of sound insulation for the exhausting fans


APPENDIX 1 : DOUBLE-COATED CLADDING ARVAL CN 125

hertfordshire noise study ve isft versiond · the furnace/boiler process area will therefore have a...

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