Bartrand T.A.,Corona Environmental Consulting LLC |
Clancy J.L.,Corona Environmental Consulting LLC
Journal - American Water Works Association | Year: 2014
Naegleria fowleri (N. fowleri) is a free-living, trophic amoeba that is nearly ubiquitous in the environment and can be present in high numbers in warm waters. It is the causative agent of primary amoebic meningoencephalitis (PAM), a rare but particularly lethal disease with a very low survival incidence. Although N. fowleri was isolated from drinking water supplies in Australia in the 1980s, it was not considered a drinking water threat in the United States until recent cases were associated with a groundwater system in Arizona and surface water systems in Louisiana. N. fowleri in drinking water treatment and distribution systems can be managed using disinfectant concentrations typically encountered in well-run plants although nitrification and attendant low disinfectant residuals may pose a challenge for some systems. The greatest challenge for N. fowleri control is in premise plumbing systems where conditions are largely outside the control of utilities, residuals might be low or nonexistent, and where water temperatures could be high enough to support rapid growth of the amoebae. This article reviews published studies describing the environmental occurrence, survival, pathogenicity, and disinfection of N. fowleri. In addition, this article provides information about this little known and poorly understood parasite with respect to its occurrence in the environment; how the amoeba amplifies in water systems such that it can cause infection; how N. fowleri has been successfully controlled for decades in water systems through treatment and distribution system management in Australia; and the knowledge gaps and information needed to address N. fowleri as an emerging pathogen in US water supplies. 2014 © American Water Works Association.
Jensen V.B.,University of California at Davis |
Darby J.L.,University of California at Davis |
Seidel C.,Corona Environmental Consulting LLC |
Gorman C.,Corona Environmental Consulting LLC
Critical Reviews in Environmental Science and Technology | Year: 2014
Nitrate contamination of drinking water sources has become one of the most important water quality concerns across the United States. Nitrate presents unique water treatment challenges and small water systems are particularly affected by the high costs of addressing nitrate impacted supplies. The goal of this investigation was to provide an overview of nitrate treatment options, highlighting the most recent advances and elucidating costs and common problems in application. No single treatment option is ideal for all situations; new technologies continue to be investigated to effectively remove nitrate while limiting cost and maximizing sustainability. Copyright © Taylor & Francis Group, LLC.