Page 20 - pipeline.pdf

Reinstatement of Agricultural Subsoils

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Full biological reinstatement of the subsoils is likely to cost upwards of £5/m in
addition to the costs for the physical re-pulverisation processes – this is because
there needs to be a comprehensive set of site wide subsoil sampling and
laboratory testing undertaken before any stabilisation commences. This is
necessary to establish baseline parameters for the pH levels as well as the key

nutrient indicators such as Potassium, Nitrogen, and Magnesium.

Rapid biological reinstatement often involves the addition of a synthetic ‘re-
agent’ chemical, (such as Iron Sulphate), to the re-pulverised stabilised
materials. Water is then added to dilute the highly acidic re-agent – thereby
neutralising the elevated pH. This process is relatively easy to illustrate in a test
tube either in the laboratory or on site but in general the specialist companies
who promote this technique may not be willing to offer a cast-iron guarantee
over the reinstatement results – and those who will tend to offer such a
guarantee work within ‘phoenixed’ companies which may have left behind
unsuccessful reinstatements on previous projects.

From a commercial perspective rather than paying £5/m to try and offer some
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degree of guaranteed biological reinstatement it may be more cost effective to
compensate the landowner for the potential effects of the elevated pH levels at
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a cost of £1 to £2/m or as compensation to allow the longer term natural
reinstatement process to be realised, as detailed on the following page:-