Community sound levels associated with Allianz Field

Abstract

Allianz Field, a 20 000 seat outdoor stadium in St. Paul, MN is the new home of the Minnesota United Loons MLS team. At the start of the project, community ambient levels were initially measured near three residential areas for the environmental review process. Although exposed to noise from a nearby interstate highway and arterial roadways, sound levels were within Minnesota noise standards. Following completion of the stadium, updated background readings were taken to reflect changes in three years since the initial ambient levels were measured. Sound levels were then monitored during the first night game at the venue. Readings showed that crowd level barely exceeded ambient levels and were below the Minnesota standards. Stadium sound system levels were not audible. An evaluation of the potential noise impacts from predicted concert noise was then prepared. While a database of maximum mix levels at 100 feet from various groups was available, these values had to be converted to L10 levels governed by the state standards. Examination of the time history data for selected events provided needed conversion from mix peak to L10. Concert levels projected at the three original monitoring locations show some initial standard violations. Calculating backward in the prediction process showed that concerts with a mix level of 90 dBA would be in compliance with daytime standards while a mix limit of 80 dBA would suffice for late evening performances.