WESTFIELD—The city’s Water Department reported that in November the city did not meet an adequate residual chlorine level in water at the Sackett Street Storage Tank for a period of several hours.
According to a notice issued by the department and accompanying this article, the department “did not ensure adequate contact time” with chlorine or another similar disinfectant for surface water from the Granville Reservoir on Nov. 16 and 17, 2017. Chlorine is used for disinfectant of giardia and viruses, according to the notice.
David Billips, Director of Westfield Department of Public Works.
According to Director of the Westfield Department of Public Works Dave Billips, the water “fell slightly below the threshold,” although chlorine was still present.
“We test the water all the time. It was a formality, basically,” Billips said.
“The most important thing is that the water was tested and there was nothing in it,” Billips added, referring to potentially harmful contaminants.
The water came from the Granville Reservoir, which the department stopped using on Oct. 30, 2017, due to “storm related source water turbidity.”
The reservoir was not utilized again until Nov. 16, 2017, though city wells were being used during that time. The issue occurred following the use of the reservoir.
According to the notice sent, treated water should have a “minimum chlorine residual of 0.2 mg/L.” The water however, was below that for more than 4 hours on Nov. 17, and just under 4 hours on Nov. 16. According to Massachusetts Department of Environmental Protection (MassDEP) standards, the department was to notify them if chlorine is under 0.2 mg/L for 4 or more hours, but this was not done.
The Granville Reservoir on May 17, 2017. (WNG file photo)
According to the notice and Billips, the lower chlorine residual was due to the surface water mixing with well water, which resulted in the inadequate treatment. Billips added that before the water from the Granville Reservoir reached the well water, it was already treated.
The notice reported that no giardia was found in the surface water.
It also stated that the “situation does not require that you take immediate action” and that the city would have notified residents immediately.
The treatment plant made transition to meet the MassDEP standards at 9:20 a.m., on Nov. 17, according to the notice. They will now be looking at the “start-up procedures and equipment needs to prevent future violations and will confer with MassDEP regarding those improvements.”
The full text of the notice is as follows:
Important Information About Westfield Water Resources Drinking Water
In order to ensure proper disinfection of surface water, Westfield is required to: (1) ensure surface water must be in contact with a minimum concentration of chlorine or a similar disinfectant for a minimum amount of time (this is referred to as “contact time”); and (2) ensure the treated water entering the distribution system has a minimum chlorine residual of 0.2 mg/L. We routinely monitor your water for chlorine residual and to ensure adequate chlorine contact time. We use the Sackett Water Storage Tank to ensure sufficient contact time. We measure the chlorine residual after the Sackett Tank to demonstrate compliance with the minimum chlorine residual for the distribution system.
On November 16, 2017, Westfield began use of the Granville Reservoir after ceasing its use on October 30, 2017 due to storm related source water turbidity. Our wells remained online prior to and during the start-up of the reservoir. On November 16 and 17, 2017, we did not ensure adequate contact time for the treated surface water to achieve 4-log inactivation for Giardia and viruses. Subsequent tests performed on samples taken on November 20, 2017 showed no Giardia present in the surface water. The surface water mixed with well water from the distribution system within the tank which resulted in inadequate treatment of the surface water. When the surface water plant is online, the tank would contain surface water with sufficient chlorine residual to ensure all water in the tank is adequately treated. The main valve from the storage tank to the water system was closed to allow the tank’s chlorine residual to rise overnight before serving the City. During this time the water treatment plant and several homes in Southwick received storage tank water with chlorine residual under the 0.2 mg/L standard.
On November 17, 2017, our chlorine residual entering the distribution was below the minimum of 0.2 mg/L for more than four hours. On November 16, 2017, the residual was below 0.2 mg/L for just under 4 hours. When the required chlorine residual is less than 0.2 mg/L for four or more hours, we are required to notify the Massachusetts Department of Environmental Protection (MassDEP). This requirement was not met.
The Treatment Plant made the transition to full operation to meet the surface water treatment standards on November 17, 2017 at approximately 09:20 a.m. The Treatment Plant disinfection helps maintain sufficient chlorine residuals in the distribution system. While it was off-line during early November, measured disinfection residual levels were reduced in the distribution system. Routine distribution bacteria and chlorine residual samples collected on or after November 16, 2017 met applicable standards. We are reviewing Treatment Plant start-up procedures and equipment needs to prevent future violations and will confer with MassDEP regarding those improvements.
This situation does not require that you take immediate action. If it did, you would have been notified immediately. Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. These symptoms, however, are not caused only by organisms in drinking water, but also by other factors. If you experience any of these symptoms and they persist, you may want to seek medical advice.
For more information, please contact Heather Miller, System Engineer, Westfield Water Resources at 413-572-6209. You may also call the Department of Public Works at 413-572-6226.
