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Water-related Response Activities

Systematic Water Quality Assessment in Rural West Virginia

Systematic Water Quality Assessment in Rural West Virginia

Objective: To assess contamination of groundwater sources used for drinking water for bacterial contamination and heavy metals in rural areas of WV.

Background: More than 15% of America (approximately 40 million people) obtains their water from household wells and springs. In West Virginia, many people live in remote, low density rural communities which limit the feasibility of providing public utilities to homes. While the EPA regulates water in public drinking sources, it does not regulate private drinking water wells that are often used in rural areas. Private drinking wells can be contaminated by leaks from septic tanks; agricultural runoff in the form of animal wastes, fertilizers and pesticides; industrial waste from nearby businesses and dump sites; household wastes; and naturally-occurring pollutants. The public health risk from drinking contaminated water from private wells is not well characterized. This study supports the West Virginia Department of Health and Human Resources (WVDHHR) Source Water Assessment and Protection (SWAP) and Wellhead Protection (WHP) programs, which were developed to protect the state’s drinking water resources. One of the goals of SWAP is to monitor and characterize current ground water quality and quantity. There is also a need to establish residential water well quality information for bacteria and nutrients. However funding for this program is limited.

Methods: Several HSB science staff traveled to West Virginia in August 2010 to partner with staff from the WVDHHR to collect well water samples and test them for biological and heavy metal contamination. Drinking water samples from rural households (approximate sample size 400) using private water wells were collected using a standardized procedure. Samples have been analyzed for basic water quality parameters, radon, total coliform and E. coli, and a panel of 18 inorganic chemicals.

Results: Arsenic, although found in concentrations that exceeded EPA MCL in 10 of the samples collected and analyzed, does not seem to be a widespread problem in West Virginia private wells. The majority of wells tested below the standard with respect to arsenic. Radon was consistently elevated in the majority (75.3%) of the samples analyzed. Although this is consistent with the EPA Map of Radon Zones, which lists much of the state in the moderately to highest potential risk, this study confirms that radon is present in concentrations above the EPA standard for drinking water and a need for appropriate risk management strategies exist. The presence of E. coli or coliform was found in over a third (34.9%) of the samples analyzed, with both being detected in seven samples (4.8%). The samples that tested positive were from all 10 counties originally tested; therefore, the samples could not be correlated back to a single contamination source.

Impact: A sheet of pertinent information specific to the three contaminants of interest was included in the packet of each residence where elevated concentrations of arsenic or radon, or the presence of E.coli and/or coliform was detected. These sheets provided information on the potential sources of contamination in private wells, where to have water tested for the elevated contaminants, and ways to reduce general contamination in drinking water systems. The results of this study will be used to help better quantify the extent and prevalence of contamination in private drinking water systems in West Virginia specifically, but also generally in rural portions of the United States dependent on private drinking wells for potable water.

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Pilot Study to Assess Risk Factors for Well water Contamination after Flooding

Pilot Study to Assess Risk Factors for Well water Contamination after Flooding

Objective: To assess risk factors for well water contamination after flooding.

Background: About 15% of the US population, or nearly 50 million people, obtains their drinking water from sources not protected by the Safe Drinking Water Act, such as private wells. CDC recently reported that the percentage of waterborne disease outbreaks associated with these unregulated sources of drinking water is increasing. Even when well-constructed and maintained, wells are at risk for contamination from flooding. Wells can become contaminated by human pathogens such as Escherichia coli O157:H7, Giardia, Cryptosporidium, and enteric viruses, nitrates from fertilizer, and pesticides applied on nearby lands. There is minimal information about which characteristics of flooding events are the most important risk factors for well contamination. This project looks at contaminants in flood water to assess their potential public health significance.

Methods: In May 2010, Nashville, TN experienced significant flooding following heavy rainfall. HSB staff traveled to Nashville in May to collect 10 floodwater samples, and subsequently in June and August, 2010 to collect well water samples from flooded and non-flooded wells. In April 2011, Kentucky experienced significant flooding. From May 1–4, at team worked with the Kentucky Department of Public Health (KDPH) to collect flood water samples from 4 different affected regions of Kentucky. From July 25–26, a team collected follow-up surface water samples from these same locations.

Results: Tennessee: This study was the first to demonstrate that dead end ultrafiltration (a procedure which involves pumping 100 liters of water through a dialysis-style filter to capture microorganisms) could be used successfully to collect and test flood water samples. We found that flood water was heavily contaminated with total coliforms, E. coli, Enterococcus, and Salmonella. Of the four inundated wells that were sampled, one was heavily contaminated with total coliforms, E. coli, Enterococcus, and Salmonella. This well had been cleaned prior to the flood, but not after the flood. Thus, this suggests the flood water contributed directly to the well water contamination. Kentucky: Further strengthening our 2010 results from Tennessee, we again found that flood water was heavily contaminated; total coliforms, E. coli, Enterococcus, and Salmonella were identified in every sample we tested. All samples also had elevated iron and manganese levels.

Current Status: All fieldwork and laboratory and statistical analyses have been completed for both studies, and each health department received a copy of their respective report. Two separate manuscripts are being written and are currently in progress. Additionally, we presented results to the Kentucky Department of Public Health (KDPH) on September 29, 2011.

Impact: Following our well water testing in Tennessee, we worked with the health department to send letters to all participating homeowners to let them know their well water results and to provide recommendations for cleaning if necessary. The results from both Tennessee and Kentucky fill a gap in the literature about what is in floodwater, and can serve to strengthen current recommendations to limit exposure and take precautions.

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Assistance in state and local response to harmful algal blooms (HAB)

Assistance in state and local response to Harmful Algal Blooms (HABs)

Objectives: To assist states with their questions about and responses to HAB events

Background: In June 2015, EPA published guidance in the form of health advisories for levels of two cyanotoxins in drinking water (

  • Microcystins: The recommended health advisory level is at or below 0.3 micrograms per liter for microcystins in drinking water for children pre-school age and younger (less than six years old). For school-age children through adults, the recommended health advisory levels for drinking water are at or below 1.6 micrograms per liter.
  • Cylindrospermopsin: The recommended health advisory level is at or below 0.7 micrograms per liter for cylindrospermopsin in drinking water for children pre-school age and younger (less than six years old). For school-age children through adults, the recommended health advisory levels for drinking water are at or below 3.0 micrograms per liter.

Methods: HSB provides technical assistance and consultation to public health representatives during a bloom event upon their request. For example:

  • 2014-2015. The State of Ohio Department of Health requested assistance from CDC in preparing for possible microcystin contamination in drinking water derived from Lake Erie. A large Microcystis aeruginosa bloom formed in the lake and was predicted to be worse than the bloom of 2014. The state specifically asked if their recommendation that vulnerable populations (e.g., immunocompromised patients, pregnant women) follow EPA’s new guidelines for exposure to microcystin-LR for children.

    HSB collaborated with NCEZID and EEHS to create a response supporting their recommendation as reasonable since it offers similar guidance to what is offered by EPA (EPA 2015. Drinking Water Health Advisory for the Cyanobacterial Microcystin Toxins (see, page 2). HSB and NCEZID also collaborated to provide assistance in addressing specific uses of water from the public water system, including household use and use in hospitals, restaurants, and other venues.

  • 2015. The National Parks Service (NPS) in Nevada requested assistance in addressing the public health effects associated with a cyanobacteria bloom in Lake Mead. The bloom was an unusual event likely driven by the long regional drought. HSB provided materials from the Harmful Cyanobacteria Tool Kit (See and participated in outreach and education with the public and medical communities. HSB also assisted consolidating bloom-related illness surveillance by creating a process to collect all reports of bloom-associated health symptoms in one place.

Current Status: HSB has developed public information tools for partners to use in during cyanobacteria harmful algal blooms. HSB scientists contribute to CDC and state newsletters, including CDC’s A Drop of News, describing the public health activities associated with the HAB in Grand Lake St. Marys, Ohio in the summer of 2011.

Impact: HSB’s technical assistance and outreach and educa materials increas states’ capacity to address HAB events and protect public health.

More information about Cyanobacteria and Algal Blooms

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Evaluation of health communication messages designed to prevent illness and injury after flooding in Iowa

Evaluation of health communication messages designed to prevent illness and injury after flooding in Iowa

Objective: To assess the effectiveness and preferred sources of health messages communicated to the public following the disaster.

Background: During June 2008, heavy precipitation and 500-year flood events resulted in the displacement of thousands of families throughout Eastern Iowa.

Methods: Three hundred and twenty-seven households were surveyed in four counties hit hardest by the flooding. A 48-item questionnaire containing items on demographics, housing, health information sources, and eight specific health issues was administered. Almost all participants (99.0%) received information on at least one of the health topics covered by the survey. Most participants received information regarding vaccination (84.1%), mold (79.5%), safe use of well water (62.7%), respirator use (58.7%) or stress (53.8%). Television (TV) was the primary (54.7%) and preferred (60.2%) source of health information for most people, followed by the Internet (11.0% and 30.3% as source and preference, respectively).

Results: Public health messages were received by a wide audience in the flood-affected communities. Along with more traditional health communication channels such as TV, radio, or newspapers, continued emphasis on the development of health information Websites and other technological alternatives may result in useful and effective health communication in similar situations.

Impact: New health messages were communicated to the public targeting health topics and populations where need for additional information and clarification was identified. The lessons learned will provide guidance for effective health communication efforts following other disaster settings.

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Exposure to polluted drinking water: The body burden of environmental contaminants in a vulnerable population, Addis Ababa, Ethiopia

Exposure to polluted drinking water: The body burden of environmental contaminants in a vulnerable population, Addis Ababa, Ethiopia

Objective: The objectives of this study were to be as follows: 1) to characterize trace metal exposures among residents of the Akaki-Kaliti sub-city; 2) to compare trace metal exposures between residents of the Akaki-Kaliti sub-city to residents of a nearby region that lacks direct exposure to water from the Akaki River; and 3) to provide the Ethiopian Federal Ministry of Health with information to assist in making regulatory decisions regarding discharge into the Akaki River.

Background: The Akaki River in Ethiopia flows from north to south and passes through the densely populated residential, commercial, and industrial areas of Addis Ababa, the Ethiopian capital city. The river is potentially polluted by various discharges from tanneries, breweries, wineries, battery factories, and slaughter houses. These pollutants are discharged directly into the river either before or after partial treatment. In addition, domestic wastewater, human excreta, and surface run-off contribute to Akaki River pollution. As a result, high concentrations of metals (arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel), nitrates, coliform, and other pathogens have been found in the surface and ground water and its surrounding soil.

Despite its bad odor, black color, and potential toxicity, the river is still used for various daily activities, including laundry, bathing, swimming, irrigation, and drinking. One population particularly at risk is the Akaki-Kaliti sub-city. Located about 25 km south of Addis Ababa, Akaki-Kaliti residents are directly subjected to the various pollutants discharged into the river from central Addis Ababa. However, no health impact studies of exposure to the Akaki River have been conducted. Thus, the MOH is without the information needed to justify and guide interventions.

The Ethiopia MOH originally requested assistance from the Health Studies Branch, NCEH, CDC in February 2010 to assess the body burden and health effects of exposure to the Akaki River water. Due to various logistical problems in Ethiopia, the investigation was delayed until spring 2011.

Methods: From June 24-July 7, 2011, the HSB team collected questionnaire, drinking water, urine, and blood samples from 100 community members who lived in close proximity to the Akaki River, and 50 community members who lived further from the Akaki River to help assess the body burden and health effects of exposure to water from the Akaki River among residents of the Akaki-Kaliti sub city.

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