1. 15th of March 2006
Remediation of Agricultural Diffuse Water Pollution by Farm Ponds and Wetlands
Fabrice Gouriveau
PhD, School of GeoSciences
Supervisors
Dr. Kate Heal & Dr. Graham Russell (School of GeoSciences)
Dr. Andrew Vinten (Macaulay Institute)

2. CONTENTS Background Objectives of the Study Study Sites
Materials & Methods
Anticipated Research Outcomes

3. Background Agriculture and diffuse water pollution
Agricultural water pollution: NO3-, P, pesticides, faecal pathogens from arable fields, grasslands, farmyards, etc.
“Diffuse pollution”: spread over catchment, significant collective impact; difficult to identify and contain
Degradation of water quality & aquatic ecosystems: siltation, toxicity to organisms and eutrophication
High costs: loss of profit for fisheries, paper mills, tourism; water filtration/treatment; loss of biodiversity & enjoyment

4. Background Mitigation of agricultural diffuse water pollution
Among other “Best Management Practices” …
… Ponds and Wetlands are recommended to catch contaminated farm runoff and improve its quality !

5. Background Mitigation of agricultural diffuse water pollution
Ponds and wetlands improve water quality by:
Uptake, inactivation of pollutants by microorganisms & plants
Adsorption on the surfaces of plants, sediments, litter
Settling of suspended solids
Die-off of pathogens
Good treatment efficiency but variable temporally and spatially !
Negative impacts: ecosystems, safety, health, GHG’s, pollution
Many questions: long-term performance, optimal design, carrying capacity, impact on biodiversity, etc.

6. Objectives of the Study
Assess the water treatment performance of farm ponds/wetlands
Assess the ecology of farm ponds/wetlands
Assess the socio-economic aspects of farm ponds/wetlands
Develop a model for farm ponds/wetlands

7. Study Area
Study Area
… But a local fieldwork !
A global issue…

8. Study Sites * Old Castles beef/arable farm
(large wetland, vegetated, low pollution)
* Kennetsideheads dairy farm
(small pond, non vegetated, higher pollution)

9. Materials & Methods
1) To assess water treatment performance of farm ponds:
Monitor water quality at inlet, outlet (samplers, probe)
Describe hydraulic balance (flow meters, tracers)
Assess sedimentation rate & sediment quality (cores)
Manipulate water level & hydraulic residence time

10. Materials & Methods 2) To assess the ecology of farm ponds:
Vegetation surveys (quadrats)
Macroinvertebrate surveys (kick sampling)

11. Materials & Methods 3) To assess socio-economic aspects of farm ponds:
Collect data on construction/maintenance costs and benefits (questionnaires, databases)
Assess farmers’ "acceptance" of treatment ponds
4) To develop a model of ponds/wetlands:
Adapt, calibrate and run an existing model

12. Anticipated Research Outcomes
Information on how ponds perform water treatment and on the factors influencing their performance
Information on the impacts of the ponds on biodiversity
Evaluation of the cost-effectiveness of ponds/wetlands
Recommendations for “optimum” pond design and management
Modelling of the pond system
Communication and technical tools for farmers, SEPA

13. Questions and Suggestions are very welcome !
Thanks for your attention !
Questions and Suggestions are very welcome !