David Hart Building Surveyors

Percolation Tests or Site Suitability Assessments are required for the design and installation of all septic tanks or waste water treatment systems for domestic houses.

The purpose of of the assessment is three fold

Will the site allow the waste water to percolate through the soil in order to prevent ponding of the effluent and contamination of local drains and ditches.

Will the soil treat the effluent sufficiently to clean the effluent before it enters underground water possibly causing contamination

Will the site be large enough to accommodate a suitable system.

Depending on the Local Authority area, site assessments are either carried out either by their own personnel or by FETAC qualified assessors.

The test involves the excavation of a large trial hole and three to six test holes into which water is poured and the time it takes to percolate away is recorded. The level of the water table established by the trial hole and the time taken for the percolation will determine the results of assessment.

Where the water table is to high or the percolation to slow, the test will be a failure, also in situations where percolation is to fast, this will also be a failure.

The test will also determine whether a septic tank or a more advanced system will be required. The  size and type of percolation area will also be determined by the test results. Raised  percolation area or soil filters may also be required to provide separation between the treated effluent and the local water table.

For a free consultation, email us and we will phone you back