Blogs —› Percolation

The Environmental Protection Agency (EPA) is developing a National Inspection Plan for Domestic Waste Water Treatment Systems (to be called the ‘Inspection Plan’ throughout this document) as required under the Water Services (Amendment) Act 2012. Domestic waste water treatment systems can and do cause pollution when they are not properly sited, installed or maintained. This discussion document sets out the general principles which the EPA proposes to use in the Inspection Plan, drawing on experience and best international practice in science and regulation. The EPA invites interested parties and individuals to submit comments for consideration.

See link to draft National Inspection Plan >>

Draft Septic Tank Inspection Plan

How does a percolation area work?

A percolation system is now standard for all new septic tanks installed in Ireland today. These systems are engineered to treat the partially treated effluent from the septic tank and to distribute this treated liquid into the underlying ground water. If constructed correctly, and the site has the right conditions a standard percolation system will last trouble free for many years with little maintenance. A typical percolation system is composed of a series of trenches half a meter wide and 18m long. Each trench is made up of the following components as seen in the image below, 250mm of clean stone, a 4” distribution pipe, a second layer of clean stone to cover the pipe and a geotextile membrane covered with a layer of soil brought up to ground level. It is important that the trench is ventilated for an adequate oxygen supply. This is achieved by connecting the pipes at the end of each trench together and pointing a single pipe out of the ground for ventilation. This ventilation pipe can be brought up near a fence or boundary if desired. Effluent from the septic tank has to be fed into a distribution box. The purpose of this box is to ensure that each trench receives an equal volume of wastewater. Over dosing one trench will cause that trench to breakdown.

Home Builders: Molloy Precast will provide you with a Site Suitability Report; however, this report is based on a site characterisation report completed by a competent and qualified person i.e. a site assessor. This page provides you with a list of names and contact details county by county of site assessors.

Site Assessors: To be included in this list, free of charge, please phone John Brennan on 057 93 26000 or email john.brennan@molloyprecast.com.