The noise assessment was conducted to evaluate the noise levels at the nearest noise residential properties from a new plant construction on existing LNG receiving (re-gasification) terminal. The project consisted of the noise assessment of an existing noise sources at the LNG Terminal and the noise levels estimation from a new noise source (new plant station).

The objective of this project was to generate a specific noise control to guarantee permissible sound levels at the nearest noise sensitive areas. The noise levels target at the nearest noise sensitive residential property was 45 dBA in Leq units, but taken into consideration the tonal characteristics of the noise source under investigation.

The first step in our noise assessment was the identification of all noise sources in a typical daily operation at the LNG Terminal, for instance we assessed compressor piping, LNG combustion vaporizes Gas vents, etc. Once we identified the noise contribution from each noise source at the LNG Terminal; different noise sensitive residential properties close to the LNG Terminal were chosen.

Because the construction of the proposed plant can generate noise levels in excess at these nearest noise sensitive properties, the local authority imposed a noise threshold to be avoid from the on site construction. Therefore, our second step was to determine an estimation of noise levels at these nearest residential properties from the on site construction.

To complete this requirement different noise levels calculation were developed in our offices to advise the contractor, also a detailed construction program that can avoid any levels higher than the local authority imposition. The daily construction working period was followed by four fixed noise measurement station at nearest noise sensitive properties and three mobile noise stations close to the construction site to identify any specific noise source contributing above the noise levels target. As a part of this study we used vibration measurements to evaluate if the on site construction work were affecting nearby residential properties.

The results noise levels showed no noise level higher than the noise threshold imposed by local authority and the vibration measurement showed satisfactory vibration magnitudes of nearest residential properties for residential buildings.

After the completion of the construction noise assessment, we undertook the noise evaluation contribution of the new plant at the nearest residential property. We worked with the designate target of 45 dBA measured in Leq units. Therefore, the noise control would provide enough information to guarantee that the noise levels at nearest noise sensitive property is under this noise range. To study the noise plant contribution to the overall ambient levels, different noise calculations were undertaken. The main objective at this level was the break down of every noise sources generated from normal operation within the proposed plant and studies them separately. The noise information included on these separate elements was acoustic energy (Sound Power Levels), the noise radiation type of noise source elevation and radiation directivity.

This information is essential to determinate the priorities for noise control, therefore a noise mitigation measures can be pre-selected by each of the noise sources within the new plant. The calculation and the use of noise prediction software allow us to include the noise source geometrical dissipation according to distance, atmospheric, ground attenuation, and wind and temperature effects.

Finally after analysing different noise control mitigations we arrived at the conclusion that the proposed plant must be undertake a noise control measures by the application of acoustical blankets plus acoustic enclosures and gas vent silencers and motor cooling air silencers on different elements. These mitigation measurements were analysed not to be interfered with safety condition of the plant.

After the construction different noise monitoring were undertaken to demonstrate that our noise control project was producing optimal noise mitigation and therefore satisfactory noise levels at the nearest noise sensitive properties.

Call us now for a free informal chat on 0800 840 6244.

Send us an Email: info@premiermeasurements.co.uk

NATIONAL COVERAGE WITH OFFICES THROUGHOUT THE UK