Copyright © 2013 – Cylenchar Limited Dr Peter J Hurley – Cylenchar Limited UK

Mitigation of Site Risk

Knowing what is happening to the site chemistry and its physical consequences, mitigation of pollution risk becomes common sense.

• Don’t shoot steel over legacy lead. The chemistry says it increases risk significantly so why do it?
• Or shoot ‘better’ lead. Makes sense to not use antimonial lead, and better grades are available at minimal cost uplift. Are birds at significant risk from range lead, if there is adequate site cover?
• Design ranges to better capture spent projectiles. By confining and concentrating the potential hazard we can better manage it.
• Ranges cannot be sustainable if spent shot is left in-situ. Whilst periodic removal a lead can be problematic, the one saving grace of steel is – its magnetic. Magnetic brooms are routinely used in the U.S. building industry and available from a variety of suppliers, and can be used to recover ‘loose’ steel shot…
• Treating the range with apatite or similar phosphate as a surface dressing can have a beneficial effect of immobilising lead in-situ. However, plants and other soil flora will see lead phosphate as a nutrient and will attack it liberating the lead once more. Life span of treatment efficacy 1 to 3 years.
• Precipitation on the site will exit by one of 3 routes; surface run-off, subsoil drainage and transpiration. We need to discourage surface run-off so we need to encourage soil drainage, that way lead is retained on-site and in-situ. Transpiration of plants, particularly trees and shrubs is also a pretty good way of getting rid of site water.
• Maintaining site cover is critically important. We must not to allow highly contaminated bald spots to persist. These are precisely the zones we need to manage.
• Monitor site soil permeability. We need to know if we’re impairing site permeability. As an added note, apatite lime dressing, particularly with iron oxides makes for a pretty good soil aggregation agent or cement and can impair natural drainage.
• Counter ‘iron pan’ with mechanical intervention to assist surface drainage. Fork, till or in the last resort – plough.
• Install a range drainage system to capture all run-off and monitor run-off for potential contaminants. This makes sense especially if you have a contaminated site, you have a legal obligation to manage risk on that site. And by creating a fixed route for run-off we can intervene with premeditative treatment should it prove necessary.
• ‘IF’ intervention proves necessarily, I would recommend incorporation of a heavy metals reactive filter / barrier within the range drainage system and projectile traps. There are numerous suitable reagent systems. Sulphide based reagents are in my opinion the best in offering long term treatment. Apatite / lime and synthetic apatite, are probably the most widely used. As a slow sand reactive barrier fill they have greater durability than surface treatment because they’re not available to be broken down by site flora, but phosphate treatment is not suitable for all heavy metals. Other agents can be incorporated to address other contaminants as necessary.

  Contents

  Environmental Risks Arising from Changes in Ammunition Materials
  The Contaminant – Metallic Lead?
  Does Steel Shot Reduce Environmental Risk?
  European Soils – Typical Profile and Predicted Impact of Steel Shot
  Site Risk! - Added Pathways
  Mitigation of Site Risk

Copyright © 2013 – Cylenchar Limited

ANY FUTURE CHANGES – THINK HOLISTICALLY!

If I leave you with one message it is that for any future changes to ammunition materials to ‘think holistically’. As a change intended to mitigate wild-fowl poisoning, if extrapolated beyond its immediate intended application can indeed have knock-on undesired environmental consequences.

Peter J. Hurley

Cylenchar Limited

May 18, 2013

http://www.cylenchar.com/ESCGA_Moscow_2013.pps

http://www.cylenchar.com/ESCGA_Moscow_2013_Notes.pdf

http://www.cylenchar.com/Article.pdf