The professional noise assessment document submitted by applicants Express Concrete to support their Waterside Way concrete batching plans makes for an interesting read.
It logs current levels of noise at the site perimeter as LA90 48db (equivalent of somewhere between bird calls and quiet suburb/conversation at home: http://www.industrialnoisecontrol.com/comparative-noise-examples.htm )
The concrete batching plant once operational will generate 80db (equivalent of garbage disposal, freight train etc) on an ongoing basis, according to guidance BS5228, although we have been advised that this estimate is on the low side.
It is unclear too whether this estimated noise level takes into consideration the noise of trucks servicing the plant, which will include the following (information taken from a report by planners in Haringey, responding to a request by London Concrete to break planning conditions by increasing the amount of vehicles servicing a concrete batching plant there. Note: 4 of the 5 directors of Express Concrete are previously of London Concrete):
“the main sources of noise from the concrete batching plant are vehicle movements and associated concrete fill operations, particularly as the latter is noisier because vehicle engines operate at fast idle to power the rotating mixing barrel. However, in the appeal decision it was also noted that the vehicle engines also operate at fast idle whilst manoeuvring within the yard. They also need to operate as such at the end of the day or when the mixers were out of service and washed out etc. Other potential sources of intrusive noise and disturbance that would increase as a result of the increase in truck movements would be the use of hammers or drills to dislodge encrusted concrete from the inside of the mixing barrels.”
It is clear from this statement that a concrete batching plant generates a considerable amount of ongoing noise throughout the day. It is also clear from the noise assessment at this spot that current noise levels in this green corridor are slight. Traffic levels are minimal.
Has anyone visited the Hanson concrete batching plant just off Durnsford Road? The noise from operations at that plant is audible as you approach, and includes noise from road sweeping vehicles too, which are not mentioned in the noise assessment above.
Every increase of 3db represents a doubling of sound intensity, so an increase in decibels from 40 (approx current noise level on the Wandle Trail beside the Cappagh parking lot) to 80 (approx minimum level expected from the proposed concrete plant) is the equivalent of a 10,000% increase in noise levels (https://www.engineeringtoolbox.com/sound-intensity-d_712.html).
The Wandle Trail is categorised as Metropolitan Open Land, a Green Corridor, a quietway and part of the Wandle Valley Regional Park, a well-used leisure and commuting route that pedestrians and cyclists are advised to take between Earlsfield and Colliers Wood rather than busy Garrett Lane, Plough Lane, Haydons Road and Merton High Street.
Is it appropriate to introduce a new, noisy, heavily industrial usage to a site that evidence shows is presently quiet during much of the day? Is it even allowed under existing planning policy?
If any members of the planning applications committee haven’t yet walked this section of the Wandle Trail, we suggest you do so to enjoy the peace and quiet while it lasts.