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Integrated Water Quality Assessment 2013

WESTERN RIVER BASIN DISTRICT

Integrated Water Quality Assessment 2013 – WRBD

Environmental Protection Agency

Integrated Water Quality Assessment for the Western River Basin District 2013

Published by the Environmental Protection Agency, Ireland

September 2014

Edited by Alan Stephens and Garvan O’Donnell

The collation and summation of data for this report was carried out under the direction of

Micheál Lehane (Programme Manager, Environmental Monitoring and Assessment). The

authors gratefully acknowledge the contribution of all EPA staff members who provided

input to this report.

Disclaimer: Every effort has been made to ensure the accuracy of the material contained in

this publication, however, neither the Environmental Protection Agency (EPA), the

author(s), or other staff accepts responsibility whatsoever for loss or damaged occasioned,

or claimed to have been occasioned, in part or in full as a consequence of any person acting

or refraining from acting, as a result of a matter contained in this publication.

ENVIRONMENTAL PROTECTION AGENCY

An Ghíomhaireacht um Chaomhnú Comhshaoil

PO Box 3000, Johnstown Castle Estate, Co. Wexford, Ireland

Telephone: +353 53 9160600 Fax: +353 53 9160699

Email: [email protected] Website: www.epa.ie

LoCall 1890 33 55 99

Regional Inspectorate, John Moore Road, Castlebar, Co. Mayo.

ISBN: 978-1-84095-556-9

Cover Photo – Nahasleam Lake, Co. Galway, Photographer Ruth Little.

mailto:[email protected]

http://www.epa.ie/


1 | P a g e Environmental Protection Agency

Contents

1 Introduction ......................................................................................................................... 2

2 Physico-Chemical Quality ...................................................................................................... 3

2.1 Rivers ....................................................................................................................................... 3

2.1.1 Key Issue: Nutrient Enrichment – Phosphorus (as Ortho-Phosphate) Concentrations .. 3

2.1.2 Case Study: Ortho-Phosphate Kilcolgan River ................................................................ 6

2.1.3 Case Study: Ortho-Phosphate Clare River....................................................................... 6

2.1.4 Overall Physico-Chemical Assessment of Rivers in WRBD .............................................. 7

2.2 Lakes........................................................................................................................................ 9

2.2.1 Key Issue: Nutrient Enrichment – Phosphorus (as Total Phosphorus) ............................ 9

2.2.2 Case Studies .................................................................................................................. 11

2.2.3 Overall General Physico-Chemical Assessment of Lakes in WRBD ............................... 12

2.3 Transitional and Coastal Waters ........................................................................................... 15

2.3.1 Key Issue: Nutrient Enrichment –Trophic Status .......................................................... 15

2.4 Groundwater ......................................................................................................................... 17

2.4.1 Key Issue: Nutrient Enrichment –Phosphorus and Nitrates .......................................... 17

2.4.2 Groundwater Summary ................................................................................................ 21

3 Biological Quality ................................................................................................................ 23

3.1 Rivers ..................................................................................................................................... 23

3.1.1 Key Issue: Nutrient Enrichment .................................................................................... 23

3.2 Lakes...................................................................................................................................... 25

3.2.1 Key Issue: Nutrient Enrichment .................................................................................... 25

4 Pressures ............................................................................................................................ 26

4.1 Point Source Pressures.......................................................................................................... 26

4.1.1 Examples of Point Source Pressures on Rivers in the WRBD ........................................ 28

4.2 Diffuse Source Pressures ....................................................................................................... 29

5 Overall Integrated Quality .................................................................................................. 30

6 References ......................................................................................................................... 32



1 Introduction The Western River Basin is a hydro-geologically distinct area made up of 89 water

catchments or drainage systems and includes all of counties Mayo and Sligo, most of Galway

and small parts of Roscommon and Clare. There are 14,200 km of river channel,

approximately 1000 km2 of lake area, 105 groundwater bodies and 4700 km2 of transitional

and coastal water area. For the purpose of managing compliance with the Water

Framework Directive (WFD) the Western River Basin is defined as a district, the Western

River Basin District (WRBD).

Many of the water bodies in the WRBD are designated protected areas under European and

national legislation (SI 94 of 1997, Wildlife (Amendment) Act 2000). Key pressures in the

WRBD include agriculture, aquaculture, discharges from municipal waste water works and

emissions from domestic waste water treatment systems.

This assessment summarises the latest (2013) monitoring data, provides an assessment of

the data and focuses on the key issue that affects water quality in the WRBD, nutrient

enrichment. It also contains case studies and focuses on the key pressures affecting water

quality in the WRBD.

Nutrient enrichment is defined as inputs of the nutrients phosphorus and nitrogen to

watercourses at concentrations above background level, which result in the commencement

of the process of eutrophication, which can lead to undesirable effects in the water body

such as excess organic matter and depletion of oxygen concentrations.

The assessment of water quality in the WRBD will be presented using four Key Indicators:

1. Physico-Chemical Quality

2. Biological Quality

3. Pressures

4. Overall (Integrated) Quality



2 Physico-Chemical Quality

2.1 Rivers

2.1.1 Key Issue: Nutrient Enrichment – Phosphorus (as Ortho-Phosphate)

Concentrations

Map 1. Compliance of WRBD river monitoring stations with ortho-phosphate EQS for

2013.



Map 1 shows the compliance (High, Good or Moderate) at WRBD river monitoring stations

with the ortho-phosphate Environmental Quality Standard (EQS) in 2013. The EQS is the

maximum concentration of ortho-phosphate allowed in a river with “good ecological status”

under the terms of the WFD. The ortho-phosphate EQS standards are: Good ≤0.035 mg/L P

and High ≤0.025 mg/L P (SI 272 of 2009). A number of river stations are Good and Moderate

with respect to the EQS, e.g. Kilcolgan, Clarinbridge, Ballindine, Tubbercurry, Ballydangan

and Yellow rivers, while the majority of rivers are High (i.e. fully compliant).

Fig. 1. Compliance with ortho-phosphate EQS for WRBD river stations for 2013.

Figure 1 shows the relative compliance (High, Good or Moderate) of ortho-phosphate

concentrations at WRBD river stations with respect to the EQS in 2013. 92.7% of river

stations in the WRBD are High with 3.4% Good and 3.9% Moderate. This compares

favourably to the national picture where 27% of river stations are Moderate, 14% Good and

59% High (see Figure 2 below).

Fig. 2. Compliance with ortho-phosphate EQS for all national river stations 2013.

92.7%

3.4% 3.9%

Compliance with Ortho-Phosphate EQS for WRBD River Stations

2013

High

Good

Moderate

59%

14%

27%

Compliance with Ortho-Phosphate EQS for all National River Stations 2013

High

Good

Moderate



The long-term trend for ortho-phosphate for all rivers monitoring stations in the WRBD is

presented in Figure 3. There has been a reduction in the overall mean ortho-phosphate

levels since the early 2000s.

Fig. 3. Long-term trend of ortho-phosphate concentrations at all river monitoring stations in

WRBD.

High phosphorus concentrations at river monitoring stations generally result in a decline in

biological status of rivers. Although rivers in the WRBD are more compliant with the ortho-

phosphate EQS relative to the rest of the country and the overall levels of ortho-phosphate

are reducing, there remain several rivers that require programmes of measures to reduce

the ortho-phosphate concentrations and improve biological conditions.

0.000

0.020

0.040

0.060

0.080

0.100

0.120

Me

an O

rth

o-P

ho

sph

ate

(m

g/L)

Year

Annual Mean Ortho-Phosphate Concentrations in WRBD Rivers 1979–2013

High/Good

Good/Moderate



2.1.2 Case Study: Ortho-Phosphate Kilcolgan River

Figure 4 shows long-term 3-year rolling mean values for ortho-phosphate in the Kilcolgan

river at three different stations (0100, 0200, 0400) from 1979 to 2013. All stations fail the

ortho-phosphate EQS Good/Moderate boundary.

Fig. 4. Long-term 3-year rolling mean values for ortho-phosphate in the Kilcolgan river for

monitoring stations 0100, 0200 and 0400.

Station 0200 shows elevated ortho-phosphate concentrations throughout the period

studied. Ortho-phosphate concentrations have fallen from 2001 to 2003 onwards but still

remain high. This monitoring station (29K010200) is a site of special interest as it is in

unsatisfactory biological condition (Biological Q value 3, 2012). The key pressure identified

for this station is municipal waste water discharges. The other two monitoring stations

studied show ortho-phosphate levels considerably less than station 0200 and an

improvement in ortho-phosphate concentrations from 2001 to 2003 onwards but still above

the Good/Moderate EQS boundary.

2.1.3 Case Study: Ortho-Phosphate Clare River

Figure 5 shows long-term 3-year rolling mean values for ortho-phosphate in the Clare River

at two monitoring stations (0800 and 1300) from 1979 to 2013. This river was chosen as an

example of a river with relatively low ortho-phosphate concentrations. The ortho-phosphate

concentrations start to rise from the mid to late 1990s, exceed the Good/Moderate

boundary, remain Good for a long period and return to High for the 2011–2013 period.

0.000

0.100

0.200

0.300

0.400

0.500

Me

an O

rth

o-P

ho

sph

ate

(m

g/L)

Year

Kilcolgan River Stn. 0100

Stn. 0200

Stn. 0400

High/Good

Good/Moderate



Fig. 5. Long-term 3-year rolling mean values for ortho-phosphate in the Clare River for

monitoring stations 0800 and 1300.

2.1.4 Overall Physico-Chemical Assessment of Rivers in WRBD

As part of the determination of the ecological status of a water body, a statistical method

has been derived for assessing the physico-chemical results (i.e. nutrient and oxygen

concentrations) as a support to biological quality elements (e.g. macroinvetebrate and fish

populations) in the determination of ecological status.

This physico-chemical assessment is based on compliance with the EQS for ortho-

phosphate, biochemical oxygen demand (BOD), ammonia and nitrate (total oxidised

nitrogen (TON)). This assessment is undertaken in 3-year rolling cycles and the results of the

assessment of monitoring stations, on surveillance rivers only, in the WRBD are given below

in Table 1. Surveillance rivers are the rivers that are monitored to assess long-term trends in

water quality in the RBD. All surveillance rivers in the WRBD met the compliance criteria for

this statistical assessment and the overall compliance for these rivers with the EQSs remains

good over the period 2007–2013. The river stations that show poor compliance with the

ortho-phosphate EQS in Map 1 were not included in this assessment as they are not part of

the surveillance monitoring programme.

0.000

0.020

0.040

0.060

0.080

0.100

0.120

Me

an O

rth

o-P

ho

sph

ate

(m

g/L)

Year

Clare River Stn. 0800

Stn. 1300

High/Good

Good/Moderate



River

Monitoring Station Code

2007–2009

2008–2010

2009–2011

2010–2012

2011–2013

Abbert 30A01-0500 Pass Pass Pass Pass Pass

Ballinglen 33B01-0100 Pass Pass Pass Pass Pass

Ballysodare 35B05-0100 Pass Pass Pass Pass Pass

Behy 34B08-0400 Pass Pass Pass Pass Pass

Black (Shrule) 30B02-0100 Pass Pass Pass Pass Pass

Bonet 35B06-0600 n/a n/a n/a n/a Pass

Bundorragh 32B01-0200 Pass Pass Pass Pass Pass

Bunowen (Louisburgh) 32B03-0100 Pass Pass Pass Pass Pass

Castlebar 34C01-0200 Pass Pass Pass Pass Pass

Clare (Galway) 30C01-0800 Pass Pass Pass Pass Pass

Clare (Galway) 30C01-1300 Pass Pass Pass Pass Pass

Clydagh (Castlebar) 34C05-0030 Pass Pass Pass Pass Pass

Deel (Crosmolina) 34D01-0300 Pass Pass Pass Pass Pass

Dunneill 35D06-0200 Pass Pass Pass Pass Pass

Glenamoy 33G01-0100 Pass Pass Pass Pass Pass

Glennamong 32G03-0100 Pass Pass Pass Pass Pass

Gowlan (Sligo) 35G03-0100 Pass Pass Pass Pass Pass

Moy 34M02-0050 Pass Pass Pass Pass Pass

Moy – ford 2 km u/s Gweestion River

34M02-0650 Pass Pass Pass Pass Pass

Moy – ardnaree bridge

34M02-1100 Pass Pass Pass Pass Pass

Owendalulleegh 29O01-1000 Pass Pass Pass Pass Pass

Owenmore (Sligo) 35O06-0900 Pass Pass Pass Pass Pass

Owenriff (Corrib) 30O02-0100 Pass Pass Pass Pass Pass

Robe 30R01-0600 Pass Pass Pass Pass Pass

Screeb 31S01-0570 Pass Pass Pass Pass Pass

Tubbercurry 34T02-0200 Pass Pass Pass Pass Pass

Table 1. Physico-chemical assessment of surveillance rivers in the WRBD.



2.2 Lakes

2.2.1 Key Issue: Nutrient Enrichment – Phosphorus (as Total Phosphorus)

Map 2. Compliance of WRBD lake monitoring stations with TP guide EQS for 2013.



Map 2 shows the compliance (High, Good or Moderate) of WRBD lake stations with respect

to the total phosphorus (TP) guide EQS in 2013. There is currently no formal EQS for TP.

Based on EPA research (Free et al., 2007) a guide EQS was set for TP at 0.025 mg/L. The

guide TP EQS standards are: Good ≤0.025 mg/L P and High ≤0.01 mg/L P. Note that the

current EPA standard operating procedure for TP has a limit of quantitation equal to the

High/Good EQS boundary, i.e. 0.01 mg/l. A number of lakes are Good, e.g. Lough Gill, Lough

Arrow, and Moderate, e.g. Cross, Keel, and Templehouse lakes with respect to the TP EQS,

while the majority of lakes are High. This information is presented as a percentage of the

total number of WRBD lakes in Figure 5 below.

Fig. 5. Compliance with TP guide EQS for WRBD lakes 2013.

For 2013, 90.7% of lake stations in the WRBD are High, with 5.6% Good and 3.7% Moderate.

This compares favourably to the overall national picture where 59.6% are High, 14.5% Good

and 25.9% Moderate (see Figure 6).

90.7%

5.6% 3.7%

Compliance with TP Guide EQS for WRBD Lake Stations 2013

High

Good

Moderate

59.6%

14.5%

25.9%

Compliance with TP Guide EQS all National Lakes 2013

High

Good

Moderate



Fig. 6. Compliance with TP guide EQS for all national lakes 2013.

Similarly to the situation with rivers in the WRBD, high TP concentrations in lakes can be

indicative of Poor biological conditions. Overall, lakes in the WRBD are more compliant with

the guide EQS for TP than elsewhere in the country but several lakes are in need of remedial

action to reduce phosphorus levels.

2.2.2 Case Studies

Lower Lough Corrib

Lower Lough Corrib, Co. Galway, has High compliance with TP guide EQS (see Map 2). Three-

year rolling mean TP concentrations for the time period 2007–2013 are plotted in Figure 7.

Lower Lough Corrib has remained High throughout this period with no sign of deterioration.

Fig. 7. Trend in 3-year rolling mean TP for Lower Lough Corrib.

Belhavel Lake

Belhavel Lake, Co. Sligo, has Moderate compliance with TP guide EQS (see Map 2). Three-

year rolling mean TP concentrations for the time period 2007–2013 are plotted in Figure 8.

Belhavel Lake has remained Moderate throughout this period.

0.000

0.010

0.020

0.030

0.040

0.050

2007-2009 2008-2010 2009-2011 2010-2012 2011-2013

Me

an T

P (

mg/

L)

Year

Lough Corrib Lower

TP

High/Good

Good/Moderate



Fig. 8. Trend in 3-year rolling mean TP for Belhavel Lake.

2.2.3 Overall General Physico-Chemical Assessment of Lakes in WRBD

In a similar manner to rivers and as part of the determination of the ecological status of a

lake, a statistical method has been derived for assessing the general physico-chemical

results to compare with the biological quality elements (e.g. macroinvertebrate and fish

populations) of a lake to derive the overall ecological status. This physico-chemical

assessment of lake chemistry is based on compliance with EQS for Oxygenation, Nutrients,

Acidification/Alkalisation, Thermal Status and Specific Pollutants. The results of this

assessment for all lakes monitored in the WRBD are presented in Table 2. In the case of

lakes, the compliance is graded High, Good or Moderate. The majority of lakes in the WRBD

have consistently displayed Good or High compliance with the EQSs in the 3-year rolling

assessments over the period 2007–2013.

Galway lakes, Aughrusbeg and Tully improved from Moderate to Good and Nambrackmore

improved from Good to High in the most recent 2011–2013 assessment period. A few small

lakes, such as Belhavel and Templehouse, Co. Sligo and Cross, Co. Mayo consistently show

only Moderate compliance. Carrowmore Lake (Co. Mayo), which is an important angling

amenity and drinking water source, declined from Good to Moderate with the EQS due to

elevated phosphorus results in the most recent 2011–2013 assessment. Arrow, Kilsellagh

(both Co. Sligo) and Loughaunore (Co. Galway) showed a decline in compliance with the EQS

in the most recent assessment period.

0.000

0.020

0.040

0.060

0.080

0.100

2007-2009 2008-2010 2009-2011 2010-2012 2011-2013

Me

an T

P (

mg/

L)

Year

Belhavel Lake TPHigh/GoodGood/Moderate



Lake Name Lake Code 2007–2009

2008–2010

2009–2011

2010–2012

2011–2013

Acorrymore WE_33_1892 High High High High High

Aille WE_30_532 Good Good Good Good Good

Anaserd WE_31_211 High High High High High

Anillaun WE_30_348 High High High High High

Ardderry WE_31_76 Good Good High High High

Arrow WE_35_159 Good High High High Good

Aughrusbeg WE_32_436 Good Moderate Good Moderate Good

Aunwillan WE_31_120 High High High High High

Ballin WE_32_364 n/a Moderate Moderate Good Good

Ballynahinch Lake

WE_31_228 High High High High High

Ballynakill WE_32_479 Good Good Good Good Good

Ballyquirke WE_30_340 Good Good Good Good Good

Beaghcauneen WE_32_402 Good Good Good Moderate Moderate

Belhavel WE_35_155 Moderate Moderate Moderate Moderate Moderate

Bofin WE_30_335 High High High High High

Bunny WE_27_114 Moderate High High High High

Carra WE_30_347 Good High High High High

Carrowmore WE_33_1914 Good Good Moderate Good Moderate

Corrib Lower WE_30_666a High High High High High

Corrib Upper WE_30_666b High High High High High

Cross WE_33_1889 Moderate Moderate Moderate Moderate Moderate

Cullin WE_34_406a Good Good Good High High

Cutra WE_29_37 n/a n/a Good Good Good

Derryclare WE_31_227 High High High High High

Doo WE_32_490 Good High High High High

Easky WE_35_136 High High High High High

Enask WE_32_333 High High High High High

Fadda WE_32_501 High High High High High

Feeagh WE_32_510 High High High High High

Gill WE_35_158 Good Good Good Good Good

Glenade WE_35_156 Good Good Good Good Good

Glencar WE_35_139 Good Good High High High

Glencullin WE_32_487 Good Good High High High

Illauntrasna WE_99_102 Good Good Good High High

Keel WE_33_1895 Good Good Good Good Good

Kilsellagh WE_35_17 Good Good High High Good

Knappabeg WE_32_483 Moderate Good Good Good Good

Kylemore WE_32_509b High High High High High



Lake Name Lake Code 2007–2009

2008–2010

2009–2011

2010–2012

2011–2013

Lannagh WE_34_403 Good Good Good Good Good

Lettercraffoe WE_30_344 Good Good Good Good Good

Levally WE_34_368 Good Good Good Good Good

Loughaunore WE_31_177 High High High High Good

Mask WE_30_665 High High High High High

Maumwee WE_30_343 High High High High High

Moher WE_32_406 High Good Good Good Good

Nahasleam WE_31_208 High High High High High

Nambrackmore WE_32_500 Good Good Good Good High

Pollacappul WE_32_509a High High High High High

Rea WE_29_194 Good High High High High

Ross WE_30_345 Good Good High High High

Shindilla WE_31_171 Good High High High High

Talt WE_34_405 High High High High High

Templehouse WE_35_157 Moderate Moderate Moderate Moderate Moderate

Tully WE_32_474 Good Good Good Moderate Good

Washpool WE_34_402 Good Good Good High High

Table 2. General physico-chemical assessment of WRBD lakes.



2.3 Transitional and Coastal Waters

2.3.1 Key Issue: Nutrient Enrichment –Trophic Status

Map 3. Trophic status of transitional and coastal water bodies in WRBD 2012.



The trophic status of transitional and coastal waters is assessed using the EPA’s Trophic

Status Assessment Scheme (TSAS) which captures the cause–effect relationship of the

eutrophication process and considers the following:

Enrichment of waters by nutrients (dissolved inorganic nitrogen and phosphorus)

Accelerated algal growth (phytoplankton and opportunistic macroalgae)

Undesirable disturbance (oxygen content)

Trophic status assessments are based on the analysis of data collected over a period of 3

years, and each water body assessed is categorised as either eutrophic, potentially

eutrophic, intermediate or unpolluted with respect to nutrient enrichment. The current

status assessments are based on the period 2010–2012.

With the exception of one water body, all of the areas assessed in this period were found to

be unpolluted with respect to nutrient enrichment. This compares favourably with the

national average and shows the highest percentage of unpolluted water bodies for any RBD

(Table 3). The only water body classified as intermediate status was Killary Harbour. This

assessment is based on reduced oxygen concentrations in the inner harbour. Further

investigation is needed to identify the cause of the deviation in oxygenation status here. In

relation to the Moy Estuary, although currently classified as unpolluted, elevated growth of

green macroalgae is still of concern.

Trophic Status Western (%) National (%)

Eutrophic 0 7

Potentially Eutrophic 0 8

Intermediate 5 28

Unpolluted 95 57

Table 3. Trophic status of western and national water bodies.



2.4 Groundwater

2.4.1 Key Issue: Nutrient Enrichment –Phosphorus and Nitrates

Groundwater, which originates from rain that soaks into the ground, is an important natural

resource in Ireland. It flows through and is stored in the fractures in bedrock and the pore

spaces of sand and gravel deposits. In the past the focus was on its use as drinking water;

however, under the WFD there is an increased emphasis on the environmental quality of

groundwater, as well as its value as a potable water supply. Groundwater plays an essential

role in the hydrological cycle and is critical for maintaining river levels and surface water

ecosystems. In many Irish rivers, more than 30% of the flow is derived from groundwater,

rising to 90% in periods of low flow. Therefore, the quality of groundwater can have a major

impact on the quality of river water.

In Ireland, approximately 26% of the public and private drinking water supply is from

groundwater. Most of the private group schemes and small supplies are reliant on

groundwater and many have inadequate treatment. Therefore, it is critical that

groundwater is protected to maintain the quality of drinking water and ensure the water is

safe to drink without the requirement for excessive levels of treatment.

Ortho-Phosphate in Groundwater

Map 4 shows the locations and the associated mean ortho-phosphate concentrations for

groundwater monitoring points in the WRBD in 2013.



Map 4. Mean ortho-phosphate concentrations in the WRBD in 2013.



Fig. 9. Mean ortho-phosphate concentrations in groundwater in the WRBD.

Overall, there has been a general decrease in ortho-phosphate concentrations over the

period 2007–2013. The Irish WFD Threshold Value concentration of 0.035 mg/l P should be

considered when assessing the contribution of ortho-phosphate in groundwater to rivers.

The majority of the regionally important karst groundwater bodies in the WRBD were

classified at poor chemical status during the first WFD reporting cycle because of

groundwater contributions of phosphate to rivers that are less than good status. The mean

ortho-phosphate concentration was ≥0.035 mg/l P at five of the 30 monitoring locations in

in the WRBD in 2013.

Nitrate in Groundwater

In general, the mean nitrate concentration at groundwater monitoring locations in the

WRBD is relatively low when compared to the national average nitrate concentration. Map 5

shows the locations and the associated mean nitrate concentrations in 2013 for

groundwater monitoring points in the WRBD.

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2007 2008 2009 2010 2011 2012 2013

Pe

rce

nta

ge o

f M

on

ito

rin

g Si

tes

Sample Period

Ortho-Phosphate (mg/l P)

>0.05

0.035 - 0.05

0.025 - 0.035

0.015 - 0.025

<0.015



Map 5. Mean nitrate concentrations in the WRBD in 2013.

Figure 10 summarises the mean yearly nitrate concentrations from 2007 to 2013 for the

groundwater monitoring programme in the WRBD.



Fig. 10. Mean nitrate concentrations in groundwater in the WRBD.

The mean nitrate concentration at groundwater monitoring locations in the WRBD has

decreased over the period 2007–2013. In 2013 the mean nitrate concentration at any

monitoring location did not exceed the Irish WFD Threshold Value concentration of 37.5

mg/l NO3 and the concentration in any individual sample did not exceed the Drinking Water

Standard of 50 mg/l NO3. The mean nitrate concentrations were <9 mg/l NO3 at all

monitoring locations in the WRBD in 2013.

2.4.2 Groundwater Summary

A number of factors may have influenced the reduction in mean ortho-phosphate and

nitrate concentrations including: reductions in inorganic fertiliser applications since 2004,

improvements in storage for organic fertiliser and the implementation of land spreading

restrictions as part of the Good Agricultural Practice Regulations (SI 610 of 2010). Above

average rainfall in 2008–2009 and the resultant increase in dilution (particularly in 2009)

also contributed to a noticeable decrease in the mean ortho-phosphate and nitrate

concentrations.

It is important that groundwater is protected to maintain the quality of drinking water and

so that the groundwater contribution to ecosystems, including rivers, is of good quality.

Nitrate concentrations in the WRBD are relatively low. While large areas of the WRBD were

classified as being at poor status in the first WFD reporting cycle due to the contribution of

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2007 2008 2009 2010 2011 2012 2013

Pe

rce

nta

ge o

f M

on

ito

rin

g Lo

cati

on

s

Sample Period

Nitrate (mg/l NO3)

> 50

37.5 - 50

25 - 37.5

10 - 25

5 - 10

< 5



ortho-phosphate from groundwater to surface water bodies there has been a general

decrease in ortho-phosphate concentrations over the period 2007–2013.

The progress made in improvement of nitrate and ortho-phosphate concentration in the

WRBD highlights the importance of continuing with programmes of measures to ensure that

overall nutrient loss to groundwater of nitrates and phosphates is minimised. Continued

improvements in the understanding of the interactions between groundwater and surface

water are very important to maximise the effectiveness of any programmes put in place.

However, microbial pollution was evident at the majority of monitoring locations,

particularly in catchments with karst limestone aquifers. Therefore, microbial pollution may

also be present in other private group schemes and small supplies and groundwater

protection measures need to be maintained to ensure the water is safe to drink without the

need for increased levels of treatment.



3 Biological Quality

3.1 Rivers

3.1.1 Key Issue: Nutrient Enrichment

Map 6. Biological classification (High, Good, Moderate, Poor, Bad) of WRBD rivers for the

period 2011–2013.



Map 6 shows the current biological classification (High, Good, Moderate, Poor, Bad) of

WRBD rivers for the period 2011–2013. A survey of the biological quality elements (e.g.

macroinvetebrates and fish populations) was undertaken at 414 sites on 211 rivers over a 3-

year cycle and each site received a biological classification. The biological classification along

with the physico-chemical assessment of the water quality at the site is used to determine

the overall ecological status of the water body.

Biological Quality Element Classification

Classification Number of River Monitoring Sites

%

Q4-5, Q5 High 110 (5 sites at Q5) 27

Q4 Good 219 53

Q3-4 Moderate 60 14

Q2-3, Q3 Poor 24 5.8

Q1, Q1-2, Q2 Bad 1 0.2%

Total 414 100

Table 4. Biological quality element classification of river monitoring sites in WRBD 2011–

2013.

From Table 4 it can be seen that only five sites on four rivers achieved the highest biological

classification (Q5) and 110 sites on 75 rivers (27%) currently achieve a High biological

classification (Q5 or Q4-5). These rivers are Recess and Boleyneendorrish, both Co. Galway,

Bonet, Co. Leitrim and Yellow (Foxford), Co. Mayo. The maintenance of sites classified as

High is particularly important as they are used as a benchmark to assess other sites.

Two-hundred and nineteen sites on 137 rivers (53%) are currently classified as Good.

Therefore 80% of river sites in the WRBD are classified as Good or better. Sixty sites on 47

rivers have a Moderate classification. Twenty-four sites on 19 rivers have a Poor

classification and one site (Tubbercurry Stream, Q2) currently receives a Bad classification

(see Section 4.1.1 Example 4).



3.2 Lakes

3.2.1 Key Issue: Nutrient Enrichment

Map 7. Biological classification of WRBD lakes in WRBD for the period 2011–2012.



Map 7 shows the most recent biological classification of WRBD lakes covering the period

2010–2012. A survey of the biological quality elements is undertaken at 58 lakes on a 3-

year cycle and each lake receives a biological classification. The majority (69%) of the 58

lakes monitored in WRBD are classified as High (16 lakes) or Good (24 lakes). Only two lakes

are classified as Bad (Aughrusbeg, Co. Galway and Templehouse, Co. Sligo).

The biological classification along with the physico-chemical assessment of the lake water

quality is used to determine the overall ecological status of the lake.

4 Pressures The causes of water pollution (or pressures) in the WRBD are common to Ireland as a whole

and can be generally broken into two categories, point source and diffuse.

4.1 Point Source Pressures

The point source pressures are discharges from municipal waste water works, industrial

effluents, landfill sites and water abstraction sites. The number of such sites is relatively

small, for example, there are 100 municipal waste water works in the WRBD (of which 68

are serving populations of over 500 and 32 serving populations under 500). However, it is

evident the performance of many waste water treatment plants has been poor and that

significant pollution has and is being caused by these plants and associated inadequate

sewer systems. It can be seen from Table 4 below that of the 85 monitoring stations in

unsatisfactory condition 24 of these can be attributed to point source pressures. Of these

24, 18 are waste water works.

Suspected Pressure (Cause of Pollution)

Type of pressure

County Galway

County Mayo

County Sligo

Total %

Municipal waste water

Point 4 10 4 18 21

Industrial Point n/a 5 1 6 7

Agriculture Diffuse 5 16 5 26 31

Forestry Diffuse n/a 7 2 9 11

Aquaculture Diffuse n/a 3 n/a 3 3

Other n/a 2 2 3 7 8

Unknown n/a 7 4 5 16 19

Total 18 47 20 85 100

Table 5. Suspected causes of pollution for WRBD river stations in unsatisfactory condition

(i.e. biological classification less than Good).



Map 8. Point source pressures and river stations in unsatisfactory condition (i.e. biological

classification less than Good) in the WRBD.



4.1.1 Examples of Point Source Pressures on Rivers in the WRBD

1. The 0200 monitoring station on the Kilcolgan River is in poor biological condition

(see Maps 8) and three monitoring stations (0100, 0200 and 0400) are only

moderately compliant with the ortho-phosphate EQS (see Map 1). It can be seen

from Map 8 above that Loughrea waste water treatment plant is upstream of

monitoring station 0200. It is likely that discharges from the Loughrea waste water

works are at least partially responsible for the unsatisfactory condition of the

Kilcolgan River.

2. In the case of the Clarinbridge River, sampling sites 0300 and 0400 display only

Moderate and Good compliance with the ortho-phosphate EQS, respectively. Again,

this less than optimal compliance with the EQS is reflected in the biological

classification with both these sites classified as Poor (see Map 8). From Map 8 it can

be seen that Athenry WWTP is located upstream of sampling site 0300. The upper

sections of the river (above Athenry WWTP) are in satisfactory condition (see Map

6). Again, there is evidence that emissions from the Athenry waste water works are

contributing to the unsatisfactory condition of the river.

3. For the Ballindine River (tributary of the Robe River), sampling sites 0100 and 0200

are less that optimally compliant with the ortho-phosphate EQS; only Good and

Moderate compliance, respectively. These sites also have Poor biological

classifications as can be seen in Map 8. The Ballindine WWTP discharge is located

between these two sampling sites (see Map 8) and again discharges from the

Ballindine waste water works are likely to be contributing to elevated ortho-

phosphate concentrations and Poor biological classification at these monitoring

sites.

4. Tubercurry River site 0200 is another site showing only moderate compliance with

the ortho-phosphate EQS and is the only river site with Bad biological classification in

the WRDB (see Map 8). The waste water works in Tubbercurry has a discharge into

the river upstream of this station. Again, the waste water works is likely to be at least

partially responsible for the pollution in the Tubercurry River.

Since 2007, with the introduction of the Waste Water Discharge (Authorisation) Regulations

(SI 684 of 2007) the EPA is responsible for the authorisation and regulation of waste water

discharges from waste water works owned, operated or used by the water service authority

(Irish Water). In 2013, nine Waste Water Discharge Licences (WWDLs) were issued by the

EPA within the WRBD for waste water works serving populations of greater than 500. In

addition, six have been issued to date in 2014. This brings the total number of licensed

WWTPs in the WRBD to 38. Also to date, 30 Certifications of Authorisation (CoAs) were

issued to smaller waste water works (serving less than 500 people). Thirty WWDLs and two

CoA applications are still under assessment by the EPA. These authorisations place stringent

conditions on the operation of waste water discharges to ensure potential effects on

receiving waters are strictly limited and controlled. The aim of the authorisation process is



to ensure that at least good water quality is achieved and all EQS are complied with. The

EPA is charged with ensuring that the requirements of the authorisations are met. This is

done by monitoring and auditing the discharges on an on-going basis.

Under the Water Services Investment Programmes (WSIP) (the most recent of which was

the 2010–2012 programme) significant investment has been made in new and upgrading

waste water treatment plants and sewer infrastructure. Irish Water proposes to invest €1.77

billion in the period 2014–2016 on water service capital projects including increasing waste

water treatment capacity and improving environmental compliance.

4.2 Diffuse Source Pressures

The diffuse sources such as Domestic Waste Water Treatment Systems (DWWTs) (e.g. septic

tanks), of which there are estimated to be approximately 120,000 in the WRBD and diffuse

pollution from agriculture and forestry are by their nature and extent more difficult to

assess and manage. Invasive species can also be considered diffuse source pressures. Since

the WRDB is a largely rural region these diffuse causes of pollution are particularly

important and challenging to manage.

The Water Services (Amendment) Act 2012 and SI 223 of 2012 place the responsibility for

the operation and maintenance of DWWTs on home owners and sets out the requirements

for an inspection regime to ensure DWWTs are working satisfactorily. Since the inspections

commenced in July 2013, to date approximately 143 inspections of DWWTs have been

completed in the WRDB of which, approximately 45 (31%) were found to be non-compliant.

Diffuse discharges from agriculture (phosphorus and nitrogen) are also difficult to address.

Legislation through the Nitrates Directive (SI 610 of 2010) is the main measure for

addressing agricultural pollution. These regulations also provide statutory support for good

agricultural practice to protect waters against pollution. Although there have been

decreases in the phosphorus and nitrogen concentrations in water bodies (2nd Review of

Ireland’s Nitrates Action Programme and EPA report under Article 29(1)(b) of the European

Communities (Good Agricultural Practice for Protection of Waters Regulations 2010)), which

may be attributed to improvements in agricultural practices in recent years, a significant

portion of farms nationally may be non-compliant with the nitrates regulations (Focus on

Environmental Enforcement in Ireland 2009-2012). A third national Nitrate Action Plan

(NAP) to achieve compliance with the Nitrates Directive is currently being implemented. The

NAP includes limits on farm stocking rates, limits for nitrogen and phosphorus application

rates, prohibited spreading periods, minimum storage requirements, requirements

regarding maintenance of green cover in tillage lands and set back distances from waters.

An effective education, inspection and enforcement regime is needed to ensure full

compliance with the Nitrates Directive.



The targets set by Food Harvest 2020, to increase agricultural output, will provide welcome

economic development, but will also pose significant challenges in meeting the

requirements of the WFD.

5 Overall Integrated Quality Nutrient enrichment is the main cause of water pollution in the WRBD. The compliance of

river monitoring stations against the physico-chemical EQSs (in particular ortho-phosphate

but also nitrate and ammonia) is usually complimentary to the biological assessment at the

same river stations. River sites and lakes with poor biological conditions often display poor

compliance with the ortho-phosphate EQS (see examples discussed in Section 4.1.1).

The WRBD is less affected by nutrient enrichment than other river basin districts in Ireland.

In 2013 92.7% of river monitoring stations and 90.7% of lakes monitoring stations in the

WRBD display a high level of compliance with the relevant ortho-phosphate EQS. This

compares favourably with corresponding overall national figures of 59 and 59.6%,

respectively. In addition, all WRBD rivers and lakes continued to show good overall

compliance with EQSs for all key physico-chemical parameters (including nutrients and

oxygen) in the most recent assessment period 2011–2013. In relation to transitional and

coastal water bodies, the most recent assessment undertaken in 2012 found that 95% of the

water bodies are classified as unpolluted compared to 57% nationally.

The overall level of ortho-phosphate in rivers in the WRBD is decreasing; since 2002 the

annual mean ortho-phosphate concentrations at river monitoring stations in the WRBD

have been falling. There remain several examples of unacceptably high phosphate or TP

concentrations in river, lake and groundwater monitoring stations. Carrowmore Lake (Co.

Mayo), an important angling and drinking water resource, was found to have elevated

ortho-phosphate in 2013 causing it to only achieve Moderate compliance with the EQS.

Despite indications of an overall decrease in nutrient concentrations in Ireland (EPA report

under Article 29(1)(b) of the European Communities (Good Agricultural Practice for

Protection of Waters Regulations 2010) the number of river sites in the WRBD achieving

High classification has decreased with a loss of Q5 and Q4-5 biological sites. Of the 414

active biological monitoring stations on 211 rivers only five stations on four rivers currently

display the highest biological classification (Q5). These rivers are Recess and

Boleyneendorrish, both Co. Galway, Bonet, Co. Leitrim and Yellow (Foxford) Co. Mayo. In

addition 105 biological monitoring stations on 73 rivers currently display the second highest

classification (Q4-5). Therefore, only 110 out of 414 (27%) biological monitoring stations in

the WRBD achieve a High classification (Q5 or Q4-5). It is particularly difficult to reverse the

loss of a Q5 site and so it is important that the remaining sites are protected.

Diffuse agricultural pollution (31%) and waste water discharges (21%) and are the main

causes of river monitoring stations failing to achieve at least good biological classification in



the WRBD (see Table 5). Improved compliance with the Nitrates Directive and

improvements in waste water infrastructure and operational practices is required to

improve and protect water quality at these sites. In 16 cases (19%) the source of pollution

at the river monitoring station is unknown or not determined. In these cases investigations

are required to identify sources of pollution and the appropriate mitigation measures and

then these measures must be completed. This will require the co-operation of all interested

parties including local authorities, Irish Water, EPA, OPW, IFI, NGOs, farmers and the general

public.

Revised river basin districts management plans are being put in place (Timetable and Work

Programme for the Development of the Second Cycle River Basin Management Plans) to

ensure compliance with the WFD (all water bodies achieve at least good ecological status

and to avoid deterioration). These plans will seek to protect, improve and manage the water

resources in a sustainable manner and will cover the period up to 2021. A new governance

structure has been put in place to facilitate the delivery of WFD compliance.



6 References SI 272 of 2009: European Communities Environmental Objectives (Surface Waters)

Regulations, 2009. http://www.irishstatutebook.ie/

Free, G. et al., 2007. A Reference Based Typology and Ecological Assessment System for Irish

Lakes. ERTDI Report 57.

http://www.epa.ie/pubs/reports/research/water/ertdireport57.html

SI 610 of 2010: European Communities (Good Agricultural Practice for Protection of Waters)

Regulations, 2010. http://www.irishstatutebook.ie/

SI 684 of 2007: Waste Water Discharge (Authorisation) Regulations, 2007.

http://www.irishstatutebook.ie/

Water Services (Amendment) Act, 2012. http://www.irishstatutebook.ie/

SI 223 of 2012: Water Services Acts 2007 and 2012 (Domestic Waste Water Treatment

Systems) Regulations, 2012. http://www.irishstatutebook.ie/

SI 94 of 1997: European Communities (Natural Habitats) Regulations, 1997.


Wildlife (Amendment) Act, 2000. http://www.irishstatutebook.ie/

2nd Review of Ireland’s Nitrates Action Programme (review of submissions received under

public consultation (Report and recommendations to the Department of the Environment,

Community and Local government and the Department of Agriculture, Food and the Marine

in relation to submissions received and suggested measures to be included in 3rd Nitrates

Action Programme, December 2013.

http://www.environ.ie/en/Environment/Water/WaterQuality/NitratesDirective/

Focus on Environmental Enforcement in Ireland 2009–2012, EPA, 2014

http://www.epa.ie/pubs/reports/enforcement/

EPA report under Article 29(1)(b) of the European Communities (Good Agricultural Practice

for Protection of Waters Regulations 2010


Food Harvest 2020 http://www.agriculture.gov.ie/agri-foodindustry/foodharvest2020/

EU Water Framework Directive (2000/60/EC). Timetable and Work Programme for the

Development of the Second Cycle River Basin Management Plans

http://www.environ.ie/en/Publications/Environment/Water/FileDownLoad,38703,en.pdf


http://www.epa.ie/pubs/reports/research/water/ertdireport57.html








http://www.epa.ie/pubs/reports/enforcement/


http://www.agriculture.gov.ie/agri-foodindustry/foodharvest2020/

http://www.environ.ie/en/Publications/Environment/Water/FileDownLoad,38703,en.pdf

ENVIRONMENTAL PROTECTION AGENCY

An Ghníomhaireacht um Chaomhnú Comhshaoil PO Box 3000, Johnstown Castle Estate, Co. Wexford, Ireland

Telephone: +353 53 9160600 Fax: +353 53 9160699 Email: [email protected] Website: www.epa.ie LoCall 1890 33 55 99

© Environmental Protection Agency 2014

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