Water Quality

Water Quality Legislation

There is a vast amount of information relating to water quality legislation. Current Legislation is aimed at using the law to control and monitor the following areas:

  • Drinking Water
  • Salmonid Waters and Fisheries
  • Nitrates and Phosphorus
  • Water Quality
  • Water Pollution
  • Dangerous Substances
  • Urban Waste Water Treatment

If you would like to take a more in depth look at the legislation surrounding water quality, please take a look at the following websites:

Useful Websites

Visit the Environmental Protection Agency Website or the Irish Statute Book Website

The EU Water Framework Directive is an important piece of EU environmental legislation which aims at improving our water environment. It requires governments to take a new holistic approach to managing their waters. It applies to rivers, lakes, groundwater, estuaries and coastal waters. Member States must aim to achieve good status in all waters by 2015 and in some instances by 2021 and 2027. Currently all water bodies in the county have been assigned a status under the requirements of the Water Framework Directive the local authority carries out routine monitoring of the river network throughout the county known as the operational monitoring. In addition investigative monitoring is carried out where appropriate in catchments to improve the status of poor and moderate waters and includes inter alia additional sampling/monitoring, farm surveys, licensing of discharges, investigation of pollution complaints and assessment of septic tanks. Various measures including basic and supplementary are required to improve the status of waters which are less than good status and maintain waters which are already at good status.

Bathing water monitoring is carried during the Bathing water season at a number of sites. Bathing Water Results - available from the following link http://splash.epa.ie/

Discharge Licences

Louth County Council processes applications for licences to discharge effluent to waters (Section 4 licences) under the Water Pollution Acts 1977-as amended. Occupiers of commercial premises must ensure that they comply with the necessary requirements. Application forms are available for download for the necessary discharge licence.

Application Form - Surface Waters.pdf (size 816.8 KB)

application form groundwater.pdf (size 1.3 MB)

Checklist_for_Discharge_to_waters.pdf (size 15.4 KB)


Discharge of Trade and/or Sewage Effluent to Surface Waters

In all instances the discharge of effluent (trade and/or sewage effluent) to surface waters requires a licence under Section 4 of the Local Government (Water Pollution) Acts 1977 – 2007 and will require the detailed evaluation of the impact of the wastewater on receiving waters and should include inter alia the following:

  • A discharge licence application
  • The chemical and microbiological characteristics of the effluent
  • The chemical and microbiological condition of the receiving waters
  • Biological quality rating of the receiving waters performed in accordance with EPA methodology.
  • Flow data of the receiving waters indicating 95%ile flow and dry weather flow
  • Assimilative capacity of the receiving waters with regard to the impact of the proposed discharge on the quality of the receiving waters.
  • Must have regard for relevant water quality standards and guidelines


Discharge of effluent to Groundwaters

A licence will apply to trade effluent discharges to groundwaters and domestic discharges exceeding five cubic metres in any 24 hour period

To evaluate the impact of wastewater on receiving waters the following is required. (This may require the applicant to engage the services of a qualified hydrogeologist)

  1. A Water Pollution Licence Application Form completed in accordance with the Licence Application Explanatory Notes.  
  2. A description of the chemical and bacteriological composition of the effluent
  3. A description of the chemical and bacteriological condition of the receiving groundwater at the discharge location
  4. Aquifer characterisation and vulnerability rating of the site
  5. Where the discharge is to a locally or regionally important aquifer, an examination of the aquifer in respect of extent, estimated volume of water and estimated rate of recharge will also be required
  6. Details of the source of the water supply for the development and details of any other wells and wastewater treatment systems within 100 meters of the development’s treatment plant or percolation area (maps indicating the locations of these features to be included) 
  7. An assessment of the associated impacts of the discharge on the chemical and microbiological quality of the groundwater having consideration for the relevant legislation 

In general, it is not suitable to discharge industrial/commercial effluent or communal housing effluent to groundwaters in the following circumstances:

  • Where the site is hydraulically unsuitable and has insufficient percolation
  • Where the groundwater has inadequate assimilative capacity or is already polluted
  • Where nitrogen levels in the groundwater are known to be high or where nitrogen loading analysis indicates a potential problem with reference to nitrogen levels
  • Where the Groundwater Protection Response is R3 unless the requirements of the Groundwater Protection Schemes (GSI, 1999) can be met


Groundwater Assimilative Capacity Assessment

Groundwater investigations are intended to deal with two issues:

(a)    Attenuation – the adequacy of effluent treatment before a relevant receptor (e.g. well, stream, groundwater dependent terrestrial ecosystem) is reached.

(b)   Hydraulics – the ability of the underlying geological materials to accept the maximum volume of effluent generated.


Hydrogeological Assessment

For all industrial and commercial discharges to groundwater and for domestic sewerage discharges greater than 5m3/24 hour period to groundwater a full hydrogeological assessment shall be carried out.  This assessment should include:

  • The hydrogeological conditions of the area in which the aquifer is located (including aquifer category)
  • Prediction of pollutant attenuation beneath the percolation area.
  • Prediction, based on appropriate calculations, of the vertical and horizontal movement of effluent beneath and away from the percolation area.
  • An assessment of the risk of deterioration in the quality of the water therein due to the entry of harmful substances
  • An assessment of the risk to human health or water supplies, living resources and the aquatic ecosystem and potential interference with the use of the water for agriculture, commercial, domestic, fisheries, industrial or recreational purposes due to the entry of the effluent to the aquifer.


In most circumstances, the hydrogeological site investigation and assessment will require the following:

  • Drilling and testing of boreholes
  • Trial pits
  • Percolation tests
  • Permeability measurements in subsoil and bedrock
  • Subsoil particle size distribution
  • Vulnerability rating
  • Groundwater levels
  • Water table gradient
  • Recharge
  • Existing groundwater quality.


Investigations  should have regard for the following Department of Environment, Heritage and Local Government Circulars – SP5/03 and BC16/06, British Standards 5930 – 1999 Code of Practice for Site Investigations, Sustainable Rural Housing – Guidelines for Planning Authorities (DOEHLG), Environmental Protection Agency / Geological Survey of Ireland – 1999 - Groundwater Protection Schemes, 2001 – Groundwater Protection Responses for Onsite Systems for Single House, EPA Wastewater Treatment Manual – Treatments Systems for Small Communities, Business, Leisure Centres and Hotels, EPA Guidelines 2000, as amended by Code of Practice – Wastewater treatment and Disposal Systems serving single houses (p.e. < 10) – 2009 and the Western River Basin District, Programme of Measures and Standards, Draft Technical Framework for Site Assessment of large scale onsite Wastewater Treatment Systems discharged to groundwater.

Note:Aquifers with elevated nitrate levels are not considered suitable for the disposal of effluents.