City of Albany, NEW YORK
Since the 1930s, the City of Albany, New York, has used the 200 million gallon Loudonville open-air reservoir as a backup for the city’s primary Alcove reservoir. If the Alcove treatment plant shut downs or a water main breaks, the Loudonville reservoir could supply water to Albany’s 100,000 residents for up to ten days.
This system, which uses chlorine disinfection, has served the city well for more than 70 years; but expected changes to federal government regulations regarding both the amount of chlorinated organic compounds, or trihalomethanes, in open-air drinking water systems and the way that these compounds are measured, prompted the City of Albany to look for a more robust method to disinfect its drinking water.
The city evaluated its options and decided to implement an ultraviolet (UV) light disinfection system. After putting the project out to public bid, the City of Albany selected Trojan to provide and install the UV technology. “Trojan had the best package,” says Mr. Bill Simcoe, assistant commissioner with the City of Albany water department, “Their bid was the most economical, and they’ve got a great reputation in the industry.”
The company will install four TrojanUVSwift™ units, which will be located between the Loudonville reservoir and the city distribution system. Collectively, these four units can treat up to 40 million gallons of drinking water per day. As water passes through the Trojan units, ultraviolet light emitted by the lamps inactivates both by-products caused by the chlorination process as well as a wide range of human pathogens including bacteria, viruses, and protozoa.
“We’re being proactive by installing the Trojan system,” says Mr. Simcoe. “It minimizes the use of chlorine, it helps us gain a better overall level of confidence in the disinfection process, and it prepares the city to comply with new federal regulations that are forthcoming.”
Albany will continue to filter and treat water with chlorine, relying on the UV system as a secondary disinfectant to reduce trihalo-methanes - carcinogens that can form when chlorine is added to drinking water. In addition, ultraviolet light also destroys certain microorganisms such as Cryptosporidium and Giardia more effectively than chlorine does. “Ultraviolet light and chlorine offer us the best disinfection combination,” says Mr. Simcoe.
Although hundreds of smaller water supplies use UV systems for disinfection, Albany is among the first large municipalities to employ this technology to protect its drinking water. This trend is expected to grow as cities seek ways to enhance disinfection and reduce contamination risks. The United States Environmental Protection Agency and the New York State Department of Health have both approved UV as a drinking water disinfection technique.
The TrojanUVSwift™ units will be mounted into 24-inch pipes that draw water out of the Loudonville reservoir. By using a few high-intensity UV lamps, these compact units consume little space and will spare the City of Albany from constructing large buildings to house UV equipment.
“Trojan’s UVSwift units are straightforward to install,” says Mr. Paul Bassette, project manager with Malcolm Pirnie Incorporated, an engineering firm that the City of Albany hired to consult on the project. “The process simply requires modifying the piping and adding some controls. Also, with UV there are no additional chemicals on-site, which is always attractive.”
Mr. Bassette worked closely with Trojan during the bidding process. “Trojan provided good technical support,” he says. “They answered all my questions, and they’re up on the regulations and rules for disinfection. They’re a front-runner when it comes to UV technology.”