WATER QUALITY MONITORING REPORT 2015 – 2019 Data Environmental Protection Unit [email protected] January 2021 0 | P a g e Table of Contents 1. Executive Summary ......................................................................................................................... 4 2. Introduction .................................................................................................................................... 5 3. Rivers of the Isle of Man ................................................................................................................. 6 4. General Quality Assessment (GQA) ................................................................................................ 9 4.1. Biology ................................................................................................................................... 10 4.2. Chemistry .............................................................................................................................. 10 4.3. Nutrients ............................................................................................................................... 11 5. Environmental Implications .......................................................................................................... 12 5.1. Discharge Licensing ............................................................................................................... 12 5.1.1. Septic Tanks .................................................................................................................. 14 5.1.2. Private Sewage Treatment Works ................................................................................ 14 5.1.3. Manx Utilities Sewage Treatment Works ..................................................................... 14 5.2. Agriculture ............................................................................................................................ 18 5.3. Mining Legacy ....................................................................................................................... 18 5.4. Urban Drainage ..................................................................................................................... 18 6. GQA Assessments ......................................................................................................................... 19 6.1. Biology ................................................................................................................................... 19 6.2. Chemistry .............................................................................................................................. 20 6.3. Nutrients ............................................................................................................................... 23 6.3.1. Phosphate ..................................................................................................................... 23 6.3.2. Nitrate ........................................................................................................................... 26 7. Additional Monitoring ................................................................................................................... 28 7.1. River Neb Heavy Metal Catchment Monitoring .................................................................... 29 7.2. Historic Landfill Leachate ...................................................................................................... 33 8. DEFA Bathing Water Strategy/Environmental Quality Standards ................................................ 34 8.1. Background ........................................................................................................................... 34 8.2. Phase 1 – Bathing Water Standards ...................................................................................... 35 8.3. Phase 2 – Environmental Quality Standards ......................................................................... 35 8.3.1. Heavy Metal Screening – All Island ................................................................................... 35 9. Conclusions ................................................................................................................................... 36 10. Further Work ............................................................................................................................. 36 11. Appendices ................................................................................................................................ 38 11.1. Appendix 1 – List of all sampling sites (codes and names) ............................................... 38 11.2. Appendix 2 – General Quality Assessment of Rivers Biology ........................................... 40 1 | P a g e 11.3. Appendix 3 – General Quality Assessment of Rivers Chemistry ....................................... 42 11.4. Appendix 4 – General Quality Assessment of Rivers Nutrients ........................................ 44 11.5. Appendix 5 – RAW Data .................................................................................................... 46 List of Figures Figure 1. Northern sampling sites locations and ID codes (chemical analysis (pink) or biological analysis (yellow)) .................................................................................................................................................. 7 Figure 2. Eastern sampling sites locations and ID codes (chemical analysis (pink) or biological analysis (yellow)) .................................................................................................................................................. 8 Figure 3. Southern sampling sites locations and ID codes (chemical analysis (pink) or biological analysis (yellow)) .................................................................................................................................................. 8 Figure 4. Western sampling sites locations and ID codes (chemical analysis (pink) or biological analysis (yellow)) .................................................................................................................................................. 9 Figure 5. Flow diagram detailing DEFA's policy for issuing discharge licenses. .................................... 12 Figure 6. Location of all discharge licenses issued by DEFA. Existing licenses are licensed for discharges before 2005 when licensing was introduced. ....................................................................................... 13 Figure 7. Location of treated sewage effluent discharges .................................................................... 15 Figure 8. Balladoole sewage treatment works installed in 2017; treats sewage for residents of Ramsey and ceased the discharge of crude sewage being discharged into Ramsey Bay. ................................. 16 Figure 9. Ballagarey sewage treatment works installed in 2019; treats sewage for the Glen Vine area and upgraded an old style sewage treatment works. .......................................................................... 16 Figure 10. Location of Manx Utilities discharge licenses ...................................................................... 17 Figure 13. Chemical classification for the Northern region. ................................................................. 21 Figure 11. Chemical classification for the Eastern region ..................................................................... 21 Figure 12. Chemical classification for the Southern region. ................................................................. 22 Figure 14. Chemical classification for the Western region. .................................................................. 22 Figure 17. Phosphate classification for the Northern region ................................................................ 24 Figure 15. Phosphate classification for the Eastern region. ................................................................. 24 Figure 16. Phosphate classification for the Southern region. ............................................................... 25 Figure 18. Phosphate classification for the Western region. ................................................................ 25 Figure 21. Nitrate classification for the Northern region ..................................................................... 27 Figure 19. Nitrate classification for the Eastern region ........................................................................ 27 Figure 20. Nitrate classification for the Southern region ..................................................................... 28 Figure 22. Nitrate classification for the Western region ...................................................................... 28 Figure 23. Monitoring locations in River Neb/Foxdale Stream catchment .......................................... 29 Figure 24. Concentration of lead (Pb) in water samples (the red line is the Environmental Quality Standard (µg/L)) .................................................................................................................................... 30 Figure 25. Concentration of Iron (Fe), Manganese (Mn) and Zinc (Zn) in water samples .................... 31 Figure 26. Sampling locations at Cross Vein Mines .............................................................................. 32 Figure 27. Concentration of lead (Pb) and suspended solids in water samples during adverse weather in 2019 .................................................................................................................................................