21.4 Emergency Response Planning & Disaster Recovery
Key Takeaways
- The Incident Command System provides a standard organizational structure that lets agencies who have never worked together operate under unified command.
- America's Water Infrastructure Act requires community water systems serving more than 3,300 people to conduct risk and resilience assessments and prepare emergency response plans.
- Emergency response plans must be exercised, because a plan that has never been tested fails on details such as outdated contact numbers and unavailable equipment.
- Mutual aid networks such as WARN provide pre-negotiated agreements so that assistance can arrive without contract negotiation during an emergency.
- Loss of pressure in a distribution system creates backsiphonage risk and typically triggers a precautionary boil-water advisory in consultation with the primacy agency.
21.4 Emergency Response Planning & Disaster Recovery
Water and wastewater utilities are designated critical infrastructure, and they are expected to keep operating through the events that disrupt everything else.
Hazards to Plan For
| Category | Arizona-relevant examples |
|---|---|
| Natural | Monsoon flooding and flash floods, extreme heat, wildfire and post-fire debris flows, dust storms, drought and shortage declarations, earthquake |
| Infrastructure | Main breaks, power outages, pump station failure, SCADA failure, treatment upset, tank failure |
| Chemical | Chlorine release, chemical spill, delivery incident, overfeed |
| Contamination | Backflow event, source contamination, distribution intrusion, intentional contamination |
| Security | Vandalism, theft (especially copper and backflow assemblies), trespass, cyberattack |
| Supply chain | Chemical shortage, parts unavailability, fuel |
| Workforce | Pandemic, key staff loss, labor action |
Regulatory Framework
America's Water Infrastructure Act (AWIA) Section 2013 requires community water systems serving more than 3,300 people to:
- Conduct a risk and resilience assessment covering malevolent acts and natural hazards, including physical barriers, source water, treatment and distribution infrastructure, electronic and computer systems, monitoring practices, chemical storage and handling, and operation and maintenance.
- Certify completion to EPA.
- Prepare or revise an emergency response plan within 6 months of certifying the assessment.
- Review and recertify both on a 5-year cycle.
Wastewater utilities carry parallel obligations through AZPDES permit conditions requiring an overflow emergency response plan, and through the Risk Management Program and Process Safety Management requirements where threshold quantities of hazardous chemicals are stored.
Emergency Response Plan Contents
| Section | Content |
|---|---|
| Roles and responsibilities | Who does what, with authority to act and a chain of succession |
| Notification | Internal and external call lists with 24-hour numbers, regulatory notification requirements and deadlines |
| Communication | Public information, media, customers, and coordination with health authorities |
| Specific response procedures | One for each identified hazard |
| Resources | Equipment, materials, contractors, laboratories, alternate water sources |
| Mutual aid | Agreements and contacts |
| Facility information | Maps, schematics, valve locations, shutdown procedures, hazardous material inventory |
| Alternate operations | How to run manually, alternate sources, interconnections, emergency disinfection |
| Recovery | Restoration sequence, flushing and sampling, return to normal |
| Training and exercises | Schedule and documentation |
[!IMPORTANT] A plan that has never been exercised will fail on details. Exercises reveal disconnected phone numbers, a generator connection that does not fit the rental unit, a valve that will not close, a key contact who retired two years ago, and the fact that nobody knows the password to the SCADA historian. Exercise types escalate: a tabletop discussion, a functional exercise testing specific capabilities, and a full-scale exercise with field deployment. Document every exercise, capture the lessons in an after-action report, and revise the plan — an after-action report filed without plan revisions accomplishes nothing.
The Incident Command System
ICS is a standardized structure within the National Incident Management System that lets organizations who have never worked together operate under a single, understood framework.
| Function | Responsibility |
|---|---|
| Incident Commander | Overall authority and responsibility |
| Operations | Carries out the tactical response |
| Planning | Situation status, resource tracking, incident action plan |
| Logistics | Facilities, services, materials, personnel support |
| Finance/Administration | Cost tracking, procurement, claims, time |
Core principles: common terminology (plain language, no agency-specific codes), manageable span of control (roughly 3 to 7 reports per supervisor), unity of command (one supervisor per person), unified command where multiple agencies share jurisdiction, and modular expansion so the structure grows only as the incident requires. A small event may have an incident commander and nothing else.
The practical value is that when a utility, a fire department, a county health department, and a state agency all respond to a chlorine release, ICS is what prevents four organizations from operating four separate incidents at the same address.
Mutual Aid
Water/Wastewater Agency Response Networks (WARN) are utility-to-utility mutual aid programs organized by state. Their value is the pre-negotiated agreement: terms for reimbursement, liability, workers' compensation, and indemnification are settled in advance, so that during an emergency a request for a portable pump, a generator, a crew, or laboratory support does not stall in contract negotiation.
Other resources include the Emergency Management Assistance Compact between states, contractor standby agreements, equipment rental agreements, and state and federal emergency management.
Specific Response Scenarios
Loss of Pressure
Depressurization allows backsiphonage of contaminants through cross-connections and intrusion through main defects.
Response: isolate the affected area, restore pressure as quickly as possible, flush thoroughly, collect bacteriological samples, and consult with the primacy agency about a precautionary boil-water advisory. Advisories are lifted only after satisfactory bacteriological results and restoration of adequate pressure and residual, with public notification of the rescission.
Possible Contamination
Water systems use a credibility-based escalation: a threat is possible when circumstances warrant investigation, credible when corroborating information supports it, and confirmed when analytical or epidemiological evidence establishes it. Actions escalate accordingly — site characterization, sampling, isolation of the affected area, public notification, and provision of an alternate water supply.
[!WARNING] Do not flush a suspected contamination event before sampling. Flushing destroys the evidence needed to characterize the contaminant and determine the extent, and it can spread the contamination further into the system. Isolate first, sample, then decide on flushing.
Chemical Release
Evacuate and account for personnel, notify emergency responders, isolate the source only if it can be done safely by trained personnel with appropriate protection, establish an exclusion zone accounting for wind direction, and notify downwind populations. Reportable quantity releases require notification to the National Response Center and state authorities.
Extended Power Outage
Start standby generation and shed non-essential loads, prioritize disinfection and pumping, arrange fuel resupply for extended outages, monitor storage levels closely, and prepare public messaging about conservation.
Recovery and Continuity
Recovery is a planned sequence, not an improvisation: damage assessment, prioritized restoration driven by public health rather than by convenience, flushing and disinfection of affected infrastructure, bacteriological clearance, rescission of any advisory, documentation for reimbursement, and an after-action review.
Continuity of operations planning addresses the longer horizon: essential functions and the maximum tolerable downtime for each, succession of authority, alternate work locations, vital records protection, and critical vendor dependencies. In a state where a single extreme heat event can coincide with a power failure and a wildfire in the source watershed, planning for concurrent rather than sequential hazards is realistic rather than pessimistic.
A community water system serving 12,000 people completes its risk and resilience assessment and certifies it to EPA. What is the next required action and its deadline?
An operator receives a credible report of possible intentional contamination at a storage tank. Crews propose immediately flushing the affected zone to remove any contaminant. Why is this the wrong first action?
What is the principal operational advantage of belonging to a Water/Wastewater Agency Response Network?