Thursday - February 13, 2014

Disruptive activities at Water Treatment Plant last week

The Lake Oswego Tigard Water Partnership project team apologizes for the disruption and inconvenience experienced by water treatment plant (WTP) neighbors during the sheet piling installation last Wednesday and Thursday.

We understand construction activities are disruptive. However, this day and a half of noise and vibration from the sheet piling was the worst out of the roughly 110 days of construction to date.

The piles were part of a “shoring” method which is commonly used to protect and support existing structures in close proximity to new excavations. The use of an “impact” hammer to drive the piles is prohibited by the project’s conditions of approval, issued by the City of West Linn, as it tends to be more disruptive to neighbors. As an alternative, the contractor’s engineer recommended the vibratory installation approach to installing the sheet piles, which is permitted within the conditions of approval.

The project team received numerous calls and emails from frustrated neighbors. In response, a representative from the Partnership visited neighbors near the site and provided neighbor feedback to our contractor. Unfortunately, the storm also meant that many more families were home due to school and work closures and made it difficult for people to leave or take a break.

Although an email construction notice describing the planned new sheet piling activity and its potential impacts was sent on January 24 and this work was also discussed at the bi-monthly neighborhood meeting on Tuesday February 4, the intensity of the noise and vibration was not anticipated. Going forward, we will endeavor to provide the most accurate and descriptive updates based on the information we have at the time. We also encourage neighbors to read the email updates, attend the bi-monthly meetings, call for the latest information or visit the information kiosks at the site, as construction schedules can change.

The results from the vibration monitors located at the two neighboring properties are available online here. The data indicates vibrations well below thresholds for residential damage; however, we acknowledge that neighbors experienced something intrusive and disruptive. We will have copies of the report available at the next bi-monthly neighbor update meeting on Tuesday, February 18.

Our goal is to avoid a repeat of this event and we are working closely with our contractor to explore other shoring methods to reduce the vibration experienced last week by neighbors.

If you feel that you have experienced property damage as a result of this work, please call Scott Matthew at the City of Lake Oswego on 503-635-0220 or email to discuss the claims process.