When you see white plumes being blown out of big industrial stacks, many people will assume that’s Air pollution, and along with Water pollution and Noise this can lead to concerns and justifiable questions. Certainly the large white plume from behind the Finishing department can be seen for some distance, but it is only one of many emissions that we actively manage. The Finishing plume is from the extraction unit that captures fumes from our anodising process, which it then passes through a large water scrubbing unit that takes out any contamination before jetting a harmless plume of warm moist air out into the atmosphere. In fact, when the extraction unit was installed in 1996, the scrubber was not legally required, but Martin-Baker considered it necessary for the environment.
Another change you may have noticed is the number of “new” white plumes that have appeared from stacks around the site. These are evidence of new very high efficiency heating appliances that we now specify when replacements are required.
Water pollution uses a term of “mobility” and it relates to how fast and how far a substance is likely to move through the ground. Heating oil, which we require, is regarded as being Highly Mobile.
As we all know, water (and pollutants) will pass quickly through certain ground especially Alluvium and river gravel. This extends all the way under the Denham site and underneath all this is one of the largest layers of Chalk in the South of England. Chalk holds water which eventually comes out of your tap, so we all have a vested interest in preventing water pollution and there are comprehensive arrangements in place to stop this from happening.
All of our chemical tanks, waste areas and stores are protected with outer bunds to contain anything that may leak, as are all the heating oil tanks, and any underground pipes have been replaced with over ground pipes in case of leaks.
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All the connecting pipe work to our waste Chemical tanks is doubled skinned i.e. one pipe inside another, so leaks or a break will be contained, and every three weeks we inspect the site to check for any signs of problems, which includes a check on the noise we make! There is even a special shut off valve fitted to the sewer in case anything gets into it that may endanger people working in sewers downstream of us or, perhaps worse, completely stop the local sewerage works from functioning!
As a matter of routine, all Finishing staff who use chemicals (and some other volunteers) are trained in Finishing Procedure F34 which deals with chemical spills, how to neutralise them and how to prevent chemicals gaining access to the environment or into the public water system. All of these have to prove their understanding of the procedure by achieving an 80% pass mark on a 12 question exam. Operators are also trained in practical methods of containing potentially dangerous chemical spillages.
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The shape and size of a zone depends on the condition of the ground, how the groundwater is removed, and other environmental factors. When we define a zone we find out how the groundwater behaves in that area, what constructions there are to get the water out into the public water supply, and the process for doing this. From this we can develop a model of the groundwater environment on which to define the zones. We divide groundwater source catchments into four zones as follows:
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Any pollution that can travel to the borehole within 50 days from any point within the zone is classified as being inside zone 1. This applies at and below the water table. This zone also has a minimum 50 metre protection radius around the borehole. These criteria are designed to protect against the transmission of toxic chemicals and water-borne disease.
The outer zone covers pollution that takes up to 400 days to travel to the borehole, or 25% of the total catchment area – whichever area is the biggest. This travel time is the minimum amount of time that we think pollutants need to be diluted, reduced in strength or delayed by the time they reach the borehole. |
The total catchment is the total area needed to support removal of water from the borehole, and to support any discharge from the borehole.
Sometimes, we define a fourth zone. This is usually where local conditions mean that industrial sites and other polluters could affect the groundwater source even though they are outside the normal catchment area.