Security Assessment of Public Water Supplies
While an attack by foreign terrorists may be unlikely, home grown
terrorists and ordinary vandals are a threat to the safety of drinking
water. The U.S. Environmental Protection Agency requires public
water systems serving at least 3,300 people to conduct security
assessments. Various organizations offer security self-assessment
tools, including the National Rural Water Association. Consider
these items: 
- Coordination
- Access to Facilities
- Access to Documents
- Access to Computer Systems
- Monitoring
- Water Disinfection
- For more information
Coordination
- Ask your local law enforcement staff and public works/utility director to review your security measures.
- Ask your local emergency manager to review your response plans. Develop mutual aid agreements with neighboring communities for emergency water supplies.
- Train personnel in security awareness. Post the response actions for reporting threats or acts of terrorism. Call 911 or the local sheriff if suspicious activities occur.
- Plan for public notification.
- Practice response plans on a regular schedule.
- Develop local capacity to communicate with local health care facilities. The Health Alert Network (HAN) is in use by most emergency health professionals.
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Access to Facilities
- Restrict access with physical barriers to reservoirs, treatment
system vents, and intakes. Prohibit parking or stopping on roadways
near facilities. Fix all broken barriers, security fences, hatches,
and manholes
immediately. - Lock all facilities. Do not leave keys in equipment.
- Evaluate the reliability and security status of current and former employees. Post “Employee Only” signs at entrances to restricted areas. Tell employees to question any strangers in restricted areas.
- Store chemicals in secure facilities. Require chemical suppliers to provide their personnel with photo-identification. Use only reliable and known suppliers and contractors. Only accept deliveries of intact containers of chemicals that have been ordered.
- Install security lighting, motion detectors, and surveillance cameras.
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Access to Documents
- Limit access to water distribution maps and plans of facilities.
- Require contractors and consultants to maintain security to their copies of maps and plans.
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Access to Computer Systems
- Obtain technology security such as firewalls, anti-virus software, and intrusion detection software to protect computer systems.
- Limit computer access and passwords to personnel who need to know.
- Join the appropriate Information Sharing and Analysis Center (ISAC).
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Monitoring
- Keep good records. Discuss unusual events with law enforcement.
- Ask your local law enforcement officials to routinely patrol facilities and to strictly enforce parking restrictions.
- Visit all facilities daily.
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Water Disinfection
- Maintain a free chlorine residual of at least 0.2 parts per million at the ends of the distribution system. If you don’t currently disinfect your system, consider adding a disinfectant.
- Check chemical quality on a regular basis.
- Larger systems should consider installation of chlorine residual recorders that will send an electronic alarm if the chlorine residual drops.
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For more information:
- MDH
Community Water Systems District Engineers
or the MDH main office (651-201-5000) - Water Security Publications Database, EPA
- Safe Drinking Water Hotline 1-800-426-4791, EPA
- Vulnerability Assessment & Security Resources, MRWA
- Water Infrastructure Security Enhancements (WISE), AWWA
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