Frequently Asked Questions

An expert study determined that two large Induced Draft (ID) fans were rotating at slightly different speeds, contributing to the noise. Synchronizing these speeds was suggested to potentially reduce the noise.

A: To fix the noise from the fans, we replaced the fan motors in February 2024, which successfully reduced the noise. But we didn’t stop there. We also contracted with a third-party sound engineering firm to design a Quiet Fan Technology (QFT) noise control solution, designed specifically to further reduce the sound of the ID fans. The engineering firm also conducted modeling to both analyze the ID fan acoustics and customize the design of noise reducing QFT inserts. Based on this analysis, they designed and manufactured QFT inserts that were custom-made for Reworld™ ID fans.

In early 2025, we researched additional engineering measures targeting noise reduction, finalized an engineering test plan, and engaged testing companies and noise consultants. Based on these external recommendations, we constructed new flue gas transition pieces, and subsequently replaced ductwork fan transition pieces.

The first round of testing was conducted by an independent consultant in December 2023. Subsequent testing has been conducted after completion of the different modifications.

We remain committed to working with the Bristol-Burlington Health District (BBHD) and the community to evaluate noise and ensure we’re addressing their concerns.

Engineering testing in February 2025 led to work including new transition duct pieces being fabricated and installed to improve airflow and reduce acoustic impact. Additional work in March 2025 included a multi-million-dollar replacement of Unit 2’s Spray Dryer Absorber vessel and ductwork. Unit 2’s ID Fan transition piece was also replaced. In April 2025, the same ID fan work was completed for Unit 1.

Please see our update to the BBHD on December 10, 2024 here and a detailed list of all work done through January of 2025 here.

The original installation of the Quiet Fan Technology (QFT) occurred in early June 2024. Additional modeling and analysis by the engineering firm led to an enhanced design for the QFT inserts. This enhanced modification was completed in November 2024.

After completion of the most recent upgrades in 2025, Reworld™ Bristol hired a third-party consultant to measure the noise. The results showed that the noise levels were below the standards set forth in the City of Bristol Code of Ordinances and the state regulations.