501 | A survey of ferruginous minewater impacts in the Welsh coalfields |
502 | Investigations into the status of fisheries, biological and water quality in the River Pelenna catchment, prior to the treatment of discharges from abandoned coal mines : PL/EAW/95/3 |
503 | NRA Welsh Region South West Area Minewaters Workshop, 23 May 1995, Swansea : summary report |
504 | The impact of ferruginous minewater break-outs on the environmental quality of the Rivers Rhymney, Ebbw and Sirhowy : summary report |
505 | A survey of ferruginous minewater impacts in the Welsh coalfields |
506 | A review of the industrial uses of continuous monitoring systems : incineration processes : a report produced for NCCA and ETSU by Entec |
507 | Temporal variability in chlorophyll-a : concentrations in the coastal environment : final report |
508 | Biological river quality 1995 according to the general quality (GQA) scheme [map] : scale 1 : 750 000 |
509 | Chemical river quality 1993-1995 according to the general quality assessment (GQA) scheme [map] : scale 1 : 750 000 |
510 | Guide to groundwater vulnerability mapping in England and Wales |
511 | NRA regional, area and catchment boundaries |
512 | NRA navigation strategy |
513 | A guide to sustainable urban drainage : protecting the quality of our environment |
514 | Achieving the quality : annex : programme of environmental obligations agreed by the Secretary of State for the Environment, Transport and the Regions and for Wales for individual water companies |
515 | Estuarial migration of Atlantic salmon in the river Dee (North Wales) |
516 | The effect of the voluntary initiative on water quality |
517 | Desktop study of methods for the monitoring of particulate emissions from positively pressurised baghouses |
518 | The NRA in business : annual review and summary accounts 1993-94 |
519 | Discharges of waste under the EC titanium dioxide directives : report of the National Rivers Authority |
520 | NRA report of the blue-green algal monitoring 1990 : a report by the toxic blue-green algae task group |
521 | Cardiff Bay barrage : assessment of impact on salmonid fisheries : annual report 1990 : year one pre-barrage construction |
522 | Report on monitoring of environmental quality in the Severn Estuary |
523 | A better quality of life : a framework for change : July 2001 |
524 | Advisory committee for Wales first annual report 1991 |
525 | Water pollution incidents in England and Wales - 1993 : report of the National Rivers Authority |