QED, WM3 and MCERTS: The Environment Agency and On Site Analysis

QED on site

A recent MCERTS policy update from the Environment Agency fully supports on site or rapid measurement techniques to be used for regulatory purposes, provided their protocol is followed and a certain amount of confirmatory testing is used. The accuracy and quality control procedures inherent in the QED make it highly suitable for use for regulatory purposes, enabling huge savings in project time and costs.

In 2021 the Environment Agency updated the guidelines for chemical testing of soils in their publication LCRM: Stage 1 risk assessment – GOV.UK (www.gov.uk) . This update includes a significant change in their requirements for the use of rapid measurement techniques (RMTs) for contaminated land projects:

“The MCERTS standard covers laboratory accreditation to ISO/IEC 17025. Laboratories can be permanent or mobile. They can also include organisations that take samples and do on-site analysis.”                                                                                                                           LCRM Stage 1 Risk Assessment

A certain amount of MCERTS analysis has always been a requirement for any project that is under Environment Agency supervision or control. It has never been a requirement for projects where the Environment Agency is not involved. This means that the majority of analysis does not need to be MCERTS accredited. Examples of projects where the Agency is not directly involved are:

  • Site investigation to identify extent of a pollution plume
  • Management of the excavation of contaminated material for transfer to a treatment or disposal facility (most remediations)
  • Management of a treatment process
  • Confirmation that incoming waste material is correctly described on the waste transfer notes

On projects where the EA has some form of supervision or control rapid measurement techniques results will be accepted as part of the overall data package if the new protocol is followed.

This update represents a transformation in the EA’s position on in situ analysis. It reflects the EA’s acceptance of QED analysis, which has been gained through its ever-widening use in the UK and abroad over many years. The QED’s robust and defensible data, achieved in minutes, gives major cost savings on projects of all types and sizes, from remediating a dairy yard to major remediations such as the Ford Dagenham site, HS2, ex gas works remediations in UK, Singapore and USA, monitoring reedbeds in Southern Sudan and site investigations at Fort Lauderdale airfield and managing drilling waste from gas exploration projects in Mozambique .

Advantages of RMTs

WM3 v1.2 notes the advantages of rapid management techniques:

  • improve the quality of site investigations
  • get immediate results
  • make quicker decisions
  • screen many samples at the same time
  • potentially reduce investigation and remediation costs
  • improve how you take samples for laboratory analysis
  • help develop the conceptual site model
  • define areas of contamination
  • support other analytical methods

The protocol has been introduced to maintain high quality standards of analysis and data keeping. It should be used as part of a quality management system.

Environment Agency  Protocol for RMTs

The recommended management techniques protocol involves:

  • giving an appropriate person, the authority and overall responsibility for their use
  • defining the roles and responsibilities of all staff
  • document control and record keeping
  • training
  • standard operating procedures and sampling plans
  • quality assurance, including internal and external quality control
  • maintenance
  • auditing of the staff

Backup confirmatory testing

A proportion of the samples, which is to be agreed with the EA, must receive confirmatory analysis from a third party. This applies at the start of the treatment to confirm the material is suitable for the process and the first runs at the end of the treatment to confirm the material has been treated and meets the limits set in the treatment specification. Periodically samples from the treated material will still need to go for lab testing for validation of the onsite method. However if rapid methods carried out at the same time agree (within reason) with the lab or there is a lines of evidence basis to show the rapid method is correct, the QED (or other on site method) can then be used for the day to day management of the treatment process. In this case rapid methods data is accepted by the EA for regulatory purposes and the number of samples sent to the lab can be significantly reduced:

“You can use the ‘demonstration of method applicability approach’ to show that your rapid measurement technique data correlates to laboratory MCERTS/UKAS data by taking duplicate samples. The data from the rapid measurement technique does not have to provide results that match the laboratory results. They must however, be demonstrable and reliable. If the samples show acceptable results, you can lower duplicate laboratory MCERTS analyses.”

 LCRM Stage 1 Risk Assessment

 On the Crossrail project just 66 samples out of more than 14,000 were sent for verification, but typically 1 in 50 or 1 in 100 is seen as sufficient.

Data sets from multiple projects by the same organisation can be used as a “lines of evidence” data set to demonstrate the performance of the rapid analysis method. The EA endorse a “lines of evidence” approach.

LCRM guidance on risk assessment covers in more detail how rapid methods can be verified and this is suitable for both waste and SI/remediation management.

Suitability of the QED and XRF

The accuracy and quality control procedures inherent in the QED and XRF make them highly suitable for use for regulatory purposes. QROS provide thorough training for QED operators.  Any issues are flagged automatically and support is immediately available. The QED is additionally serviced and its software update yearly.

The QED hydrocarbon analyser can reliably identify and differentiate between all petroleum hydrocarbon derived materials as well as coal tar, creosote and bitumen and will be suitable for classification of all oily waste, coal tar and bitumen impacted materials.

When MCERTS and QED disagree

Sometimes lab results do not agree with the QED results. In this case, the Environment Agency  will take a “lines of evidence” approach to interpreting the data. It is well known that samples containing naturally occurring organic compounds such as peat and decayed leaves give an artificially high TPH result when analysed by most MCERTS accredited TPH laboratory methods. The QED sees these background organics but screens them out, reporting them as present but separate from TPH results. A set of QED results will be considered correct where it shows a material as degraded fuel and all significantly below 1000 mg/kg when background organics have been detected. This is despite a lab analysis of the same sample showing a TPH value of over 1000 mg/kg, unless they have followed the full sample clean-up procedure and the C21+ aromatics bands contribute less than 75% of the TPH value.

See also: Demonstration of method applicability (DMA) bit.ly/3ZeBWvu

 XRF Analysers

For heavy metals and other elements such as sulphur or chlorine, X Ray Fluorescence (XRF) is a technique that has been in use since the 1940s. The latest portable XRF analysers are safe to use, have detection limits that easily exceed regulatory limits and meet the EA requirements for the use of on site methods. Like the QED it takes approximately 3 minutes to generate a result.

Mobile Laboratories

Many companies both in the UK and overseas have set up a mobile laboratory with both a QED and XRF. A single operator uses both instruments to generate a full set of results within 5 minutes per sample.

A mobile laboratory operator gives recipients of RMT data the confidence that all of the Environment Agencies guidance is followed. Even users hiring analysers for the first time can be confident that the built in QC will comply with E A guidelines.

QED users have confidence in their analysis, whilst getting real time results at very low cost. The analyser is available for hire or purchase. We’re always happy to talk if you have any questions!