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Surface Water and Groundwater Status
Donal Daly
Hydrometric & Groundwater Section
Environmental Protection Agency
Acknowledgement: Colleagues in EPA and on WFD Groundwater Working Group
Water Freamework Water Freamework Directive Water Status Directive Water Status
““A measure of the A measure of the present”present”
Based on an evaluation of: pressures, physical settings
and monitoring results
Status is the key element determining the measures to be employed in the Reliability Based Decoding Management Plans to
achieve the objectives of the Water Framework Directive
Ecological Status for Surface Waters
Pass WFD
Fail WFD
Interim Status Assessment of Rivers
River Quality – WFD Interim Status
Ecological Class Number of Water Bodies
HHiigghh 117733 ((99%%))
Good 738 (40%)
Moderate 509 (28%)
Poor 389 (21%)
Bad 41 (2%)
Interim Status Assessment of Lakes
Lake Quality – WFD Interim Status Biological Class Number of Lakes Surface Area (km2)
HHiigghh 7766 ((2288..00%% )) 336699..66 ((3377..11%% ))
Good 75 (27.7% ) 204.4 (20.5% )
Moderate 94 (34.7% ) 397.9 (40% )
Poor 17 (6.3% ) 7.1 (0.7% )
Bad 9 (3.3% ) 16.5 (1.7% )
Main Causes of “less than good” Status Surface Water Bodies Discharges from Wastewater
Treatment Plants (nutrients)
Diffuse Agriculture (resulting in inputs of Phosphorus and N)
Forestry (sediment and Phosphorus)
Urban areas
Groundwater Bodies (GWBs): the
management unit of the WFD (not aquifers)
GROUNDWATER BODIES ARE NORMALLY LARGE
(10s to 100s km2)
WILL HAVE SEVERAL SW
BODIES ASSOCIATED
WITH EACH ONE
3-Dimensional
Geological/hydrogeological
boundaries
Aquifer bounda
ry
Groundwater
boundary
Groundwater Status
Groundwater Directive
The overall aim of the WFD is to achieve “Good StatusGood Status” for all GWBs by 2015
Scale: Status assesses Average Average GWB ConditionsGWB Conditions
Local issues are managed under site specific “Prevent or Limit”“Prevent or Limit” legislation, but they may still impact on status
GWB Results:Quantitative Status
4 GWBs at Poor Status2 due to
unsustainable long-term 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 and sea lettuce2) Groundwater as an input and a pathway
to surface water3) Groundwater Dependent Terrestrial
Ecosystems 4) Phosphate in groundwater impacting on
surface water ecosystems5) Groundwater Threshold Values6) High status sites7) Nitrate Trends
Who undertakes water body classification? Environment Protection Agency
undertakes and is responsible for this work
Small Stream Risk Score method not used for status; but part of investigative monitoring
Drifting Ulva blooms (Green tides) (‘sea lettuce’!!) on the Brittany coast
N
n
Nitrogen, TRAC Waters and Sea Lettuce 16% of TRAC waters are eutrophic or potentially
eutrophic. Why? Due to the presence of nutrients, mainly Nitrogen & Phosphorus.
Coastal waters (median) for N = 2.6 mg/l (or 12 mg/L) at fresh water interface
Main Nitrogen Sources diffuse agriculture
Short–term Implications: A potential health hazard An expensive and difficult collection & disposal issue
Medium to long–term Implications: Investment in upgrading 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 Groundwater as a contributor to surface watersurface water
Weathered/broken rock zone as pathway for water and contaminants
Hook Head, Co. Wexford
Pollardstown Fen - a GWDTE
Groundwater as a contributor Groundwater as a contributor to groundwater dependent to groundwater dependent
ecosystems (GWDTEs)ecosystems (GWDTEs)
Surface of Groundwater Progress Very little
Environmental Supporting Conditions not known: Nitrogen & Phosphorus environmental
quality standards needed groundwater level and flow conditions
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
Groundwater Threshold Values (TVs)
TVs are in the Groundwater Regulations and have been reported to the world
TVs are mean concentrationsmean concentrations TVs are notnot Emission Limit Values TVs are trigger valuestrigger values that prompt further investigation: notnot
the boundary between GOOD and POOR status TVs must be appropriate to the receptor, e.g.
n Human use (drinking water) n Surface watern Wetlands
Parameter Threshold Value Test Reason for TV
Nitrate 37.5 mg/l NO3 Drinking Water/General GWQ Protect Human Use
TCE/PCE 7.5 ug/l General GWQ Protect Human Use-Point Source
Chloride 24 mg/l Cl Saline Intrusion Upper Limit of NBL
Conductivity 800 uS/cm Saline Intrusion Upper Limit of NBL
MRP 35 ug/l P Surface Water Quality SW EQS
Ammonium 65 ug/l N Surface Water Quality 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 Water Bodies 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
Some Context!!Some Context!!
SinéadSinéad The Stray CatThe Stray Cat
holiday house in west of Ireland
Sewage pipe!!
26
Ponded effluent
27
28
Start of percolation
test
Next dayConclusion: Conclusion: site is not site is not suitablesuitable
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 Results of Status
Test:Test:
2 Ground Water Bodies at POOR STATUS
Nitrate Trends in Rivers NO3 concentrations are stable
43% of all (surveillance + operational) stations had concentrations <10mg/l, with 21% >25 mg/l
Over 70% of surveillance stations had concentrations<10mg/l NO3, with 3% >25mg/l
But more time and data needed to test for statistical significance.
Groundwater Surface