Guidance

MCERTS competency standard: flow and event duration monitoring (EDM) inspectors

Updated 13 January 2026

Applies to England

1. Introduction

The Environment Agency set up the Monitoring Certification Scheme (MCERTS) to provide a framework of standards you can use to monitor emissions that affect the environment. MCERTS covers:

• the performance standards your monitoring equipment must meet
• the level your staff must be qualified to
• how to accredit laboratories and inspect sites in line with European and international standards

This document sets out what you must do if you want to become certified to inspect flow monitoring or event duration monitoring (EDM) systems.

2. Competency standard

2.1 Individuals are appointed as either MCERTS inspectors or Assistant inspectors. This document defines the appointment procedures and competency requirements for MCERTS inspectors and Assistant inspectors.

2.2 MCERTS inspectors are technical specialists who can demonstrate considerable experience and expertise. A key role of MCERTS inspectors is to apply professional judgement to assessments. They will be able to assess potential effects of deviations in flow monitoring arrangements and quantify these as part of an uncertainty calculation. MCERTS inspectors can work alone or can supervise the work of others.

2.3 Assistant inspectors must have technical expertise on flow measurement systems. However, they have not demonstrated the expertise and experience required to make independent judgements on all aspects that may affect the uncertainty of an installed flow measurement or EDM system. Data and information recorded by Assistant inspectors must be quality checked and controlled by an MCERTS inspector. Any subsequent professional judgement must be applied by an MCERTS inspector. An Assistant inspector may progress to becoming an MCERTS inspector.

2.4 There is a trainee grade for individuals working with an MCERTS inspector. A trainee can progress to become an Assistant inspector or MCERTS inspector.

2.5 The MCERTS inspector must visit the site of the inspection. It is not acceptable for them to conduct a desktop review of an inspection carried out by an Assistant inspector.

3. Operation of the scheme   

3.1 CSA Group Testing UK Ltd (CSA) operates the scheme on behalf of the Environment Agency. CSA also provides additional procedures and guidance.

3.2 MCERTS inspectors and Assistant inspectors are assessed and appointed by CSA in line with this standard.

3.3 MCERTS inspectors assess that flow and EDM arrangements are in line with:

• Minimum requirements for the self-monitoring of flow: MCERTS performance standard
• MCERTS: requirements for installing and using event duration monitors

4. The competency standard

4.1 General requirements

4.1.1 MCERTS inspectors must have:

• appropriate qualifications, training and experience
• appropriate knowledge of inspection requirements
• the ability to make professional judgements regarding conformity with the inspection requirements
• appropriate knowledge of the technologies employed
• an understanding of the significance of any deviations found

4.1.2 Assistant inspectors must have:

• appropriate training and experience
• appropriate knowledge of inspection requirements
• appropriate knowledge of the technologies employed

4.1.3 MCERTS inspectors and Assistant inspectors must be able to demonstrate to the satisfaction of CSA that they:

• know how to operate within an acceptable quality system, for example, EN ISO 9001 Quality management systems - Requirements
• have knowledge of effluent treatment processes
• understand safety issues connected with on-site inspection work
• can use appropriately calibrated and traceable instrumentation and measuring systems
• understand and comply with the code of conduct – see section 7
• can demonstrate that they operate procedures and calculations for determining measurement uncertainty

4.1.4 MCERTS inspectors or Assistant inspectors may be self-employed or an employee of a company that is independent of the permit holder.

4.2 Scope of appointment

4.2.1 The scope of an MCERTS inspector or Assistant inspector may be limited to certain technical areas, which must be defined on the inspector’s certificate of appointment. Applicants are required to list in their application, the technical areas that they consider to be within their field of competence, along with any areas they wish to exclude from their scope.

4.2.2 Appointment of an MCERTS inspector or Assistant inspector must be based on one or more of the subjects from the following:

• site process configuration
• open channel flow systems
• closed pipe flow systems
• other flow measurement systems
• EDM systems (including event alarms and level measurement)

4.3 Qualifications and experience requirements

4.3.1 MCERTS inspectors must have relevant experience of flow measurement or EDM that is acceptable to CSA. Typically, this will be a minimum of 5 years’ experience in effluent flow measurement or EDM and 20 joint inspections with an appointed MCERTS inspector.

4.3.2 Experience in flow measurement does not need to be related solely to effluent monitoring applications. CSA will consider other industry sectors involving flow measurement. Typically, submission of a maximum of 5 inspection reports from industry sectors other than effluent is acceptable. These reports will be reviewed in conjunction with other relevant details, such as number of years of experience, training and competence for the stated industry sector for the flow measurement.

4.3.3 An applicant may be asked to provide further evidence, before or during the site assessment and interview, to demonstrate their experience and knowledge.

4.3.4 MCERTS inspectors are normally expected to have relevant theoretical training. Typically, this will be in:

• the fundamentals of liquid flow
• calculation of measurement uncertainty
• principles of open-channel measurement
• the principles of flow meters used for part-filled and closed conduit flow monitoring

4.3.5 MCERTS inspectors of EDM systems will be expected to have relevant experience and training in the fundamentals of liquid level measurement and alarm activation. They should understand the calculation of measurement uncertainty and be aware of the sources of level measurement uncertainty.

4.3.6 Assistant inspectors are expected to have relevant experience and technical training in the physical measurement of flow monitoring arrangements and EDM systems (depending on scope). Typically, this will include a minimum of a year’s experience in flow measurement.

4.4 Inspection provider

4.4.1 Inspection providers are companies that employ MCERTS inspectors. Applicants must be associated with an approved inspection company.

4.4.2 CSA maintains a list of companies that are approved inspection providers. These companies have been appointed by CSA to deliver the MCERTS site inspection service. The process of appointing a company includes an audit of the inspection provider’s quality management system, including an audit of spreadsheets, templates or other software that an inspector may use to prepare inspection reports.

4.4.3 If an inspection company’s application for approval is pending, a service provision agreement provided by CSA must be submitted by the applicant. This must be submitted with the endorsement of the inspection provider.

4.5 Knowledge requirements

MCERTS inspectors must demonstrate their competence in the following areas, according to their scope (detailed knowledge requirements are available from CSA).

1. Health and safety – planning and access, method statements and risk assessment

2. Selection of flowmeters – open channel, closed conduit, and other types of flowmeters, for example velocity or area

3. Types of processes

4. Flow measurement techniques – open channel, closed conduit or other

5. Types of instrumentation used

6. Local effects that may impact on – open channel and closed conduit

7. Signal processing technology

8. Telemetry, data logging, and supervisory control and data acquisition technology

9. Measuring equipment used by inspectors – calibration and traceability

10. Flowmeter performance – hydraulics and instrumentation

11. Measurement uncertainty – spreadsheet tools or software used to determine uncertainty

12. MCERTS concessions

13. Maintenance and verification procedures

14. Management systems

15. EDM – alarm activation, level measurement, weir and hydraulic condition assessment, and pump operation

Assistant inspectors are only expected to satisfy the above knowledge requirements, where necessary, for the technical scope applicable to their application.

CSA have published an overview of resources (Bulletin 30) to help applicants gain the knowledge needed to become an MCERTS inspector or Assistant inspector.

4.6 Calibration of survey and test equipment

MCERTS inspectors and Assistant inspectors must be able to demonstrate that equipment used for relevant on-site inspections is fit for purpose. The calibration of all equipment used must be traceable to national standards to the satisfaction of CSA.

4.7 Integrity and impartiality

MCERTS inspectors and Assistant inspectors must be able to appreciate the potential for conflicts of interest during the inspection of operator’s flow monitoring arrangements. Inspectors must comply with the code of conduct – see section 7.

5. Appointment of MCERTS inspectors and Assistant inspectors

5.1 Conformance assessment

5.1.1 Applications for appointment to an MCERTS inspector or Assistant inspector must be submitted on an application form available from CSA.

5.1.2 Applicants must submit supporting written evidence of their experience and formal training. All records of experience must be signed by a person deemed to be competent to assess the applicant’s performance. This signature must confirm the satisfactory performance of the applicant in carrying out the recorded work.

5.1.3 CSA must decide whether an individual complies with this standard by assessing written records of experience and observing a practical on site assessment.

5.1.4 Applicants for MCERTS inspector must pass an interview carried out by a technical panel appointed by CSA.

5.1.4 During the interview the applicant must:

• demonstrate the suitability of any software or spreadsheets that they intend to use for data handling and manipulation during inspections
• carry out the calculations necessary to indicate compliance of effluent flow monitoring arrangements with a required uncertainty target
• be able to explain the content and interpret the data produced by their software or spreadsheets

5.2 Appeals and complaints

5.2.1 CSA must handle appeals and complaints related to the appointment of inspectors.

5.2.2 MCERTS inspectors, Assistant inspectors or their employers must keep a record of complaints made against them, which are relevant to the scope of this standard. They must notify CSA of these within 10 working days.

5.3 Status of appointment

5.3.1 MCERTS inspectors and Assistant inspectors are appointed for 5 years. CSA must carry out ongoing surveillance throughout this period.

5.3.2 The appointment must be awarded to an individual, on a personal basis, for work with a specified employer.

5.3.3 An inspector’s appointment may be transferable for work with another employer. CSA must make sure that the inspector is competent to use any different measurement equipment or software used by the new employer.

5.4 MCERTS register

CSA must maintain a publicly available register of all companies that employ MCERTS inspectors and Assistant inspectors.

6. Reassessment of MCERTS inspectors and Assistant inspectors

6.1 MCERTS inspectors and Assistant inspectors must undergo reassessment before the end of the 5-year period to maintain their appointment. This reassessment must take account of the latest version of this standard and an inspector’s ongoing experience. It will confirm that they have retained their technical knowledge and are aware of any relevant new developments in flow measurement techniques.

6.2 To be eligible for reappointment, an inspector must demonstrate that they have:

• carried out inspections of flow measurement or EDM installations on a regular and frequent basis over the 5-year period – typically on at least 50 occasions
• not had a gap of more than 2 continuous years from inspecting effluent flow- measurement and EDM installations
• kept up to date with relevant developments in the flow-monitoring field, for example, by participating in a documented continual professional development programme
• kept up to date with changes to relevant international standards
• acted in line with the code of conduct

7. Code of conduct

MCERTS inspectors and Assistant inspectors must comply with this code of conduct:

1. The inspector must comply with the confidentiality, independence, impartiality and integrity requirements as specified by CSA. Details are available from CSA.

2. Any potential conflict of interest must be immediately raised with CSA.

3. The inspector must provide feedback to operators on inspection findings in the form of a written report. The feedback must identify the areas requiring attention but not provide a detailed design solution.

4. The inspector must not suggest or recommend a single company to carry out remedial work to the detriment of potential competitors.

5. The inspector must comply with the rules for the use of the MCERTS logo – see ‘Guide to MCERTS Product Certification’.

8. What to do next

If you have any questions or would like more information on becoming an inspector or about how to apply, please contact:

CSA Group Testing UK Ltd
Unit 6, Hawarden Industrial Park
Hawarden
Deeside
CH5 3US

Telephone: +44(0) 1244 670 900

E-mail: ukinfo@csagroup.org

Find out more about MCERTS on the MCERTS collection on GOV.UK.

Contact the Environment Agency if you need any help.

General enquiries

National Customer Contact Centre
PO Box 544
Rotherham
S60 1BY

Email enquiries@environment-agency.gov.uk

Telephone 03708 506 506

Telephone from outside the UK (Monday to Friday, 8am to 6pm GMT) +44 (0) 114 282 5312

Monday to Friday, 8am to 6pm.