Percolation Test in Cork
Percolation Testing in Cork
O.S.C is the most successful percolation testing company in Cork.
Percolation Testing in Cork O’Sullivan Consulting Percolation for planning permissions in the South West of Ireland. The testing is done by a fully qualified site assessors here in Cork. There is
engineering insurance in place to cover up to amounts of €1,000,000 in value. We also have public
liability insurance in place to give our clients peace of mind while we are working on their properties.
Our reports are very detailed and include full E.P.A.C.O.P Site Assessment report, desk study, maps,
O.S map showing local features, B.S 5930 soil test report, timed and dated digital photographs of
the test in progress and top quality sewer system construction drawings consisting of plan, two
cross sections and a long section. These drawings are level related and will be easy to follow for
individuals involved in the construction of the effluent system during civil works. While the majority
of our testing is undertaken for clients seeking planning permission for either new builds or home
extensions, this is also a valuable service available to people who are interested in upgrading an
existing septic tank system that is not up to correct standards. We offer a excellent top quality
service at a fair price.
What is a Percolation Test in Cork?
A percolation test is a test to determine the absorption rate of soil for a septic drain field or
“leach field”. The results of a percolation test are required to properly design a septic
system. In its broadest terms, percolation testing is a simply observing how quickly a known
volume of water dissipates into the subsoil of a drilled hole of known surface area. While
every local authority will have its own laws regarding the exact calculations for the length of
line, depth of pit, etc the testing procedures are generally the same.
In general, sandy sol will absorb more water than soil with a high concentration of clay or
where the water table is close to the surface.
Testing method for Cork
A percolation test consists of digging holes in the soil of the proposed drainage area to a
specified depth, pre-soaking the holes by maintaining a high water level in the holes, then
running the test by filling the holes to a specific level and timing the drop of the water level
as the water percolates into the surrounding soil. There are various empirical formulae for
determining the required size of a leach field based on the size of facility, the percolation
test results, and other parameters. The drainage or percolation area is designed based on
these test results.
For leach line testing, test holes are drilled, most commonly twelve inches in diameter,
Ideally, these should be drilled to depths matching your trench invert level. For better, more
conclusive results, holes are used in a pattern of one hole at each corner of the proposed
leach field and one test hole in the centre. Testing of these holes will result in a value with
units of minutes per inch. This value is then correlated to a predetermined county health
code to establish the exact size of the leach field.
After the test is completed the results are used to design a suitable polishing filter or
percolation area for the site, though the end result is a different type of septic system,
established through a different calculation if needs be.
Finally, for leach line systems and horizontal seepage pits, a “deep hole” (TRIAL-HOLE) is
drilled to find the water table or the approximately twelve feet (dry). Exact depths will again
depend on local health codes. In the case of a vertical seepage pit, local groundwater data
may be used, or if the drill hole reaches groundwater, the pit will be backfilled again
according to county health codes.
In Ireland there is a requirement for an area to be mapped around the site, photographic
recording of the test, BS5930 soil analysis, detailed test reporting as well as level related
detailed sewer system construction drawings to be included in the full site assessment