The Environment Agency has published detailed new guidance on automatic water sampling equipment used for monitoring treated discharges from wastewater treatment works, industrial processes, untreated wastewater and receiving waters under the MCERTS monitoring certification scheme.

The Agency has published the guidance for:

• manufacturers of automatic water sampling equipment who need to know what standards to meet to be able to use their equipment for regulatory purposes in England and Wales
• test organisations who carry out testing of the equipment on behalf of manufacturers to see if it meets the required standard

Automatic water sampling equipment (samplers) are used for monitoring treated discharges from wastewater treatment works, industrial processes, untreated wastewater and receiving waters.

Product certification under MCERTS comprises 2 phases:

• laboratory testing – used to determine performance characteristics, where such testing requires a highly controlled environment
• surveillance – initial and continuing which comprises an audit of the manufacturing process to confirm that the manufacturer has provisions to make sure manufacturing reproducibility and to control any design changes to make sure that they do not degrade performance below the MCERTS requirements

The Environment Agency has appointed CSA Group Testing UK Ltd as the certification body to operate the monitoring certification scheme MCERTS on standards that must be met to monitor emissions that affect the environment.

The role of the certification body is to assess and certify compliance with the MCERTS requirements for defined applications and conditions.

The guidance covers the standard which is required for the testing of samplers: EN 16479:2023 Water Quality – Performance requirements and conformity test procedures for water monitoring equipment – Automatic sampling devices (samplers) for water and waste water.

The EA requires operators of regulated processes to use MCERTS certified samplers - the main performance requirements against which a sampler will be assessed are:

• sample volume bias and repeatability
• maintenance of sample line velocity over the certified conditions including the specified lift height range and when subject to power supply variation
• sample integrity
• timing accuracy
• immunity to ambient temperature variation

The performance requirements and conformity tests apply to samplers that:

• sample aqueous wastewater from non-pressurised (that is open to atmosphere) channels or vessels
• sample over extended periods to collect discrete or composite samples based on time or flow proportional sampling
• are intended to be permanently or temporarily sited

Samplers used at wastewater treatment works final effluent or influent for the purpose of monitoring the performance of the treatment process, as required under the Urban Waste Water Treatment Regulations (UWWTR), will also be assessed against the requirements specified in EN 16479.

Scope of the MCERTS scheme

MCERTS for automatic water samplers covers:

• processes falling under the Environmental Permitting Regulations
• consented discharges for processes regulated through provisions of the Water Resources Act,1991
• sites falling under the Urban Wastewater Treatment Regulations (UWWTR)
• sites falling under other relevant directives, for example, the Water Framework Directive
• other monitoring of the aquatic environment

MCERTS certificates are valid for 5 years. After this time, the certification is reviewed and any necessary retesting will be identified to maintain the certification.

Modifications to certified samplers are allowable so long as manufacturers can demonstrate that the design changes do not degrade the performance of the sampler below the MCERTS requirements.

Click here to access the detailed guidance online