SENECA FALLS — On Sept. 26, several Seneca Falls Middle School students and a teacher in a classroom where the windows were open reported headaches and nausea.
Their illness likely was caused by sewer pipe rehabilitation work at nearby Boston Avenue. The school is on Troy Street.
School Superintendent Jeramy Clingerman said the teacher didn’t feel well and nine students went home ill. Eight of the nine returned the next day and one still felt ill two days later but has since returned.
Several hundred feet south of the classroom, workers from Green Mountain Pipeline Services were using a Cured In Place Pipeline (CIPP) process on deteriorating sewer lines, part of a town sanitary sewer rehabilitation project in that neighborhood.
The CIPP process involves the use of a polyester and vinyl ester resins impregnated in a felt liner that is inserted into the deteriorating sewer pipe. Styrene, a volatile organic compound, is mixed with the resin to help it harden and cure.
High pressure air and steam are injected to harden the liner. The practice is seen as a quick, effective and less costly alternative to the traditional excavation, replacement of the pipe and restoration of the ground.
The town began CIPP work in late August in various locations across the former village. Selected for rehabilitation were pipes that were in poor structural condition but could be rehabilitated using the trench-less liner.
“The application and curing of the liner system resin results in odors. Typically, odors are localized to the adjacent manholes, but may also be noted inside the adjacent residences if adequate sewer lateral traps and vents are not in place,” said Peter Baker, engineer for the project from Barton & Loguidice Engineers.
Baker note that CIPP work was done to sewers on Porter and Troy streets earlier that week and did not result in any complaints or illnesses.
Prior to starting the CIPP process, a written notification is provided to area homeowners connected to the sewer pipe to be lined, advising them that they may notice odors. Baker said the entire process takes between four and six hours; the odors typically occur within about three hours while the resin is applied and cured in the pipeline.
Baker said styrene is a regulated chemical that has had threshold limits established to provide worker protection. He said studies have been done on the effects of styrene on sewer lining employees and communities.
“The results of the studies indicate that while odors are a common occurrence, the levels of styrene present are below exposure guidelines and do not present a long-term health risk,” he said. “Although concentrations of styrene are below exposure guidelines for workers, individuals have different sensitivities. Styrene odors can be detected at low concentrations and the odors can be considered a nuisance to those not used to working around it.”
The weather also has a role in styrene odors and how they travel. On Sept. 26, there was little breeze or air movement, which would have allowed the odor to dissipate.
During the investigation, representatives of the school district, Baron & Loguidice and the contractor evaluated the conditions that may have caused the incident.
“We believe that a combination of weather conditions resulted in increased odors from the CIPP process. Additionally, the windows in that particular classroom were open during this time frame,” Baker said. “While odors were noted, it was some time after that students and teachers developed symptoms.”
Additional CIPP work will be done over the next two weeks, but none at locations within 1,000 feet of the school. Baker said, however, that future CIPP work may be needed in other areas adjacent to the school.
School and town officials and the contractor have developed an action plan to enhance communications and minimize the risk of future incidents. The plan includes these steps:
• The district will receive all neighborhood notifications handed out for the remaining CIPP work.
• Any CIPP work to be done within 1,000 feet of any school will be performed during the morning when students are more likely to be inside.
• CIPP work will not be performed at night to avoid disturbing nearby residents.
• The contractor will monitor weather conditions and avoid CIPP during stagnant ambient air conditions.
• The school will be contacted at the start of resin application and when resin curing is completed. During that time, it is recommended that classroom windows be closed.
• Air quality monitoring along the school grounds will be performed during these events.
“Barton and Loguidice has been responsive from the very first time we engaged with them about the problem,” Clingerman said. “They are monitoring the air quality in addition to trying to reduce the odors when working near the schools.”
“Our number one priority is the health and safety of our students and staff so we will continue to pay attention to their work and any impacts on the schools,” he added.