Useful Data for Irish River Conservation / Water Quality

IFI submission highlights a number of important environmental issues in relation to Bord na Mona landbank

Environmental Impact Assessment Report in relation to applications by Bord na Mona for Substitute Consent for its historic peat extraction activities on 41 individual bog units and future peat extraction activities on selected individual bog units situated across Counties Offaly, Westmeath, Laois, Meath, Kildare and Longford

IFI have reviewed the maps supplied and we note that huge areas of Bord na Mona owned peatlands have not been included. Our understanding is that this EIAR relates only to 41 sites where Bord na Mona proposes continuing the harvesting of peat.

Our knowledge of a number of the Bord na Mona sites which have not been included, is that maintenance of the drainage systems of these peat extraction areas is still undertaken. These drainage maintenance schemes involve the regular excavation of significant quantities of peat and we ask why these sites were not included as part of this EIAR.

IFI concerns relating to water quality issues include:

• The WFD Ecological Status/Potential for numerous waters draining these Bord na Mona peatland areas is “Poor”, while for many the WFD Risk calculation is that they are “At Risk”.

• The WFD Characterization Reports for numerous waters draining these Bord na Mona peatland areas identifies peat extraction as a significant pressure, with organic pollution the main impact associated with peat extraction.

• To facilitate peat harvesting deep drainage channels were constructed throughout these sites. Deepening of fisheries water-courses adjacent to and downstream of peatlands was also undertaken to facilitate this peat harvesting. These significant alterations lowered the water table within surrounding peat-lands and result in the associated peat being exposed to air, facilitating the rapid breakdown of this organic matter, releasing nutrients, principally ammonia to waters.

• The drying out of the peats exacerbates the washout of peat solids to surface waters. The potential for peat particles to become windblown is exacerbated by drying out also.

• Silt settlement ponds are used extensively on Bord na Mona properties, but are likely to retain heavier suspended solids only, with limited retention of dissolved nutrients. The ability of a silt settlement pond to retain fine particles depends upon regular maintenance, as it relates to residence time within the pond and as suspended solids settle out in the pond the retention time for water within that cell and the efficiency of the system reduces significantly. The efficiencies of these ponds in relation to their retention time needs to be considered, with a specific focus upon periods of high precipitation.

• Suspended solids pollution of surface waters from working peatland areas is not limited to carryover from silt settlement ponds, but may occur as a result of direct run-off from haul roads and stockpiles of peat. Wind-blown peat is another significant source. The potential for suspended solids generation from excavations in subsoils below peat deposits should also be considered.

• To date the main water protection/mitigation measure employed by Bord na Mona at peatland sites is the use of silt ponds. Silt ponds do not address the threat of ammonia pollution from working/cut-over peatland areas.

• Peat extraction requires the drainage/pumping of waters from relatively shallow peat deposits.
Of concern to IFI is the potential that the temperatures of this drainage water may (at certain times of the year) be significantly elevated when compared to typical groundwater recharge and/or the surface waters to which it is being discharged.

• Following on from the above point, this drainage water is likely to pumped/flow through a large drainage system which may include multiple, large surface area silt settlement ponds. Given the relatively shallow depth of the silt ponds and potential for full sunlight penetration, IFI have concerns that there is potential for a significant increase in temperatures of this drainage water prior to discharge to surface waters.

• Given the important link between water temperature and biological/biochemical reactions, the temperature of drainage waters being discharged to fisheries streams/rivers is critical in that some key constituents of water, either change their form (ionization of ammonia) or alter their concentration, as with dissolved oxygen. Considering that ammonia losses from drained peatland are the principal water quality issue it is important that this issue be adequately addressed.

• These operations involve significant machinery/plant/light rail infrastructure, throughout.
Fuels/hydraulic oils/lubricants etc. have potential to pollute both surface and ground waters. IFI ask that this EIAR address the potential for surface/ground water pollution at machinery storage/repair-maintenance/refueling locations.

• The Dept. of Agriculture and the Marine document, “Land Types for Afforestation” Working Document 2016, includes former and existing industrial cutaway peatlands as an example of lands unsuitable for afforestation. Commercial afforestation on such peat deposits poses a significant environmental threat to water quality. In addition such afforestation is likely to require the bog drainage system is maintained, leading to continued ammonia run-off to surface water. A significant threat comes from forest harvesting on such sites, especially where such plantations, which are now maturing, have been established prior to the implementation of the Forest Service guidelines. IFI ask if such sites have been included in the maps relating to the 41 bog units supplied and we ask that this EIAR consider commercial afforestation on all Bord na Mona peatland sites.

• We note that a number of the sites relate to the production of peat and the processing of peat for use in horticulture. Certain aspects of this production are likely to include the addition of nutrient/minerals and other materials to peat. IFI request that the potential for contamination of ground and surface waters by such nutrients/minerals at these facilities be addressed.

• Thermal pollution from the Edenderry Power Plant is of concern to IFI. Given the important link between water temperature and biological/biochemical reactions, the temperature of cooling waters being discharged to fisheries rivers is critical in that some key constituents of water either change their form (ionization of ammonia) or alter their concentration, as with dissolved oxygen. Considering that the ammonia losses from drained peatland are the principal water quality issue and the extensive peat workings on both sides of the Figile River for some considerable distance upstream, it is important that this issue be adequately addressed.

• Relating to the above point the section of the Cushaling River (upstream of Edenderry Power Plant) in County Kildare represents some of the best salmonid habitat within the Figile catchment. This potential was underutilized because of a number of water quality issues, including run-off from peat-lands. IFI do however hope that fish stocks in this section of channel will improve significantly as a result of improvements/upgrading of Derrinturn WWTP and significant upgrades at a large industrial site, both of which were contributing to the unsatisfactory biological conditions. IFI believe that the improvements in water quality referred to above will lead to the restoration of salmon spawning in the Cushaling River, and that when this happens, these Cushaling salmon will be an important/integral component of the salmon populations of the Barrow SAC.

• The addition of biocides to cooling waters at power generation plants to prevent biofouling of their cooling systems is a widespread practice internationally. With reference to the Edenderry Power Plant IFI request that this EIAR address if such practices are undertaken at this facility.

• In relation to the above point, trihalomethanes (THMs), a large group of organic compounds are formed when organic material reacts with chlorine. Given the high organic content of the Figile River water (from which the Edenderry power plant abstracts cooling water) linked to extensive Bord na Mona peatlands through which the Figile and its tributaries flow, IFI have concerns regarding the potential for significant discharges of THMs to the Figile River. IFI request that the potential for negative impacts upon the aquatic biota of the Figile River by discharges of THMs be addressed in this EIAR.

• The potential for large scale fires on cut-over/”peatlands being worked” is significantly greater compared to sites that have not been subject to drainage/drying out or sites that have been rewetted.
IFI request that the potential for run-off of significant quantities of deleterious matter to surface waters following a large scale fire on cut-over peatland, and the likely makeup of the run-off be considered.

• The use of borrow pits/quarrying on Bord na Mona peatland sites may lower water levels within surrounding peats and act to exacerbate drying out of such peats, with an increase in release of ammonia to surface waters. Quarrying operations also represent a potential source of suspended solids pollution of surface waters.

IFI concerns relating to habitat/hydro-morphology include:

• An examination of OSI 6 & 25 inch sheets highlight significant modifications to watercourses flowing through, adjacent to and downstream of these peatland sites. The modifications noted (through both desktop checks and on-site visits) included:

o Realignment/Straightening
o Deepening
o Widening
o Culverting/piping of waters
o Construction of on-line silt ponds to facilitate commercial peat extraction.
o Differences in height where waters are lifted to facilitate drainage

• Realignment/straightening of watercourses is problematic for a number of reasons including the fact that it results in a net loss of habitat. Realignment of channels often results in a highly degraded hydro-morphology with the loss of natural sinuosity and natural instream variation characterized by the pool/glide/riffle sequence. Realignment may also negatively impact upon gravel recruitment at the realigned site and in waters downstream.

• The deepening of watercourses in, or adjacent to peatland sites, (in addition to the release of ammonia and suspended solids to surface waters) may result in the removal of all/most gravels from long stretches of fisheries waters where the excavation depth extends down to the subsoils beneath the watercourse. In such cases the potential for natural restoration in waters flowing through peatland areas is usually limited, given the relatively low gradient and other hydro-morphological issues referred to in the above point. Human intervention is likely to be necessary to facilitate recovery of the fisheries habitat on long stretches of watercourses draining peatland areas.

• The widening of watercourses, (regularly associated with realignment and deepening) often results in a highly degraded hydro-morphology with the loss of natural sinuosity and natural instream variation characterized by the pool/glide/riffle sequence. In shallow waters a braided channel with limited depth for fish to reside is often the result, while in deeper waters an overabundance of aquatic plants clogging the channel is regularly encountered.

• Culverting is potentially damaging to fisheries waters as it may (1) block/impede the free passage of fish, (2) result in a loss of fisheries habitat and (3) hinder the detection of pollution.
Our experience is that many of the culverts on Bord na Mona peatlands to facilitate the industrial light rail system are very long. The depth at which such culverts were installed also acts as a control re drying out of peats, as all peats upstream of the culvert at a higher elevation will be subject to drying out.

• Construction of on-line silt ponds results in a loss/degradation of fisheries habitat. The efficacy of any silt pond relates to residence time in the pond and as peat settles out in the pond the ability for the pond to retain peat is reduced. Because of this, these ponds are subject to regular maintenance whereby accumulated peat deposits are removed.

• Pumping operations and flow control weirs have potential to impact on both upstream and downstream fish passage, watercourse base flows and water quality. We request that this AIER address these issues.

• IFI have noted significant gradient differences on watercourses on peatland sites where water is lifted from one to the other using archimidean screws. Such practices represent a barrier to the free passage of fish.

• With reference to the Edenderry Power Plant and any other Bord na Mona industrial facility IFI request that any abstractions from surface waters and/or groundwater be considered with a focus upon potential impacts on flow rates in associated surface waters and also recharge of groundwater to surface water bodies.

• With reference to the Edenderry Power Plant and any other Bord na Mona industrial facility that includes an abstraction from surface waters, the issue of screening to prevent fish and other aquatic animals becoming entrained within the abstracted water and/or impinged upon screens should be addressed. Of particular concern is the potential for significant mortalities, where fish become trapped on screens and/or enter cooling water systems. Numerous factors influence the likelihood of fish mortality at/in such sites including, but not limited to:

o Flow velocity in the vicinity of screen
o Rate of abstraction relative to total flow in river/flow attraction
o Screen spacing
o Size of fish resident and migrating through the location
o Potential for screens to become clogged which is likely to increase flow velocities in the vicinity of screen
o Angle of the screen
o Surface area of the screen

• IFI consider that any abstraction should protect all age classes of all fish species resident within the area of the abstraction or likely to migrate through that section of watercourse.

IFI is keen to build on recent water quality improvements in the Black River, which drains 21% of the Barrow River catchment and to restore and increase populations of salmon over large sections of this system while the Shannon Salmon Restoration Project is a key IFI project is committed to the restoration of sustainable stocks of salmon throughout the Shannon Catchment. Large areas of the catchments of the above named rivers are dominated by Bord na Mona peatlands.

Habitat restoration in rivers such as Inny, Brosna, Figile and Philipstown Rivers will be central to these plans.

Many of the watercourses draining directly from Bord na Mona peatland sites have small catchment areas with limited flows, and should be regarded as highly sensitive to anthropogenic inputs/alteration.
Other larger and important fisheries watercourses flow through, adjacent to and downstream of the Bord na Mona sites and while many of these represent excellent fisheries habitat, in many cases the habitat of these watercourses has been degraded by deepening/widening, realignment and silt deposition.

IFI request that this EIAR examine the hydro-morphological damage to watercourses outside the boundary of the boundary of the Bord na Mona sites.

We request that the applicant address the root causes of the elevated ammonia concentrations in surface waters/pumped waters from their peatland sites.

IFI welcome the Bord na Mona, Biodiversity Action Plan 2016-2021 statement that “the main aim of rehabilitation will be to re-wet former production areas as much as possible to maximize the benefits for biodiversity and carbon”.

Yours sincerely,
Donnachadh Byrne
Senior Fisheries Environmental Officer

Please note that any further correspondence regarding this matter should be addressed to

Senior Fisheries Environmental Officer, Inland Fisheries Ireland, 3044 Lake Drive,
Citywest Business Campus, Dublin 24

IFI submission starts on Page 13 of the submissions document: