How many water and wastewater plants does Water Corporation operate in WA?
We operate more than 270 water and wastewater treatment plants throughout the State and, of necessity, most are close to the communities they serve.
What chemicals stored at water or wastewater treatment plants pose an offsite risk?
Chlorine gas is the only chemical at either a water or wastewater treatment plant that might generate an offsite risk. Other chemicals such as acids and alkalai’s are unlikely to escape offsite as they are stored in accordance with strict regulatory requirements.
What form of chlorine is used and what quantities of chlorine are typically stored at water or wastewater treatment plants?
Chlorine is in the form of gas and it is stored in purpose-designed pressure cylinders. The amount of chlorine stored is proportional to the size and type of facility. In general, the amount of chlorine stored ranges from two cylinders at most sites through to 4–14 cylinders at large metropolitan treatment plants. Over the years, new technologies and treatment processes have reduced reliance of chlorine and this will continue.
Why is chlorine used?
Chlorine gas disinfects water and makes it safe to drink by killing germs. It also helps remove contaminants such as iron and manganese, which can cause water to stain. Chlorine is portable and has a long shelf life.
What security arrangements are typically in place at Water Corporation chlorination storage sites?
High level security precautions are used to prevent damage from vandalism, theft and to protect relevant Water Corporation sites. Sensitive and hazardous chemicals and equipment are housed in secure buildings. Electrified security fences, razor wire, electronic alarm system, video surveillance, security patrols and appropriate signage help secure the sites. Water Corporation has an infrastructure protection program for all its assets, which continues to evolve in a dynamic and sensitive external security environment. The Water Corporation’s security, emergency and incident management framework is the forefront of the national water sector.
What is the risk of a chlorine leak?
There is a low risk of a chlorine leak being significant enough to have an offsite impact. Water Corporation chlorine facilities must comply with the Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007 and Australian Standard 2927:2001 The Storage and Handling of Liquefied Chlorine Gas. Water Corporation also has its own design standards, which have been developed in accordance with national and state regulations.
Water Corporation and its predecessors have been using chlorine to disinfect water since the 1940s, without any recorded community impact that has resulted in injury or illness. Through its hazard and safety management systems, modern plant designs and appropriate siting of facilities, Water Corporation aims to maintain this unblemished record.
We always aim to improve emergency planning and response procedures and are available to discuss its emergency plans with any business or property owner located near its chlorine storage facilities.
If the risk of a chlorine leak is low, why are you alerting the community?
The statutory requirements governing the storage and handling of chemicals are constantly evolving and regulated by the WA Department of Mines and Petroleum (DMP). To comply with the latest legislative requirements, Water Corporation must formally notify people living near any of its facilities that store chemicals with the potential for a significant offsite impact.
The DMP’s latest legislative requirements are outlined in the Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007 on its website at www.dmp.wa.gov.au/6651.aspx
How would you know if there was a chlorine leak from a Water Corporation facility?
Chlorine gas has a distinctive smell and this is the most obvious way of detecting it. If you can smell chlorine, it has the potential to impact on your health.
At very low levels (around 3 to 5 parts per million) chlorine gas smells similar to household bleach.
At higher concentrations (around 10 parts per million) chlorine gas can be very irritating and exposure to it for more than a few minutes can cause nose, throat and lung irritation, especially to people with heightened sensitivity, such as asthmatics.
Water Corporation chlorination facilities have multiple chlorine gas leak sensors, which are continually monitored at a central control room. Should a sensor detect a chlorine leak, a red light will be activated at the facility and it will start to flash. The alarm will also register at the central control room and our personnel will be immediately dispatched to investigate. If our personnel are on-site when a sensor detects a chlorine leak, then a siren will sound in addition to the flashing red light.
What is classified as a significant chlorine leak and what would be the response?
Should a significant chlorine leak occur (above 20 parts per million), the Department of Fire and Emergency Services (DFES) will be called to site, in addition to Water Corporation personnel. DFES will take control of the incident and make contact with any people in the vicinity of the leak.
What can you do if you suspect a chlorine leak?
Our comprehensive chlorine monitoring and alarm system has a proven track record of success, but it is not infallible.
If you suspect a chlorine leak, contact our 24-hour Faults, Emergencies and Security number on 13 13 75.
Department of Fire and Emergency Services can be contacted on 000.
Move up-wind of the chlorine smell if you can. Or if you are inside, it is advisable to close all doors and windows; and turn off air conditioners.