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Restoring The Avoca River

Report to the Eastern Regional Fisheries Board, Dublin by University of Newcastle

Restoring the Avoca River: an integrated
social/technical scoping study of acid mine
drainage remediation options.
Aidan Doyle
Paul L Younger
Catherine J Gandy
Richard Coulton
(Unipure Europe Ltd)
University of Newcastle
(With additional information by
Fisheries personnel)
University of Newcastle University of Newcastle Restoring the A Restoring the Avoca River voca River

Table of Contents Page


1. Introduction
1.1 Background
1.2 Objectives of Study
1.3 Previous Work
1.4 Acknowledgements

2. The Avoca Mine Site and Surrounding Area
2.1 Location and Description
2.2 Geology
2.3 Hydrogeology
2.4 Mine wastes, the mined landscape and concepts of remediation
2.4.1 EU LIFE Project approach to the heaps
2.5 Catchment characteristics Fisheries context
2.6 Miscellaneous other economic and location considerations Arklow and oysters
2.6.2 The former IFI factory
2.6.3 Tourist attractions
2.7 Catchment management planning
Maps 14

3. Stakeholder Analysis and the Case for Action
3.1 Ways of Understanding
3.2 Stakeholder analysis. What and Why?
3.3 Who are the stakeholders?
3.4 Stakeholders Identified
3.4.1 Primary Stakeholders
3.4.2 Secondary Stakeholders (Key Stakeholders)
3.5 Stakeholders who responded to this study
3.5.1 Local Residents
3.5.2 VADA
3.5.3 Anglers
3.5.4 Hospitality Businesses
3.5.5 Aquaculture
3.5.6 Wicklow County Council Local Authority stated commitment Projects, Proposals and Ownership Other water contamination concerns in the lower catchment Economic Development
3.5.7 The Environmental Protection Agency (EPA)
3.5.8 Department of Communications and Marine and Natural Resources (DCMNR)
3.5.9 The Central and Eastern Regional Fisheries Boards
3.5.10 Dúchas
3.5.11 East Coast and Midlands Tourism
3.5.12 Mining Heritage Trust of Ireland (MHTI)
3.6 Root definitions. The concerns and aspirations of stakeholders and where they concurr

4. Data sources and quality
4.1 List of data provided by ERFB and other contacts
4.2 Creation of database
4.3 Quality and usefulness of data from disparate sources

5. Hydrochemistry
5.1 Principles of calculating acidity from pH and metals concentrations
5.2 Mine water discharges
5.3 Surface water sampling sites

6. Flow data: gauged and estimated
6.1 Avoca River
6.2 Deep Adit
6.3 Ballymurtagh Adit

7. Biological effects of mine water pollution on Avoca River
7.1 Effects of mine water pollution on the Avoca River fish kills
7.2 Fish stock surveys 2001/2002
7.3 Future work on biology of Avoca River to facilitate future demonstration
of the benefits of remediation

7.4 Future potential of catchment
Maps and Photographs

8. Remedial options for the Avoca mine waters
8.1 Definition of design flows and design contaminant loadings
8.2 Availability of land for treatment systems
8.3 Additional assumptions lying behind definition of treatment options
8.4 Option 1: Do nothing
8.5 Option 2: Completely active treatment
8.6 Option 3: Completely passive treatment
8.7 Option 4: Hybrid passive-active system
8.8 Preferred option
8.9 Further data requirements to support confident
design and costing of preferred option

8.10 Towards robust cost-benefit analysis of the case for treatment

9. Conclusions and Recommendations
9.1 Future work in developing stakeholder engagement
9.2 Identifying and securing funding
9.3 Site survey information requirements
9.4 Hydrological and hydrochemical data collection
9.5 Proposed forward programme

10. References

11. Appendices

A scoping study has been undertaken on behalf of the Eastern Regional Fisheries Board (ERFB) of the Republic of Ireland to identify and develop outline costings for remediation measures which can restore the Avoca River to the status of a salmonid fishery. The focus of the study is the provision of alternatives on remediation measures that are required to reduce the levels of acidic mine drainage entering the Avoca River from the abandoned copper mines in the area. The lower reaches of the Avoca River is the most polluted river in Ireland. It has received toxic acid mine leachate and effluent for over 200 years and there is a perception that the catchment is so compromised that it has a limited fishery value. However, electrofishing surveys carried out by the Fisheries Boards in the Avoca River catchment in 2002 indicate that salmon and trout fish stocks are present in the system and that the system has excellent potential as a recreational salmon and sea trout fishery.
The study has pursued the following key objectives:
Collation of all previous data and reports concerning the site, entering the information into a purpose-written MSACCESS
Undertaking a preliminary (but fairly comprehensive) stakeholder analysis, in order to identify the key socioeconomic
hurdles which need to be overcome if the river is to be restored to salmonid fishery status
Analysis of available data (supplemented with some further data collected on site) in order to derive design
parameters for possible remediation options
Proposal of alternative remedial options and provision of costings for those which could achieve the desired objectives, given constraints of available land etc.
An extremely promising community of interest exists in the catchment, which is keen to see the polluting discharges abated, and the salmonid status of the Avoca River restored. The basis exists for the development of a broadly-based partnership with the necessary momentum to secure funding, develop a treatment solution and ensure long-term maintenance of the necessary
facilities, rooted in the local community. A number of technical options were considered in the study, including do nothing, a pipe line to the sea, hydrogeological and revegetation approaches, passive treatment, active treatment and hybrid passive-active treatment. The preferred option is
unequivocally active treatment. If this were combined with a polishing wetland, some of the ancillary benefits of the passive treatment option could be added to the active treatment approach, at relatively modest additional cost. Before such a solution can be designed in detail, there is a need for a further programme of work with the following components:
a minimum one year programme of hydrological and hydrochemical monitoring (hopefully implemented by
ERFB) to yield a complete, synchronous data set
site surveys of the parcels of land suitable for installation of treatment works
on-site treatability trials to confirm treatment design parameters
cost-benefit analysis of the case for treatment
development of an inclusive partnership, spanning local and national governmental agencies, local residents and relevant elements of the private sector
In conclusion, with the strong level of partnership between the stakeholders and the scientific knowledge to develop a suitable treatment system for the acid mine drainage from the Avoca River, there is a promising future for the Avoca catchment. This river has the potential to be restored as a significant state asset. In terms of its recreational angling potential it could generate at least €750,000 per annum, (Indecon, 2003). The value of this river once restored would be enormous to the local community, bringing economic, tourism, social and cultural benefits.

1. Introduction
1.1 Background
Pollution of the Avoca River by mine water discharging from drainage adits of abandoned copper and sulphur mines at Avoca, in County Wicklow, Ireland, is a long-recognised problem. The river is severely affected by the mine water and is considered by the EPA to be the most severely polluted stretch of river in Ireland. This report is the fruit of a scoping study which was commissioned by the Eastern Regional Fisheries Board (ERFB) of the Republic of Ireland (as coordinating partner of a broad-ranging stakeholder group) to identify and develop outline costings for remediation
measures which can restore the Avoca River to the status of a salmonid fishery.
1.2 Objectives and methods of study
1.2.1 Scope of work and key objectives
The purpose of this study was defined by ERFB as follows: to provide a number of alternatives on remediation measures that are required to reduce the levels of AMD entering the Avoca River. The specific study area is from Whites Bridge (East Avoca) downstream to the estuary of the river in Arklow.To meet this purpose, a number of key objectives have been pursued, as follows:
to collate all previous data and reports concerning the site, collating the information into an MSACCESS database
to undertake a preliminary (but fairly comprehensive) stakeholder analysis, in order to identify the key socio-economic hurdles which need to be overcome if the river is to be restored to salmonid fishery status
to analyse available data (supplemented with some further data collected on site) in order to derive
design parameters for possible remediation options
to propose alternative remedial options and provide costings for those which could achieve the desired objectives, given constraints of available land etc.
1.2.2 Methodology: scientific and engineering aspects
In terms of scientific and engineering work, the study reported here was almost wholly a desk study, as requested by the ERFB. A number of site visits helped in gaining an appreciation of the study area and its problems, and also facilitated collection of some targeted water samples which permitted resolution of some issues arising from pre-existing data. Most of the analysis has used standard hydrochemical and hydrological techniques, implemented using spreadsheet
technology. The technical basis for the analyses performed is detailed by Younger et al. (2002).
1.2.3 Methodology: social perspectives
We are combining technical evaluation, leading to remediation of the mine water, with an enquiry into stakeholders understanding and potential engagement. Local knowledge and scientific information should be combined in order to solve practical problems (see for example Ortiz 1999). Through stakeholder analysis we investigate ways of combining technologies with local peoples intimate knowledge and sense of place. Knowledge that aspires to become applicable
or be of practical use has to be developed jointly with the users of the knowledge (Brulin 2001.441). To develop tools for informed management decisions and focussed sustainable intervention we consider all of the issues at stake. Collaboration amongst mine water scientists, fisheries personnel, geologists, resident communities and others is aimed at continued data collection and the development of a management regime that will prove culturally suitable for resident
community ownership. The scope of the projects, our minimum locus of agreement, is defined by the stakeholders.
Groups and individuals agree on what our proposals are rather than merely their own individual goals. The ultimate aim is the development of a partnership in terms of tactics (specific application) and strategy (medium and long term developments) (Amezaga and OConnell 1998). This report is intended to provide the foundation for such a partnership. Social fieldwork has been conducted following appropriate research protocols for working in local communities. Respondents are made fully aware of the purpose (and consequences) of the enquiry. Data was acquired at a personal
conversational level from open-ended questions. The project board provided advice and contact details of all groups and individuals.

There has been a significant amount of previous work carried out on the Avoca Mines area, addressing:
the geology and hydrogeology of the area (e.g. Flynn, 1994; OSuilleabhain, 1996; Gallagher and OConnor, 1997)
the characterisation of the principal polluted discharges and their impacts on the Avoca River (Gray, 1994a,b, 1995a,b)
reviews and pilot-scale trials of possible remediation methods applicable in this setting (Gallagher et al., 1998; Prescott and Kilkenny, 1997; Kilkenny and Good, 1998), which were principally funded through an EU LIFE project.
While all of the above studies have yielded data which are central to the interpretations and recommendations presented in this report (as will become clear in later sections), the latter trials are particularly pertinent to the focus of our work. Trials undertaken at the site have included the use of waste magnesium hydroxide slurry from the Premier Periclase factory, where it is used to remove suspended solids and silica from seawater. Whilst the use of waste magnesium hydroxide to treat the Avoca mine water can be perceived as environmentally beneficial, it is important to review the
implication of using this material on the overall operation of the mine water plant before deciding whether to use magnesium hydroxide instead of other reagents. This review is implemented in Section 8.2. In addition, trials in West Avoca demonstrated the use of sewage sludge as a soil amendment for promoting revegetation of acid-generating metalliferous spoil. While revegetation was successfully achieved, it does not appear that this will in itself hinder infiltration sufficiently to suppress the generation of acidic leachates within the spoil heaps. (This is a common finding in similar revegetation studies elsewhere; Younger et al. 2002).
Beyond Avoca, there is of course a vast amount of experience worldwide in the characterisation and remediation of polluted mine drainage. The most comprehensive synthesis on this topic to date (Younger et al. 2002) demonstrates that the technology is available to fully remediate the Avoca discharges. A few brief examples from other countries where similar high-sulphur orebodies have also been mined for many centuries suffices to demonstrate the feasibility of
remediation at Avoca.
Example 1 - Wheal Jane tin/zinc mine, Cornwall, UK.
Wheal Jane was the last of a large number of mines which once worked the tin and zinc bearing lodes of the Carnon Valley (between Truro and Falmouth, Cornwall). After the mine was abandoned in March 1991, the workings flooded to
river level and gave rise to a substantial discharge of acidic, metalliferous waters to the Carnon River. A flow of contaminated water ranging between 90 and 300 l/s has continued ever since, prompting the development of an extensive programme of remedial measures. The history of these developments has been recently recorded by Younger (2002). The key points of relevance to Avoca are:
(i) For an acidic metal mine discharge of this type, with multiple ecotoxic metals and highly elevated acidity coupled with a high flow rate (much higher than at Avoca), only active treatment was capable of achieving treatment objectives. A temporary treatment plant was operated from 1992-2000, based on conventional lime dosing, flocculation, and sedimentation technology. The long-term treatment commissioned at Wheal Jane in the autumn of 2000 is a state-of-the-art active treatment plant, comprising a high-density sludge alkali dosing plant, designed and commissioned by Unipure Environmental. This plant is equipped to treat up to 350 l/s of mine water, and is achieving the major improvements in water quality required by the regulators. During its first full winter of operation, the Unipure plant successfully treated a total of 4.4 Mm3 of water, removing a total of about 1000
tonnes of metal which would otherwise have been discharged to the Carnon River.
(ii) Early in the search for a long-term treatment strategy, the NRA undertook to evaluate the possibility of developing a wetland-based passive treatment solution for the Wheal Jane site. The Wheal Jane Pilot Passive Treatment Plant (PPTP) has generated large volumes of interesting data. However, with the benefit of hindsight, it is now clear
that the PPTP suffered from an unfortunate design flaw: it was essentially configured back-to-front, inasmuch as acid-generating aerobic processes were sited upstream from the crucial alkalinity-generating anaerobic processes. Useful insights into the capability of passive processes to cope with extreme mine water discharges were nevertheless gained.

Example 2 - Norwegian copper / zinc mines (information provided by D Banks)
Treatment of copper / zinc - containing mine water in Norway has been achieved using conventional active treatment (alkali dosing), electrolysis and pilot-scale trial wetlands. Chemical treatment and electrolysis have been employed at Kongens Gruve and Folldal Mines to reclaim copper metal from mine water. The procedure is cited to have a 99 % removal rate for copper (albeit the last 10% of removal is estimated to be as expensive as the first 90%). Three pilot-scale trials have been carried out using wetlands to treat runoff from copper / zinc mines in Norway. One of these, at Storwartz
Mine, consisted of 6 tanks containing (in order): an anoxic stripping cell; crushed limestone; anaerobic wetland (two tanks); aerobic cell; zeolite polishing cell. Copper was removed from the water at an average rate of79 % but zinc proved more difficult to remove, with an average rate of only 37%. Iron was readily removed at an average rate of 75% with the most effective removal occurring in the tank containing crushed limestone. Kongens Mine is very similar to Avoca, in
that surface runoff (including runoff from a number of overlying mine waste tips) drains rapidly down through voids and fractures into the mine complex. In 1999, a wetland system was constructed to treat the water, consisting of an anoxic limestone basin, four anaerobic compost basins and a final aerobic lagoon. The system removed 8998% copper and 80- 93% zinc. This system was then replaced in August 2002 by a system comprising a single anaerobic compost basin. It is
too early to comment on the efficacy of the new basin but initial results are somewhat disappointing with only 15-20% removal of copper.
In summary, experience worldwide (Younger et al. 2002) shows that passive treatment is feasible for waters such as those at Avoca, provided flows are modest. Where flows are high (> 10 l/s) the acidity loadings are likely to be such that active treatment methods based on alkali dosing are most likely to be required.
1.4 Acknowledgements
In the development of understanding of background issues and problems associated with the project it has been necessary to meet with many people. We have met a variety of public and private stakeholders: officers with statutory responsibility, anglers, former miners, business people and interested local residents - at a variety of locations: office, hotel, fish farm, fishery, boathouse, public house, and at the mine sites. A clear indication of the goodwill of many of the respondents is
that time has been taken off work to meet with us in the winter weather. In response to our questions we have been met with openness and kindness. Answers to our open ended questions have been essentially informal, though nevertheless focussed. We extend our warmest thanks to all respondents / participants. We are particularly grateful to the following organisations and individuals who have contributed significantly to the development of this report:
Annamoe Trout Fisheries; Wesley Atkinson; Aughrim Anglers Association; Ned Bayley; Charlie Berdon; Michael Brady; Brian Breslin; Derek Byrne; Donnachadh Byrne; Dudley Byrne; Patrick Casey; Sean Casey; The Central Fisheries Board; Kevin Clabby; Tom Clinton; Coillte; County Wicklow Film Commission; Nick Coy; Dr Martin Critchley; Gareth De Brun; Karen Delanty; Department of Communications, Marine and Natural Resources, Exploration
and Mining Division; Vibeke Dikjman; Pat Doherty; Brendan Driver; Colm Driver; Tom Driver; DUCHAS; East Coast and Midlands Tourism; Eastern Regional Fisheries Board; Paddy Egan; Michael Enright; Environmental Protection Agency; ERA MAPTEC Ltd; Jim Fagan; Padraic Fitzpatrick; Francis Fanning; Loreto Farrell; Gerry Flood; Paul
Gallagher; Piers Gardiner; Geological Survey of Ireland, Groundwater Section; Billy Hannon; David Harrington; IDAS; IFI; IFA; Coran Kelly; Martin Kelly; Nicky Kerwin; Fred Lochlain; Tom Lyng; Michael Lynham; Lord Meath; Peadar McArdle; Michael McEvoy; Alan McGurdy; Peter Moore; John Morris; Brian Nally; Jim OBrien; Dr Pat OConnor; Tony ONeill; Seoirce OToole; Lynn Paterson; Steffen Petersen; Rathdrum Anglers Association; George Reynolds; Dr William Roche; The Meetings public house, Avoca; Vale of Avoca Development Association; Wicklow Anglers
Association; Wicklow County Council; Geoff Wright; Donal Young.
We are grateful to the ERFB for a chance to present them with our work in progress report in December, and for their unstinting hospitality on that occasion, as indeed at other times.
We wish to express our particular thanks for their extra organisational effort to Peter Driver and Stewart McGrane; and to Andy and Marie Merrigan for the significant contribution of their time, effort and understanding. We acknowledge the unreserved dedication of Josie Mahon to the execution of the stakeholder engagement, and indeed the whole programme of research. The enthusiasm of the Blackrock ERFB staff has been exemplary, far surpassing the ordinary expectations of the delivery of duty. Thank you once again to all. CFB & ERFB staff have extensively provisioned this report with data relating to fish stocks, fish kills, etc.
External technical review comments have been provided by Bruce Misstear of Trinity College Dublin and David Banks of Holymoor Consulting Ltd. (Unfortunately some participants were unable to respond).

2. The Avoca Mine Site and Surrounding Area
2.1 Location and Description
The Avoca Mines are located within the Avoca River Catchment which covers an area of 650 km2. The East and West
Avoca Mines are separated by the Avoca River, which flows through the Vale of Avoca, a noted beauty spot and tourist
attraction. To the north of the mines, the Avoca River is formed (at the Meeting of the Waters, famed in verse) by the
confluence of the Avonbeg and Avonmore Rivers while, 6.5 km to the south, it is joined by the Aughrim River whence
it flows a further 7.5km to the sea (which it meets at the fishing port of Arklow). Several smaller tributaries join the Avoca
River close to the mine water discharges, including the suggestively-named Sulphur Brook to the south of East Avoca
Mines, and the Vale View and Red Road (again, a name suggestive of long-standing acid drainage) streams to the north
and south respectively of West Avoca Mines. (see map 1, map 2 & photo 1 pages 13,14 & 33)
2.2 Geology
Southeast Ireland lies within the Caledonian-Appalachian orogenic belt, to the south of the Iapetus Suture (a tectonic line which marks the Ordovician collision zone between two palaeo-continents which corresponded roughly to the present North America and Europe). The mineralisation at Avoca lies within the Avoca Formation, a sequence of 455 million year old Ordovician volcanic and sedimentary rocks formed in response to the Iapetus closure. The Avoca Formation forms part of the Duncannon Group (Gallagher & OConnor, 1997). (see map 3 page 15) The outcrop pattern of the Avoca Formation is lenticular in shape, being 2-4 km wide by 15 km long, with the long axis of the outcrop following the regional NE-SW Caledonian trend. The Avoca Formation can be subdivided into three members:
1. The oldest unit is the Castlehoward Member which is confined to the river valley and the area adjoining this to
the northeast. This member is 450 to 1200 m thick and comprises sericitic tuffs with felsic horizons.
2. The Kilcashel Member (700 to 1050 m thick) underlies the central part of the Avoca district and consists of
altered, silicified tuffs notable for their high chlorite content.
3. The youngest unit is the Tigroney Member which is 350 to 1800 m thick and is dominated by sericitic lithic and crystal tuffs and felsites with some chloritic crystal tuffs. The bedrock lithologies in the Avoca Area have undergone a common structural evolution. The Avoca Formation and its
enclosing sediments join and dip towards the southeast. A set of normal faults run NW-SE and another NNE-SSW, some of which cut through all members of the formation. The mineralisation at Avoca occurs as massive and stringer sulphides and is regarded as volcanogenic in origin (i.e.
seafloor volcanic-exhalative deposits, formed by ancient equivalents of black smoker submarine springs seen today at mid-ocean spreading ridges). The main ore zones at the Avoca Mines occur at the top of the Kilcashel Member at its contact with the Tigroney Member, where a few metres thickness of banded sulphides occur. Pyrite makes up over 95 % of the ore, and while this is typically regarded as an uneconomic gangue in many similar orebodies, at Avoca it was extensively worked as an ore for sulphuric acid production. The other major ore minerals in the Avoca deposits are chalcopyrite, sphalerite and galena, providing copper, zinc and lead respectively. Minor minerals, such as arsenopyrite, tetrahedrite and bismuthinite, as well as some gold and silver, are also present. A detailed account of economic geology of the catchment and a brief history of the mine sites are given in appendices I and II.
2.3 Hydrogeology
There is no doubt that the dominant hydrogeological features of the study area are the flooded mine voids themselves, which collect drainage from a large volume of ground and old workings and deliver it to the Avoca River in the form of major point discharges (from the portals of the Ballymurtagh Adit and the Deep Adit). In common with many other mining areas, however, the internal dynamics of the flooded mine void system are poorly characterised. As part of a study
carried out by the Geological Survey of Ireland (GSI) in 1995 the drilling of 5 boreholes took place in the area surrounding Avoca mines, which complemented 54 pre-existing boreholes which were suitable for groundwater level monitoring. However, most of these boreholes were drilled into the surrounding crystalline bedrock rather than the mine voids so are of little help in assessing the hydrogeology of the flooded mine void system. The permeability of the bedrock proved to be very low and it was deduced that groundwater movement occurs largely through fissures and fractures (some of which may well have been induced by mine void caving). Specific yield in the volcanic rocks is low, resulting in relatively large fluctuations in water level following small variations in aquifer recharge and discharge. This is accentuated by the fact that sub-soils (drift deposits) are thin over most of the area. (see map 4 page 16)
Groundwater levels were found to be generally between 5 and 15 m below ground level and did not tend to fluctuate greatly. However, a significant head difference exists between the bedrock and the enclosed mine voids, with water levels outside the mined features being substantially higher (Flynn, 1994). This head difference causes groundwater to flow into the mined zone, confirmed by the occurrence of seepage faces flowing into the opencast mines from adjacent areas. This is consistent with the concept of the mine voids acting as master drains for this area.
In summary, virtually all of the groundwater in the area can be assumed to ultimately discharge into the Avoca River, principally through the network of shafts and adits to discharge into the Avoca River via the Deep Adit (for the East Avoca Mines) and the Ballymurtagh Adit (for the West Avoca Mines). Small amounts of water (generally too small to accurately measure) also discharge to the river as diffuse flow and as minor adit discharges (Flynn, 1994).
2.4 Mine wastes, the mined landscape and concepts of remediation
The East Avoca mine site includes colourful spoil heaps: the product of old and recent mining activities. Gallagher et al. (1998, p. 10) note their composition, distribution, volume and appearance. They estimate the total volume of spoil in East Avoca as 1,035,809m3, with Mount Platt accounting for 69% of the total. The volume of surface spoil heaps in West Avoca is estimated as 422,278m3. The mine sites cover 63 ha, and the spoil heaps comprise some 40% of this area, i.e. around 26 ha, with the open pits a further 14%, or 9ha. They proffer the qualitative observation that the appearance of the mine site is dominated by the barren red-brown spoil that covers its surface and contrasts with the verdant surroundings of the Avoca valley (Gallagher et al. 1998, p.10). They note that weathering leaches a significant portion of the metal content of the heaps. Some heaps were reclaimed in the 1970s, by means of re-mining since they were then of ore grade. In the 18th and 19th centuries ore was dressed manually on the ground. Large piles of low grade ore
cobbings were created through this process. Mount Platt, a single large heap, was produced in the 1970s from large volumes of spoil from the Cronebane open pit. The current spoil heaps are heterogeneous in composition and sulphide grade. The dominant surface texture, a fine clayey matrix, provides a resistance to permeability within many of the heaps.
2.4.1 EU LIFE Project approach to the heaps
The EU LIFE project addressed means of revegetating the heaps, trialling the use of windrow-composted sewage sludge. Such approaches are of course nothing new: many organic materials can be used to develop sufficient moisture retention and metal-sorption capacity in mine spoils that they will support plant growth. From the mine water remediation perspective, however, the over-riding concern remains the bulk permeability of the mine wastes, which is rarely reduced by the development of root channels and other macropores associated with growing plants. Hence infiltration of water into the material still occurs and gives rise to contaminated leachate, which typically sinks to a perched water table within the spoil and migrates to discharge elsewhere, away from the plant root zone. Not surprisingly, therefore, the EU LIFE project report found that even under pine or birch cover there is a high level of background contaminant transport in the
spoil by infiltrating rainwater. The EU LIFE projects proposed regrading of open pits to replicate natural slopes are seen as symptoms of a general pervading attitude that the mine areas are problems rather than opportunities. As Gallagher et al. (1998, p. 22) have noted:
Whether the visual impact of mining is a negative environmental impact is largely a matter of aesthetics. However, they go on to note the scientific interest of the heaps and open pits as being as worthy of preservation as any historical building or artefact.
The scenery afforded by the mine sites is subject of significant judgmental bias. Parkes (1999) has noted that the mining landscape is powerful [in its] own right adding that many mine sites in the UK are protected as Sites of Special Scientific Interest (SSSIs) as a consequence of their uniqueness. Parkes expresses the need to look at these sites in alternative ways.
I see not eyesores, but awesome pits, symbolic of so many things. I see
not a scarred landscape, but a history - a visible record of human
endeavours - a mine heritage landscape. With more time, it would be
possible to find numerous literary quotations to illustrate how the
of mined areas becomes suffused into peoples consciousness,
and becomes part of their local identity.
Furthermore the mine sites have developed new ecosystems; naturally occurring remediation via metallophytic floral uptake presents unique opportunities to study natural processes of ecosystem renewal, such as must have occurred following the last glaciation. Respondents to our research have expressed interest in the uniqueness of the geological landscape as it has been exposed through mineral extraction. The open pits of Tigroney and Cronebane present an invaluable opportunity to view volcanogenic facies and mineralogy. One geological respondent equated the exposed rock
formation as being like the nude to the artist. (see photo 2 page 33)
Beyond these considerations, uncritical acceptance of mined landscapes as being inherently problematic potentially has some negative economic consequences. Respondents within the mining section of GSI expressed their concerns that there is a prejudicial view of mining that generates difficulties for the development of future mineral prospects. Mining very often gets a bad press, whether deserved or not. There appears to be a consensus amongst our respondents that the
exposed geology in the Avoca pits should be the subject of educational interpretation. Such educational interpretation might also serve to break down some of the stereotypes concerning the damage (rather than value) associated with mining operations.
2.5 Catchment Characteristics Fisheries Context
In general terms, the Avoca catchment is an exceptionally clean river system with several unmanaged fisheries along its length. Three trout production farms are located on its tributaries. The EPA through the national rivers monitoring programme has classified the Aughrim, Avonbeg, Avonmore, Ow rivers and the Derry water as being unpolluted (1998-2000 report). These rivers have Q values ranging from 4-5 which indicates good water quality and high invertebrate
community diversity. The catchment is predominantly upland. In the upper reaches the catchment consists of the Wicklow mountains to the east, north and north west. Forestry, agriculture, tourism, industry, horticulture and aquaculture are the main land uses in the catchment. For 230 years mining was a very productive activity in the catchment. Currently almost 11.5 kms of river has been very
seriously polluted principally caused by leachate from the old copper mines, resulting in a Q value of 1 (which indicates very poor water quality). The average volume of acid mine drainage coming from this site is 35 litres per second, depending on weather conditions. The impact of the Avoca Mines on these pristine waters is detrimental to the biota and visually disturbing. The clear waters turn a sterile yellow brown which covers the bed of the river, inhibiting the growth of algae and limiting primary productivity. The toxic impact on aquatic invertebrates and fish lead to severely diminished
populations. However as recent electrofishing surveys have shown there is some fish life present in the polluted stretches (eel, lamprey and minnow Section 7), although salmonids are virtually absent in the badly affected areas. Prior to 1850, records indicate that the Avoca was an excellent salmon river. Dr. A. J. Went, a noted fisheries biologist in A Lost Irish Salmon River (1979), wrote that in 1800 the Avoca was deemed as remarkable for the great quantities of salmon which it produced. By the 1850s fish were destroyed for 8 miles due to the mines being worked to a considerable extent. In 1924, there were records of salmon getting upstream during floods specimens of salmon parr and smolts were recorded from the upper reaches of the Avoca and Aughrim rivers.
Today, on the Avonmore River small brown trout (circa 20 cm) are the most prominent feature of catches (OReilly, 2002). Larger trout are also taken; some of these may be sea trout. He describes the Avonmore as a lovely wide river with good instream diversity which presents many angling opportunities. The angling water extends from Clara Bridge to Whites Bridge. Angling on the Avonbeg is for small trout in beautiful countryside. Access to the river is very difficult due to heavy bank cover in some areas. The Aughrim and its tributaries the Derry Water and the Ow also provide trout angling. The average size of trout in the Aughrim is greater than for the Avonmore and Avonbeg with trout ranging from 220 to 340 g. Larger trout are taken from time to time. Sea trout are taken during the summer and this fishery is well regarded locally. Escapee rainbow trout can
feature in anglers catches in the Aughrim also. The Derry Water is a good trout fishery which is not heavily fished. Trout to 400 g are taken and good angling stocks are present. The underlying bedrock of the Ow River is granite and is well populated with small trout. Heavy bank cover is problematical for anglers. The Avoca main channel is occasionally angled by some local anglers for rainbow trout, sea trout and salmon. It is not uncommon for anglers to observe dead fish in the channel. The Avoca has some excellent angling water ranging from shallow runs, glides to deep holding pools allied to the often spectacular landscape of the river corridor and surrounding area.
2.6 Miscellaneous other economic and location considerations
The mine sites should be considered in the broader context of historical and more recent actions relating to the local economy. We note the proximity of the port of Arklow, its expansion, and concomitant concerns over sewage, and other pollution. Discharge from the former Irish Fertiliser Industries (IFI) factory, located near Arklow, has had a significant impact on water quality in the lower Avoca River. We also consider other important tourism initiatives, and important
tourist foci and designated country walks. (Much of the following information has been provided by Power 1998, Merrigan and Moore, various urls).

2.6.1 Arklow and oysters
An inquiry into the oyster fishing in the region in 1846 was advised that the Arklow oyster beds were inexhaustible. The area was judged to have the chief oyster breeding beds in Britain and Ireland. From the time of the famine, up until the 1860s, oysters were shipped from Arklow in huge numbers. Over a three month period in 1850 (March to May) 24,000 barrels of oysters were sold to French, English and Irish merchants. By this time the oysters, although abundant, were being poisoned by the mine workings. From Oyster Fisheries: Ireland (1864) we find that the oysters required four months transplanting to purge them of their copper flavour. In 1863, the total catch from the region was 58,000 barrels. Many of these were rebedded before sale on the Welsh coast and off North Co. Dublin to remove the metallic taste. Various sources describe the once thriving oysterculture carried out at the mouth of the Avoca, and the impact of mining on these fisheries concerns. We note Power (op cit.) and various websites of minutes of Dáil and Seanad Éireann:
There are oyster-beds on the coast the produce requires to be freed from a peculiar flavour by the [cleaner?] waters of the Welsh and English coast before it is fit for [food?]. The produce of the copper and lead mines of the Vale of Avoca is shipped from the port. There are cordite and
explosives works, established by Messrs Kynoch of Birmingham, England. In 1882 an act was passed providing for the improvement of the orethe ore harbour and for the appointment of harbour commissioners (oyster 1 url). Seanad Éireann - Volume 2 - 06 February, 1924:
... The Arklow oysters were particularly good, and the French scraped up
these beds and paid what were ... There is no doubt that we could establish
oyster beds ... (oyster 2 url. file currently unavailable).
Dáil Éireann - Volume 197 - 07 November, 1962:
Fisheries... Why can we not establish oyster beds....? Mr. Dillon: We are
about to spend £6 million on the nitrogenous fertiliser factory at Arklow
(oyster 3 url. file currently unavailable).
Consideration should be given to the potential for oyster fisheries following treatment of acid mine drainage from the Avoca River.
2.6.2 The former IFI factory
Irish Fertilisers Industries factory is no longer in operation, and we believe it is currently scheduled for demolition. Until recently IFI discharged trade effluent (rich in nitrogenous compounds including free ammonia) directly into the Avoca River, under licence from the Environmental Protection Agency. The impacts of this discharge are not documented (so far as we have been able to ascertain) but are locally considered to have been significant.
2.6.3 Tourist attractions
Coy (1998) has noted that: at present almost 40% of all Irish coach tours pass through or close to Avoca. Dubliners make more than three and a half million day trips to County Wicklow each
year and many of these currently drive through the mine site, which is bisected by the main road, without being aware of it. With the Meeting of the Waters at one end and Ballykissangle [sic] at the other, the valley is already a tourism promoters dream. Avoca Handweavers
The mill, established in 1723, is Irelands oldest surviving business, famous for woven articles of clothing and accessories. Produce is sold to visitors and there is a café.
The Meeting of the Waters
Made famous by the poem by Thomas Moore the confluence of the rivers Avonmore and Avonbeg is a world famous visitor attraction. A capacious and friendly public house and restaurant is located here. Limited visitor accommodation will also soon be provided.
The chapel in the TV programme Ballykissangel was built by Avoca miners in 1862. The show brought tourists and helped to sustain local gift shops and Fitzgeralds public House in Avoca village. It is three years since the TV series ended and memories and tourists are waning. (see photo 3 page 34)
Moteee Stone
In the Vale, on the way to Rathdrum, sits a massive boulder of native Wicklow granite deposited as a glacial erratic during the last ice age. On a clear day you can see Wales from the top. This large erratic granite stone in a prominent location from which the mine sites can be viewed. In legend it was cast there by the giant Fionn MacCumhaill.
Avondale Forest Park, 528 acres, contains one of Europes most diverse collections of deciduous trees. Power notes the forest of Avondale; the Botanical Jewel reigning supreme. The demesne was laid out in 1777, and the Georgian mansion. Avondale House, birthplace of Charles Stewart Parnell. Part of the house is a museum dedicated to him. The Irish National Foresters movement developed the estates after 1906 as a training college and research station.
Although prone to flooding, Woodenbridge Golf Course is Irelands most picturesque and second oldest. Moore (1998) notes that Woodenbridge, is one of the most beautiful 18 hole golf courses in Europe, and the proximity of other courses:
Arklow Links, European Club at Brittas Bay is one of the great natural links of the world, and Druids Glen venue for the Irish Open. (Moore 1998, for the Vale of Avoca Tourism Committee).
Country Walks
A number of designated walks the Red Walk, the White Walk and the walk to the Mottee Stone bring visitors through the Avoca mines areas. VADA is instrumental in promoting these and is responsible for their signposting. Avoca Tourist Information Office provides information on guided walks in the area.
2.7 Catchment management planning / Water Framework Directive
The forthcoming need, under the EU Water Framework Directive, to plan for and manage natural waters on the basis of catchment management plans must be taken into account when developing plans for the restoration of the Avoca River. This Directive, adopted by the Irish Government in 2000, requires that all waters achieve good ecological status. Based on the existing monitoring criteria, and relevant quality elements, the Avoca River is seriously in breach of this Directive.
River Basin District plans are being developed by the Department of the Environment and Local Government to facilitate the implementation of the Water Framework Directive. It is anticipated at the time of writing, The Eastern River Basin District plan which includes the Avoca catchment will be
launched shortly. For a number of years the Eastern Regional Fisheries Board has been developing a catchment management plan for the Avoca with stakeholders. It is intended that this will be an integral part of the overall River Basin District plan for the Eastern Region.

Map 1 Avoca Catchment, County Wicklow, Ireland. (Courtesy of ERFB)
Map 2 Avoca mine area & surrounding district, Ireland. (Courtesy of GSI)
Map 3 Geology of the Avoca District (Courtesy of GSI)
Map 4 Groundwater level contour map of the Avoca District (Courtesy of GSI)

3. Stakeholder analyses and the case for action
Most problems have owners. Ownership confers obligations, and the rights of individual people or groups reciprocate with obligations. This section addresses the questions of problem ownership, public participation and stakeholder engagement: why, who and what. We need to examine means of inclusion in this ownership problematic by which an individual, acting as a citizen, can be identified as a potential partner. We identify the purpose of stakeholder analysis, responsibilities, stakeholder typologies, stakeholder identification and stakeholder inputs and expectations. It is also vital that any technical intervention with respect to mine water is not considered in isolation from other problems and initiatives about the site and about the river catchment.
3.1 Ways of Understanding
We are concerned here with how different forms of knowledge should come together to inform our project development. We need to consider how the gap between scientific and traditional knowledge can be bridged. Scientific understanding is largely abstract: separate from knowledge possessed by people outside its discourse. Local people have lived with the specific problem for a long time, and will have to live with the consequences of proposed projects for a long time. They
are the primary stakeholder: people most significantly impacted by the project. Groups or organisations which have statutory obligations are secondary stakeholders and both of these need to come together to agree technical process. The physical characteristics of the Avoca mine sites have been widely documented, particularly as a result of recent interest in remediation. This has largely been provisioned through studies by secondary stakeholders, particularly representatives of GSI and Irish Universities. As well as historical texts about the area our attention has also been drawn
to historical letters from landowners to the Government dating from 1901, (supplied by Ned Bayley). These indicate that the scale of this environmental disaster is large as is the length of time it has been allowed to continue - over 200 years. Much time, energy and resources have been spent in the past particularly by local communities in Avoca to alleviate this situation. In the 1900s, Colonel Charles Bayley, a landowner in the catchment spent more than thirty years convincing
the Government that suitable treatment was a necessity to restore this river and it was a project that was feasible.
(Appendix III).
These letters have proven important in highlighting some issues and potential problems concerning the future management of proposed projects, and have been discussed by primary stakeholders.
3.2 Stakeholder Analysis. What and Why?
Stakeholder analysis is the first step in building the relationships of understanding needed for the success of any participatory project or policy. It concerns people upon whom a proposed project has an impact. It assesses their interests, and the ways these interests affect the viability of the project. It provides the social context and background to the project the reason for doing it. It defines the projects purpose. It helps to identify appropriate forms of participation. It provides
the starting point, by establishing which groups to work with, and sets out approaches so that the aims of a project can be achieved. This analysis informs the parameters of the design of the project by identifying roles and goals of different groups, and is intended to formulate the appropriate means of engagement of these groups. It combines institutional appraisal and social concerns in a single framework.
3.3 Who are the Stakeholders?
Stakeholders are people or groups or institutions with interests in a policy, programme or project. Stakeholders commonly claim to represent a broad constituency (sometimes broader than is actually the case).
Primary stakeholders are immediate communities of interest: those people and groups ultimately affected by the problem or the project. This includes intended beneficiaries or people negatively affected winners or losers, and those involved or excluded from the decision making process.
Secondary stakeholders are the intermediaries in the project delivery process, and include government agencies and other institutional bodies. These may not perceive themselves as stakeholders they simply own the process. They may aid or deliver the process. These may include informal groups of people prepared to act as intermediaries. They can be broadly broken into funding, implementing, monitoring or advocacy organisations otherwise governmental, NGO and private sector organisations.
Key stakeholders are those who can significantly influence, or are important to the success of the project. Their support or lack of support will significantly influence the success or failure of the project.
Specific stakeholders are key individuals, such as heads of agencies, who have both personal interests at stake and formal institutional objectives.
Unwitting Stakeholders are people who should be concerned, but are as yet not fully aware of the scope of the issues. Groups and individuals can be more than one or sometimes all of these types of stakeholders. Most of these may be composed of people who have already recognised the critical nature of specific issues, and are addressing them, or can help to do so. (ODA 1995; World Bank 1995; Glick, Hatcher and Ashton 2002).
3.4 Stakeholders Identified
Stakeholder analysis is aimed at enhancing stakeholder involvement in the participatory process, prior to their actual involvement in decision making activities. The commissioning agent (ERFB) has supplied the University of Newcastle with a list of people who they understood would wish or should have an input into this programme. This has been augmented during the progress of the study as our appreciation of the area and the problem grew.
3.4.1 Primary Stakeholders
These have been identified for us as local residents, particularly people active in local heritage initiatives and mining heritage activities, and especially members of the Vale of Avoca Development Association (VADA), anglers on the catchment, and people with businesses which are directly impacted by the environment. Some commercial fishing interests are current stakeholders: IDAS Fisheries and Annamoe Trout Fisheries, some commercial fishing interests are not currently stakeholders but may become stakeholders in the future, Wexford district netsmen for example.
3.4.2 Secondary Stakeholders (Key Stakeholders)
Organisations with statutory obligations associated with the problem have been identified. These are the site owners or potential site owners and organisations currently contributing to pollution at or near Avoca, and primarily comprise various representative bodies within local and central government. They also include groups by whose action (inaction) significant progress can be made to develop an intervention at the site (or otherwise), and to progress potential through
such intervention. These are the local authority Wicklow County Council (WCC), particularly environmental and economic development and tourist sections, and various branches of the Department of Communications, Marine and Natural Resources (DCMNR), [Roinn Cumarsáide, Mara agus Acmhainni Nádurtha] like Exploration and Mining Division (EMD) and the Geological Survey of Ireland (GSI). Other stakeholders include agencies under the aegis of this Department such as The Central Fisheries Board, (CFB), [An Príomh Bhord Iascaigh] and the Eastern Regional Fisheries Board (ERFB), [An Bord Iascaigh Reigiunach an Oirthir]. The Environmental Protection Agency (EPA), [An Ghníomhaireacht um Chaomhnú Comhshaoil], is a government agency with some responsibilities. Stakeholders including Dúchas, the Heritage Service, [An tSeirbhís Oidhreachta], East Coast and Midlands Tourism, and The Mining Heritage Trust for Ireland (MHTI), [Iontaobh Oidhreacht na Mianadóireachta] and, The Irish Farmers Association are
included here. By degrees of personal involvement and enthusiasm many of these stakeholder definitions overlap. Various coalitions of secondary stakeholders, such as county development boards, have not been canvassed at this stage. It will be necessary to key with some of these at the next phase of development of this work. We include a summary of the functions of these organisations as far as they concern the outline of this survey, alongside some of our observations of their role, or potential role, in an advance programme, as identified through elite interviews and personal conversations.
3.5 Stakeholders who responded to this study
3.5.1 Local Residents
Some local residents have been met with. The enquiry has always been met with enthusiasm and kindness. We are particularly grateful to those residents who turn up to meet us time and again on our visits to the site often taking time from work to do so. We have met with Avoca and Glendalough miners, and are grateful for their personal insights to conditions at work, and personal understanding of local geology, which, in turn, helps us and informs our process and
understanding. Many individual respondents overlap with the following groups, and are considered under these headings.
3.5.2 VADA
The Vale of Avoca Development Association was formed to cater for the future development and prosperity of the area through an area action plan. The association succeeded in getting a village renewal scheme for Avoca, including the creation of a village park. The Old Court house has been developed into a heritage centre and a focal point in the village. It provides permanent offices for the local library and tourist office. The history committee of the association have carried out studies of Avoca mining heritage leading to long term preservation. A miners park and a nature and sculpture parks are also proposed (Merrigan 1998: Moore 1998; VADA urls). VADA notes the fame brought by Ballykissangel, and is in a ideal position to build on the benefits that can flow from
developing this theme. They note the important miners chapel of Saints Mary and Patrick, built in 1862, which featured in the TV series. VADA is actively engaged in maintaining and preserving the East Avoca mine site, and has succeeded in raising funds for the preservation of one of the engine houses that was in immediate danger. It has a track record for environmental and heritage engagement. (see photo 4 page 34) We are all encouraged by the enthusiasm for the development of a programme of mine water remediation expressed by VADA and other residents. It is important to stress, however, that the residents are wholly opposed to any notion that the heaps or mine sites should be defiled in any way. If we take the earlier arguments about aesthetics on board then the
people who would stand to be most aggravated by ugly prospects are the people who have to look at them every day. This is clearly not the case here. Local attitudes define the mine sites and heaps in many ways: never ugly! All residents met with, and represented through VADA, are adamant that the heaps add a specific beauty to the place, as well as being an integral part of the vast important heritage of the locale. When we are preparing root definitions it is important to note
the strength of local feeling in favour of the mine sites. This in no way detracts from the programme of work in hand. No one interviewed would be prepared to sacrifice the water quality for the landscape. But there is no need to do this! Intervention for water quality must give full consideration to the important mine sites, including the open pits and colourful heaps.
3.5.3 Anglers
We have met individually with anglers and representatives of anglers, and groups representing angling clubs. These are people who spend much of their leisure time in and around the river, and as such constitute the eyes and ears (and nose) of the catchment. They are able to report to the ERFB when specific problems arise, such as fish kills through pollution spills; or agricultural contamination incidents mentioned below (WCC). They have an everyday understanding of the
river and its problems. Specifics of septic tank runoffs, for example, are noted at Clara Vale, below the bridge by anglers. A focus group was held with significant representation of three angling clubs, the Rathdrum, Aughrim and Wicklow Anglers Associations. These people in turn represent over five hundred members, a significant constituency. These respondents were wholly in agreement with any proposal to clean the river. Some of the angling groups currently form a volunteer riparian stewardship group, looking after all of the problems with the water that they are able. This includes
removing storm detritus day or night. Respondents can do little about the water chemistry. They would be prepared to act if there was something they could do. Many of the anglers would be willing to work with the maintenance of a filter system, so long as they were able to continue to reap the benefits in their sport. Concerns were raised by representatives of these groups about commercial interests and power relationships in the long term.
3.5.4 Hospitality Businesses
Hoteliers and publicans based in the catchment have expressed a general enthusiasm for any intervention that improves the quality of the environment. Some of these are active on various development and tourist boards, and as such constitute key stakeholders. They have, and will contribute freely of their understanding of issues in the development of the project. One hotel hosts an annual dinner for the remaining mining fraternity, and this occasion could provide a focal point firsthand for engagement with heritage.
3.5.5 Aquaculture
One respondent for the Aughrim River fish farmers observed that those in the aquaculture business are being asked to pay significant sums of money to filter their effluent. They have to fit drum filters at considerable expense, yet as things are they are filtering water to put back into a river that is perceived as dead. The businesses are at a loss as to why they should clean water to put into what they perceive to be a poisoned river. However it is evident that cleaning the river will have important favourable consequences for local employment. With the river cleaned brand names such as Wicklow Trout or Smoked Wicklow Trout will be products of international proportions, with significant employment opportunities. The image would sell a product, and the product would be both Trans Atlantic and All Irish. Further up the catchment a fisheries owner has watched flows for many years. Fishing people are close to the river, quite literally, and watch and note its changes. He notes other concerns here relating to E.coli from sewage in the upper catchment; and that childrens bathing was stopped here because of pollution fears. The stakeholders we met who have commercial interests are wholly in agreement with any intervention that will improve water quality.
3.5.6 Wicklow County Council Local Authority stated commitment
We note Wicklow County Councils stated key interests in the mine water and the site, in terms of options and objectives, as applicable to the Avoca-Avonmore Catchment, as stated in WCC Catchment Conversion Plan:1998 2008 (at Wicklow url):
Water Quality Objectives
Strategy: Enhance water quality in the Lower Catchment and maintain good water quality in the Upper Catchment.
Improve wastewater treatment facilities within the Catchment both commercial, industrial and municipal [sic]
Reduce the discharges of Acid Mine Drainage (AMD) into the river
Treat AMD entering the river
Implement a groundwater protection plan
Avoca Mines Conversion Objectives
Strategy: To develop an integrated plan for the mine site which would address its conservation and redevelopment as a major themed heritage tourism centre while addressing and mitigating adverse environmental damage in partnership with all stakeholders.
Implement a leachate/AMD treatment programme with a view to treating the Acid Mine Drainage contribution before 2007
Reduce the visual impact of spoil heaps for sensitive receivers.
Instigate comprehensive feasibility study of AMD treatment and complete within two years.
Investigate fishing and spin-off tourism benefits of treatment of AMD within two years.
Conduct further site investigations to understand the contributors to AMD.
Investigate fund options for treatment of AMD.
Contextually sensitive revegetation of spoil heaps to be implemented selectively.
Tourism and Recreational Development Objectives
Objectives [selected for relevance]:
Development of the Avoca Mine site as a mining interpretative location in accord with a development plan.
Targets [include]:
Identify the recreational needs (water and land) in the Catchment within one year.
The preparation of a conservation plan for extant industrial archaeology at the Avoca Mine sites within one year.
Prepare and publish a fully developed and costed feasibility study for themed mine heritage and tourism centre within two years.
Identify funds for emergency conservation measures and mine heritage centre within two years.
WCC has identified environmental needs and understanding of resident communities through a Community Sector Survey which emphasised a high level of environmental awareness in the catchment (Wicklow url2). A significant 97% of respondents expressed specific concern over water pollution [] The area being a catchment and the graphic nature of the contamination of the lower Avoca River with metalliferous precipitate. The Department of the Environment survey in 1990 reported the two highest percentages of people who responded that they were extremely concerned, in the categories of pollution of rivers, sea and of drinking water / quality. However total expression of concern regarding water pollution was 62%. The catchment area appears therefore to be endowed with a very high level of concern in respect of water pollution.
Further to this -
In response to whether respondents had specific local environmental concerns; 53% positively did. Those concerns specified encompassed a wide range of issues from Nuclear pollution, agricultural pollution, chemical/pharmaceutical pollution, sewage pollution, drinking water quality, litter, dumps, roads, deforestation, small bird numbers, mine pollution and traffic were reported. By far the most frequently stated was pollution arising from particular chemical plants and less frequently pharmaceutical plants. The distinction between the two may not be correct due to the technical nature of the stages in pharmaceutical/chemical plant production processes and the lack of distinction recognised by the general public. Projects, Proposals and Ownership
WCC was responsible for commissioning technical investigations into site regeneration, via the EU LIFE project. Much of the aforementioned is a direct response to this. The local authority is caught in the impossible situation of having to deal with significant potential pollution problems, such as the disposal of domestic and clinical waste, and being the regulator of pollution discharges. Notable amongst the latter are the illegal dumping activities highlighted recently in national press. Its proximity to a megacity with remoteness of aspect makes the county a target for polluters in various
guises. We have noted primary stakeholders concerns with the need for comprehensive, catchment wide, programmes related to pollution discharges. An unfortunate set of circumstances, particularly relating to crisis management and subsequent failure to project consequences of technical decision making, led to the abandoned mine, Ballymurtagh open pit (with mine waters running through it and discharging into the river) being used by WCC as a landfill site. This finally closed at the end of December 2002. Throughout the active life of the landfill site no consideration was given to keeping
landfill leachate and mine based groundwaters apart. At the time there was no knowledge of the impact of the landfill on the receiving watercourse. As a result of this, through interaction with water running through the mine, and open access of the mine floor to abandoned deep mine workings, leachate from the landfill is animated by, and further contaminates, mine groundwaters. These flow to the surface at Ballymurtagh adit, and after passing under the main road and a short passage overground, enter the river. WCC owns the land where treatment of Ballymurtagh discharge will take place. It also owns significant responsibilities with respect to the discharge itself. Initial conversations with environmental section of WCC show an understanding of the issues at stake, especially in respect to WFD, and a willingness to make the necessary resources available to put things right. Other water contamination concerns in the lower catchment
Concerns of respondents to WCCs research were also noted in relation to pharmaceutical industries discharges. We understand through ERFB colleagues that as far as they know there are no current issues relating to this. The fertiliser factory finally closed in 2002, and is currently being decommissioned. It may, however, still pose water quality concerns into the future. Respondents have made us aware of some of the technical concerns of the Irish Fertiliser Industries (IFI)
plant which was located not far upstream from Arklow. IFI had been State controlled, and was critical in its time to the economy of the Nation. As such there were few constraints to its development. Furthermore, as the river here was perceived to be dead pollution was of no particular concern. Damage from the plant began to be recognized in the 1970s. In 1995 ammonia recovery was implemented, before which elemental nitrogen was pumped into the river. The 90s intervention reduced the volume from 2 tons of total nitrogen to less than one ton, of which ammonia represented one third of the total. The IFI landfill site, within the curtilage of the plant, was engineered over forty years ago primarily to accommodate the waste products from phosphoric acid. This included gypsum, which may be mildly radioactive, and carbon from burning heavy fuel oil. Although this landfill is well bunded with clay a hundred year flood could catastrophically activate these materials. Economic Development
Within the aforementioned WCC-generated documents there is a strong commitment to the development of the mine site itself. The Council has a commitment to the film industry, and accommodates tours of film locations. We note a Michael Collins Trail, a Braveheart Trail, and Ballykissangel. The WCC film commission also has a commitment to the
development of location of films in the County. Respondent from WCC economic development team has worked in close liaison with VADA and various tourist initiatives and activities. Respondent would welcome any intervention to improve the water quality, and hence angling
tourist potential. Respondent would wish to see remediation co-ordinated with other development activities. Respondent suggested the possibility that government could consider possibilities of local zoning for economic development, such as tax incentives for location of small-medium enterprises in the valley and around the site, especially as far as regeneration or tourist based industries are concerned.
3.5.7 The Environmental Protection Agency (EPA)
The EPA conducts on-going surveys to assess river water quality and trends, with respect to physico-chemical water quality standards and biological characteristics []
The Groundwater monitoring programme is implemented primarily by the EPA, local authorities and the Geological Survey of Ireland. Monitoring is undertaken to assess general groundwater quality and in particular the quality of groundwater used for public and private drinking water supplies (EPA url). EPA will own some responsibility for enforcing WFD (at some point in the future). Regulation as far as Avoca is concerned has been identified by EPA personnel as the current responsibility of the local authority (WCC). Because Avoca is not active it is not currently a scheduled industry under the aegis of EPA.
EPA representative met with pointed to the fact that the Avoca mine water discharge represents the single worst river pollution in Ireland. The respondent agrees wholly with the principle that the mine water should be remediated. EPA is also interested in the development of catchment strategy plans.
3.5.8 Department of Communications, Marine and Natural Resources (DCMNR).
We note the Departments stated key roles and functions as they are germane to this report:
Supporting the sustainable management, development and contribution of Irelands inland fisheries
Promoting minerals and hydrocarbons exploration and development for the optimum benefit of the Irish economy, consistent with the highest standards of safety and environmental protection
Supporting and facilitating the development of the marine and natural resources sectors by promoting effective research, technology, development and innovation Within DCMNR the Exploration and Mining Division is charged with:
The application of the Minerals Development Acts 1940 to 1999 to minerals exploration and development
The encouragement of the early identification and responsible development by private investors of the Nations mineral deposits in accordance with best international practice
Enhancing the attractiveness of Ireland for international and national minerals investments by active
promotional measures. Many of these functions are wholly complementary to proposed remediation of the mine site. We have been unable to ascertain any potential conflict of interest with these stated objectives and a proposed remediation project. The Geological Survey of Ireland GSI is the Irish National Earth Science Agency. It is responsible for providing geological advice and information, and for the acquisition of data for this purpose. GSI produces a range of products including maps, reports and databases. Members of GSI have made significant contributions to this survey, both in terms of supplying reports and technical data and giving time to answer questions about the site, its problems and its potential. It is important to note that whilst opinions (sometimes of a technical nature) have been proffered by individual members of the Department these do not necessarily reflect the policy or views of the Department. Our consideration was largely confined to the East Avoca site and discharge, comprising the open pits of Tigroney and Cronebane, and the heap known as Mount Platt. There was a general consensus amongst experts within the Department that the mine sites are unique and have considerable educational potential. This is the most important historical mining site in Ireland. One respondent described the exposed geology as the Rockery in the Garden referring to Wicklows status as the Garden County. They would not like to see this landscape destroyed particularly the exposed geology, but, without exception, would be pleased to see actions taken to remediate the water.
The Department has been charged with establishing land ownership around the mine sites. Avoca Mine Ltd went into receivership in the 1980s, since which time the title to the ownership of the mines (and the surrounding area, and consequently the ownership of the problem of discharge of pollution into the main river) is under examination. It would appear that this dispute is internecine ownership and responsibility ultimately rests with one or other government department. National Government owns the responsibility of the East Avoca mine site.GSI provided technical support to the EU LIFE project, and at that time identified scope and potential for study areas in ecology, geology and environmental engineering about the mine sites. The mine sites have become habitats in their own right, for roosting bats and peregrine falcons. They are a unique ecosystem. The spoil heaps are stabilising themselves and there is no serious concern over wind borne pollution. There is no known risk to human health from metal ingestion. Geologists here have pointed to parallels with the Mynydd Parys mines in Wales and Wheal Jane in Cornwall. Respondents also pointed to the initiatives abroad that generate an economy through celebration of mineral heritage cultural parks such as those in the Asturias and Andalusía regions of Spain, and the Killhope Lead Mining Centre in County Durham, England. Nearer to home the Breffny Mountains are exploiting various facets of the natural and built environment, culture, folklore, etc. Tourist coach itineraries visit the Breffny mountain landscape, why not Avoca? Respondents drew attention to the formal layouts of Mount Usher Garden. The rockery in the garden can be enhanced as an interpreted setting. A risk assessment relating to general health and safety concerns will need to be carried out prior to any exercise which invites the attention of the general public.
As well as publicising Irelands unique mineral heritage, part of the remit of the mining division is making miningattractive to potential investors. If the global economic climate was right there may be scope to develop mining prospects here. A central concern was cost. Respondents wholly concurred that something must be done and anything will cost something. Best option is to celebrate the site, its history, and its geological uniqueness. Overall proposal is remediation of water tied to broad collection of cultural/heritage/educational measures.
Our attention was drawn by geologists to the wider geological uniqueness of the catchment as represented by the mines at Glendalough and elsewhere.
3.5.9 The Central and Eastern Regional Fisheries Boards
The Central and Regional Fisheries Boards are the State agencies responsible for conserving, protecting, developing, managing and promoting Irelands inland fisheries resources. They have the remit to support sustainable economic activity, job creation and recreational amenity. They are the statutory agencies responsible for inland fisheries in the State and operate under the aegis of the Department of Communications, Marine and Natural Resources. The principal function of the Central Fisheries Board is to support, co-ordinate and provide specialist services to the
Regional Fisheries Boards and advise the Minister on inland fisheries policy. The ERFB is responsible for conserving, developing, managing and promoting the inland fisheries and sea angling
resources from the east coast border with Northern Ireland to the South Wexford coast. It commissioned this report into remediation of the Avoca River mine waters. In 2001 The Eastern Regional Fisheries Board embarked on a catchment management approach for the Avoca catchmentas enshrined in recent fisheries legislation (1999 Fisheries Amendment Act). This process involved developing a set of principles, guidelines and a methodological framework with the various stakeholders in the Avoca catchment to assist in the sustainable development and management of this resource. The principal purpose of the Avoca Catchment Management group is to agree a plan between the stakeholders which will aim to environmentally rehabilitate this river and its tributaries bringing environmental, social and economic benefits to all. A primary objective of the group is to restore the river to its full potential as a salmonid fishery. The Avoca catchment management group believe this is essential in meeting the requirements of the Water Framework Directive. A process of consultation with stakeholders in the catchment was initiated, the main issues were identified and the
responsibilities of the various players were discussed. Parallel to this the Central and Eastern Regional Fisheries Boards carried out a comprehensive fish stock assessment survey and independently ERFB undertook a baseline water sampling programme. Findings from the fish stock survey were positive with juvenile trout widely distributed and juvenile salmon present at 74% of the sites sampled. ERFB URL notes the strategic location of its region in relation to its proximity to major airports and ferryports [which] means that quality angling is only a one hour drive away. In view of the reduction of the salmonid potential of the Avoca River in respect to its proximity to Dublin and ferryports a massive resource under its charge is not realised.
3.5.10 Dúchas
Dúchas colleagues have been particularly helpful in working with us to facilitate meetings with other stakeholders. We are also grateful for their supplying us with historical letters about the Avoca mine water problems. We have been shown important mine sites in the upper part of the catchment, especially at Glendalough.(see photo 5 page 35). They have assisted at mine site visits. In keeping with Water Framework Directive, water is above all a heritage issue. WFD notes that water is not a commercial product like any other but, rather, a heritage which must be protected, defended and
treated as such (WFD.1.1).
Dúchas has responsibility for the implementation of EU Habitats Directive. The lamprey and fresh water pearl mussels, present in the Avoca catchment, are protected under this directive, and are an indicator of water quality. Dúchas personnel have a professional stake in the wildlife of the catchment, and an interest in the roosting bats and the peregrine falcons in the East pits. There are unique species of macro fauna present in the upper reaches of the catchment. We have been made aware of the erosion of the important mine sites of the upper catchment by storm water. These sites
have an international importance, but not at present are not recognised as being of national significance. Interventions to protect these by diverting storm water channels are piecemeal. As always meagre resources due to low priority are perceived as the cause. In the wider scheme of things if mining heritage were given greater consideration across the county and the catchment then this might prove helpful in reprioritising these sites. Much of the upper catchment is designated as a Special Area of Conservation (SAC), and although acidic runoff is perceived as being linked to fish kills or absences of fish there is no scope for intervention in the immediate vicinity. It was explained to us that this is partly the result of conifer plantation in a tributary valley above the Upper Lake,
Glendalough. Although no intervention can be considered it is possible that the aggregate acidity of the catchment does not help this predicament. Dúchas personnel are engaged in scoping the wider Avoca Catchment Plans, and have been instrumental in their foundation. Essentially Dúchas colleagues met with are strongly in favour of any intervention to ameliorate the condition of the water, particularly Avoca mine waters, and would strongly support (as resources permit) heritage and educational initiatives.
3.5.11 East Coast and Midlands Tourism
East Coast and Midlands Tourism has a responsibility to promote tourist access to the county for angling, walking, equestrian, golf and other activities. Tourist angling in the Avoca catchment is not especially important at this moment in time but it would welcome developments in that field. It would be supportive of systems that cleaned the river and amplified the angling dimension. It would be supportive of heritage interpretation and provision some support in terms of infrastructure, information, etc. Their involvement would key the developments of the site with initiatives such as
special walks.
3.5.12 Mining Heritage Trust of Ireland (MHTI)
Representatives of MHTI were met with at ERA MAPTEC, and as individuals within GSI. Individual respondents who, as a result of personal mining engineering and mining geological backgrounds, had an earlier interest in the development of a mining heritage centre were also met with. We aggregate their appreciation of the site and its potential, because by and large they concur. An earlier lease to develop a commercial heritage concern on the Avoca site has lapsed. MHTI boasts a significant membership, in Ireland and elsewhere. The Mining Heritage Society of Ireland was founded in 1996 to develop public awareness, appreciation, conservation and enjoyment of all facets of mining heritage throughout Ireland. The Society converted to a Trust in 2001. (MHTI url)
It has presented exhibitions at GSI Dublin offices as a focus on heritage week 2001. It has many spectacular sites under its aegis in Ireland: Bunmahon, Allihies, Mount Gabriel, others - the Avoca site is probably its most important in terms of scale and visual impact. We are particularly grateful to MHTI for images, maps, information (such as information about groundwater flows in relation to climate) all given freely and with conviviality. Although it is widely understood that there has been ancient mining in the catchment, at Avoca and other sites, it is, as with all mine sites, difficult to establish evidence of this because the surface expression of the sites invariably are altered by more recent extractive activities. Members have extensive knowledge of and contacts with heritage groups elsewhere, particularly Parys Mountain in Wales. Much needed heritage interpretation could be better effected if there was beneficiation of water. One of the ways of doing this might be through a heritage based process. In earlier times copper was extracted from the water through precipitation process described as heap leaching. Reinstating this process could actively beneficiate the water as well as providing the locus for education activities and research.
Respondent noted: we know that the heaps are not toxic in the air because of the grain size of the shale even in drought conditions this would not be affected. Therefore the heaps in and of themselves are not problematic. (Some - but not all MHTI respondents perceived the heaps themselves as an important asset). Respondents would like to see the site served in its industrial setting with serious conservation measures to preserve the engine houses. MHTI and VADAare each aware of the work that the other is doing, which is entirely complementary. At Allihies in West Cork stonemasons from Cornwall have been employed in the restoration of engine houses. The expertise is available to Avoca when needed. Silver mines at Nenagh, another important heritage site, were awarded significant heritage funding. Another important factor re Avoca is its proximity to Dublin. Underground workings are accessible, and with the right package (and insurance) underground tours could be effected. The MHTI is strongly supportive of actions that clean the river whilst respecting the integrity of the mine sites.
3.6 Root definitions. The concerns and aspirations of stakeholders and where they concur
Stakeholders are not merely people with an opinion they are people, groups and organisations that have an interest something at stake in a proposal or project. They may also have influence over the project. They are therefore both people who are effected by, and people who can effect a project.
Residents, especially active through VADA, are active in environmental issues and the preservation of built heritage in the area. Respondents are keen to preserve the unique heaps as integral to any development. We have not met with anyone with opposing views, and this attitude is not in conflict with any other current initiative or group understanding.
Intervention with mine water pollution so as to improve the quality of the water in the river is welcomed by all respondents met with. In earlier social surveys (WCC, EU LIFE) local residents have clearly prioritised water quality concerns, especially in the lower catchment. All stakeholders engaged with in this enquiry have expressed unreserved enthusiasm for cleaning up the worst river pollution in Ireland.
Respondents who participate in active environmental activities or riparian stewardship would assist a remediation project where feasible. An intervention that relies on active participation (volunteers or possibly stewards employed through an economy amplified as a consequence of water improvement) can be considered. The goodwill is there to actively man a project (subject to definition of details). Technical planning may goahead under the assumption that issues of maintenance will be addressed.
Businesses would benefit significantly from water quality improvement. This would have spin-off benefits forall.
Most respondents agree the importance of an interpretation of the mine sites and buildings. No one disagrees that there is a complementarity in acting to improve water quality, create access to the site (although representatives of DCMNR reserve judgement concerning access due to duty of care issues and public safety liability), celebrate mining heritage, and develop a programme of education and research.
The important mine buildings need full conservation consideration. Other important cultural sites relating to mining in the catchment need consideration within this framework.
These strategies all key with broader tourist initiatives.
A clean Avoca River will be an asset that will lead to realising significant economic potential.
Any measures towards remediation must be planned and delivered with full sensitivity to the site, its cultural, heritage, economical, geological, wildlife, flora and tourist concerns and potential.
The local authority has a continued commitment to improving water quality for a very long time (effectively, for ever).
Both Local Authority and National Government are ultimately responsible as owners of the problems within the context of WFD.

4. Data sources and quality
4.1 List of data provided by ERFB and other contacts
The ERFB supplied hydrochemical data, collected over the period October 2001 to September 2002, for the discharge from the Deep Adit and sites upstream and downstream of the discharges in the Avoca River. A limited amount of data was also available for the remainder of the catchment, providing a useful comparison between the largely unpolluted water constituting the majority of the catchment and the highly polluted river downstream of the mine water discharges.
In addition, the ERFB supplied statistics on rod catches from local angling clubs on the tributaries to the Avoca (Aughrim, Avonmore and Avonbeg rivers) and collected further hydrochemical data for the Ballymurtagh Adit from Wicklow County Council. This data was collected by the Council during routine monitoring of leachate from their landfill site at
the Pond Lode Open Pit in West Avoca. The CFB & ERFB conducted an extensive survey of fish stocks in the Avoca catchment in 2002 (Roche, 2003). This provided data on the species present with information on the status of the fishery. The GSI provided hydrochemical data, for both the Deep Adit and Ballymurtagh Adit discharges as well as the Avoca River upstream and downstream of the discharges, from monitoring periods undertaken in November-December 1993 and August-October 1995. The data has been collated into reports by Flynn (1994) and OSuilleabhain (1996)
respectively which also contain valuable information on groundwater level monitoring and sampling and flow gauging. The most intensive sampling campaign, comprising adit flow and metal discharge rates in both the Deep Adit and Ballymurtagh Adit discharges, was carried out by Trinity College Dublin, from May 1994 to May 1995, as documented by Gray (1995a, 1995b). In addition, various sites on the Avoca River and surrounding tributaries, along with surface runoff, were sampled and analysed by Trinity College in the period May-October 1994, as reported in Gray (1994a). Flow data was also available for the Avonmore River at Rathdrum (Gray, 1994b), which was used to estimate the flows in the Avoca River (Section 6.1).
4.2 Creation of database
It is apparent from the list of data given in Section 4.1 that no continuous programme of hydrochemical sampling has been undertaken on either the mine water discharges or the Avoca River. The available data is held by various sources and collated into individual reports but there is a lack of cohesion between the data-sets with each representing discrete, short periods of sampling. Therefore, a Microsoft Access Database has been created to process all available data into a
consistent, usable format to support further work. This comprises surface water hydrochemical data, divided into 9 sites representing the discharges from both the Deep Adit and Ballymurtagh Adit and locations upstream and downstream of
the discharges in the Avoca River, as well as several tributaries to the Avoca River. Where a large enough data-set is available (i.e. for Deep Adit and Ballymurtagh Adit discharges), charts showing the most important parameters (i.e. pH, Fe, Zn, Cu) and their variation with time are given. The database also shows flow duration curves for the Deep Adit, Ballymurtagh Adit and Avoca River, essential for the calculation of design flows (Section 8.1). Finally, several short extracts are provided detailing a description of the site, the local geology and hydrogeology and mining history. The
database has been loaded onto a cd which accompanies this report.
4.3 Quality and usefulness of data from disparate sources
As mentioned in Section 4.2, no continuous programme of hydrochemical sampling has ever been undertaken in the Avoca Mines area but in order to carry out a sufficiently robust assessment to justify investment in remediation works, it is absolutely essential that at least one years worth of continuous sampling be undertaken. The ERFB data, although representing a complete chemical analysis data-set for the Deep Adit and Avoca River, excluded the Ballymurtagh Adit
and there are concerns over data quality, given the unavoidable delay in analysing the samples after initial collection. The GSI study in August-October 1995 yielded the most comprehensive hydrochemical data-set available to date for the Avoca system, covering both the adits and the Avoca River upstream and downstream of the discharges. The analyses are sufficiently detailed to support calculation of total acidities. However, the sites were only sampled on 4 occasions over
this period. Similarly, the samples collected by the GSI in November-December 1993, although comprehensive, were concerned with East Avoca alone so no data for the Ballymurtagh Adit are available for this period which, in any case, only represented 2 sampling occasions. The intensive sampling campaign by Trinity College Dublin did endure for an entire year but it appears that the only metals analysed for were iron, zinc, copper and cadmium. The omission of aluminium, manganese and lead precludes the calculation of total acidity from these data (which is a key requirement for treatment design), not least because aluminium is known (from GSI data) to be present at concentrations in excess of iron in the Deep Adit waters.
Furthermore, other ions omitted from this data-set, such as calcium and sulphate, need to be quantified accurately in order to allow calculation of possible scaling problems (with gypsum and calcite, for instance) in treatment systems. This can be a particular problem in limestone-based passive treatment systems and / or in lime-based active treatment systems (Younger et al., 2002). The data provided by Gray (1995a) are nevertheless very useful in revealing wide variation in
discharge rates from the adits over the sampling period, some of which correlate with variations in contaminant metal concentrations. Additional data were discovered in the report by Gray (1994a), including sulphate concentrations in the Deep Adit and Ballymurtagh Adit discharges from May to October 1994 and aluminium concentrations in the same discharges on several occasions. However, there was still insufficient data to support calculation of total acidities. More recent hydrochemical data for the Ballymurtagh Adit discharge and Avoca River, collected by Wicklow County Council, provided only one sampling occasion (November 2001) containing a representative hydrochemical analysis but this does not include aluminium which (as mentioned above) has been found to be present at high levels in other Avoca waters. However, these data confirm the presence of elevated concentrations of ammonium in the discharge from the
Ballymurtagh Adit, which is a pollutant cation rarely found in mine waters (it is only significant in deep, alkaline coal mine waters in the UK, for instance) and is thought to be derived from the landfill leachate which also discharges through this adit. In order to quantify the impact of the mine water discharges on the Avoca River, flow data is required for the river as
well as the discharges. There are no flow-gauging stations on the lower reaches of the Avoca River, downstream of the mine area. Therefore, the nearest permanent and operational gauging station to the study area, at Rathdrum on the Avonmore River, was used to estimate flows in the Avoca River, by up-scaling (Section 6.1). This, understandably, is not as accurate as using data from an existing flow gauging station.

5. Hydrochemistry

5.1 Principles of calculating acidity from pH and metals concentrations
Mine water pollution results from the oxidative weathering and dissolution of sulphide minerals, particularly pyrite, which takes place in mine voids exposed to air and water. Metals (e.g. iron, zinc, copper), sulphate, and, in the case of pyrite, acidity, are released into percolating waters which contaminate the groundwater and surface waters to which they discharge.
The first step in the pyrite (FeS2) oxidation process involves the production of ferrous iron (Fe2+), sulphate (SO42-) and hydrogen ions (H+) (Younger et al., 2002):
FeS2(s) + 72
O2(aq) + H2O(aq)  Fe2+
(aq) + 2SO2
(aq) + 2H+
If the environment is sufficiently oxidising the ferrous iron will be oxidised to the ferric form (Fe3+) in the presence ofbacteria:
(aq) + 14
O2(aq) + H+
(aq)  Fe3+
(aq) + 12
Upon hydrolysis, the ferric iron spontaneously precipitates as ferric oxyhydroxide (Fe(OH)3 and releases more protons
(aq) + 3H2O(aq)  Fe(OH)3(s) + 3H+
This ferric oxyhydroxide precipitates as an orange ochre that coats the stream bed and banks and can be ecologically
devastating (Younger et al., 2002). Any ferric iron not precipitating can also oxidise pyrite to produce ferrous iron and
further acidity according to:
FeS2(s) + 14Fe3+
(aq) + 8H2O(aq)  15Fe2+
(aq) + 2SO2
(aq) + 16H+
The overall result of the above reactions is to produce water with a low pH and high iron content. In addition, the acid produced by the oxidation process is able to dissolve other metals, such as copper and aluminium, from clay minerals which in themselves do not contribute to the formation of acid waters. The hydrolysis and precipitation of the metal ions discussed above releases protons, giving rise to proton acidity (H+), since the metal ions act as weak acids. Acidity can generally be defined as the amount of strong base that is needed to raise the pH of the water to any defined pH (Younger et al., 2002). The contributions of dissolved metals to total acidity are so important in most mine waters that total acidity (mg/l as CaCO3 equivalent) can be accurately calculated using the following expression:
50[2(Fe2+/56)+3(Fe3+/56)+2(Mn2+/55)+3(Al3+/27)+2(Zn/65)+1000(10 -ph)]
Other cations such as Cu (copper) and Cd (cadmium) can be added to the above expression if they are present at significant concentrations, using their atomic masses and valencies as shown. If the total acidity is not matched by sufficient alkalinity (or will not be so matched after treatment), then hydrolysis of the various metal ions will lead to development of a low pH, which will slow further metal removal reactions and degrade water quality (Younger et al., 2002).
5.2 Mine water discharges
The complete hydrochemistry data-set gathered for the Deep Adit and Ballymurtagh Adit discharges is given in the Access database (enclosed on cd). It is apparent from this that both adit discharges are of very poor quality, with low pH (~3-4), high conductivity and very high metal and sulphate concentrations. Total acidity is generally in the range 600-1000 mg/l CaCO3, with a couple of exceptions in the data collected by the ERFB but this is believed to be due to the delay in analysis of the samples after collection (Section 4.3). The effect of this poor quality water is immediate on the Avoca River, despite dilution, with a decrease in pH (from near-neutral to 5) and a significant rise in metal and sulphate levels evident compared to the relatively uncontaminated water upstream of the mines. (While high manganese concentrations do occur in waters upstream of the Avoca mines, at the Meeting of the Waters, this is the only metal present at more than background values, and is generally not ecotoxic (though it contributes to total acidity). This manganese may be sourced from disused lead-zinc mines further up the Avonbeg Catchment). It is also evident that the
adit discharges are not the only source of polluted drainage in the vicinity of the mines, with significant runoff from spoil heaps and baseflow to the river adding to the poor quality of the river water. (see photo 6 page 35) A look at the variation in hydrochemistry over time (Figures 1 and 2) reveals that, despite the gaps in the data-set representing periods when no samples were collected, an apparent improvement in water quality has occurred. This relates to the first flush, representing the products of past pyrite oxidation incorporated into solution when the mine workings begin to flood (Younger et al., 2002). With time, and the passing of the first flush, water quality gradually
improves. Iron concentrations, in particular, in the Deep Adit discharge have reduced from approximately 120 mg/l in 1993 / 1994 to less than 20 mg/l in 2002. Zinc and copper concentrations have also decreased in both discharges, although to a lesser extent. There has been little change in the pH of the Deep Adit discharge but a slight increase has been observed in the Ballymurtagh Adit discharge from 3.5 to greater than 4.

Figure 1 Variation in hydrochemistry of Deep Adit discharge (1993 to 2002)

Figure 2 Variation in hydrochemistry of Ballymurtagh Adit discharge (1993 to 2002)

Photo 1

Photo 1 (above) Mine water discharge from the deep adit outfall at the point at which it joins the Avoca River

Photo 2 (above) Exposed Geology of East Avoca Mine

Photo 3 (above) Plaque in the courtyard of Avoca Chapel

Photo 4 (above) Restored chimney at East Avoca

Photo 5 (above) Abandoned mine buildings, Glendalough

Photo 6 (above) Acid Mine Drainage lagoon at Whites Bridge, Avoca

Photo 7 (above) Water flowing through the Tigroney pit

Photo 8 (above) Sampling at point where water emerges into Tigroney Pit

5.3 Surface water sampling sites
As stated in Section 4.2, the hydrochemical data contained in the database consisted of data from 9 sites, covering the range of data collected from the various sources. The sites are as follows:
Lions Bridge: Upstream of the mine water discharges, on the Avonmore River before it joins the Avonbeg River to create the Avoca River.
Whites Bridge: On the Avoca River, a short distance upstream from the Deep Adit discharge.
Deep Adit: The main discharge from the East Avoca mine workings.
Ballymurtagh Adit: The main discharge from the West Avoca mine workings.
Coalyard: On the Avoca River, 300 metres downstream from the Ballymurtagh discharge.
Avoca Bridge: On the Avoca River, further downstream from the discharges.
Vale View Stream: Tributary to the north of the West Avoca mine site.
Red Road Stream: Tributary to the south of the West Avoca mine site.
Sulphur Brook: Tributary on the east side of the Avoca River.

6. Flow data: gauged and estimated
6.1 Avoca River
As explained in Section 4.3, flow data was not available for the Avoca River so a synthetic flow data-set was created using measured data from a gauging station at Rathdrum on the Avonmore River. This was carried out by calculating the mean flow rate per km2 at Avonmore and recalculating the flows using the catchment area feeding the Avoca River close to the mine area. The following equation was thus used to estimate flows in the Avoca:
QAvoca = QRathdrum × 362 233 where 233 and 362 are the catchment areas feeding the 2 sampling sites, Rathdrum and Avoca, respectively, as given in
Gray (1994b) and calculated using GIS.
To compare with the only flow data that was available for the Deep Adit and Ballymurtagh Adit discharges, mean monthly flows were calculated for the Avoca River for the 12 months from May 1994 to April 1995. The estimated flows are given in Table 6.1 below.
Table 6.1 Estimated mean monthly flow in Avoca River close to mine area (May 1994 to April 1995)
Month Mean flow (m3/s)
May 1994 11.19
June 1994 4.35
July 1994 1.86
August 1994 3.42
September 1994 4.66
October 1994 7.30
November 1994 14.60
December 1994 18.49
January 1995 33.25
February 1995 25.32
March 1995 19.11
April 1995 5.44
As expected, flows are highest in the winter months with a peak flow of 33.25 m3/s in January while the lowest flow was recorded in July, with a value of 1.86 m3/s. The synthesised hydrograph is shown in Figure 3.
Figure 3 Synthesised hydrograph for Avoca River close to mine area
(May 1994 to April 1995)
In order to select design flows for a proposed treatment system, an idea of the length of time for which particular river flows are expected to be exceeded is essential. Aflow duration curve consists of the cumulative frequencies of occurrence in selected discharge classes converted into percentages of the total number of days / months. The area under the curve is a measure of the total volume of water that has flowed past the gauging station in the total time considered. Although flow duration curves from monthly mean discharges can be derived, their usefulness is much less than those constructed from daily mean flows. Therefore, using measured flow rates given in Gray (1994b) for the Avonmore River at Rathdrum, estimated daily mean flows were calculated for the Avoca River close to the mine area for the period 1990 to 1993. The resultant flow duration curve for the Avoca River is shown below in Figure 4.
Figure 4 Flow duration curve for Avoca River close to mine area derived from synthesised
hydrograph using daily mean flows (1990 - 1993)
6.2 Deep Adit
Monthly mean flow rates for the Deep Adit discharge were gained from Gray (1995a), covering a 12 month period from May 1994 to April 1995. A seasonal pattern is evident from Table 6.2 and the hydrograph shown in Figure 5, with flows at their highest in the spring then declining through summer to reach lowest flows in the autumn. A peak flow of 37.3 l/s was observed in February while the lowest flow of 8.5 l/s was recorded in October. A comparison between Figures 2 and
3 shows that peak flows in the Deep Adit occur slightly later than in the Avoca River and persist for longer, due to the effects of recharge and the time taken for the groundwater flow to emerge at the discharge. Similarly, there is a lag time between the lowest flows estimated for the river and those measured in the Deep Adit discharge, with a more gradual decrease in flow shown by the discharge.
Table 6.2 Mean monthly flow in Deep Adit discharge (May 1994 to April 1995)
Month Mean flow (l/s)
May 1994 23.8
June 1994 16.8
July 1994 12.1
August 1994 10.3
September 1994 10.2
October 1994 8.5
November 1994 12.7
December 1994 18
January 1995 21.8
February 1995 37.3
March 1995 24.8
April 1995 15.8

Figure 5 Hydrograph for Deep Adit (May 1994 to April 1995)
As with the flows in the Avoca River, it is essential to know the length of time for which particular flows in the discharges are expected to be exceeded. In the case of the Deep Adit discharge, the only flow data available are monthly mean flows (Section 4.1) which are not as useful as the daily mean flows estimated for the Avoca River. However, a flow duration curve for the Deep Adit discharge was still produced and is given in Figure 6.
Figure 6 Flow duration curve for Deep Adit discharge using monthly mean flows (May 1994 to April 1995)
6.3 Ballymurtagh Adit
As with the Deep Adit discharge, monthly mean flow rates for the Ballymurtagh Adit discharge were available in Gray (1995a) for the period May 1994 to April 1995 and showed a seasonal cycle with the highest flows in spring declining through summer to reach lowest flows in the autumn. The peak flow in the Ballymurtagh Adit discharge during this period, 35.2 l/s, was recorded in February with the lowest flow of 6.1 l/s observed in October. This compares favourably with that given in Section 6.2 for the Deep Adit discharge, the only difference being a slightly slower rate of recovery in
the Ballymurtagh Adit discharge in winter due to differences in the post-mining hydrological nature of the two sites(Gray, 1995a). The mean monthly flows for the Ballymurtagh Adit discharge are given in Table 6.3 and a hydrograph is shown in Figure 7.

Table 6.3 Mean monthly flow in Ballymurtagh Adit discharge (May 1994 to April 1995)
Month Mean flow (l/s)
May 1994 23.7
June 1994 18.1
July 1994 11.7
August 1994 10.2
September 1994 9.3
October 1994 6.1
November 1994 9.8
December 1994 13.6
January 1995 19.2
February 1995 35.2
March 1995 29.4
April 1995 19.1
Figure 7 Hydrograph for Ballymurtagh Adit (May 1994 to April 1995)
As with the Deep Adit discharge, only daily mean flow data are available for the Ballymurtagh Adit discharge (Section 4.1) but the corresponding flow duration curve is given in Figure 8.
Figure 8 Flow duration curve for Ballymurtagh Adit discharge using
monthly mean flows (May 1994 to April 1995)

7. Biological effects of mine water pollution on Avoca River

Data on the effects of the mine water discharging into the Avoca River on the freshwater ecosystem have been collected by the ERFB and the Environmental Protection Agency (EPA). Routine monitoring of benthic invertebrate communities in the Avoca River downstream of the mine water discharges has consistently shown a significant impact on both diversity and productivity (Gray, 1995c). Chironomidae, a pollutant-tolerant genus, show a relative increase as a
proportion of the total macroinvertebrate population downstream of the mine water inputs. Overall, a clear decrease in faunal abundance and the number of taxa present is evident, with only a slow improvement downstream which never amounts to full recovery.
7.1 Effects of mine water pollution on the Avoca River Fish Kills
Wicklow County Council has identified a high level of environmental awareness in the catchment with a significant 97% of respondents expressing specific concern over water pollution in a community sector survey. The Eastern Regional Fisheries Board in trying to h