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  • 2016 Cyanobacteria Update

    September 8th, 2016 by Eileen Pannetier


    We are seeing more and more cyanobacteria in New England these days. While levels have not risen to those in California as described by NPR, it is an increasing threat as waters get warmer and in drier conditions like we’ve had this summer. While the NPR report is disturbing, there are things that can help prevent or at least minimize the threat to surface waters.

    What can you do? To learn more, see our compilation of information on cyanobacteria here. CEI has assisted a number of municipalities across New England in setting up a threat prevention/reduction and monitoring program. Let me know if we can be of service to your organization! 

  • Harmful Algal Blooms, Cyanobacteria and Cyanotoxins

    August 5th, 2014 by Eileen Pannetier


    Most communities deal with harmful algal blooms (HABs) and their impacts on recreational activities through pond and lake warnings and closures. HABs have been known to cause fish kills and pet deaths, as well as making people sick from swimming in cyanobacteria laden water. In some cases, HABs are so extensive that they can cause disruptions to drinking water supply, as occurred in Toledo, Ohio in August 2014. 

    HABs are formed by cyanobacteria, also known as blue-green algae but are actually photosynthetic bacteria. Their primary season runs from June to September, although they can survive all winter in reduced capacity, returning to thrive in warmer temperatures. Since temperature and nutrients, including nitrogen and phosphorus, seem to be a driving force for growth, the increasing water temperatures occurring with climate change and higher levels of stormwater runoff from increasing urbanization of water supply watersheds may exacerbate the problem. Cyanobacteria occur in fresh, brackish and marine waters and thrive in nutrient rich warm waters. When cyanobacteria concentrate, they increase to form HABs at which point they cause aesthetic color issues and may produce taste and odor compounds such as geosmin and methyl isoborneol (MIB) and dangerous cyanotoxins.

    Water Supply Disruption in Toledo, August 2014

    The fear in Toledo is that the cyanotoxins, produced by cyanobacteria, may have not been removed by conventional treatment facility including filtration and entered the distribution system. Recent advances in the ability to detect lower levels of cyanotoxins and epidemiological studies examining cyanotoxin effects on human health have heightened concerns. Cyanotoxins can cause a range of human health issues such as liver and kidney damage, neurological damage, gastrointestinal issues, and tissue damage. The risks for drinking water supplies is not well known, but likely depends on the treatment process as well as how “slugs” or mats of the cyanobacteria are handled when they enter the treatment facility. 

    Current Regulatory Status

    Cyanobacteria produce numerous types of cyanotoxins. The cyanotoxins are produced and contained within growing cyanobacteria cells. Generally, release of cyanotoxins occurs during cell death and lysis, however, some types of cyanobacteria release cyanotoxins as a soluble exotoxin in the raw water during growth if light conditions are poor. Research into the frequency and effects of these toxins is ongoing. However, it is generally thought that microcystin-LR is the most frequent and probably most toxic of the microcystins. The United States Environmental Protection Agency (USEPA) now encourages awareness of cyanobacteria in drinking water, and has funded studies examining cyanobacteria and associated health effects caused by cyanotoxins. As a result, the USEPA currently lists three cyanotoxins on the Safe Drinking Water Act’s Contaminant Candidate List (CCL3) and Unregulated Contaminant Monitoring Rules (Anatoxin-a, Microcystin-LR, and Cylindrospermopsin).

    New England Cyanobacteria Assessment

    Although some water systems are all too familiar with the challenges associated with taste and odor issues caused by some cyanobacteria, concerns about human health effects are more recently coming to light. In an effort to determine the magnitude of the cyanobacteria and cyanotoxin presence in New England drinking water supplies, Comprehensive Environmental Inc. (CEI) conducted an initial assessment on cyanobacteria and microcystins removal at four New England water treatment facilities. CEI is a progressive civil and environmental engineering consulting firm, striving to stay ahead of issues affecting our industry. Through these efforts, we provide our clients with the highest level of service and potentially pass on new information to the drinking water community. For this initial assessment, CEI collaborated with the University of New Hampshire, Center for Freshwater Biology and four New England drinking water systems to determine (for the first time) whether cyanobacteria and microcystins (liver toxins produced by many species of cyanobacteria commonly found in New England) are effectively removed through water treatment processes.

    The most effective approach to keeping cyanotoxins out of the water supply is watershed protection and management. Water suppliers are encouraged to develop a monitoring plan for cyanobacteria as well as preventative actions. By preventing cyanobacteria growth within the drinking water supply, operators will not need to rely on treatment removal methods. Water resource protection and management methods involve limitation of nutrient loading from surface runoff and erosion, stormwater discharge and wastewater discharge.

    CEI is a leader in the fields of watershed management and water treatment. For more information on HABs, cyanobacteria, cyanotoxins and their control, download the report on our study Cyanobacteria: Initial Assessment of New England Water Supplies or contact Kristen Berger, P.E., Project Manager at 1-800-725-2550 x399 or kberger@ceiengineers.com.

  • Arsenic In Drinking Water

    April 7th, 2014 by Eileen Pannetier


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  • Manganese in Drinking Water – Budgeting for Treatment

    February 13th, 2014 by Eileen Pannetier


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