Dangerous Substances Report 2005

Date released: Jan 25 2007

The EPA’s Office of Environmental Enforcement today released its first report on the implementation of the Water Quality (Dangerous Substances) Regulations, 2001.  The regulations set water quality targets for 14 dangerous substances in rivers, lakes and tidal waters to be met by 2010.

The substances are:

  • pesticides (atrazine, simazine, tributyltin);
  • solvents (dichloromethane, toluene, xylene);
  • metals (arsenic, chromium, copper, lead, nickel, zinc) and
  • other substances (cyanide, fluoride). 

These substances were selected primarily on the basis of their likely use or presence in Ireland and their potential impacts on waters by virtue of toxicity, persistence and bioaccumulation. 


“Overall, the results tell us that Ireland does not have a significant problem with dangerous substances in water compared to other industrialised nations,”

said Dr Matthew Crowe, Programme Manager, EPA’s Office of Environmental Enforcement.  

“There is, however, a need to be vigilant in relation to the protection of waters from contamination with dangerous substances and where these substances are detected further investigations are required to identify why they are there and steps need to be taken to eliminate them.”


The report has been compiled primarily from historical information and water quality data submitted to the EPA by local authorities and from additional data collected by the EPA and Marine Institute.  It provides an overview of the broad range of measures being implemented by local authorities in relation to the prevention of contamination of waters with dangerous substances.

Through the implementation of the recently published national Water Framework Directive Monitoring Programme, the EPA and Marine Institute are now responsible for the monitoring of these and other substances in Irish waters. 

Dr Crowe commented,

“The monitoring to be conducted under this programme will provide more comprehensive information about the relative presence of such substances in Irish waters, which will allow remedial actions to be targeted where most needed."


The main findings of the Report are:

  • With the exception of tributyltin, the majority of exceedances (zinc, copper, chromium, lead and nickel) detected relate to either historical mining activities or are due to the geology of an area contributing to naturally elevated levels of heavy metals in surface waters;
  • In relation to tributyltin (TBT), data collected from Marine Institute publications and from a small number of local authority reports indicates widespread TBT contamination in Irish harbours[1].   It is to be expected that future monitoring will demonstrate a gradual diminution of the threat from TBT over the coming years as the use of this product is phased out due to EU requirements;
  • While values in excess of the standards in the Regulations were reported at 143 river stations, 45 lake stations and 24 tidal water monitoring stations, these were locations targeted by local authorities as areas where these substances were most likely to occur, for example, areas where past mining activity took place;
  • There were no exceedances of the toluene and xylene standards at any station monitored and there were very few exceedances of the dichloromethane, simazine, atrazine, arsenic and fluoride standards reported;
  • As a result of work undertaken to remediate old landfills, exceedances of a number of dangerous substances that were detected in 2002 and 2003 were not detected in 2004.

Mining activity has contributed to elevated levels of heavy metals in certain areas. The recent Government decision to remediate the Silvermines area is welcome and further consideration should also be given to addressing mining impacts in other areas.

The EPA recommends that all local authorities continue to identify and assess those activities that may be potential sources of dangerous substances and to put in place appropriate implementation programmes to deal with breaches of the standards.  Monitoring should be focussed at high-risk surface waters potentially impacted on by point discharges e.g. waste water treatment plants, landfills, mining operations and relevant industries. 

[1] Tributytin was used in the past as an anti-fouling agent on boats.  In Ireland  in 1987 a ban was introduced on its use on vessels under 25m in freshwater and in the marine environment.

Note to Editor:

Regulations : The report provides information on the Water Quality (Dangerous Substances) Regulations, 2001 (S.I. No. 12 of 2001).