Hazard Analysis and Critical Control Points (HACCP): Wastewater Treatment Explained
The Hazard Analysis and Critical Control Points (HACCP) system is a preventive approach to food safety and pharmaceutical safety that addresses physical, chemical, and biological hazards as a means of prevention rather than finished product inspection. This system is used in the treatment of wastewater to ensure the safety and cleanliness of the water being treated. This article will delve into the intricacies of applying HACCP in wastewater treatment.
Wastewater treatment is a process used to convert wastewater into an effluent that can be returned to the water cycle with minimum impact on the environment, or directly reused. The latter is called water reclamation because treated wastewater can then be used for other purposes. The treatment process takes place in a wastewater treatment plant (WWTP), often referred to as a Water Resource Recovery Facility (WRRF) or a sewage treatment plant. Pollutants in municipal wastewater (households and small industries) are removed or broken down.
Understanding HACCP
The HACCP system is designed to identify potential dangers and implement controls at specific points in a process. This system, when used in wastewater treatment, helps to identify potential hazards and establish control systems that are specific to these hazards. The HACCP system is built on seven principles, which we will explore in detail.
These principles are not steps to be followed in order, but rather they are interconnected principles that form the basis of any HACCP system. Understanding these principles is crucial to understanding how the HACCP system functions in any setting, including wastewater treatment.
Principle 1: Conduct a Hazard Analysis
The first principle involves the identification of potential hazards. In the context of wastewater treatment, these hazards could be anything from chemical contaminants to biological hazards such as bacteria and viruses. This step involves a thorough analysis of the wastewater and the potential hazards it may contain.
Once these hazards have been identified, they are then evaluated based on their severity and the likelihood of their occurrence. This evaluation helps in determining which hazards need to be addressed in the HACCP plan.
Principle 2: Identify Critical Control Points
Once the hazards have been identified and evaluated, the next step is to identify the critical control points (CCPs). These are points in the wastewater treatment process where the potential hazard can be controlled or eliminated. Identifying the CCPs is a crucial step in the HACCP system as it allows for the prevention of hazards rather than trying to deal with them after they have occurred.
CCPs in wastewater treatment could be anything from the initial filtration process to the final disinfection stage. Each of these points presents an opportunity to control a potential hazard and ensure the safety of the treated water.
The Application of HACCP in Wastewater Treatment
Applying the HACCP system in wastewater treatment involves a systematic approach that begins with the identification of potential hazards and ends with the establishment of effective control measures. The application of HACCP in wastewater treatment can be broken down into several key steps.
These steps are not necessarily linear, but rather they are iterative and may need to be revisited as new information becomes available or as conditions change. The application of HACCP in wastewater treatment is a dynamic process that requires constant monitoring and adjustment.
Step 1: Preliminary Tasks
The first step in applying HACCP in wastewater treatment is to perform some preliminary tasks. These tasks include assembling the HACCP team, describing the product and its distribution, identifying the intended use and consumers of the product, and developing a flow diagram which describes the process.
The HACCP team is typically made up of individuals who have a thorough understanding of the wastewater treatment process. This team is responsible for developing the HACCP plan and ensuring its effective implementation.
Step 2: Hazard Analysis
The next step is to conduct a hazard analysis. This involves a detailed examination of the wastewater treatment process to identify where hazards may occur. The results of this analysis form the basis for the HACCP plan.
The hazard analysis involves an evaluation of the severity of each hazard and its likely occurrence. Hazards are usually categorized into three types: biological, chemical, and physical. Biological hazards include bacteria, viruses, and parasites. Chemical hazards include toxins, heavy metals, and pesticides. Physical hazards include glass, metal, and other foreign objects.
Establishing Critical Limits, Monitoring Procedures, and Corrective Actions
Once the hazards have been identified and the CCPs have been determined, the next steps in the HACCP system involve establishing critical limits, monitoring procedures, and corrective actions. These steps are crucial in ensuring that the CCPs are effectively controlled.
Each CCP must have a critical limit which separates acceptability from unacceptability. The determination of critical limits requires a thorough understanding of the hazard and its control. Critical limits may be derived from sources such as regulatory standards and guidelines, experimental studies, and expert opinion.
Monitoring Procedures
Monitoring is the scheduled measurement or observation of a CCP relative to its critical limits. The monitoring procedures must be able to detect loss of control at the CCP. Furthermore, monitoring should ideally provide this information in time to make adjustments to ensure control of the process to prevent violating the critical limits.
Where possible, process adjustments should be made when monitoring results indicate a trend towards loss of control at a CCP. The adjustments should be taken before a deviation occurs. Data derived from monitoring must be evaluated by a designated person with knowledge and authority to carry out corrective actions when indicated.
Corrective Actions
Specific corrective actions must be developed for each CCP in the HACCP system in order to deal with deviations when they occur. The actions must ensure that the CCP has been brought back under control. Actions taken must also include proper disposition of the affected product. Deviation and product disposition procedures must be documented in the HACCP plan.
Corrective actions may include reprocessing or disposing of the product, increasing the frequency of monitoring, changing the process, increasing operator training, changing the source of raw materials, or potentially a combination of these or other actions.
Verification and Record-Keeping Procedures
The final steps in the HACCP system involve the establishment of verification and record-keeping procedures. Verification ensures the HACCP plan is adequate, that is, working as intended. Verification procedures may include such activities as review of HACCP plans, CCP records, critical limits and microbial sampling and analysis.
Record-keeping is a necessary part of the HACCP system. The records must document the HACCP plan in action, showing the monitoring of critical control points, critical limits, verification activities, deviation and corrective actions taken, all of which provide documentation concerning the safety of the product.
Verification Procedures
Verification is the application of methods, procedures, tests and other evaluations, in addition to monitoring, to determine compliance with the HACCP plan. The frequency of verification should be sufficient to confirm that the HACCP system is working effectively. Examples of verification activities include review of the HACCP system and its records, revalidation of the hazards and control measures, and additional testing of the product.
Verification also includes 'validation' – the process of finding evidence for the accuracy of the HACCP system (e.g. scientific evidence for critical limitations).
Record-Keeping Procedures
Record-keeping is a vital part of the HACCP process. It provides a written documentation of the entire process, which can be useful for both verification purposes and for future reference in case of potential problems. Records should include the HACCP Plan, CCP monitoring activities, deviation and corrective action records, and verification activities.
Records should be kept for an appropriate period of time that exceeds the shelf life of the product. The records should be signed by the person doing the monitoring and by a responsible reviewing official of the company.
Conclusion
The Hazard Analysis and Critical Control Points (HACCP) system is a vital tool in the treatment of wastewater. It provides a systematic approach to the identification, evaluation, and control of hazards. By applying this system, wastewater treatment plants can ensure the safety and cleanliness of the water they produce.
While the application of HACCP in wastewater treatment can be complex, the benefits it provides in terms of safety and efficiency make it an invaluable tool. With a thorough understanding of the HACCP system and its principles, wastewater treatment plants can effectively control potential hazards and ensure the production of safe, clean water.
