City water exceeds chemical limit

Officials say levels are not a threat to public

TROY, N.Y. » City officials will soon send out a public notification informing residents that a small portion of the city’s water system was found to exceed the state’s limit for total trihalomethane.

According to quarterly water sampling results, the city’s water system exceeded the drinking water standard for TTHMin certain limited locations. The state regulation limits annual averages of TTHM’s at 80.0 ug/l. The annual average of the sample location on Project Road was 81.6 ug/l.

Trihalomethanes are a group of chemicals that are formed in drinking water during disinfection when chlorine reacts with naturally occurring organic material (e.g., decomposing vegetation such as tree leaves, algae or other aquatic plants) in surface water sources such as rivers and lakes.

Some studies suggest that people who drank water containing trihalomethanes for long periods of time (e.g., 20-30 years) have an increased risk of certain health effects.

In the notification city officials said that the slightly high level is not alarming, but they wanted to still inform the public and make them aware of the situation and what is being done to fix it. Department of Public Unities Superintendent Chris Wheland said that this the first time that the city has gone over a state limit like this.

City officials believe that a possible cause could date back to May 2017, when the city’s Department of Public Utilities was completing an upgrade to a treatment system that helps reduce the byproduct TTHM. As this system was inoperable for the month, the TTHM result was elevated during that quarter.

“We went over the 80 limit number to 81.6, which is nothing huge, but it’s something that triggered the violation with the state, so as part of the law we have to send out public notice to everybody and that’s what we’re in the process of doing,” Wheland said. “We didn’t violate the rule until this past quarter.”

The public notification says that the system shutdown in May 2017 was required to correct a chemical storage concern. The Department of Public Utilities is not planning any maintenance of critical systems that would adversely affect water quality – although emergency shutdowns are sometimes required.

“We’re not shutting that system down, we’re continuing our maintenance on the water treatment system as needed, we’re being very cautious about our key component that would reduce TTHMs and also continue the disinfecting of the water as required,” Wheland said.

Officials said TTHM’s are formed when chlorine reacts with organic material. In August 2017, the total organic material (TOC) sample yielded a result of 2.3 mg/l compared to the 2016 result of 1.8 mg/l.

“That average hasn’t gone over past 80, until this past quarter it did,” Wheland said, while noting that the level is back to normal already. “This is the first time that we’ve ever done this, so it’s more of investigating why it occurred and what procedures are we going to put in place to try to prevent it in the future and that’s what we’ve done…. So it’s more of procedure review on our side to make sure it doesn’t happen again.”

Officials said the water provided to the Project Road sample site comes from the five million gallon storage tank located on Peterson Court. As such this tank is in the planning phase of repainting, with completion anticipated in 2018. As part of the project an aeration system may be installed. Aeration has been successful at reducing TTHM’s by up to 50%. TTHM’s are volatile and easily released from water with the use of aeration.

“The city of Troy is constantly in contact with Rensselaer County Health Department and the New York State Health Department on samples taken and results of these samples. This provides information that can be used to implement new technologies that better water quality and promote sustainability,” part of the public notification published on the city’s website reads.

The notification is available online to read at troyny.gov.

Anyone with questions regarding this situation is asked to call the city’s Department of Public Utilities at (518) 237- 0319.