Bill McEvoy

ECO DESIGN | BER | PLANNINGSITE SUPERVISION | DRAWINGS | SITE ASSESMENTS | FIRE SAFETY | CASE STUDIES

Site Suitability Assessments

Site Assessments involve assessing what is the best type of waste water treatment system to serve your home – be it a conventional septic tank system, or an advanced treatment system. The assessment is carried out in accordance with the EPA, 2000 Manual: “Wastewater Treatment Manuals”. The Site Assessment includes a desk study, an on-site Visual Assessment, a Trial Hole Investigation and Percolation Tests.

Desk Study

The purpose of a desk study is to obtain information relevant to the site, the desk study involves the assessment of available data pertaining to the site and adjoining areas that may determine whether the site has any restrictions. Hydrological aspects taken into account are the presence of streams, rivers, lakes and wetlands while hydrologeological aspects include soil type, subsoil type, bedrock type, aquifer type and vulnerability class.

Visual Assessment

The purpose of the visual assessment is to assess the potential suitability of the site, assess potential targets at risk (adjacent wells) and to provide sufficient formation to enable a decision to be made on the suitability of the site for the wastewater to be treated and the location of the proposed system within the site.

Trial Hole Inspection & Percolation Test

The purpose of the trial hole inspection is to determine the depth of the water table, the depth to bedrock, and the soil and subsoil characteristics. The trial hole will also help to predict the wastewater flow through the subsoil. A percolation (permeability) test assesses the hydraulic assimilation capacity of the subsoil i.e. the length of time it takes the water level in the percolation hole to fall from a height of 300mm to 200mm above the base the test hole in the percolation area.