UP-FLOW Percolation Tests (TS 14405:2004)
Less Aggressive-More indicative of actual field conditions- Less remediation- Less cost
This technical specification provides a method for the determination of the leaching behaviour of compounds of concern from granular waste. The waste body sample is subjected to leaching by the upwards flow of water at a very slow rate (15 cm of column per day). The test should provide a more accurate predication of the likely leaching of components of concern under actual practical conditions of rainfall.
Other leaching tests in frequent use such as batch leaching at L/S 2:1 and L/S 10:1 can be regarded as aggressive and likely to predict the maximum availability of leachable components under conditions which never may be encountered on site.
This may lead to excessive and unnecessary remedial measures.
Upflow leachate is collected over the 30 day period of the test and analysed for target contaminants.
The Waste Acceptance Criteria (WAC) protocol provides an alternative limit value for sulphate using this test; re classification to ?inert? may be possible where the normal limit is exceeded.
Working in partnership with a large remediation company, SAL has demonstrated to a local authority that the data produced from this leaching process is more representative of the on site conditions and has consequently saved both parties significant expense.