LEAF is a collection of four leaching test methods developed to identify detailed characteristic leaching behaviours
of various solid materials including soils, wastes and construction materials.
These laboratory tests, using USEPA methods SW846 1313, 1314, 1315 and 1316 are designed to provide aqueous extracts
that represent the partitioning of compounds from solid to liquid under various mechanisms of interaction –
i.e. actively, mechanical, passive, chemical or all of these.
A Brief Summary of the Four Laboratory Methods
An overview has been provided below of the four laboratory test methods applied to identify leaching
characteristics.
1. USEPA SW846 1313 – Parallel Leach
The solid is sized and then tumbled (for ≥24 hours) at various pH levels e.g. pH 2, 4, 5.5, 7, 8.0, 9.0, 10.5, 12
and 13.
2. USEPA SW846 1314 - Column Leach
As illustrated in the diagram above, the solid is sized and packed into a column.
Eluent is very slowly percolated through the column and volumes of the resulting eluent are collected
periodically and analysed for the target analytes.
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3. USEPA 1315 – Monolith Leach
This method is aimed for monolithic or compacted granular material, typically cement based or stabilised materials.
The solid is emerged in eluate for various periods of time, and hence estimates of the diffusivity of target
analytes from the monolith can be gained.
4. USEPA 1316 – Parallel Leach
Solid is sized and tumbled end over end at varying liquid to solid (L/S) ratios. The
ratios can vary from 10:1 to 1:2 for liquid to solid respectively.
LEAF Testing At Envirolab
Envirolab is now NATA accredited for LEAF testing. However, as the procedures are relatively time consuming, a
discussion with our laboratory team is required prior to sample submission. This will ensure the most appropriate
method(s) and subsequent analysis of the resulting eluates. For further information or if you require LEAF testing,
call 1300 424 344 or email:
Simon
Mills
Todd Lee
Alternatively, download a copy of our Envirolab flyer on LEAF Testing.