Tuesday, 26 April 2016

Nutrients - a constant battle on the East Devon Pebblebed Heaths

Why did Aggregate Industries ever think it could bring hundreds of thousands of tonnes of farmland material to an internationally important area of habitat that has been battling against nutrients for years? And it has been years:
East Budleigh-based Clinton Devon Estates (CDE) says the heathland, opened to the public by Lord Clinton in 1930 and under the stewardship of the East Devon Pebblebed Heaths Conservation Trust, is under threat.
'Invasive' trees and shrubs, like the purple moor grass, have spread due to a build up of soil nutrients over 50 years.
These aggressive plants prevent more diverse plant and animal life from getting a foothold, making vast tracts of land virtually inaccessible to the public.
CDE director John Varley said: "The East Devon Pebblebed Heath is more than 250 million years old, but over the last 100 or we have let it go somewhat."
Natural England have carried out assessments of the condition of the heaths and concluded that they are mostly in an unfavourable recovering condition. The main problems for managers of the heaths stem from natural processes of succession, changes brought about by inputs of atmospheric nutrients and the activities of people... Annual inputs of atmospheric nutrients, particularly nitrogen, cause deterioration of the heathland communities of heather and its allies, and help to drive a conversion from heather to grass domination... Atmospheric nitrogen inputs affecting the Pebblebeds in East Devon (including ammonia) and acid deposition reach or exceed the maximum critical load for lowland heaths.
As a result, areas were fenced and low stocking density grazing schemes introduced:
Grazing alone will not achieve the aims of managing the land back to lowland heath, but to be able to bring the cattle in to graze after burning or cutting, will keep the vegetation down for longer and will also help to re-establish the important boggy areas which are home to many rare species of flora and fauna.
And yet, remarkably, the issue of nutrients was overlooked in 2010, when AI won permission from DCC to import material from Venn Ottery to Blackhill - even though some of that material would also come from farmland, even though NOx pollution from AI's HGVs and associated haulage traffic would obviously make the situation worse.

When AI applied to quarry Straitgate Farm in 2015, the company didn't want to go anywhere near the subject of nutrients - despite the fact that Natural England had raised the issue in 2012 and despite DCC's Scoping Opinion:
The potential impacts of importing nitrate rich materials into the environment of Blackhill Quarry to be processed, and the impact on the potential restoration and biodiversity of that site from such movements of material should be assessed.
AI's Environmental Statement drew a complete blank on this subject; Natural England therefore issued an objection and DCC a Regulation 22 request:
The proposal to add the silt washed from the 'as dug' quarried material from Straitgate into the lagoons at Blackhill requires further detailed investigation and analysis. The designated heathland communities surrounding Blackhill quarry are nutrient poor and an increase in available nitrogen as it leaches from the lagoons could result in a change in the vegetation composition of parts of the site and affect the composition of any regeneration that may happen as the quarry site is restored. NE advise that there may be an increase in nitrogen and other soil nutrients due to the land at Straitgate being farmed as a dairy enterprise.
There is therefore little evidence to suggest that the mineral and overburden that would be transported to Blackhill Quarry for processing would contain significant quantities of nutrients that might potentially affect the integrity of the surrounding habitats. 2.14
Further to the Regulation 22 request for additional information, Natural England remains concerned about the potential importing of nutrients as a result of processing material from Straitgate farm at Blackhill quarry.
Only in 2016 did AI finally get around to testing any material, and when we now find that the nutrient levels of that material are up to 17 times the level expected for soils at Blackhill - hardly 'little evidence' at all - it's as if AI knew what the answer was likely to be all along.

Natural England has objected to the importation of just 40,000 tonnes from Hillhead; there would be up to 25 times more material from Straitgate Farm, where "all water samples showed elevated nitrate (NO3) concentrations reflecting the agricultural catchment" 7.32.

AI needs to forget about Blackhill for good.