(503) 823-4288 coalition@nwnw.org

Noise Review Impact Hammer

by Stan Penkin

Noise Review Board Considers Action

As the impact hammer pile driver reverberates throughout the North Pearl at Hoyt Street’s Block 20 project, the Noise Review Board (NRB) met on November 9th to discuss a proposal that would reduce the harmful effects of this antiquated method.

With some 25 to 30 Pearl residents present to offer testimony and support, the board discussed its proposal to delete the exemption of impact hammer pile driving from the current construction noise ordinance and to provide that the use of this method come before the NRB for variance approval. This revision to the ordinance would require that pile driving not exceed 85 decibels, the same requirement as other construction activities. Impact hammer pile driving has been recorded as high as 110 decibels, a level that is harmful to hearing. Faced with that requirement, developers would have to consider quieter methods of pile driving such as the auger cast or to provide noise mitigation.

There was overwhelming support at the meeting for the NRB to move this forward to City council where three votes will be required to revise the ordinance. The NRB will now develop the language of the proposal which is anticipated to be presented to City Council early next year.

While the many opponents of the impact hammer will still have to suffer through the daily disruption of the current activity at Block 20, they are pleased to see progress on this issue that, if passed, will relieve future suffering for others across the city.

December Update: Pile Driving at Block 20 

Following the recent controversy over Hoyt Street Properties’ decision to utilize impact hammer pile driving at its Block 20 project, residents in the neighborhood are relieved that the noise has been somewhat mitigated compared to earlier projects that used the same method. Although the constant hammering remains a nuisance and is not nearly as acceptable as the quieter auger cast method, the foundation contractor, Dewitt Construction, at its own cost employed sound mitigation methods to help reduce the decibel level.

Advocates for quieter, less intrusive pile driving methods were heartened by the Noise Review Board’s (NRB) anticipated proposal to City Council  to delete the exemption for impact hammer pile driving from the current noise ordinance. This revision would stipulate that pile driving not exceed 85 decibels, the same as for other construction activities. The revision would further mandate that the use of the impact hammer come before the NRB for variance approval as it exceeds that level. Impact hammer pile driving has been recorded as high as 110 decibels, a level that can be harmful to hearing. Faced with that requirement, developers would have to consider quieter methods of pile driving such as the auger cast, or to provide noise mitigation that would bring the method into compliance.

The most recent fourteen and upcoming projects in the Pearl District have utilized the auger cast, a method that Hoyt Street Properties chose not to use at Block 20.