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Municipal Technical Advisory Service (MTAS)

Water and Sewer System Security

Reference Number: MTAS-846
Reviewed Date: 03/24/2023

Water and sewer systems are complex and vast operations and are open to possible terrorists attack. Much of the water and sewer system is open and cannot be totally shielded from vandalism or destruction. However, there are steps that can be taken to minimize the danger and to deal with any situations that arise.

The greatest threat to water and sewer systems, is likely from someone who is local, instead of an international terrorist group. Almost every city utility system has someone who is a disgruntled customer or ex-employee. These people may seek to damage the system in such a way as to render it difficult to provide water or treat wastewater. For example, they may destroy the power supply to the water plant making it impossible to treat and pump water. It is not likely that a substance could be introduced into the water supply that would injure or kill vast numbers of people, but many other activities could be done to damage the system. Water and sewer systems have many potentially dangerous chemicals, such as chlorine, stored on site, Also, as previously mentioned, they could choose to damage the treatment plant, pumping stations, or water storage tanks. Cities could be without water or sewer service for hours, days, or even weeks. At the greatest extreme, a terrorist could simply kill the certified and trained personnel leaving the system with no qualified operators.

Water and sewer systems should take every step to mitigate this threat. First and foremost, cities;should have planning and preparation in place to deal with an event should it occur. A plan should be developed that involves not only the utility staff, but also local law enforcement, fire, rescue, medical, and any other emergency staff that would be a part of the plan. If everyone knows their contacts and roles in an emergency it will be much easier to deal with a crisis than trying to pull this together when working under the stress of an event. Another important part of mitigating the threat is taking preventive steps now. Locking facilities and limiting access to the system is important. Cameras and alarms may be installed where appropriate. Screening personnel as part of the hiring process may prevent the disgruntled employee or ex-employee. Making utility personnel responsible for being alert to potential threats is vital. For example, personnel should always question anyone they see around the facilities to determine if they are present for legitimate purposes, and they should report any unusual activity. And, utility staff should take seriously any threat made by anyone. Sometimes it’s easy to brush off the local who has been disgruntled with the utility for years. But this may be the one time he is ready to act.

Hopefully no utility will ever have to face a terrorist action. If plans and preparations are in place the situation will go much smoother and the remedy much quicker. MTAS consultants are available to assist you with more detailed information on security measures and help you evaluate your current situation.

Cyber Security is a requirement of all water and wastewater utilities.