The validation framework is underpinned by protocols, which are agreed methodologies to assess pathogen removal. Each protocol is based on 9 key elements.
Identify the mechanisms of pathogen removal by the treatment process unit.
Successful validation of a treatment process unit identifies which reduction mechanisms apply to the process, and how they affect the target pathogen. Mechanisms may include inactivation (e.g. chlorination), physical removal (e.g. sedimentation) or predation. A single treatment process may integrate multiple reduction mechanisms (e.g. membrane bioreactor).Protocol template
Identify the target pathogens, or appropriate surrogates, that are the subject of the validation study.
A target pathogen is the one demonstrated to be most resistant to the treatment process being validated. Selection is based on prevalence, resistance to treatment, survival in the environment and pathogenicity. Availability of reliable analytical methods for the target pathogen is important for designing a validation study. If use of the target pathogen is not practicable, potential surrogates must be identified.Protocol template
Identify the influencing factors that affect the efficacy of the treatment process unit to reduce the target pathogen
Any influencing factor (e.g. feedwater characteristics, hydraulic loads or manufacturing defects) that is deemed to have a significant effect on treatment efficacy needs to be monitored, as the ultimate control of the system relies on demonstrating that these factors are within a validated range. A validation study is only applicable to treatment process units that function within the validated operational envelope.Protocol template
Identify the operational monitoring parameters that can be measured continually and relate to the reduction of the target pathogen
Operational monitoring parameters are used to measure the performance of the treatment process unit, and relate to the reduction performance of the target pathogen (treatment efficacy). Continuous monitoring of operational parameters gives assurance that the system is under control and provides alerts when treatment levels are unacceptable, triggering immediate corrective action. A risk management framework, such as the Hazard Analysis and Critical Control Point (HACCP) system, should be used to identify these factors.Protocol template
Identify the validation methodology to demonstrate the capability of the treatment process unit
Identifying the validation methodology demonstrates the pathogen log reduction capability of the treatment process unit. The validation methodology involves a testing program that quantifies the reduction of indigenous or challenge-spiked organisms or particulates, while monitoring the operational parameters to confirm that the system is within the defined operational envelope. Six key concepts have been identified, including what is monitored, how many samples and QA/QC procedures.Protocol template
Describe a method to collect and analyse data to formulate evidence-based conclusions
The data collected during the validation testing program must be representative and reliable. This element outlines parameters for the collection of quality data, a monitoring program that ensures data is relevant and statistically valid, and an analysis process that accounts for uncertainty including biases and error in measurement. The method must demonstrate that measurements are traceable to a registered standard method, where this is available.Protocol template
Describe a method to determine the critical limits as well as an operational monitoring and control strategy
A critical limit is a value that must be met to ensure that a critical control point (CCP) effectively controls a potential hazard. Critical limits need to be established for operational monitoring parameters and correspond to the point at which the treatment process is performing inadequately or outside the test envelope. The validated LRV applies when the treatment process is functioning within its critical limits.Protocol template
Describe a method to determine the LRV for each pathogen group (protozoa, virus or bacteria) in each specific treatment process unit performing within defined critical limits
The removal efficiency of a treatment process unit demonstrated by the challenge test results is determined according to the following equation:
LRV = log10 (feed concentration) – log10 (product water concentration)
Unless otherwise specified, the lower 5th percentile LRV, established during challenge testing, must be used. In most cases, the LRV attributed to a treatment process unit is limited by the sensitivity of the operational monitoring technique.
Provide a means for re-validation or additional onsite validation where proposed modifications are inconsistent with the previous validation test conditions
Re-validation or additional onsite validation testing for treatment process units may be required if there are design modifications to the unit (including critical system components such as UV lamps and membrane modules), control philosophy and operational monitoring parameters (including critical limits) that vary from the documented validation test conditions. Modifications and/or changes that require re-validation must be described.Protocol template
WaterVal provides a nationally consistent approach to the validation of water treatment technologies to enhance confidence in managing water treatment and supply.Read on
WaterVal benefits are delivered through an integrated management framework, including technology validation protocols, expert technical assessment, certification and data/information management functions.Read on
In response to a need for a consistent approach to validation, the water sector has collaborated to develop a governance structure and invest in targeted research projects that delivers a streamlined solution.Read on
Current treatment technology validation arrangements across Australia are often duplicative. Higher costs, inconsistencies and longer times to achieve validation can inhibit innovation and efficiency, while potentially increasing the risks to water management outcomes.Read on