Emergency Preparedness and Natural Disasters: Floods

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Threat of Rising Waters

Steps to Take 24 Hours Before a Dlood

With flooding imminent, these steps can help a company protect its facilities and expedite resumption of operations after the flood. This information is based upon a study of flood claims by Zurich Risk. While there is no substitute for a comprehensive flood contingency plan, these steps represent a checklist of items that, if completed, can help reduce the impact of a flood on business operations.

  1. Utilities preparation
    • Fill fuel tanks for emergency generators and fire pumps.
    • Isolate any low level electrical circuits and equipment.
    • Close any manual sewer backflow prevention valves.
    • Verify indoor fuel tanks exposed to water inundation are secured against buoyancy.
    • Where boilers and emergency generators rely upon fuel pumps to transfer fuel from bulk storage tanks to day tanks, verify the fuel pumps and their power supplies are located above the anticipated flood water levels and supplied by emergency power.
  2. Sump pump preparation
    • Obtain portable sump pumps to backup fixed sump pumps that do not have installed redundant pumps.
    • Verify all fixed and portable sump pumps are working.
    • Verify or provide emergency power for electric motor driven sump pumps that do not have engine driven pump backup.
    • Verify that emergency power circuits for sump pumps will not be exposed to damage by the anticipated flood.
    • Verify sump pump discharge lines have check valves if water backflow is possible when the pump is not running.
  3. Outside preparations
    • Clear flood exposed parking lots and other outside areas of vehicles, trailers, storage, and portable equipment from flood prone areas.
    • Verify outside structures such as fuel tanks, transformers, emergency generators, and cooling towers are anchored to secure foundations.
    • Remove debris and trash that could restrict or obstruct drain inlets, culverts, and road underpasses which carry water drainage away from the site.
    • Close perimeter gates to prevent debris floating onto the site.
    • Sandbag ramps or access ways to basement entrances or loading docks. These ramps and access ways are notorious sources of severe flooding especially when power fails and electric dewatering pumps stop working.
    • Exercise any automatic-closing flood gates to make sure they are ready to operate if needed. If possible, leave automatic gates in the closed position.
    • Install any manual flood gates.
  4. Production process preparation
    • Implement safe and organized shutdown of hazardous processes.
    • Relocate high value or critical machinery, computers, tools, dies, patterns, records, and stock above anticipated flood levels. Raise the exposed materials above the floor, move to a higher floor, or move off site to higher ground.
  5. Fire system preparation: Inspect all fire protection systems to ensure they are in service.
  6. Business data preparation: Backup computer data to an offsite location that will not be affected by the flood.
  7. Construction project preparation: Review construction projects. Protect or relocate equipment and supplies, and temporarily brace new construction.
  8. Emergency supplies preparation: Obtain and store emergency equipment and supplies in a protected location. Equipment and supplies may include emergency lighting; lumber; nails; duct tape; sandbags, sand or more modern alternatives (flood gates); tarps; battery-powered tools; manual hand tools; engine-driven chain saws; nonperishable food and water; two-way radios; portable electrical generators; portable sump pumps.
  9. Staff preparation
    • Personnel safety is the primary concern. Allow no actions to save property that jeopardize the health and well being of personnel.
    • Advise staff of concerns with potential flooding, and procedures to follow if an evacuation is ordered.
    • Apply safe work procedures to all flood preparation work. This includes the use of all appropriate personal protective equipment and electrical safety practices for damp or wet locations.
    • While it is always desirable to maintain appropriate personnel onsite during a flood emergency to maintain care, custody, and control over the site, no personnel should be endangered in this effort.
    • Plan safe work procedures for all actions taken after a flood

Final Steps Before the Flood

If flooding is expected, the following steps should be taken to minimize damage to equipment and to make post-flood recovery as rapid as possible:

  • Make sure all personnel are evacuated from the property before rise of floodwater.
  • Remove as much property and equipment as possible to high ground storage, if available. Move the highest value property first.
  • If time permits, construct flood barriers with sandbags or other materials. Even if these do not hold back flood waters, they may resist flood currents sufficiently to prevent destruction of structures.
  • When flooding is imminent, shut down all fuel burning equipment which is subject to flooding. In the case of steam boilers, it is best if these can be allowed to cool prior to immersion.
  • De-energize all electrical circuits prior to immersion in flood water.
  • Get all vehicles to high ground.

After the Water Recedes

These recommendations are intended to assist in restoring your property and equipment after a flood:

  1. Boilers 
    • Carefully inspect foundations and settings of boilers for settlement. DO NOT OPERATE a boiler if there is any evidence that the foundation has been undermined.
    • Make sure the setting (brickwork, refractory, and insulation materials) is thoroughly dry. Use portable heaters where necessary.
    • All safety appliances, such as safety and relief valves, steam gage, water column, high and low-water cutouts, and blow down must be cleaned and repaired as needed.
    • All controls must be inspected and tested before operation, especially the water level control and low-water fuel cutoffs.
    • Burners should not be fired until checked by a burner technician. An explosion may occur if the combustion controls do not function properly.
    • Boilers should not be operated if proper feed water is not available. If operation is essential, and if feed water contains mud, it will be necessary to blow down the boiler every eight hours and to open and clean the boiler at least once per week until proper water quality is re-established.
  2. Electrical Equipment 
    • DO NOT ENERGIZE equipment which has been flooded until properly cleaned, dried out, and until insulation has been tested. This includes enclosures, bus ducts, conduit, and cables.
    • Windings in electric machinery should not be dried at temperatures exceeding the rating of its insulation system. In general, a maximum temperature of 194 degrees Fahrenheit or 90 degrees Celsius may be used. Check with the manufacturer for equipment specific information and recommendations.
    • Dry type transformers should be cleaned and thoroughly dried as described for windings.
    • Oil filled transformers should be thoroughly inspected for damage and oil samples should be drawn from top and bottom for lab analysis. The laboratory should be instructed to include a Karl Fisher test for water content. Maximum water content is 35 ppm. If water is found in the oil tank, the oil charge must be renovated by a competent service firm.
  3. Before Operating Machinery 
    • Contact the manufacturer for recommendations.
    • Inspect foundations for cracking, weakness, or settlement. If settlement is suspected, check and correct alignment of all shafting, and check all stationary components for level.
    • Inspect all machine internals for silt accumulations and clean as needed.
    • Open the cylinders of all reciprocating engines or compressors and remove foreign material or water.
    • Drain and clean lubrication systems. Wipe oil-containing elements with lint-free rags and refill with new lubricants as required.
    • Carefully clean and TEST governors and controls.

The toll on electronics and equipment continues even after the water recedes. If energized during the event the affected equipment and machinery may have sustained damage to the circuit breakers, in-line fuses, motors and main fuses which may have “blown and shorted” from the initial onslaught of water infiltration. The second onslaught of damage to electronics is “ongoing and continuous” even as the water recedes. Electrical wiring, motors, computers, motor starters, contactors and control cabinets received contaminates from the flood water (ground water and salt water from flooding is very contaminated). This water contains chlorides, sulfides, heavy metals, hydrocarbons, and other biological inhibitors and environmental waste chemicals that are unhealthy, toxic, and corrosive. As the water recedes, the stainless, copper, aluminum, and plain steel substrates of micro-circuitry and electrical components which have been covered in contaminated water continue to oxidize from the contaminates in the water as the oxygen hits the contaminated metallic surfaces which increases corrosion exponentially. Painted surfaces can bubble, pop and peel. All metals can corrode and result in oxidation.

Learn more about flooding and electricity in the post on Emergency Preparedness and Natural Disasters: Floods and Electricity.

Flash rusting and corrosion enhanced by flooding and drying can be adverted with proper mitigation protocols. Fast action is the key to being able to restore sensitive electronics, equipment, and electrical gear. Some items may corrode from the secondary effects of the flooding just by being in non-climate controlled conditions and being exposed to high moisture, meaning relative humidity has reached condensing levels or the dew point has been exceeded and these items have been exposed to much higher levels of humidity than designed. Energizing them without a thorough analysis of the effects of corrosion may result in premature failure.

Equipment Restoration Candidates: if proper dewatering and corrosion control inhibitors are applied:

  • Electrical Gear: Certain transformers, controllers, electrical cabinets, breakers, switch gear and cabinets, wiring, and distribution equipment can be effectively restored and tested. Certain small controllers, case molded circuit breakers, and dry transformers may need replaced.
  • IT Equipment, Computers and Servers: Hard drives that have been immersed in flood water should be stabilized and processed for data recovery. Computers, routers, servers and switches that are subject to high moisture may be restored effectively.
  • Boilers, HVAC and Fire Pump Systems: These are all possible candidates for restoration. Certain devices such as limit switches, burner management control, motor controllers, and motors may need repaired or replaced. Pressure vessels, coils, and pumps will need preservation to ensure they may be restored.
  • Equipment and Machinery of All Types: Including restaurant and food processing, biomedical, elevators, security systems, automated access systems, machine shop equipment ,and PLC and relay logic control panels can be effectively restored but small sensitive items may need to be replaced.

Mitigation Protocol Steps

These mitigation steps are critical if restoration is to be attempted on valuable equipment and machinery and must be employed as soon as safely possible after the site is cleared for entry.

  • De-energize all lock out/tag out power sources
  • Secure and caution tape-off all open access hazards and open panels and install temporary barriers for drying purposes
  • Inspect for hazards and mitigation needs
  • Remove standing water from equipment areas; extract or pump standing water and air wash all equipment interior and exterior surfaces
  • Open all control and cabinets to expose the components and install temporary barriers for drying purposes
  • Rough clean and rinse all gross contamination areas with de-ionized water
  • Air wash all surfaces
  • Apply contact cleaner to circuit boards and low voltage electrical devices
  • Apply corrosion control inhibitors to all electronics and structural components and cabinets

Wires, Cables and Flexible Cords

When any wire or cable product is exposed to water, any metallic component (such as the conductor, metallic shield, or armor) is subject to corrosion that can damage the component itself and/or cause termination failures. If water remains in a medium voltage cable, it could accelerate insulation deterioration, causing premature failure. Wire and cable listed for only dry locations may become a shock hazard when energized after being exposed to water.

Any recommendations for reconditioning wire and cable are based on the assumption that the water contains no high concentrations of chemicals, oils, etc. If it is suspected that the water has unusual contaminants, such as may be found in some floodwater, the manufacturer should be consulted before any decision is made to continue using any wire or cable products.


Have any safety questions or lessons learned stories? We’d like to hear from you! Email us at safetyexchange@brewersassociation.org

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