Paragraph 17 Control of noise during operational stage

(1)

The noise rating level for the standard operation of Work No. 11 (the onshore electrical substation) must not exceed—

(a)

33dB L_Ar,Tr at any time at a free field location immediately adjacent to the following noise sensitive locations—

(i)

Normans Farm (grid reference 608446 228492);

(ii)

Mulberry Lodge (grid reference 608753 228577);

(iii)

Jubilee Villa (grid reference 609061 228932); and

(b)

32dB L_Ar,Tr at any time at a free field location immediately adjacent to Hollylodge Farm (grid reference 609483 229368); and

(c)

31dB L_Ar,Trat any time at a free field location immediately adjacent to Grange Farm (grid reference 608681 230164).

(2)

Prior to the commencement of operation of Work No. 11, a noise investigation protocol must be submitted to and approved by the discharging authority. The protocol must set out a process for the investigation of cumulative operational noise from the proposed National Grid substation and the Five Estuaries substation as and when one or both becomes operational.

(3)

The determination of L_Ar,Tr must be in accordance with BS 4142:2014+A1:2019. The reference method set out in Annex D to BS 4142:2014+A1:2019 (or any successor thereto) must be used in the assessment of whether tonal penalties apply. The noise investigation protocol must identify—

(a)

the required meteorological and other conditions under which the measurements will be taken, acknowledging that data obtained during emergency operation or testing of certain plant and equipment is not to be taken into account, and

(b)

suitable monitoring locations (and alternative locations if appropriate).

(4)

Within 12 months of commencement of operation of Work No. 11, the undertaker must carry out noise evaluations at the noise sensitive locations listed in sub-paragraphs (1)(a), (1)(b) and (1)(c) and submit the results to the relevant discharging authority. If the noise rating levels are found to be exceeded, the undertaker must provide details of further noise monitoring and mitigation to be agreed in writing by the relevant discharging authority.

(5)

For the purposes of this requirement “standard operation” means the ordinary operation of the substations excluding emergency operation and the testing of plant and equipment associated with emergency operation.