Ensuring Safety: Gas Detection in Water and Wastewater Treatment Facilities

Wastewater treatment facilities and onsite wastewater management systems are crucial for ensuring that we have access to clean and safe water. Toxic and hazardous vapours and gases are produced during various stages of the water treatment process, and if not properly monitored, can lead to serious health and environmental problems. Gas detection in water and wastewater treatment plants is essential to protect workers, equipment, and the environment from the potential risks and hazards that can be found throughout the water treatment process.

Common Gas Hazards at Wastewater Treatment Facilities

All wastewater that poses potential risks to human health or the environment must undergo physical and chemical processes before being discharged back into the water system. During these processes, a range of gas hazards including Volatile Organic Compounds (VOCs) are released which can result in short-term and long-term side effects.

The treatment of wastewater involves two distinct processes. The physical processes involve actions such as screening, sedimentation, and skimming. Any organic debris that is present in the wastewater will decompose and produce methane (CH_₄) and hydrogen sulphide (H_₂S) while processes such as sludging produces ammonia (NH₃), which dissolves in water to create ammonium hydroxide (NH₄OH). The next stage of treating wastewater requires the water to undergo chemical processes for further decontamination. Utilising chemicals such as chlorine (CI₂), chlorine dioxide (CIO₂), ammonia (NH₃) and ozone (O₃), the water is treated to disinfect and kill any bacteria and viruses that may be present.

Dependent on the gas hazards present, exposure to these chemicals can cause a range of symptoms and illnesses. Low level exposure to some of these chemicals can cause irritation to the eyes and respiratory system while high-level exposure can be fatal and cause pulmonary oedema.

Ensuring Worker Safety with Personal and Confined Space Multi-Gas Detectors

Eliminating gas hazards in water and wastewater treatment facilities is virtually impossible, making gas detection crucial for safety and efficiency. Depending on the stage of the treatment process and the specific hazards, portable gas detectors can be implemented to monitor for a single gas or for multiple gases. The configuration of multi-gas detectors will vary according to the treatment process stage and the specific hazards being monitored for. In some cases, additional single-gas monitors may be used to enhance the gas detection program within water and wastewater treatment facilities.

Typically, a standard confined space 4-gas monitor is suitable for use in most water and wastewater treatment facilities, monitoring for methane (LEL), oxygen, hydrogen sulphide and carbon monoxide. While carbon monoxide is commonly used for the fourth sensor, this may be substituted within your treatment facility to provide targeted protection against specific chemical risks, such as ammonia or chlorine.

Water treatment facilities may encounter substances in wastewater that can react during treatment to release hazardous gases from VOCs such as benzene, formaldehyde, ethylene glycol, and trichloroethylene. In these instances, a traditional gas detector with a dedicated electrochemical sensor may be insufficient to detect these hazards. On these occasions, a photoionisation detector (PID) may be required to provide an added level of protection. With advancements in gas detection technology, some manufacturers now provide gas detectors with the option to integrate a PID sensor that has a 10.6 eV lamp into traditional devices, such as the Ventis Pro5 from Industrial Scientific. This innovation eliminates the need for workers to carry two separate instruments, offering greater flexibility, convenience, and enhanced protection against gas hazards in water and wastewater facilities.

There are also several considerations when selecting multi-gas monitors for use in water and wastewater treatment plants. The first important consideration when selecting a multi-gas monitor is the potential for sensor combinations to result in cross-interferences. Gas sensor cross sensitivity is the tendency for a gas sensor to detect the presence of a gas other than the one that it’s specifically designed to be monitoring for. This can lead to false readings, such as a H₂S sensor picking up H₂ gas within the area.

Another common consideration within the water and wastewater treatment industry is the addition of single gas monitors to complement multi-gas monitors. Single-gas detectors like the GasBadge Pro can be used gas detection programs when an additional sensor is required for monitoring for ammonia or chlorine.

Connected Safety for Water and Wastewater Treatment

Connected safety devices are essential for safeguarding workers and lone workers in water treatment facilities. Not only are these workers at risk of facing multiple gas hazards at once, but they also face hazards from falls, medical emergencies, and dangerous conditions in isolated and confined spaces. A successful gas detection programme requires many elements including accurate sensor selection, regular calibration and maintenance, daily bump tests, stringent record keeping and proper training for personnel to ensure effective monitoring and response to gas hazards. Connected platforms like iNet Exchange and iNet Control+ play a crucial role in water treatment facilities as they help streamline these processes, reduce downtime, provide greater visibility and ensure a safer work environment.

Continuous and real-time monitoring ensures you can respond to any hazardous situations quickly before they become fatal. Lone workers are particularly vulnerable due to their isolation so multi-gas monitors connected to cloud-based software solutions, like iNet Control+, can detect immediate dangers and alert both the workers, safety managers, and nearby colleagues, should emergency assistance be required. Modern connected gas detection devices also provide automatic real-time status updates, enabling safety managers to gain insights into worker conditions, track worker locations, and verify the completion of safety actions like bump tests. This interconnected approach enhances the protection of workers and improves response times and efficiency throughout your water treatment plant.

Designing a safety system for a water and wastewater treatment facility is a big responsibility and selecting the right equipment can be crucial for saving lives. At Air-Met Scientific, our team can provide you with advice and guidance to create a tailored gas detection solution for your wastewater treatment facility.