E. Coli
Water Quality Products
May 2003
Danielle Duclos
This article provides a general overview of E. coli and drinking water as well as current and emerging monitoring and decontamination technologies.
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Chlorine Residual Boosting in Distribution Water: Problems with Chlorine Application and Disinfection Byproducts - Part 1
Water Engineering & Management
April 2003
Shin-ichi Tokuno
Previous research on the boosting of chlorine residual1 included how to increase low levels of chlorine disinfectants (free and combined chlorine) in the distribution system. Simple bench tests using a pocket photometer showed that there are no problems in boosting the low level of chlorine residual when boosting the same disinfectant to the water (e.g., free chlorine to free chlorine, or chloramine to chloramine). In the boosted chlorine residual, there is no significant instability in decay or dissipation during the time needed (72 hours) after boosting for the small utility distributors.
Impact of Mixing Chlorine and Chlorine Dioxide on Total Trihalomethane Formation - Part 1
Water Engineering & Management
August 2002
Douglas Rittmann, Ph.D., P.E., and Anthony Tarquin, Ph.D., P.E.
Two rules in 1986 amendments to the Safe Drinking Water Act are challenging many water utilities to meet stricter water quality requirements. The Surface Water Treatment Rule (SWTR)2 and the Disinfection?Disinfection By-Products (D-DBP) Rule3, are requiring utilities to implement more advanced technologies in water treatment. The Surface Water Treatment Rule emphasizes the need for utilities to meet minimum levels of disinfection for surface waters, whereas the Disinfection/Disinfection By-Products Rule limits the disinfectant byproducts. Therefore, utilities will have to implement a treatment approach that balances the benefits of disinfection against disinfection byproducts.
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Advanced Technology Brings the Power to Chlorine Dioxide
Water Quality Products
May 2002
Michael Cochran, Engelhard Corp
Chlorine dioxide is an extremely effective and powerful biocide that has been used for many years as a bleaching agent and slimicide in the pulp and paper industry, as a disinfectant in municipal water treatment and in many other industrial water treatment operations. However, significant capital and operating costs have limited the use of chlorine dioxide to large-scale applications. New technology now makes it practical to use the biocide in a wider range of water treatment applications.
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Effects of Recharge of Chlorinated State Water Project Waters to Groundwaters in Lancaster Area of California
Water Engineering & Management
April 2002
Hisam A. Baqai, P.E., G.E.
As the population in Southern California increases, more and more demands are being put on the state’s groundwater resources, further exacerbating the overdraft problem. Many communities in Southern California are recharging their aquifers with imported surface waters to combat this problem. The major recharge normally is carried out during wet weather periods when surface water is plentiful. However, recharging these groundwater aquifers with imported surface water can create the potential for water quality degradation. The problem can start when surface water is disinfected with chlorine to prevent biofouling and remove pathogens.
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Chlorination and Its Alternatives
Water Quality Products
March 2002
By Anne Penkal and Nadia Abboud, Severn Trent Services, Inc.
Purification of drinking water containing microbiological contamination requires some form of disinfection treatment to kill or render microbiological organisms harmless.
Of the available disinfection treatment methods for private water systems, chlorination in the most commonly used.
Chlorine Taste in the Customer’s Drinking Water?
Water Quality Products
March 2002
By Ron Grage, Chlorinators Incorporated
Chlorine produces bacteria-free water and eliminates algae and slime. It also removes hydrogen sulfide from ground water (wells and springs) and eliminates iron bacteria (cenothrix), which are associated with objectionable odor and taste.
Despite these important facts, some people still object to chlorine in their drinking water. Comments such as “I don’t like the way chlorine makes my water taste” are common.
Consider the Source
Water Engineering & Management
February 2002
Bill Swichtenberg
A report released by the Environmental Working Group (EWG)
and U.S. Public Interest Research Group (U.S. PIRG) has taken aim at
chlorination byproducts (CBPs) in tap water. The group‘s assessment
states that more than 100,000 women are at elevated risk of miscarriage or
birth defects because of CBPs in tap water.
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Tablet Chlorination Systems Allow Plants to Meet Stricter Government/Insurance Regulations
Water Engineering & Management
May 2000
The Fort Valley municipal water plant had used chlorine gas cylinders for many years. A pair of one-ton cylinders were in operation at the wastewater plant and 150-lb. cylinders at the McLeon and Jones water plants. However, new government and insurance regulations forced management to reevaluate its chlorination strategy.
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