Introduction
Natural disasters can cause damage and destruction to local water supplies affecting millions of people. Emergency response and recovery protocols are designed to reduce the severity of water and wastewater infrastructure damage and ensure safe drinking water. Water system recovery efforts require preliminary preparations, emergency response procedures, and long-term support. Public safety, health, and welfare are top priorities during emergency response activities. Repairs are extremely costly and include the costs of interim operations, cleanup, and other non-capital expenses. Understanding the risks associated with natural disasters in individual communities allows health officials to respond effectively when local disasters become a reality. EPA is supporting the development of small drinking water treatment technologies to bring timely relief to impacted communities. Research is focusing on household devices, mobile treatment systems, and disinfection processes to protect consumers from contamination in drinking water wells, tanks, and distribution systems.
Water system emergency response and recovery
Water system response and recovery efforts are dependent on the magnitude of the natural disaster. Devastating events encompassing large areas require more coordination between local, State, and Federal agencies than small localized events. Public health and safety response efforts are managed by local firefighters, paramedics, and police. In the case of drinking water infrastructure, natural disasters adversely impact the normal operations of electric utilities, water utilities, and city or county health departments. One way for communities to protect the public and minimize loss is to develop emergency operations, response, and recovery plans. The following section provides a composite summary of actions taken during Hurricanes Andrew (
Murphy, 1994), Hugo (
Shimoda, 1994), and Katrina (
Patterson et al., 2007) that allowed communities to get drinking treatment and distribution systems water in impacted areas back to normal.
Preliminary preparations
One approach to prepare for potential natural disasters is to develop a strategy using “What if”? scenarios. For instance, utilities can:
• Prioritize water systems in areas that are prone to fire, earthquake, flooding, and hurricane damage;
• Develop a matrix of potential hazards and determine the vulnerability of water system components;
• Estimate damage to vulnerable system components;
• Take actions to decrease water system component vulnerability such as capital projects to secure treatment plant processes and distribution system pipelines.
Utilities can setup an active training program and conduct regular training exercises. Training sessions should focus on location-specific development of “What if”? scenarios. For instance, using treatment plant plans and distribution system maps to brainstorm response actions or exploring alternative access routes to water system infrastructure to allow workers to maneuver around floods, fires, downed electrical lines, and fallen trees. Training exercises can also facilitate maintenance and testing of generators, isolation valves, and radio communications. After each training session, utilities should maintain contact information of training program attendees for distribution of emergency response plan updates.
Emergency operations plan
An emergency operations plan provides a utility or a municipality with a contingency plan for natural disasters based on information gathered during “What if”? training sessions. The plan should summarize the actions that are needed before, during, and after a natural disaster to provide a protocol for response and recovery.
The plan should contain a list of organizations and points of contact to provide technical assistance including local, State, Federal and contracted personnel. Written agreements can be set up with other water utilities, contractors, and private suppliers including annual provisions for 24 h access and phone numbers of contacts in case of emergencies.
The plan should provide contingency plans to mobilize a command center with established organizational responsibilities. Planning command center operations in advance ensures efficient response and recovery, public health and safety, regulatory involvement, and communication with the water utility personnel. The plan should include options for command center locations in strategic areas with access to power, water, parking, and communications infrastructure. Delivery of emergency resources can be defined with a matrix of appropriate transportation resources that matches the type and location of emergencies. Utilities can develop equipment and supply lists for water treatment and distribution systems and maintain an adequate supply of water tanks, different-sized portable electric generators, and treatment chemicals. Alternative suppliers should be located to handle shortages in fuel for generators and natural gas for treatment plants. Vehicles should be equipped with global positioning system (GPS) units and accurate up-to-date road maps to public water systems.
The plan should forecast the needs of field assessment crews, laboratory analysts, and accounting personnel. Supply lists for emergency responders can be developed and include health and safety items applicable to local conditions such as drinking water, sun screen, and bug spray. Utilities should identify available mobile laboratories, develop analytical supply lists, and prepare water sampling, monitoring, and analytical protocols. Boil Water advisories can be prepared in advance. Utilities should prepare standardized assessment forms and develop data entry systems with data transfer protocols for assessment information.
To support a sustainable workforce, utilities should be prepared to house homeless utility personnel, coordinate repair of damaged employee homes, and provide cooked food for utility response and recovery crews at the command post and in the field. Utilities should store food for emergencies and restock food stores annually.
When a natural disaster is imminent, many actions can be taken to strengthen water infrastructure and prevent waterborne disease. For instance, utilities can:
• Reinforce exposed facilities such as well houses and pump stations;
• Install shutters on windows and clear loose debris from plants;
• Sandbag critical water and waste water infrastructure such as building entrances and pump stations;
• Over chlorinate water supplies to protect against waterborne pathogens;
• Top off water storage tanks and close main valves in anticipation of water main and hydrant breaks;
• Isolate or shutdown exposed pipe at river crossings;
• Set electric pressure-reducing valves to manual mode.
Utilities can also prepare vehicles, equipment, and supplies for approaching natural disasters:
• Fill trucks with gas and furnish equipment to repair flat tires caused by road debris;
• Add fuel to and test generator-driven pumps at plants and deliver emergency generators to locations missing generators such as well fields;
• Fill fuel tanker trucks with fuel and install appropriate connections to refuel generators;
• Equip trucks with service and repair supplies such as T-handle wrenches;
• Supplement water supply with contracted water tank trucks.
To ensure access to critical information, utilities should secure vital records for use during emergency response. Also, check and secure two-way radios and phone gear for emergency communication. The emergency operations plan is a living document that needs to be updated on a regular basis.
Emergency response procedures
Water utility response during emergencies may require the efforts of three groups; a command or liaison group to direct the response, a field investigation group to identify the cause and extent of the damage, and a treatment response group to make repairs. Emergency response and recovery steps are listed in Table 1.
Effective emergency response communication is critical to the health and safety of the public as well as emergency responders. Emergency responders should notify the media of the location of and phone numbers for the emergency command post and assign management of warnings and advisories to a responsible individual to prevent retrieval of misinformation or inaccurate reports.
Utilities should have contact names and phone numbers for agencies that issue emergency warnings. Emergency response actions are dependent on the type of natural disaster and the conditions in damaged or destroyed areas. However, there are many common response and recovery actions that apply to water infrastructure damage and destruction.
Utilities should line up work crews and set up schedules to repair uprooted, damaged, and broken water and electric lines. Work crews typically repair hospital water systems first. Next, repair crews bring the least damaged water systems back on line to provide potable water to as many customers as possible. Distribution system water quality parameters are monitored for changes in pressure, flow, pH, tank elevation, and chlorine residual to isolate damaged and leaking sections. Repair crews transport generators to broken water mains to begin pumping water to find and repair leaks. Block by block and door to door surveys of water systems are conducted to repair leaks or shutoff service. Repair crews attach spigots to water meters to provide water to residents with damaged household waterlines and set up emergency water stations at strategic locations.
During major natural disasters, assessment and analytical crews are formed to prioritize public water systems by population served, extent of damage, accessibility and access to alternative water and power sources. These crews also assess and manage risks associated with potential exposure to waterborne pathogens and chemicals. Assessment and analytical crews collect and analyze treatment plant and distribution water samples to interpret water quality data for water system clearance by:
• Locating bacteria sample locations with up to date copies of maps and information;
• Reviewing water sampling and analysis protocols;
• Collecting and analyzing chlorine and coliform bacteria samples;
• Locating and distributing generators to minimize down-time and pressure loss to water systems;
• Immediately notifying water system operators with boil water and water system clearance information;
• Providing technical assistance to prioritized water systems following initial assessments.
The assessment and analytical crews also prioritize monitoring of source waters based on the extent of contamination. Source water quality data (e.g. coliform, turbidity, inorganics, organics) is provided to treatment plant operators for acquisition of supplies (e.g. coagulants, polymers, treatment media). These crews also arrange for delivery of chlorinated potable water tanks and mobile water treatment systems to central locations in heavily damaged and high risk areas.
Utilities and emergency response and recovery work crews must keep accurate records to document expenditures for reimbursement and historic recordkeeping. The use of infrastructure assessment forms, videos, and photographs are excellent ways to record damage, ensure follow-up, and document emergency response actions.
Long-term support
After emergency response and recovery, utilities should update the emergency operations plan based on lessons learned. Utilities can also prepare a schedule for long-term technical assistance and repairs. Emphasis should be placed on assessing water treatment and distribution system integrity and evaluation of options for long-term improvements such as dual systems with water reuse and installation of online and remote monitors. Utilities can also prioritize replacement and repair of large items such as storage tanks, generators, and clarifiers.
Emergency response efforts after Hurricane Katrina
In August of 2005, Hurricane Katrina quickly engulfed New Orleans, Louisiana and surrounding communities in one of the largest natural disasters in the history of United States.
This section serves as a case study with a chronology of emergency response efforts (
Patterson et al., 2007). Hurricane Katrina followed a course east of New Orleans through the parishes of Plaquemines, St. Bernard, and St. Tammany dumping eight to ten inches of rain at a rate of 1 inch/hour. The outer bands of the storm produced tornadoes as far away as Georgia. In addition to the direct devastation of the hurricane, levee failures resulted in the flooding of New Orleans that were blamed on strong winds, heavy rains, storm surge, and construction flaws. By August 31st, at least 80% of New Orleans was flooded with some parts under as much as 20 feet of flood water (
Bohman, 2005). EPA staff, fire fighters, police, and other first responders rescued nearly 800 people from the floodwaters (
Zucchino, 2005). Tragically, there were 1080 deaths directly related to Hurricane Katrina in Louisiana (
Zucchino, 2005).
Damage to the Carrollton Treatment Plant
The main drinking water treatment plant for the City of New Orleans (the Carrollton plant serving over 500000 residents) sustained water main breaks, fire, and flooding but was brought back on line due to the diligence of plant employees. One worker braved the storm to shutoff one of six water mains to prevent 40 to 50 million gallons per day of water from leaking out of the distribution system. The high winds and heavy rain drenched, short-circuited and ignited electrical equipment. A team of workers extinguished an electrical fire after the wind blew out a window in the powerhouse. After the levees were breeched, the Carrollton Plant was flooded causing the backup generators to be shutdown. Crews made desperate attempts to prime the boilers both manually and with a fire truck to keep the plant operating. It was not until the plant had enough city power to fire up the boilers that the pumps could draw water from the Mississippi River. By September 11th, operators were disinfecting water at the Carrollton Plant with 90 million gallons per day in circulation (
Brown 2005).
Water system emergency response
A few days after Hurricane Katrina, a multidisciplinary team of EPA emergency response, research, and water program personnel joined forces with local health and environmental officials to help residents gain access to safe drinking water supplies from hurricane-ravaged parishes surrounding New Orleans. The EPA team met at the EPA Region VI Emergency Response Center in Dallas, Texas to prepare for assessment of over 400 public water systems in an effort to restore safe drinking water to Louisiana communities. Vaccinations (Hepatitis A/B and tetanus shots) were provided to participants in need at the EPA Region VI medical facility in Dallas. A two-hour briefing included health and safety training to protect relief workers from risks as shown in Tables 2 and 3.
EPA loaded sport utility vehicles, vans, and trucks with emergency response supplies and drove 9 h from Dalas, Texas to Livingston, LA. EPA responders regrouped at the fairgrounds in Livingston that served as a mobile staging area with available electrical power, phone service, water, and gasoline. The fairgrounds in Livingston (north of Lake Pontchartrain) also provided a centrally-located field headquarters within driving distance of damaged areas. Upon arrival, the group was directed to living quarters at the Livingston Baptist Church Gymnasium.
Small drinking water assessment teams were formed to reach impacted public water systems. The objectives of the assessment teams were to assist treatment plant operators and perform initial damage assessments in the parishes east and north-east of Lake Pontchartrain. Water systems were categorized on the basis of the type of the water system (community, non-community, or transient), severity of damage, need, whether they had been visited already by LDHH, and accessibility considering flooding and loss of infrastructure (electrical power and roads). The assessment teams analyzed water samples for free and total chlorine. For those utilities that could still pump water, total coliform bacteria samples were collected as an indicator of the microbiological quality of the water. EPA provided technical expertise installing mobile diagnostic equipment and on site laboratories that quickly and accurately determined if local drinking water supplies were safe. After testing was completed, results were sent back to the treatment facilities and the LDHH for decisions regarding public health warnings (boil water and clearance information).
EPA used a drinking water system recovery database to compile information on the status of and damage to individual water systems as listed in Table 4. The status codes listed in Table 5 were upgraded as recovery efforts progressed.
Assessment teams worked from dawn until dusk with temperatures in the 90s, high humidity, and plenty of mosquitoes. Each EPA person was paired with an inspector from a State Rural Water Association or with someone from LA Department of Health and Hospitals. The two-person teams visited and assessed public water supplies in the parishes of Ascension, Livingston, St. Bernard, St. Charles, St. Tammany, St. Helena, St. James, St. John, St. Mary, St. Tammany, Tangipahoa, and Washington. Some areas in St. Bernard and St. Tammany had been virtually flattened. Downed power lines and debris were strewn everywhere. Long hours were spent in some areas locating the water treatment systems. In many instances, signs had been blown down or were destroyed. Roads were congested, gasoline supplies were scarce, and cell phone service was sporadic.
In a little over a week, the assessment teams had visited and surveyed over 400 water systems in the areas affected by Hurricane Katrina. Major problems included; loss of power, loss of pressure, no backup generators (as many as 60 generators were requested), and damage or destruction to treatment plants and water distribution systems. Louisiana Rural Water Association (LARWA) in conjunction with EPA and LDHH staged approximately 20 polyethylene water tanks at a central distribution point. When necessary, water was collected from treated sources outside of the damaged areas, chlorinated to 4 to 5 mg/L of free chlorine, and transported to areas of need. Repair and replacement of large items such as storage tanks, generators, and clarifiers were prioritized to streamline the recovery efforts.
Hurricane Katrina was followed by Hurricane Rita and recovery efforts expanded to include over 1000 affected drinking water systems. By November 3rd, 2005, safe drinking water was available to 5 million people. Twenty-six drinking water systems were still under a “boil water” advisory and 59 were inoperable impacting 100000 people. Most of the remaining inoperable drinking water systems were not coming on line due to complete destruction in many areas (
EPA US, 2005d). By October 12nd, 2006, safe drinking water was restored to all areas of New Orleans including the Lower Ninth Ward. However, many neighborhoods went without drinking water for more than a year due to unprecedented damage including a barge that blocked repairs to a major water line (
Picayune, 2006).
Multi-disciplinary emergency response
The early emergency response teams were later joined by a multidisciplinary group of more than 1000 EPA specialists to work on post Hurricane Katrina and Rita activities (
Zucchino, 2005). EPA evaluated flood water sediments, well-water safety, vegetative debris burning, air quality, and other ecosystem restoration activities (
EPA US, 2005e). EPA compiled a list of Katrina contaminants of concern that included;
E. coli, cholera, Hepatitis A/B, tetanus, mold, lead, petroleum products, and pesticides (
EPA US, 2005f). EPA facilitated the removal and management of millions of cubic yards of debris over a 90000 square mile area (enough debris to fill the New Orleans Superdome eight times). EPA collected and properly disposed of more than 3.2 million unsecured or abandoned containers of potentially hazardous waste, more than 439000 electronic goods, and over 360000 large appliances (
Zucchino, 2005). To respond to future natural disasters, EPA designated air and water sampling and analysis, risk assessment, monitoring, restoration of infrastructure, options for management of debris and sediments, management approaches for toxic materials, ecological issues, and building reentry as key aspects of recovery efforts (
EPA US, 2005g).
EPA research on emergency water treatment systems
After natural disasters, the persistence of microbial and chemical contaminants in drinking water distribution systems is a well-documented environmental concern. Loss of electrical power results in loss of pressure in water distribution systems. Without water pressure, contaminated flood water and wastewater can enter damaged water mains. The potential for cross contamination increases during repair of water, wastewater, and utility lines in impacted neighborhoods. Contaminated flood waters can also seep into private and public drinking water wells. There are currently no cost-effective water treatment systems capable of treating every contaminant in drinking water after a natural disaster. Therefore, EPA is studying the individual capabilities of multiple low-cost treatment alternatives and has chosen a multiple barrier approach to protect the consumer.
The US EPA Office of Research and Development has been working with manufacturers of water treatment systems to test, evaluate, and develop commercially-available and innovative filtration and disinfection technologies. Studies on the detection and removal of physical, chemical, and microbial contaminants allow emergency responders to fine tune treatment and analytical techniques and reduce the risk to consumers by providing the best available protection from toxic chemicals and waterborne pathogens in impacted communities and households.
EPA is verifying the ability of treatment devices to protect homes, schools, and businesses in devastated areas. Evaluating point-of-entry (whole house) systems and point-of-use (kitchen sink) devices throughout their useful life provides short-term (for emergency response) and long-term (for community recovery) data on treatment capabilities.
Point-of-use (POU) devices
POU treatment technologies offer a low cost option for treatment of drinking water during emergencies. POU devices have become prevalent and provide clean and safe drinking water to individual homes, businesses, and apartment buildings. POU devices are typically easy to install, use, and maintain and can treat a wide variety of physical, chemical, and microbiological contaminants including metals and pesticides. POU technologies can be installed with ease in remote and devastated areas. These devices are designed to provide a final barrier against contaminated water distribution systems and reduce the risk of waterborne disease outbreaks. EPA has conducted short-term studies on the removal capabilities of water filters using
Bacillus Subtilis as a surrogate for
Cryptosporidium Oocysts (
Muhammad et al., 2008). A wide variety of under-the-sink type POU devices employing combinations of membrane and carbon filters have been evaluated under microbial challenges including the bacteria
B. diminuta and
H. psuedoflava, and the coliphage viruses fr, MS2, and Phi X 174 (
Adams et al., 2008) The POU/POE devices evaluated in these studies showed varying capabilities for the removal of contaminants in water. Some devices showed significant contaminant reductions, but even the best performing technologies had some units from different production lots that showed microbial challenge organisms in their effluents. The POU RO components alone were not absolute microbial and chemical barriers in these studies. EPA is also conducting long-term studies on POU Devices such as under-the-sink activated carbon and reverse osmosis systems as shown in Fig. 1.
Point-of-entry (POE) devices
The American public has become accustomed to water treatment devices in their homes and businesses for removal of drinking water contaminants at the tap. After natural disasters, contaminants from compromised drinking water supplies can enter the body via inhalation and adsorption through the skin during household activities such as showering or taking a bath. POE treatment technologies provide added protection from contaminants in drinking water during all household and business activities. The US EPA Environmental Technology Verification (ETV) Program and NSF International (NSF) have verified the capabilities of several POE systems employing combinations of RO membranes, UV-ozone simultaneous oxidation process, and carbon adsorption for removal of microbial and organic and inorganic chemical contaminants in drinking water (
EPA/ETV US, 2004) (
EPA/ETV US, 2006) (
EPA/ETV3 US, 2007).
Pour-through devices
EPA is evaluating household microbiological purifiers for use in emergencies. Pour-through devices are challenged throughout their useful life including; clean (new), partially clean (50% of life), and dirty (100% of life). EPA is imitating the use of pour-through devices in households and is evaluating their ability to remove arsenic, lead, cadmium, protozoa, bacteria, and viruses from drinking water supplies. For instance, EPA studied the capability of numerous pour-through devices to remove arsenic from tube wells in India and Bangladesh for the Grainger Challenge (
NAE, 2007). EPA is also conducting studies on removal of microbial pathogens using a four-stage pour-through device for household tap water (
Patterson et al., 2010).
Mobile treatment systems
The EPA/ETV Program has collaborated on the development of treatment technologies capable of providing thousands of gallons per day of safe drinking water during emergency situations. These mobile water treatment systems are designed to create potable water from water of unknown quality and can be set up to support hospitals, fire stations, police stations, or other critical infrastructure (
EPA/ETV 3US, 2007). In light of emergency response needs from natural disasters and contaminated water distribution systems, robust, easy to operate, and effective multiple barrier treatment trains are necessary and essential.
ETV and NSF studied the capabilities of a Mobile Emergency Filtration System (MEFS) to decontaminate water distribution systems. The MEFS treatment train is comprised of dechlorination, a centrifuge for solids removal, media filtration with sand and activated carbon, ultrafiltration, and reverse osmosis treatment technologies (
EPA/ETV US, 2004).
EPA, NSF, the Department of Defense (DoD) and the Bureau of Reclamation tested the Expeditionary Unit Water Purifier (EUWP). The EUWP was developed to treat challenging water sources with variable turbidity, chemical contamination, and very high total dissolved solids (TDS) including seawater, during emergency situations when other water treatment facilities are incapacitated as shown in Fig. 2.
The EUWP components include feed pumps, a UF membrane system, a one or two pass RO desalination system with an energy recovery device, storage tanks, and product pumps. It has chemical feed systems for optional pretreatment coagulation and post treatment chlorination. Clean-in-place systems (CIP) are included with the UF and RO skids. Several pilot-scale challenge studies and full-scale field deployment verifications were conducted to evaluate treatment capabilities for the removal of microbials, particulates, and various organic and inorganic chemicals at low and high concentrations (
EPA/NHSRC US, 2008), (
EPA/ETV US, 2009a), (
EPA/ETV US, 2009b).
Disinfectant research
EPA is currently conducting studies on the disinfectant capabilities of chlorine, chloramine, chlorine dioxide, peracetic acid, UV, ozone, hydrogen peroxide, and simultaneous multiple disinfectants. The research objective is to determine the capabilities of these disinfectants to inactivate protozoa (Cryptosporidium oocysts, Giardia lamblia), bacteria (E. coli, B. subtilis), and viruses (MS-2) and to investigate the formation of disinfection byproduct residuals. EPA is conducting advanced oxidation process (AOP) research (combinations of UV, ozone, and hydrogen peroxide) to evaluate the degradation of organic contaminants in ground water supplies. EPA is also conducting studies on the capabilities of powdered disinfectants that can be stored in bulk or in packets to be readily available for emergency response teams after natural disasters. Two powders are combined to form chlorine dioxide for inactivation of microbial pathogens.
Summary
Natural disasters can cause damage and destruction to local water supplies affecting millions of people and can place a tremendous burden on local, state, and national resources. Strategies are in place to effectively manage the daunting tasks required to protect consumers from contaminated drinking water supplies and rectify damage and destruction to public water systems after both large and small catastrophes. Prior to an event, utilities and municipalities can use “What if”? scenarios to develop emergency operation, response, and recovery plans that are protective of public safety, health, and welfare, and that are designed to reduce the severity of damage and destruction. Government agencies including the EPA are planning ahead to provide temporary supplies of potable water to communities during emergencies. EPA is supporting the development of small drinking water treatment technologies to bring timely relief to devastated communities.
Higher Education Press and Springer-Verlag Berlin Heidelberg
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