EPA Site Suitability Assessments

The purpose of an EPA Site Suitability Assessment is to determine whether your site is suitable to discharge treated effluent to groundwater. If you are building/renovating a new/existing home or commercial facility and you do not have access to the main sewer you will need to carry out an EPA Site Suitability Assessment. This will be an important part of your planning application as it proves you can safely treat and dispose of your wastewater on the proposed site.

When specifying an on-site wastewater treatment system there are many factors to consider, it is an engineer’s job to find a practical, cost-effective solution that protects our drinking water and environment. Our engineers refer to the EPA Code of Practice 2021, S.R. 66:2015, and the Building Regulations Technical Guidance Document H for current regulations.

What is involved in an EPA Site Suitability Assessment?

  • Desk study that collects information about the site such as hydrological aspects, soil/sub-soil types, karst features, aquifer type, groundwater vulnerability, groundwater body status, groundwater protection response, presence of significant sites, and the engineer’s previous experience in the geographical area.

  • Visual assessment to assess the potential suitability of the site, and identify potential targets/receptors at risk.

  • A trial hole to evaluate the soil/sub-soil types and depth. It will also indicate the presence of a high water table or bedrock on-site.

  • Percolation test to record how fast/slow drainage is on the proposed site.

  • A full report based on the data obtained.

  • Recommendation of an on-site wastewater treatment system including the proposed layout.

Frequently asked questions

  • A percolation test consists of multiple T/P test holes that are filled with water to record how fast/slow drainage is on the proposed site.

  • A trial hole is used to evaluate soil/sub-soil types and depth. It will also indicate the presence of a high water table or bedrock on-site.

  • A suitably qualified engineer or an individual who has completed the Wastewater Treatment Site Suitability; QQI Level 6; 6N2213 course from the Local Authority Services National Training Group.

  • In most cases, you will need to hire a local contractor to excavate a trial hole and various T/P test holes. You may also need to provide a water supply to carry out a percolation test.

  • An EPA Site Suitability Assessment can cost anything from €600 - €1,200 depending on the engineer and the location of the proposed site.

  • Yes, some sites do not have suitable ground conditions or space available to install an on-site wastewater treatment system. Where sites are deemed unsuitable for discharge to groundwater, alternative options, if any, will need to be discussed with the local authority.

Contact us today

for more information on what is required when specifying and installing an on-site wastewater treatment system.