1. Define an acoustic zoning, delimiting of the acoustically classified zones, which in turn can be classified as Mixed or Sensitive, according to the Law;
2. Identify the conflict areas – areas where noise level are above the legal limits – defining priorities for action;
3. Identify who is the entity responsible for the noise sources which cause de excess levels in the classified areas;
4. Quantify and rank the contributions of different noise sources to the excess levels, grouped by responsible entity, and quantify the population exposed to the high noise levels;
5. Study appropriate noise abatement measures for each situation, both four sources under the direct responsibility of the municipality as for others, and schedule its implementation for a time horizon of 5 years – time horizon defined for the MNRP.
Characterization of the municipality and its noise sources
Municipality of Póvoa de Varzim
Located between rivers Cávado and Ave,
on the north coast of Portugal
Total area: 82,1 km²
3.035 persons//km², in the main urban area
355,5 persons//km², in suburban and rural areas
Noise sources responsibilities:
• Municipal authority: municipal roads and all the streets in the city and villages of the municipality;
• E.P. - Estradas de Portugal (national road public company): all national roads and complementary access roads;
• Euroscut Norte (private motorway company): motorway A28;
• Metro do Porto (surface metro company): line B of the surface metro;
• Several private companies: industrial noise
Major noise sources and urban agglomerations in Póvoa municipality
Sensitive zone: exclusively residential or for schools / hospitals or for sensitive leisure activities
Mixed zone: with sensitive receivers but mixed with others uses, such as commercial, services or industrial Noise limits: 55/45 65/55 Isolated Receivers mixed/sensitive - - Industrial Zone 55 65 Sensitive Zone near a large transportation infrastructure 45 55 Sensitive Zone 55 65 Mixed Zone L n dB(A) L den dB(A) Noise Zone Classification Classification and delimitation of mixed and sensitive zones, based on actual or planned land use
Municipal Noise Reduction Plan Areas and population exposed to road noise separated by responsibility
Municipal Noise Reduction Plan Areas and population exposed to rail noise and to industrial noise (industrial areas A, B, C, D) Clearly road traffics noise has the largest values of population exposed
Substantial reduction of number of people and total area exposed to levels in excess of more than 5 dB(A)
example: reduction of 71% on number of people exposed to more than 70 dB(A) of Lden.
More moderate reduction for number of people and area exposed to excess levels of less than 5 dB(A)
Just below legal limits for mixed zones it is observed a slight increase in number of persons exposed, basically due to people who were exposed to higher levels and moved to this noise class. In the exposed areas a consistent reduction is expected.
The Municipal Noise Reduction Plan presented in this paper was one of the first to be done in Portugal.
For such a Plan to be successful, the acoustic consultancy team must work together and very close to the Municipality staff, from Departments of Environment, Planning, Traffic, and the political level should also be involved to some extent.
The results show that the Plan, although not solving all noise problems in the municipality, will definitely have a positive impact on the reduction of noise levels and on the number of people exposed to the highest noise levels.
A weak point in the Plan is the lack of definition of the measures to be taken for some of the major roads in the municipality, which are managed by entities external to the municipality.
It is recommended that in future similar situations more effort is put in trying to involve in an effective way all entities with responsibilities over noise sources with impact within the municipality.