A minimum reduction of 5 decibels is acceptable whereas a reduction of 10 decibels, or more, is preferred. Care and considerations are to be given to the economic, technical and administrative feasibility of each sound attenuation feature.
Noise Reduction and Sound Attenuation can be achieved by several methods depending on feasibility:
Berming of earth at the rear of lots is an acceptable method of reducing noise levels. The maximum height for earth berms is 3.00 meters above the rear lot grade as calculated before implementation of the earth berm. The earth berm should have a 1.0 meters level area for a fence to be situated on, if required. Care is to be taken into account for any possible drainage issues relating to the implementation of such berms.
Berms may be permitted to be centered on the rear property line so that ½ the berm is located within the road right of way. This situation will be addressed on an individual basis or as governed by Alberta Transportation, if applicable.
Fences are an acceptable
method of reducing noise levels. Fences can either be constructed out of wood or
concrete. Wood fences generally have a life of 10 years whereas concrete have a
20+ year life span. Wood fences
should be limited
to 2.50 meters in height above grade. Concrete fences can be upward to 5.00
meters in height, however care should be taken as to the structural integrity
including wind loads, cost feasibility and architectural aesthetics of such
fences.
Depending on the noise reduction required and existing grade issues, a combination of both a berm and fence may be used. Design criteria and issues are outlined in each specific entity.