Surface Water and Groundwater Status Donal Daly Hydrometric

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

Interim Status Assessment of Lakes

Transitional and Coastal Water Status

Main Causes of “less than good” Status Surface Water Bodies q Discharges from Wastewater Treatment Plants (nutrients) q Diffuse Agriculture (resulting in inputs of P, PO 4 and N) q Forestry (sediment and P) q 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 (10 s to 100 s km 2) 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 q WFD + ‘Daughter’ Groundwater Directive q. The overall aim of the WFD is to achieve “Good Status” for all GWBs by 2015 Status q. Scale: Status assesses Average GWB Conditions q. Local issues are managed under site specific “Prevent or Limit” legislation, but they may still impact on status

GWB Results: Quantitative Status q 4 GWBs at Poor Status q 2 due to unsustainable longterm abstraction q 2 due to abstractions impacting on the supporting water level/flow conditions of wetlands

GWB Results: Chemical Status q 111 GWBs at POOR STATUS q Relates to 14% of Ro. Is area q Main Drivers: q MRP contributing to SW Eutrophication (101 GWBs) q Metals from Historic Mining Activities (5 GWBs) q Contaminated land / Urban (2 GWBs) q Diffuse NO 3 (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? q EPA undertakes and is responsible for this work q. 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 n

Nitrogen, TRAC Waters and Sea Lettuce q 16% of TRAC waters are eutrophic or potentially eutrophic. Why? Due to the presence of nutrients, mainly N & P. q Coastal waters EQS (median) for N = 2. 6 mg/l (or 12 mg/l as NO 3) at fresh water interface q Main N Sources q WWTPs and diffuse agriculture q Short–term Implications: q A potential health hazard (H 2 S) q An expensive and difficult collection & disposal issue q Medium to long–term Implications: q Investment in upgrading WWTPs needed q Reduction in nitrate loss to groundwater q 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 q Very little q Environmental Supporting Conditions not known: q N & P environmental quality standards needed q groundwater level and flow conditions q Progress, incl. monitoring, needed for next RBMP

Phosphate in GW: Discussion q Rivers in blue are ‘less than good’ status mainly due to diffuse pressures q PO 4 in groundwater the main cause in red areas. q Specific measures to reduce PO 4 “leakage” to GW may be needed q Will existing measures be sufficient?

Measures introduced to improve SW Phosphate in GW: Bodies will also have Discussion to consider GW q Why an issue? inputs arising from q Main cause of eutrophication of rivers diffuse agriculture q River MRP EQS low = 35µg/l P and, in places, q P readily adsorbed in soil & subsoil, but where thin, can enter groundwater OSWTSs q Where an issue? q Vulnerable aquifers (i. e. thin soil/subsoil & sinking streams) q Karst aquifers, where high proportion of surface water comes from groundwater q Note: high pressures (e. g. LUs) not needed q Main cause: agriculture q Subsidiary: 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) q TVs are in the Groundwater Regulations and have been reported to the EU q TVs are mean concentrations q TVs are not Emission Limit Values (ELVs) q TVs are trigger values that prompt further investigation: not the boundary between GOOD and POOR status q TVs must be appropriate to the receptor, e. g. n Human use (drinking water) n Surface water n Wetlands

High Status Surface Water Bodies q 9% of rivers and 28% of lakes. q Number of high quality river sites halved in last 20 years. q High status WBs are critical to species biodiversity q Deterioration to ‘good’ not allowed, therefore measures to prevent this of critical importance and a high priority q Sensitive to pressures (forestry, farming, peat extraction, rural housing) so ‘low level’ activities may cause the deterioration q Additional measures to protect these areas likely to be needed

OSWTSs (septic tanks etc) q Groundwater Status q Not a major issue q Individual wells affected q If new EPA Co. P followed, pollution of groundwater should be minimal q But a legacy of existing polluted wells, particularly from ‘soak pits’

OSWTSs (septic tanks etc) q Surface Water Status q Contributes ~7% P overall q But significant locally q Areas with minimal soakage the issue – gley soils, clayey subsoils, low permeability bedrock q A legacy of bad decision-making by LAs q The future q. EPA Co. P; Building Regs; DEHLG Circular Letter q. 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 q Results of Status Test: q 2 GWBs at POOR STATUS q Durrow WS, Laois q Ballyheigue WS, Kerry q Nitrate main driver: however many MPs > 25 mg/l NO 3 q But DWPA test only undertaken in MPs in EPA network!

Nitrate Trends in Rivers q NO 3 concentrations are stable q 43% of all (surveillance + operational) stations had concs. <10 mg/l, with 21% >25 mg/l q Over 70% of surveillance stations had concs. <10 mg/l NO 3, with 3% >25 mg/l q But more time and data needed to test for statistical significance.

Nitrate Trends in Groundwater q Trend analysis undertaken by EPA for 119 wells/springs q Statistically significant downward trend at 11 sites q Statistically significant upward trend at 12 sites q 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 NO 3 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]