Proceedings of the Institute of Acoustics

 

Thames Tideway Tunnel: the management of construction noise taking account of individual circumstances

 

G. Parry, Accon-UK, London, UK
S.W. Turner, Stephen Turner Acoustics, London, UK

 

1 INTRODUCTION

 

Perhaps without many practitioners realising it, most noise impact assessments consider the effect on the average person. There is good reason for this. For the most part the characteristics of those affected will not be known; and, for most schemes, the people affected will change over time. Furthermore, case law associated with statutory nuisance focuses the consideration on the effect on the average person originally described colloquially as the ‘man on the Clapham Omnibus’.

 

Reference to the average person can also be found in noise management policy¹.

 

This paper will describe the system set up by the Thames Tideway Tunnel project for the management of construction noise. The process recognised that, although the original assessment used the standard methods to determine the nature and extent of the impact us, the circumstances of those living and working close to the construction sites may be far from average.

 

The paper will describe the project’s Non-statutory Off-site mitigation and compensation policy² and which included the establishment of an Independent Compensation Panel (ICP), currently chaired by Graham Parry, and the role of Independent Complaints Commissioner (ICC), a position currently held by Stephen Turner. The responsibilities of these two bodies will be described, along with the issues faced and how the ICP and ICC interacted with each other.

 

Some conclusions will be drawn regarding how such an approach may be applied to future schemes so that the noise management better reflects the needs of those who are not average.

 

2 THE THAMES TIDEWAY TUNNEL (TTT) PROJECT

 

The TTT project has been designed to reduce the number of times raw sewage goes into the Thames. It recognised that the current sewage system is 150 years old and was built for a population of London less than half its current size. As a result, whenever there is heavy rainfall, the current system overflows and raw sewage enters the Thames.

 

The TTT is a 25 km tunnel designed to capture that overflow and direct it to the sewage treatment works at Beckton via the Abbey Mills Pumping Station. The tunnel starts at the Acton Storm Tanks in West London and broadly follows the line of the river until around Limehouse where it heads northeast to Abbey Mills. The tunnel has been designed with a natural gradient, being roughly 31 m below ground at Acton and dropping by 1 m every 790 m so that at Abbey Mills it is 66m below ground level.

 

Tunnel Boring Machines (TBM) were used to make the tunnel, starting at three main drive shafts, Carnwath Road, Kirtling Street and Chambers Wharf, as shown in Figure 1, locations 7, 11 and 17 respectively.

 

 

Figure 1: Plan of the Thames Tideway Tunnel The main drive sites are 7, 11 and 17

 

Once the tunnelling work commenced it needed to occur continuously. Consequently, 24-hour working was required at those sites to enable the spoil to be removed. All three of those sites were close to residential premises as can be seen from Figures 2, 3 and 4.

 

 

 

Figure 2: Carnwath Road

 

 

Figure 3:  Kirtling Street

 

 

Figure 4: Chambers Wharf

 

The silver-coloured buildings that can be seen in each of Figures 2-4 are acoustic sheds, which were purpose-built to cover the access shaft to the tunnel. These formed part of the extensive noise mitigation used on the scheme.

 

3 THE NON- STATUTORY OFF-SITE MITIGATION AND COMPENSATION POLICY (NSP)

 

The Non-Statutory Off-Site Mitigation and Compensation Policy was introduced as the examination of the Development Consent Order identified that there would be significant disbenefits in respect of the construction of the scheme which otherwise could not be appropriately mitigated.

 

The NSP acknowledged that through the terms of the Code of Construction Practice, significant and adverse impacts from the construction would be minimised as far as reasonably practicable by means of on-site mitigation. Nevertheless, the NSP stated that the policy covered those affected by:

 

a. dust (in terms of compensation)
b. light interference (in terms of compensation)
c. noise (in terms of mitigation and compensation)
d. vibration (in terms of mitigation and compensation)
e. in combination effects (in terms of discretionary mitigation and compensation)
f. other impacts of the works unique to the individual making the claim (in terms of discretionary mitigation and compensation)

 

The NSP also listed those who may qualify under the Policy as including

 

a. owner occupiers
b. residential tenants
c. independent residential landlords
d. businesses
e. special case properties such as houseboats, mobile homes, sheltered housing, care homes and non-residential sensitive buildings such as schools and hospitals
f. special cases such as shift workers, vulnerable persons who are housebound and those with medical conditions that it is proven could be exacerbated by exposure to noise or vibration

 

Compensation for any residual damage or loss was covered in the Policy.

 

It was recognised that in some situations, however, having exhausted mitigation on site it may not be possible to avoid significant observed adverse effects from noise. Under the Policy the Undertaker had to prepare and, where accepted by the beneficiary, implement mitigation or provide compensation for such situations.

 

The NSP set out examples of what may be offered:

 

a. installation of secondary glazing and additional ventilation, enabling windows to be kept closed, to provide additional noise insulation during the construction works
b. a support package that reflects ongoing costs associated with managing a property differently during the works
c. cost and expense of temporary relocation or rehousing for houseboats during certain phases of the construction programme
d. short-term respite accommodation if unacceptable disruption were to be experienced due to, for example, short periods of exposure to combined noise and vibration
e. an offer of financial compensation to cover:

 

i additional property management costs such as window cleaning, cleaning, security, insurance

ii temporary reduction of business profits

iii temporary reduction in the value of property

iv additional travel costs and car parking charges

v costs of installing blackout blinds vi any cost or loss which arises as a direct consequence of the construction of the project

vii fees and costs associated with making a successful claim.

 

The Undertaker had already identified the residential properties predicted to experience significant adverse effects due to the construction works. The Policy introduced the concept of Trigger Action Plans (TAPs) which provided a planned mitigation package to be implemented in the event of significant adverse effects being predicted to occur.

 

The Policy has to remain in place until one year after construction is completed or until all claims under the policy have been settled. With or without mitigation measures in place, the Undertaker recognised that financial damage or loss could arise as a direct consequence of construction activity. A procedure for claims for damage and loss was in place to process and settle such claims expeditiously.

 

In the Section entitled Independent Advice and Support, the NSP stated that the following bodies would be established:

 

a. Independent Advisory Service (IAS)

b. Independent Compensation Panel (ICP)

c. Independent Complaints Commissioner (ICC)

 

It was recognised that individuals may require some assistance working through this and other compensation policies; therefore the Independent Advisory Service (IAS), an independent organisation was established to provide advice to the public relating to the Policy.

 

The Undertaker was also obliged to establish an Independent Compensation Panel (ICP) composed of compensation and technical experts. The Panel members had to perform a number of functions but primarily supervised the implementation of the various policies and to determine any disputes arising out of the policies.

 

The ICP consisted of an independent chairperson and two additional members. The chairperson was specified as having experience in the field of compensation and valuation, or environmental health and the management of major infrastructure projects. The two additional members had to be chosen from the expert advisory panel detailed below on the basis of their specialty field.

 

The ICP would also receive advice from the expert advisory panel in relation to the following areas or professions:

 

a. Noise and vibration

b. Transport

c. Building surveying

d. Quantity surveying

e. Chartered engineering (Mechanical, Structural, Electrical and Civil) with directly relevant experience including tunnelling projects in highly developed and complex urban environments

f. Chartered surveying

g. Medical advice from an appropriate qualified medical professional on the potential effects of exposure to noise and vibration on the health of individuals or groups of individuals

h. Legal advice.

i. Exceptional hardship specialists

 

An Independent Complaints Commissioner had to be appointed. That role was to ensure that the correct process has been followed where a party was not satisfied with the response of the ICP. In such circumstances, the party could refer the decision-making process for review by the commissioner, who would then evaluate the ICP’s decision-making process in that case. Should the commissioner find that due process had not been followed, then the claim would be returned for a re- evaluation by the ICP.

 

4 THE ROLE OF THE ICP

 

For the most part, the Independent Compensation Panel consisted of a Chair, a Noise & Vibration Specialist and a Medical Expert. The ICP was also assisted by valuation/compensation experts. It met, typically, every fortnight and considers a range of claims. These may include:

 

• requests to have alternative office accommodation;
• holiday breaks;
• the provision of Air Conditioning units;
• respite hotel accommodation;
• and temporary rehousing etc.

 

Each and every claimants’ circumstances were different and the Panel had to consider the claimant’s issues which could include

 

• a variety of health issues;
• stress;
• difficulties working from home;
• night workers who needed to sleep during the day;
• people studying from home etc.

 

No single case was the same and the Panel needed to understand fully the demographics of those people who lived or worked in close proximity to a construction site.

 

As part of their deliberations, the ICP considered

 

• the results from noise & dust monitoring;
• the programme of future works; and
• the S61¹ applications which included predictions of noise levels at selected representative properties often for a year in advance.

 

Evidence which was provided by the claimant could include their medical history, a statement regarding how the project was affecting them and what type of respite they were seeking.

 

Ultimately, the ICP make an award which is binding on the Thames Tideway company, which they can appeal to the ICC but never have to date.

 

5 THE ROLE OF THE ICC

 

The Independent Complaints Commissioner was a single individual. As indicated above, the primary function of the ICC was to respond to appeals against decisions made by the ICP. There was also a second function: To investigate unresolved complaints to ascertain whether the project had met its commitments and complied with its agreed policies and practices.

 

If individuals were not content with the ICP decision, they had the right to communicate directly with the ICC (by email) and set out their reasons for their appeal. After acknowledging receipt, the ICC had to examine the process followed by the ICP. Tideway had asked the ICC to try to complete the evaluation of an appeal within 28 working days.

 

The examination of the appeal involved reviewing various documents including:

 

• The original claim;
• The minutes from the relevant meeting(s) of the ICP when the appellant’s claim was considered; and
• Any other relevant information

 

As the focus of the ICC was on process, there was rarely a need to visit the relevant construction site. Instead it was simply a question of determining if the ICP had taken fully into account all the evidence they had in front of them and whether the ICP had demonstrated that a coherent decision had been made.

 

The appellant was informed by the ICC of its decision. In the case of upholding an appeal, the ICC noted that the appellant’s claim would be referred by to the ICP but that doing so did not necessarily mean it would change its decision.

 

6 CONCLUSIONS

 

The main conclusion is that the Thames Tideway Tunnel project has demonstrated that it is possible to take account of the impact on those people who are more affected by noise than the average person. Both the ICP and ICC were able to act completely independently and the staff at Tideway were always very helpful in enabling those functions to be effectively carried out.

 

It was imperative that the ICP was fully familiar with the individual construction sites and the surrounding environs. To that end, the ICP chair regularly visited sites, along with other members of the ICP as necessary, especially when it was known that there was a phase of construction work occurring that could cause a significant adverse impact. Those site visits also noted that a large proportion of claims could have been avoided or mitigated if contractors had fully implemented Best Practicable Means.

 

Overall, a key role of the ICP was to ensure that claims which came from people who are disadvantaged in society were treated with the utmost empathy.

 

For the ICC, having to focus only on the process was the correct approach, rather than the alternative of effectively replicating the membership and the activity of the ICP. However, it was essential that any appeal was rigorously evaluated, meaning that every point made by the appellant had to be clearly addressed by the ICC. Such meticulous work greatly assisted in the confidence that was had with the process.

 

Arguably, it is more straightforward for a project of the nature of Tideway to implement such a process, with its discrete construction sites and with no operational noise impact from the project once it is completed.

 

Consequently, this means of addressing the impact on those persons who do not have an average response to noise could be used for any project with similar attributes. It is likely to be more challenging for a linear project such as a new road or railway or for a warehouse development where there is also an operational noise impact once the construction work is over.

 

Nevertheless, there is a case of investigating whether the principles of the Tideway process could be applied even in such schemes.

 

7 REFERENCES

 

1. Department for Transport, UK Airspace Policy: A framework for balanced decisions on the design and use of airspace, Paragraph 5.39 (2017)
2. Thames Tideway Tunnel, Non-Statutory Off-Site mitigation and compensation policy, 2015, revised 2017 - https://www.tideway.london/media/1655/non-statutory-off-site-mitigation-and-compensation-policy.pdf (checked August 2024)