1 / 22

Strategic Management of Non-Point Source Pollution from Sewage Sludge

Strategic Management of Non-Point Source Pollution from Sewage Sludge. L. Bolton 1 L. Heathwaite 1 , P. Whitehead 2 and P. Quinn 3 1 Department of Geography, University of Sheffield 2 Aquatic Environments Research Centre, Reading University 3 University of Newcastle upon Tyne.

keegan
Download Presentation

Strategic Management of Non-Point Source Pollution from Sewage Sludge

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Strategic Management of Non-Point Source Pollution from Sewage Sludge L. Bolton1 L. Heathwaite1, P. Whitehead2 and P. Quinn3 1Department of Geography, University of Sheffield 2Aquatic Environments Research Centre, Reading University 3 University of Newcastle upon Tyne

  2. Sewage Sludge Disposal UK, 1991/1992* 9% OTHER 6% INCINERATION 26% SEA DISPOSAL 11% LANDFILL 47% RECYCLING TO FARMLAND *WaterUK

  3. Sewage Sludge Disposal UK, 2000* 22% INCINERATION 11% LANDFILL 12% OTHER 55% RECYCLING TO FARMLAND *WaterUK

  4. Benefits of recycling to land Fertiliser- agronomically useful quantities of nutirents and trace elements Increases soil quality Cheaper than mineral fertilisers (up to £100/ha) Most environmentally sustainable method of disposal Best option in most circumstances: EU and UK government Supported by environmental groups Surfers Against Sewage Sewage Sludge or “Biosolids”

  5. Drawbacks of recycling to land Accumulation in soil/transfer to groundwater/surface water Heavy metals Diffuse nutrient pollution Fertiliser governed by nitrogen application can lead to excess phosphorus Controlled by 1986 EU Directive (86/278/EEC) and ADAS Safe Sludge Matrix Sewage Sludge or “Biosolids”

  6. HIGH TRANSPORT RISK HIGH SOURCE POTENTIAL Critical Source Areas C S A

  7. Sludge not applied when risk of P loss is identified Soil P index ≥3* UK 56% arable and 30% grassland soil P index ≥3 Current thinking has little understanding of the vulnerability of sludge P loss to receiving waters Is it possible to minimise nutrient loss by applying sludge to land outside CSAs regardless of soil P index status? Soil P Index *UK Code of Good Agricultural Practice, 1998

  8. Arable farm receiving regular sewage sludge treatments, SE England Upper Chalk Perched water table Groundwater dominated system 20m unsaturated zone Study Area

  9. Field A Prior to Application • 30ha field, ephemeral ditch • Mean soil Olsen’s P 38.8 mgL-1, areas of soil P index 5 • Digested sludge cake and lime stabilised sludge treatment September 2001 • Dominated by subsurface flow P index 2 3 4 5

  10. Field A Post application • Mean ditch total phosphate 0.475 mgL-1 • Mean soil water total phosphate 0.451 mgL-1 P index 2 3 4 5

  11. Field B treated with digested sludge cake, October 2003 Soil Olsen’s P prior to treatment 22.00mgL-1 Adjacent control field not treated Both fields are tile drained Nutrients concentrations in tile drains from both fields monitored Field B

  12. Field B: tile drains control (untreated) sewage sludge treated

  13. Field A P concentration in ditch water relatively low P not lost from this field: retained in soil or no connectivity High initial soil P is not coincident with transport No CSAs for surface water Field A and Field B

  14. Field B Rainfall occurred during application Incidental loss of P very important in this situation Land drains effectively turned the whole field into a CSA Field A and Field B

  15. Field Scale Connectivity Modelling TopManage Digital terrain analysis to visualise the effects of land management on hydrology TOPCAT timeseries modelling of flow and nutrients Catchment Scale Modelling INCA-N and P models Modelling

  16. low initial P medium initial P 1.6 high initial P 1.2 0.8 0.4 high initial P medium initial P 0 low initial P 0 30 70 Pleaching: 100% cereal catchment; low connectivity Total P leaching kg ha-1 y-1 Biosolids P input kg ha-1 y-1

  17. Pleaching: 100% cereal catchment; high connectivity low initial P 2.8 medium initial P 2.4 high initial P 2 1.6 1.2 0.8 high initial P 0.4 medium initial P 0 low initial P 0 30 70 Total P leaching kg ha-1 y-1 Biosolids P input kg ha-1 y-1

  18. Nutrient Export Risk Matrix Output gained from scenario tests with plot and field scale INCA is being used to fill in the nutrient availability axis on the NERM High risk FERTILISER APPLICATION AND SOIL MANAGEMENT Low risk SOIL TYPE FLOW CONNECTIVITY

  19. Phosphorus Export Risk Matrix High risk FERTILISER APPLICATION AND SOIL MANAGEMENT Low risk FLOW CONNECTIVITY

  20. Phosphorus Export Risk Matrix Series of questions are asked relating to: • Flow Connectivity • Hill slope form • Hedgerows • Remediation options • Fertiliser Application and Soil Management • How much P do you intend to apply • Current soil P index • Prototype PERM available on www.sheffield.ac.uk/SEAL and www.ncl.ac.uk/wrgi/TOPCAT/

  21. Sewage sludge has an environmental and economical use when applied to land Export of P occurs when transport and source factors coincide as CSAs P export can be controlled by strategic management of applications of sewage sludge Conclusions

  22. Acknowledgements • EPSRC (GR/N26074/01)The SEAL Project: Strategic Management of Non-point Source Pollution from Sewage Sludge • Roger Pryor for access to field site • Lister Noble (Farm Systems) for P index data • Thames Water and Terra Ecosystems for sludge data

More Related