Why Is the Water Quality in the River Doe Lea So Poor?”
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“Why is the water quality in the River Doe Lea so poor?” Dissertation submitted as part requirement for the Degree of Master of Science in Urban Water Engineering and Management By: Mark Stevens Supervisor: Prof. David Lerner The University of Sheffield Department of Civil & Structural Engineering September 2011 Declaration: Mark Stevens certifies that all the material contained within this document is his own work except where it is clearly referenced to others. _____________________ ii ABSTRACT: STEVENS, M. 2011. Why is the water quality in the River Doe Lea so poor? MSc Urban Water Engineering and Management Dissertation, Department of Civil and Structural Engineering, University of Sheffield The Doe Lea River has a long history of pollution issues which once earned it the reputation of the most polluted river in Europe. Water quality has succumbed to the pressures of mining heritage, industry, agriculture, urban growth and major highways which dominate the catchment. The catchment has a poor chemical and biological classification status with the Environment Agency and ecological statues varies between poor and bad. Conditions of poor flow are often observed, which intensify water quality issues. In order to determine the reasons for the degradation of surface water quality, a project has been devised to take a snapshot of the water chemistry. Fifty water samples were collected simultaneously across the whole catchment and repeated for each season of the year. Analysis of these samples has developed understanding of pressures and influences that are contributing to water quality degradation. Via a mass balance analysis, it has been possible to locate particular areas of concern, determine sources and quantities of pollution and devise land management options to alleviate pollution stresses. Significant pressures have been determined as the result of diffuse runoff from agricultural and urban landuses, mine related discharges and discharges from sewage treatment works. Considerable influxes of nitrate and phosphate provide the greatest water quality stresses and poorest quality waters are located in the lower urbanised reaches of the catchment. Metalliferous discharges from ex-colliery sites are observed in numerous locations and industrial polluters are pinpointed. Solutions are suggested and further study identified to improve the water quality in the river to meet the water framework directive targets of 2015. Key words: Doe Lea, river, analysis, catchment, water quality, diffuse pollution, mine drainage, nitrates, phosphates, sampling, mass balance, landuse iii ACKNOWLEDGEMENTS: Thanks must go to my dissertation supervisor, Prof. David Lerner whose guidance and input has enabled me to complete this project. Also the assistance of Andrew Fairburn in the University laboratories has been invaluable both in analysing the samples and teaching me the use of the water quality analysis equipment. A special acknowledgment must go to Tina Bardill of the National Trust without whose help the project would not run. Credit for organisation and co-ordination of the sampling events must go to Tina who has also proved an invaluable resource of local knowledge. Thanks are also extended to the fifty volunteers that joined in with each Doe Lea Dip. Without their time, a snapshot of the catchment simply would not be possible. iv CONTENTS: Content: Page Number: Abstract iii Definition of terms vii Summary of figures viii 1.0 Chapter of introduction 01 1.1 An introduction to the Doe Lea River catchment 01 1.2 Aims and objectives of the project 03 1.3 Water quality in the Doe Lea and the WFD standards 04 1.4 What knowledge is available from previous studies of the Doe Lea? 06 1.5 What parameters are being investigated to determine water quality? 10 1.6 Potential problems and anticipated errors in the data 10 1.7 Conceptual interactions 12 2.0 Methodology of data collection and analysis 14 2.1 The Doe Lea catchment and sampling locations 14 2.2 Times and dates of data collection 15 2.3 Laboratory techniques and sample analysis 16 2.4 Quality of and confidence in collected and analysed data 17 2.5 Hypothesis and expectations of sampling data 18 2.6 Representation of collected data 18 2.7 Additional field data collection 19 3.0 Analysis of Doe Lea River samples 20 3.1 Comparison of samples with EA river monitoring data 20 3.2 Agricultural pollution in the Doe Lea 22 3.3 Mining Influences on the Doe Lea Catchment 27 3.4 Industrial influences on the Doe Lea 31 3.5 Urban influences on the Doe Lea 31 3.6 Further analysis of the catchment, flow and mass balance 34 3.7 Defining catchment precipitation 36 3.8 Land use in the Doe Lea 37 3.9 Soil types within the catchment 40 3.10 Description of catchment geology 44 3.11 Summary of artificial contributions and abstractions 45 3.12 Conceptual interactions of river and groundwater 47 3.13 Estimations of flow 48 3.14 Flow estimations for April analysis 48 3.15 Flow estimations for the July analysis 49 3.16 Analysis by method of mass balance 53 v 3.17 Effects of seasonal variability on water quality in the Doe Lea 59 4.0 Discussion 61 4.1 The mass balance analysis and finding of interest 62 4.2 Seasonal variability of the April and July dips 66 4.3 Expectations of November and February dips 66 4.4 Problems encountered with techniques, conditions and findings 67 4.5 How can the project be improved for future dips? 69 4.6 Further study 70 5.0 Conclusions 72 5.1 Summary of suggested changes to future sampling 75 5.2 How do the project results compare to initial hypotheses? 75 5.3 Why is the water quality in the Doe Lea so poor: A final summary 76 6.0 References 79 Appendix A: 85 A.1 Analysis of water samples for April sampling 85 A.2 Flow estimation for April Sampling 90 A.3 Laboratory results for April sampling 91 A.4 Mass balance results for April sampling 92 A.5 Analysis of water samples for July sampling 97 A.6 Flow estimation for July Sampling 102 A.7 Laboratory results for July sampling 103 A.8 Mass balance results for July sampling 104 A.9 Comparison of April and July sampling results 109 Appendix B: 111 B.1 Detailed map of the North half of the Doe Lea Catchment 111 B.2 Detailed map of the South half of the Doe Lea Catchment 112 Appendix C: 113 River sediment monitoring and dioxin analysis in the Doe Lea: A literature 115 survey of Environment Agency studies between 1991 and 1998 117 Appendix D: 119 D.1 Enlarged map of landuse in the Doe Lea Catchment 119 D.2 Plot of additional known land users across the catchment 120 vi DEFINITION OF TERMS: BOD Biochemical Oxygen Demand BPEO Best Practice Environmental Option BETP Biological Effluent Treatment Plant CBC Chesterfield Borough Council CEH Centre for Ecology and Hydrology CIWEM Chartered Institute of Water & Environmental Management CoGAP Code of Good Agricultural Practice CSC Catchment Science Centre DEFRA Department for Environment, Food & Rural Affairs DNRA Dissimilatory Nitrate Reduction to Ammonium DO Dissolved Oxygen EA Environment Agency GIS Geographical Information System HOST Hydrology of Soil Types MAFF Ministry of Agriculture, Fisheries and Food NERC Natural Environment Research Council ND Nitrate Directive NRA National Rivers Authority NRFA National River Flow Archive NSA Nitrate Sensitive Area NSRI National Soil Research Institute NT National Trust NVZ Nitrate Vulnerable Zone SEPA Scottish Environmental Protection Agency SS Suspended Solids SSSI Site of Specific Scientific Interest STW Sewage Treatment Works SUDS Sustainable Urban Drainage System USEPA United States Environmental Protection Agency UWWTD Urban Waste Water Treatment Directive WFD Water Framework Directive vii SUMMARY OF FIGURES: Chapter One: Figure 1.1 Map of the Doe Lea Catchment in Derbyshire, UK Figure 1.2 Assessment of the Water Framework Directive ecological status within the Doe Lea Catchment Figure 1.3 Representation of Environment Agency data for current water quality against the EU Water Framework Directive standards for 2015 Figure 1.4 Representation of river dioxin concentrations Figure 1.5 The remains of Coalite Chemicals in 2011. Figure 1.6 Rainfall maps displaying the percentage of average rainfall across Britain for the months of March, April, May and June 2011 Figure 1.7 Presentation of conceptualised interactions within the catchment Chapter Two: Figure 2.1 Map of the 50 sampling sites within the Doe Lea Catchment Chapter Three: Figure 3.1 EA values for phosphate and nitrate against samples from the Catchment Science Centre Figure 3.2 Comparison of results with published results from the EA Figure 3.3 EA classifications for Phosphate and Nitrate in UK rivers Figure 3.4 Plot of EA data showing reduction in N & P in the River Doe Lea over the past 5 years Figure 3.5 Doe Lea N & P against the EA classification Figure 3.6 A plot of the mining influences in the Doe Lea Catchment Figure 3.7 Concentrations of heavy metals at sampling point 33 Figure 3.8 Effects of nitrification in Pools Brook after an influx of ammonium at Long Duckmanton STW. Figure 3.9 A Conceptual interaction of pathways of pollutants to the river Figure 3.10 Rainfall estimates over the Doe Lea catchment Figure 3.11 Maps of the land use in the Doe Lea catchment Figure 3.12 Distribution estimate of precipitation for a range of land uses viii Figure 3.13 Plot of soil types in the catchment as described by the NSRI Figure 3.14 Plot of HOST soil types in the catchment Figure 3.15 Geological features of the Doe Lea Catchment Figure 3.16 Plot of known discharges/abstractions to/from the Doe Lea