March 2025 | Campbell Associates

Air pollution and uk schools – public awareness of the issue grows

Air Quality & Dust

AIR POLLUTION IN AND AROUND SCHOOLS IS IN THE NEWS FREQUENTLY:

Thousands of British children exposed to illegal levels of air pollution – Exclusive: More than 2,000 schools and nurseries close to roads with damaging levels of diesel fumes – Full article

London’s most polluted schools to be given air-quality audits – Mayor Sadiq Khan announces first 50 schools to undergo audits to help identify measures to minimise the impact of pollution on children – Full article

Reports from the WHO and UNICEF site studies that show air pollution hits children harder than adults. The following excerpt from the WHO report makes the case clear:

The evidence also shows a relationship between exposure to ambient air pollutants and adverse effects on the development of lung function. Reversible lung function deficits, chronically reduced lung growth rates and lower lung function levels are associated with exposure to air pollution. Moreover, the evidence shows clearer relationships for particulate matter and traffic-related air pollution (indicated by nitrogen dioxide) than for other pollutants. Based on current knowledge, air pollutants seem to interact with other environmental factors, such as allergens, viruses and diet, that influence the overall impact of air pollutants on children’s health.

Children spend up to 40 hours a week in school or in childcare facilities. Put another way, that’s almost 50% of the time they spend awake. So it’s little wonder that parents are eager to understand what steps teachers and administrators are taking to 1) quantify the problem, and 2) manage the effects.

Part of the problem is the location of most schools. Urban schools are often located near major roads – so they are easy for a majority of the school population to access.

There is plenty that can be done. The National Education Union and British Lung Foundation have teamed up to provide schools with guidance.

Aeroqual offer cost effective, simple and accurate system to help quantify and monitor key pollutants. This helps and inform and educate pupils, staff and local administrators on the issues facing schools particularly in urban areas.

Peak particle velocity – why do we monitor it?

Construction Resources

With increasing activities in and around our cities the importance of vibration has become a prominent feature. You might have heard of PPV, but what exactly is it and how does that affect us and our projects?

VIBRATION (PPV) – ALL THE ANSWERS!

What is vibration and where does it come from?

Ground vibrations are associated with different types of elastic waves propagating through the ground. These are surface waves, and bulk longitudinal waves and transverse waves (or shear waves) propagating into the ground depth. Typical frequency range for environmental ground vibrations is 1 – 200 Hz. Waves of lower frequencies (below 1 Hz) are usually called microseisms, and they are normally associated with natural phenomenae, e.g. water waves in the oceans.

Ground vibration is measured in terms of Peak Particle Velocity (PPV) with units in mm/s or mm/s-1. It should be noted that the PPV refers to the movement within the ground of molecular particles and not surface movement. The displacement value in mm refers to the movement of particles at the surface (surface movement).

Environmental ground vibrations generated by rail and road traffic may cause annoyance to residents of nearby buildings both directly and via generated structure-borne interior noise. Very strong ground vibrations, e.g. generated by heavy lorries on bumped roads, may even cause structural damage to very close buildings. Typical values of ground vibration particle velocity associated with vehicles passing over traffic calming road humps are in the range of 0.1 – 2 mm/s.

The main sources of ground vibrations at construction are pile driving, dynamic compaction, blasting, and operation of heavy construction equipment. These vibrations may harmfully affect surrounding buildings, and their effect ranges from disturbance of residents to visible structural damage.

Why do we monitor and what are the limits?

Ground vibration can cause serious structural damage but can also be a nuisance to local residents. There are clear limits mentioned for vibration due to construction/demolition in BS 5228-2. In table B.1 – page 36 of BS 5228-2 you will find the guidance on effects of vibration levels. These levels set out the human response to vibration, as in nuisance. When we look at potential damage to buildings table B.2 comes into place. Depending on the type of building there are different limits which are generally higher than the nuisance limits. In general, magnitudes of ground vibrations that are considered to be able to cause structural damage to buildings are above 15 mm/s.

Every ground vibration can be recorded and measured automatically. Since it is simple for everyone to protect people, buildings, infrastructure, soil, air and watercourses from negative environmental impact these days we see more and more demand for continuous automated monitoring so construction & demolition can move forward and communities can be developed with minimal disturbance.

To minimize the impact of vibration caused by construction & demolition works governing bodies often set limits that are aimed to protect individuals from levels likely to cause nuisance and potential cosmetic damage to buildings. You will often see limits of 10 mm/s which is a level likely to cause complaints and is close to the level of potential cosmetic damage in lightweight structures.  Amber alerts can also be sent at lower levels to give warning that vibration levels are getting closer to the limits.

It is also useful to store a waveform (very detailed data) when high vibration levels are recorded. This enables you to investigate the actual frequency content of the vibration event. BS 5228-2, table B.2 gives separate limits by frequency which can therefore be accurately assessed.

Please note that the levels in the tables below are for guidance.  You will see separate guidance/ limits on vibration close to historic buildings, utilities infrastructure and sensitive measurement equipment found in universities and hospitals.

HOW CAN CAMPBELL ASSOCIATES ASSIST YOU?

Our vibration monitors, processes and temporarily stores measurement data from vibrations and air shock waves locally in the instrument. Measurement data is automatically transmitted over the mobile phone network and the Internet to the Sonitus Cloud; our web-based measurement system according to an individual and adjustable schedule. Alerts are automatically sent by e-mail and SMS to those responsible when a measurement is registered that exceeds set limits or if a failure occurs, such as a cable break.

The monitor is fully automated and has full remote access to view & download data, print reports, set alerts and change settings. They are easy to install, maintain and can easily be relocated on site to ensure you can work confidently on site knowing you are working safely within vibration limits.

References:
Skipp, B.O. (ed), Ground Dynamics and Man-made Processes, The Institution of Civil Engineers, London, 1998.
Krylov, V.V. (ed), Noise and Vibration from High Speed Trains, Thomas Telford Publishing, London, 2001.
Santos, J.A. (ed), Application of Stress-Wave Theory to Piles: Science, Technology and Practice, IOS Press BV, Amsterdam, 2008.
Bull, J.W. (ed), Linear and Non-linear Numerical Analysis of Foundations, Taylor & Francis, New York, Abingdon, 2009.
AVA Monitoring – http://avamonitoring.com/en/vibration-measurement/ 2017

Vibration measurements from sheet piling

Construction Resources

VIBRATION MEASUREMENTS FROM SHEET PILING

The ‘press in’ technique is a popular method of sheet piling on sensitive sites as it produces less noise and vibration that traditional dynamic systems.

This short article discusses vibration measurements made of a test pile and discusses why levels were higher than expected.

The process

The steel U sections are loaded onto the system and these sheets are gripped by a plier.  Varying pressure of up to 150 tons is applied to the sheet to insert it into the ground.  This is performed in stages, where the pile is inserted using downwards force and then lifted vertically before applying downward force again.

For this investigation an AVA M60 vibration monitor with triaxial geophone was placed 2.8 meters from the test pile.  The process takes several minutes for each sheet and this is dependent on ground type and conditions.

Figure one shows the measurement position and rig under investigation

Figure 1 – Measurement position

The PPV (Peak Particle Velocity) vibration levels in each 3 orthogonal directions can be seen in figure two. 

Figure 2 – Measurement data

The vibration levels increase as the pile gets deeper.  On this occasion vibration levels were higher than expected towards the end of the process.  The operator reported that the pile had hit limestone and this generated more vibration as the rig needs to apply more pressure to insert the sheet.

However, the detailed time history in figure 3 shows that the highest PPV recorded is where the pile is pulled up in a vertical position and not when the sheet is driven into harder ground. This could also be seen visually from the attended measurement on site.

Figure 3 Event time history

In the press in method varying pressure is applied to the pile.  Where there is hard ground the pressure is increased and this can cause the sheet to flex.  When the plier gripping the sheet is released the sheet straightens releasing energy as a transient vibration event.  This is illustrated in figure 4 below.

When working in areas sensitive to vibration, and where possible, pressure should be released slowly to reduce the impact of sheet piles straightening.

By having the M60 vibration monitor on site, they were able to accurately identify the source of vibration and have visible data to back it up.

References:
Ground-borne vibrations due to press-in piling operations
D.J. Rockhill, M.D. Bolton and D.J. White Cambridge University Engineering Depart

Smart cities – air quality

Air Quality & Dust

Practicalities of rolling out air quality sensor networks – Harnessing smart city infrastructure

Poor air quality is a major issue in communities across the UK and it continues to climb the agenda with public awareness growing of the real detrimental health effects. In order to identify issues, it is important to be able to make accurate measurements to quantify the problem areas. Low-cost air quality sensor-based systems are becoming more popular as they now provide scientifically credible data at reasonable cost, have lower servicing requirements and they come in a form factor that means they can be deployed in roadside locations. Previously these issues have been dealt with by diffusion tubes, which are also low cost and small enough to be located anywhere. However, the disadvantage of diffusion tubes is the manpower required to deploy and collect them and the lack of temporal data to see problem days and times of the day. This high time resolution data is important for managing air quality.

Locating Sensor Based Monitors The systems require a secure location to mount them which in a city/town centre is not always easy to find. They also need power to run effectively, as solar does not yet provide the supply in the UK to run year-round without major compromises to the data collection rates and quality. Finally, these systems will need communications such as wifi, LAN or cellular coverage. These issues multiplied many times for a high-density network can be a challenge, but it is not a challenge unique to Air Quality sensors.

Our towns and communities are filling with ‘smart city’ infrastructure such as street lighting, charging points, bus shelters, mobile phone masts and much more. All of this hardware will have similar issues when it comes to locating them. If air quality sensors are considered with other infrastructure, then costs can be reduced significantly. If we take the rollout of 5G for example, this will require a huge investment in new hardware and many more sites will be required. It is estimated 40 to 50% of operating costs for mobile phone infrastructure is for rent paid to property owners for mast locations.  Adding air quality sensors to the mast could provide additional revenue and value for communities. 

With joined-up thinking air quality monitoring networks can be rolled out sooner and more efficiently. This will enable decision-makers to tackle the issue more effectively to protect us all from the serious adverse health effects of poor air quality.

Aerial footage of Cemex Barrington Chimney being demolished

Project Updates

In 2018, our team took out their drone to capture some aerial footage of the explosive demolition of Barrington Chimney (CEMEX) in Cambridgeshire.  

Erith is commissioned on site to undertake the controlled demolition, and with Swantest, they were using Campbell Associates remote, cloud-based environmental monitoring solution to measure the impacts on the environment, providing real-time data, including SMS and email alerts.

The 58-year-old chimney was toppled by Erith with explosives, a 56m (184ft) tall chimney overlooking the peaceful Barrington Village. 

Environmental monitors were installed on the north, east, south and west boundaries of the site to measure the impact of the demolition on the environment. Swantest chooses Campbell Associates to supply the Sonitus Cloud solution, using the Aeroqual | Dust Sentry for Mcerts PM10 monitoring, the AVA | Trace M80 for vibration monitoring (with 8 months battery life), and the (just supply power) Sonitus Systems EM2030 Noise Monitor. 

Today with new technologies, we can connect from anywhere in the world with remote mobile connections, allowing us to see data, audio, and video in real-time. These technologies can be implemented into small aerial drones, environmental monitors and vehicles.

Ferrybridge power station | demolition monitoring

Demolition Resources

Campbell Associates have been assisting civil engineer giants Keltbray with their environmental monitoring with their demolition and clearing of the power stations at Ferrybridge, West Yorkshire.

The coal-fired towers were situated on the River Aire in West Yorkshire, next to the junction of the M62 and A1 motorways. They will have been a looming landmark on the landscape for more than 50 years for many a traveller of those roads. But these towers have been decommissioned and need to be brought to the ground after the power stations closure in 2016. The site is set to be cleared by 2021.

Keltbray’s challenge on the project was to easily and effectively monitor noise, vibration and dust emissions generated by their activity. They needed to be able to remotely access the data gathered from across the project and easily download the reports.

They chose the Sonitus noise, AVA vibration & Aeroqual Dust Monitor which proved to be uncomplicated and cost-effective; a total of 15 monitors across the site. During the cooling tower blowdown in June 2019 and October 2019 additional dust monitors were required to measure the aftereffects. With the level of interest, the project was drawing, large crowds of on-lookers were expected during the cooling towers blowdown meaning the safety of the public was paramount.

The monitors still provide Keltbray with reliable, accurate measurement data stored in real-time which they can use to keep a clear picture of what is and was happening on site. With the additional feature of trigger alerts when pre-set levels are exceeded; they are confident in their monitoring. 

How does aeroqual obtain accurate results from sensor systems?

Air Quality & Dust

Electrochemical and solid state sensors to detect Nitrogen Dioxide at ppb levels have been available for many years, but the problem has always been their near 100% cross response to ozone. This is not helped by the way Ozone and Nitrogen Dioxide mirror each other, with one dropping as the other rises, so their combined value can be meaningless. One way around this is to measure Ozone and subtract its contribution from the combined value. However, most sensors for ozone have a near 100% response to Nitrogen Dioxide. The relative difference in response to the two gases by two sensors has been used to estimate both, but this requires complex web-based algorithms and results can be variable. More recently some sensors have been developed which use an Ozone “filter” above the sensor to remove Ozone and therefore its cross response, but this has been shown to deteriorate with time, so that their correlation to reference analysers deteriorates rapidly as the ozone cross response of the sensor increases. It also reduces the response to Nitrogen Dioxide, especially if a thicker layer is applied to reduce deterioration.

The solution is to use an ozone sensor which measures ozone without NO2 cross-response. This is achieved by Aeroqual’s unique, patented GSS (Gas Sensitive Semiconductor) sensor. Not only is it specific to Ozone, its unique ABC (Automatic Baseline Correction) technology means its calibration stays stable long-term. We can therefore measure the sum of the Nitrogen Dioxide and Ozone concentrations with one sensor and Ozone with another. Accurate Nitrogen Dioxide values can therefore be calculated live, within the instrument and without the need for web-based algorithms. As a result, co-location studies have repeatedly shown correlation between the AQS and bigger and more expensive reference analysers with an R2 better than 0.95.

You may also be interested in the articles below:

Measuring high noise levels at a clay pigeon shooting range

Noise

MEASURING HIGH NOISE LEVELS

The Campbell Associates team recently went to a clay pigeon shooting range as part of an experiment to capture accurate high sound pressure levels. They took measurements from various shot guns at a distance of 0.5m from the trigger, using a sound level meter (see picture x).  This type of measurement is sometimes required to assess the hearing protection used by individuals participating in gun related leisure activities.

The sound level meter used was a Norsonic 140 sound Analyser and was tested in three configurations.

  1. The standard meter which has a 140dB full scale range. 
  2. The standard meter in high level mode which boosts the full scale range to 150dB.
  3. The standard meter with a quarter inch high level microphone capsule.  This increases the full scale measurement range to 160dB.

The Results:

  1. In the standard mode the system frequently overloaded when the microphone was positioned closer than 1 meter from the gun being fired.

Figure 1.

  1. How does a high range option work – How do you get an extra 10dB from a standard ½” microphone?

When the extended measurement range is activated the standard 200v microphone has its polarization voltage lowered.  This is reduced from 200 V to about 70 V. The microphone sensitivity will then be reduced by 10 dB and the instrument will be able to measure peak signals up to 150 dB. The change in the polarisation voltage will lead to a small change in the frequency response for the microphone. This change is automatically compensated when the extended measurement range is selected. Corrections are specific to each microphone type and should not be mixed.

With this option activated in the sound level meter most measurements were achievable.

Figure 2

However at a distance of half a meter from the gun with heavier shot the sound level meter did see overloads with measured levels over 150dBc peak.

  1. Using a quarter inch microphone

With an adaptor, a ¼” microphone will fit onto a standard half inch preamplifier and you can then measure levels with a standard sound level meter.With this microphone it was possible to measure peak levels without overloads with the highest peak of 157.9dBc

Figure 3.

Why quarter inch microphones?

Quarter inch microphones are inherently lower in sensitivity than ½” microphones.  The smaller surface area means the microphone diaphragms are less flexible and the same sound pressure impinging on them leads to less voltage coming from the capsule.  This reduced voltage is desirable for very high sound pressure measurements as it is high signal voltages that lead to overloads!

How to measure beyond 160dB?

1/8th inch microphone – This allows measurements to 175dB.  With a 120V preamplifier supply it can measure to 178dB.

Preamplifier voltage – For extremely high sound pressure measurements it is important to not only have a microphone with low sensitivity; you must also have a preamplifier which can handle high signal voltages to avoid clipping of the signal. For your sound level meter (or PC analyser) to display accurately these measurements a preamplifier with a 120V supply is preferable.

What is section 61?

Construction Resources

We have put together a detailed guide on section 61. From what it is, why it’s important and how to adhere to it easily and simply using our automated Noise, Vibration and Dust monitors.

Section 61 is commonly referred to when discussing construction or demolition related noise and vibration pollution impact on the environment. Section 61 of the Control of Pollution Act 1974 is referred to when a construction or demolition firm applies to the local authority for consent to carry out works, which are likely to have a significant impact on the neighbourhood due to its generation of noise and vibration. A section 61 application outlines the works which are planned to take place, the working hours of the site and a plan to mitigate potential noise and vibration impact by best practical means. 

WHY SHOULD A CONSTRUCTION OR DEMOLITION FIRM APPLY FOR A SECTION 61? 

A section 61 application demonstrates to the local authority a pro-active approach to reducing environmental impact, outlining what methods are in place to minimise disruption to the neighbourhood, thus reducing the number of potentials complaints. By having section 61 consent, a local authority may not issue a section 60 notice. Having section 61 consent in place minimises the likelihood of the contractor’s work being stopped, as a mitigation plan is already in place.

INFORMING THE COMMUNITY IS KEY TO REDUCING LIKELY COMPLAINTS?

Informing the community of your works and outlining how you plan to reduce environmental impact is likely to deter complaints. By notification, local communities are much more accepting of disruption as due to the section 61 application, there is demonstrated initiative to minimise any negative impact in the local community. Building a rapport with the community and regularly updating them of planned events shows consideration to the community and the environment they live in, which should ultimately help reduce complaints and demonstrate to the local authority you are reducing your impact in the community and on the environment. 

THE BENEFITS OF A SECTION 61 APPLICATION 

  • Reduced environmental impact
  • Consideration plans in place to help protect the community and reduce the number of complaints
  • Can protect you from further legal action – Section 61 can be used in an appeal against a noise abatement notice
  • Evidences that the developer has considered the environment and has set out to reduce environmental impact by best means practical
  • Reduced risk for your site to be penalised
  • Cannot be served a section 60 noise abatement notice

HOW A SECTION 61 AVOIDS LEGAL ACTION BEING TAKEN AGAINST THE DEVELOPER? 

Section 61 – Prior consent is an agreement between the developer and the council, which can outline a noise and vibration mitigation plan. With this agreement in place it protects the developer from legal action being taken under Section 60 of the Control of Pollution Act 1974 or Section 80 of the Environmental Protection Act 1990.

When must you apply for a section 61? 

As a developer, you must apply for a section 61 within 28 days before the intended works are to take place. If you have carried out any works prior to this date, except for any minor preparation, then a prior consent will not be issued. 

WHAT SHOULD BE INCLUDED IN A SECTION 61 APPLICATION? 

  • A site location plan with (NVD) noise, vibration and dust monitoring locations detailing the site boundary, nearby roads and railways
  • Nearest sensitive receptors or residential properties should be highlighted
  • The main contractor’s contact details (name, address, etc)
  • Objective of the works to be carried out i.e. demolition of a car park 
  • A method statement of the works that will be undertaken, outlining any phases of the works, machinery to be used and methods employed
  • The working hours of the site, including any exceptions
  • Evidence that noise, vibration and dust impact are considered, outlining how you will mitigate the impact on the environment, either by sound barrier or continuous monitors, for example

WHAT IS NVD?

  • NVD is a term created by Campbell Associates that abbreviates Noise, Vibration and Dust. This term is notably referred to in the construction and demolition industry where there is a requirement for continuous noise, vibration and dust monitoring.

WHY IS CONTINUOUS MONITORING BENEFICIAL FOR CONSTRUCTION AND DEMOLITION PROJECTS? 

Continuous monitoring enables the contractor to mitigate problems in real time and evidence noise, vibration and dust levels continuously. Real time monitors offer the contractor a useful tool to help prove or disprove complaints in question. As false claims can be made maliciously against a developer or contractor, having factual real-time NVD monitoring data can provide valuable evidence in any case.

For example, using a NoiseSens – Noise Monitor with an AI powered audio recording feature will help identify the reasons for a noise breach. A simple playback of an audio recording can help distinguish if the noise event was site related or not. I.e. a passing motorbike. Audio recordings can be played back on the Sonitus Cloud™️ via a mobile, laptop or computer. 

WHAT CAN I USE TO CONTINUOUSLY MONITOR NVD ON SITE? [USING A SIMPLE AND COST-EFFECTIVE SOLUTION!]

The Sonitus Cloud™️ allows for real time monitoring of noise, vibration and dust monitoring on site by uploading measured data to one platform. Such interfaces allow for seamless and cost-effective solutions for monitoring without the need to attend the site and download data. SMS and email warning alerts are instantly received for breaches so you can mitigate exceedances on site promptly.  

With the NoiseSens Noise Monitor we can measure noise continuously in real time. Instant alerts enable a fast reaction to noise events, which can help reduce or eliminate possible complaints from nearby residents. The NoiseSens monitor is a plug and play device, housed in a weather protective enclosure or integrated into a Dust monitor to continuously measure the noise level. Such a device is configured remotely, for site engineers to put power to the device and the monitor will automatically start-up and log without any human command prompt. 

Sonitus Cloud allows web integration of the remote Vibration Monitors, which silently communicate around the site via a cellular 2G & 3G connection. BS5228 specifies using a monitor that measures Peak Particle Velocity in 3 directions. The VibrationSens monitors use a simple-to-mount tri-axial geophone that can be fixed in many settings, such as to walls, to the ground or underground. Such systems save project engineers time and money compared to monitors that require regular weekly charging, configuration and downloading on site. Measuring vibration is important because the human response to vibration is particularly low (1mm/s can be felt and is likely to cause complaints), therefore low-level vibration can be perceived by residents of causing damage to their property.

Our air quality & dust monitors are used for measurement of fine particles. Such monitors will continuously monitor the dust levels on site and report the average readings to the Sonitus Cloud. Air Quality is a growing concern in the UK with an estimated 40,000 deaths per year because of poor air quality. The Sonitus Cloud will display real time warnings for dust exceedances and allows you to monitor and measure your work’s impact remotely.

CAN NOISE BE PREDICTED ON CONSTRUCTION AND DEMOLITION SITES? 

Yes! Using Datakustik CadnaA noise modelling software it is possible to predict noise levels at sensitive buildings and receptors. CadnaA allows the integration of Google maps, open street maps and imported drawings to map noise sources, terrains, model machinery, barriers and buildings in a CadnaA project. It is possible to accurately map the surrounding road and rail networks to realistically predict the noise levels at any point of any day in any given position. Appropriate noise barriers can be drawn in the model with the ability to demonstrate a before and after result, calculated and presented in a 3D print or 3D video presentation as the image above. The noise models can be presented to the local authority to demonstrate full consideration of the project site and visualise how you will effectively reduce the noise impact in the community.

WHAT IS A SECTION 60 NOTICE? SHOULD I CONSIDER A SECTION 61 AGREEMENT PRIOR TO UNDERTAKING WORKS?

A section 60 notices outlines to the developer or contractor a specific order of operation. This notice may outline conditions imposed on the site, such as a change in working hours, noise limits, plant or machinery that may or may not be used, and other site working methods. Best Means Practical on site should be considered by the local authority when issuing the notice in relation to minimising noise. With this insight, some argue it is far better to apply for a section 61 consent prior to undertaking works rather than later be issued with a section 60 order.

WHAT GUIDANCE IS AVAILABLE FOR NOISE AND VIBRATION CONTROL FOR CONSTRUCTION AND DEMOLITION SITES? 

Many local authorities now produce codes of practice for noise, vibration and dust control in their district. These codes of practice documents commonly refer to guidance and the limits set out in BS5228: 2014 Code of practice for noise and vibration control on construction and open sites parts 1 (noise) and part 2 (vibration) and the IAQM Guidance on the assessment of dust from demolition and construction. There is guidance on preferred mounting positions, mitigation and limits.

BS5228:2014 Code of Practice for Noise and Vibration Control also outlines recommendations for noise mitigation measures that should be considered. Noise limits are not set in BS5228; however, these can be easily determined by carrying out a background noise assessment prior to any works undertaken on site; the noise limit is implemented based on measured results. Some local authorities will outline noise limits within section 61 consent or referral to a code of practice written by the local authority. 

Vibration limits and guidance are clearly defined in BS5228:2014 Part 2 where limits for ‘human response to vibration’ and ‘cosmetic damage’ are defined in tables B1.1 and B1.2. The standard gives guidance and examples on actual measured vibration levels undertaken on working sites, with vibration results for various plant machinery at different distances. You will also find guidance on how to mitigate vibration to nearby sensitive receptors. 

WHERE SHOULD NOISE MONITORING EQUIPMENT BE INSTALLED ON A CONSTRUCTION SITE? 

Noise monitors are normally installed to the edge of the site boundary, nearest to sensitive receptors (the residential and commercial occupiers which are likely to be affected by the works). If practical, it is sometimes best to measure in various positions on site to cover more sensitive receptors if this is feasible. Limiting factors can be due to safety, security, power or the project scale. 

There are various power solutions for remote monitors; many monitors can run on 240-volt mains power, 110-volt generated power, battery power and/or solar power. Noise monitoring equipment should be calibrated within the recommend manufacture interval or according to the set standard you are working to. The instrument should be mounted according to the manufacture guidance and field calibrated, prior to undertaking any measurements. 

The microphone should be mounted in a free field (at least one metre away from any reflective facade or barrier) and mounted at a height of approximately 1.2 to 1.5 metres above ground level. The monitor should be mounted above the hoarding or a correction applied. 

HOW SHOULD VIBRATION MONITORING EQUIPMENT BE INSTALLED ON A CONSTRUCTION SITE?

The VibrationSens monitors can be fixed in soft ground, mounted to a heavy floor plate on a hard surface or bolted directly to a structural wall. When considering structural and human response to vibration it is common practice to measure Peak Particle Velocity in all three directions; transverse, vertically and longitudinally.

Vibration monitors may be installed to the edge of the site boundary nearest to sensitive receptors, fixed on or near to sensitive equipment or structures that need protecting. It is common to see numerous vibration monitors around a construction site, particularly where there are very sensitive receptors or complex building layouts that should be protected. Vibration monitors are commonly left for long periods of time in unsafe locations through the demolition and ground works phase, so it is always useful to have a monitor with a long battery life with cloud based connectivity.

It is important to highlight vibration monitors should be calibrated every 2 years in a certified laboratory.

References

BS5228 2014 Code of practice for noise and vibration control on construction and open sites parts 1 (noise) and part 2 (vibration) and the IAQM Guidance on the assessment of dust from demolition and construction.

Section 61 – https://www.legislation.gov.uk/ukpga/1974/40/section/61

Section 60 – https://www.legislation.gov.uk/ukpga/1974/40/section/60

City of West Minister Code of Practice – https://www.westminster.gov.uk/code-construction-practice

Manchester City Council – Guidance on completing an application for prior consent – http://www.manchester.gov.uk/download/downloads/id/24984/prior_consent_section_61_application.pdf

Chris Anderson @ Spectrum Acoustic Consultants – https://www.linkedin.com/pulse/section-61-applications-providing-information-chris-anderson

Able Acoustics – http://www.ableacoustics.com/Section_61_Consent.html

Cass Allen – http://www.cassallen.co.uk/section-60-and-61-notices

London’s ‘low emission zone’ for nrmm

Air Quality & Dust

BACKGROUND

Air pollution is one of the most significant challenges facing London. London is in breach of European legal limits for Nitrogen Dioxide (NO2) and many areas exceed safe limits for Particulate Matter (PM) as set by the World Health Organisation. The Mayor has proposed measures to tackle emissions from road transport in particular diesel vehicles. This is to be extended for NRMM relating to construction sites which is also a significant contributor to adverse Air Quality in London. Current estimates of emissions from NRMM used on construction sites are shown to be responsible for 7% of NOx emissions, 14% for PM2.5 and 8% of PM10 emissions across the Capital.

WHAT DO CONSTRUCTION AND DEMOLITION COMPANIES NEED TO DO?

In order to comply with the GLA’s NRMM LEZ policy there is a requirement for developments to keep an inventory of all NRMM used at the site. 

This inventory of all NRMM will state the emission limits for all equipment. All machinery should be regularly serviced and service logs kept on-site for inspection. This documentation should be made available to local authority officers as required.

The NRMM register is an automated online inventory which is handled at: http://nrmm.london/

Details of all NRMM with a net power between 37kW and 560kW should be recorded as it is delivered to the site with an indication of the proposed duration of use no matter how short or long this may be. If you know what machines will be used they can be entered in advance, this can be particularly useful where an exemption is required.

REGIONS COVERED FOR NRMM STANDARDS

This map shows the area of the Non-Road Mobile Machinery (NRMM) standards will apply. These standards have been active since 1st September 2015. There are two zones – Greater London (shown in blue), and the Central Activity Zone (CAZ) and Canary Wharf (shown in orange). The central London areas have a tighter emissions standard applied to them.

A Useful Practical guide can be seen here:

http://nrmm.london/sites/default/files/NRMM-Practical-Guide.pdf

Campbell Associates offer automated web based monitors for construction and demolition sites.  This includes PM10, PM2.5 particulate/ dust monitors, NOx, NO, NO2 ,  Noise and Vibration for sale and hire.