Surface Water and Groundwater
Status
Donal Daly
Hydrometric & Groundwater Section
Environmental Protection Agency
Acknowledgement: Colleagues in EPA and on WFD Groundwater Working Group
WFD Water Status
“A measure of the present”
Status is the key element determining
the measures to be employed in the
RBD Management Plans to achieve the
objectives of the WFD
Based on an evaluation of:
pressures, physical settings and
monitoring results
Ecological Status for Surface Waters
Pass
WFD
Fail
WFD
Surface Water Body Classification
process
Interim Status Assessment of
Rivers
River Quality – WFD Interim Status
Ecological Class
High
Good
Moderate
Poor
Bad
Number of Water Bodies
(9%)
738 (40%)
509 (28%)
389 (21%)
41 (2%)
173
Interim Status Assessment
of Lakes
Lake Quality – WFD Interim Status
Biological Class
High
Good
Moderate
Poor
Bad
Number of Lakes
(28.0%)
75 (27.7%)
94 (34.7%)
17 (6.3%)
9 (3.3%)
76
Surface Area (km2)
37.1%)
204.4 (20.5%)
397.9 (40%)
7.1 (0.7%)
16.5 (1.7%)
369.6 (
Transitional and Coastal Water
Status
Main Causes of “less than good”
Status Surface Water Bodies
 Discharges from Wastewater Treatment
Plants (nutrients)
 Diffuse Agriculture (resulting in inputs
of P, PO4 and N)
 Forestry (sediment and P)
 Urban areas
GWBs are classified as either POOR or GOOD
STATUS for both quantitative and chemical
elements
GWB
boundary
Aquifer
boundary
GROUNDWATER
BODIES ARE
NORMALLY LARGE
(10s to 100s km2)
WILL HAVE
SEVERAL SW
BODIES
ASSOCIATED
WITH EACH ONE
3-Dimensional
Geological/hydrogeological
boundaries
Groundwater Bodies (GWBs): the management
unit of the WFD (not aquifers)
Groundwater Status
 WFD + ‘Daughter’ Groundwater Directive
The overall aim of the WFD is to achieve
“Good Status” for all GWBs by 2015
Scale: Status assesses Average GWB
Conditions
Local issues are managed under site
specific “Prevent or Limit” legislation, but
they may still impact on status
GWB Results:
Quantitative Status
 4 GWBs at Poor Status
2 due to
unsustainable longterm abstraction
2 due to abstractions
impacting on the
supporting water
level/flow conditions
of wetlands
GWB Results:
Chemical Status
 111 GWBs at POOR STATUS
 Relates to 14% of RoIs area
 Main Drivers:
 MRP contributing to SW
Eutrophication (101 GWBs)
 Metals from Historic
Mining Activities (5 GWBs)
 Contaminated land / Urban
(2 GWBs)
 Diffuse NO3 (2 GWBs)
Issues Arising (Selected)
1) Nitrogen & TRAC waters
2) Groundwater as an input and a pathway to
surface water
3) Groundwater Dependent Terrestrial
Ecosystems (GWDTEs)
4) Phosphate in karst groundwater impacting on
surface water ecosystems
5) Groundwater Threshold Values (TVs)
6) High status sites
7) OSWTSs
8) Nitrate Trends
Who undertakes water
body classification?
 EPA undertakes and is responsible for
this work
Small Stream Risk Score (SSRS) method
not used for status; but part of
investigative monitoring
Drifting Ulva blooms (Green tides) (‘sea lettuce’!!)
on the Brittany coast
N

Nitrogen, TRAC Waters
and Sea Lettuce

16% of TRAC waters are eutrophic or potentially eutrophic.
Why? Due to the presence of nutrients, mainly N & P.

Coastal waters EQS (median) for N = 2.6 mg/l (or 12 mg/l as
NO3) at fresh water interface
 Main N Sources
 WWTPs and diffuse agriculture
 Short–term Implications:
 A potential health hazard (H2S)
 An expensive and difficult collection & disposal issue
 Medium to long–term Implications:
 Investment in upgrading WWTPs needed
 Reduction in nitrate loss to groundwater
 Lag time for reduction???
No longer sufficient to ‘see’
groundwater largely in terms of wells
Springs
Wells
Groundwater as a contributor to
surface water
Weathered/broken rock zone as
pathway for water and contaminants
Hook Head, Co. Wexford
Groundwater as a contributor to
groundwater dependent ecosystems
(GWDTEs)
Pollardstown Fen - a GWDTE
GWDTEs - Progress
 Very little
 Environmental Supporting Conditions not
known:
 N & P environmental quality standards
needed
 groundwater level and flow conditions
 Progress, incl. monitoring, needed for
next RBMP
Phosphate in GW:
Discussion
 Rivers in blue are
‘less than good’ status
mainly due to diffuse
pressures
PO4 in groundwater
the main cause in red
areas.
Specific measures to
reduce PO4 “leakage”
to GW may be needed
Will existing measures
be sufficient?
Phosphate in GW:
Discussion
 Why an issue?
 Main cause of eutrophication of rivers
 River MRP EQS low = 35µg/l P
 P readily adsorbed in soil & subsoil, but
where thin, can enter groundwater
 Where an issue?
 Vulnerable aquifers (i.e. thin soil/subsoil
& sinking streams)
 Karst aquifers, where high proportion of
surface water comes from groundwater
 Note: high pressures (e.g. LUs) not
needed
 Main cause: agriculture

Subsidiary: OSWTSs
Measures introduced
to improve SW
Bodies will also have
to consider GW
inputs arising from
diffuse agriculture
and, in places,
OSWTSs
GWB Group
Average MRP
Concentration
Galway Karst
36 mg/l
Mayo Karst
34 mg/l
Cork Karst
25 mg/l
Clare Karst
28 mg/l
Roscommon Karst
25 mg/l
Kerry – Limerick
Karst
45 mg/l
Groundwater Threshold
Values (TVs)
 TVs are in the Groundwater Regulations and have
been reported to the EU
 TVs are mean concentrations
 TVs are not Emission Limit Values (ELVs)
 TVs are trigger values that prompt further
investigation: not the boundary between GOOD and
POOR
status
Parameter
Threshold
Value
Test
Reason for TV
 TVs 37.5
must
to theGWQ
receptor,
e.g.
Nitrate
mg/lbe
NO3 appropriate
Drinking Water/General
Protect Human
Use
Human
TCE/PCE  7.5
ug/l use (drinking
Generalwater)
GWQ
Surface
Chloride  24
mg/l Cl water Saline Intrusion
 Wetlands
Conductivity 800 uS/cm
Saline Intrusion
MRP
35 ug/l P
Surface Water Quality
Ammonium 65 ug/l N
Surface Water Quality
Protect Human Use-Point Source
Upper Limit of NBL
Upper Limit of NBL
SW EQS
SW EQS
High Status Surface
Water Bodies

9% of rivers and 28% of lakes.
 Number of high quality river sites halved in last 20
years.
 High status WBs are critical to species biodiversity
 Deterioration to ‘good’ not allowed, therefore
measures to prevent this of critical importance and a
high priority
 Sensitive to pressures (forestry, farming, peat
extraction, rural housing) so ‘low level’ activities may
cause the deterioration
 Additional measures to protect these areas likely to
be needed
OSWTSs (septic tanks etc)
 Groundwater Status
 Not a major issue
 Individual wells affected
 If new EPA CoP followed, pollution of
groundwater should be minimal
 But a legacy of existing polluted wells,
particularly from ‘soak pits’
OSWTSs (septic tanks etc)
 Surface Water Status
 Contributes ~7% P overall
 But significant locally
 Areas with minimal soakage the issue – gley
soils, clayey subsoils, low permeability
bedrock
 A legacy of bad decision-making by LAs
 The future
EPA CoP; Building Regs; DEHLG Circular
Letter
Some sites are “unsuitable” in practice
Some Context!!
Sewage pipe!!
holiday house in
west of Ireland
Sinéad
The Stray Cat
Ponded
effluent
32
33
Start of
percolation
test
Next day
Conclusion: site
is not suitable
34
20-30% of
impact due to
OSWTSs
Map source: CDM &
Eastern RBD RBPM
Gley soils &
limited soakage
Map source: CDM &
Eastern RBD RBPM
Drinking Water
Protected Areas
 Results of Status Test:
 2 GWBs at POOR STATUS
 Durrow WS, Laois
 Ballyheigue WS, Kerry
 Nitrate main driver: however
many MPs > 25 mg/l NO3
 But DWPA test only
undertaken in MPs in EPA
network!
Nitrate Trends in Rivers
 NO3 concentrations are stable
 43% of all (surveillance + operational)
stations had concs. <10mg/l, with 21%
>25 mg/l
 Over 70% of surveillance stations had
concs.<10mg/l NO3, with 3% >25mg/l
 But more time and data needed to test
for statistical significance.
Nitrate Trends in
Groundwater
 Trend analysis undertaken by EPA for 119
wells/springs
 Statistically significant downward trend at 11
sites
 Statistically significant upward trend at 12
sites
 Environmentally and statistically significant
upward trend at 2 sites
There is no rivers EQS for nitrate.
If one is chosen that is lower than the 37.5 mg/l NO3
TV, then it will have implications for groundwater body
status.
Arabic Proverb
Literally
“Into the well from which you drink do not
throw stones”
[Care for the water upon which you depend]