| 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 |
|---|
