Modern waste tips which contain organic rubbish will carry the 14C levels appropriate to the time the material was living. If the composition of the rubbish is largely current, 'modern' organic material, e.g. garden waste, then these levels transmit directly to the 14CH4 formed by their decomposition.
CH4 which originates from sources of geological age e.g. coal measures or oil products do not contain 14C. There is, in this case, a clearly measurable difference between CH4 originating from decomposition of matter in the waste tip (~100% 'modern') and CH4 from coal measures or oil products (0% 'modern').
14C values between 0% and 100% 'modern' levels are more difficult to interpret, these possibly arising from mixtures of ancient and modern sources or, directly from older peat deposits. Often this can be resolved from knowledge of the site and its environs, and, in the case of a nearby peat deposit, a measurement of the peat age may help.
Due to the dumping of objects manufactured with dials originally made using luminous paint containing 3H, certain sites may also still show enhanced 3H levels in the exuding CH4 and/or leachates.
A measurement of the stable isotopes 13C/12C (as δ13C) is included routinely with the 14C in methane measurement. Measurement of the tritium in the water content of the landfill gas or of the water formed in the combustion of the methane is offered as a possible option.
Process involves a number of steps:
In whatever form, the collected gas sample should be capable of yielding a minimum of approximately 1g of carbon for the liquid scintillation counting method, or 5mg carbon for the AMS procedure.
No results will be disclosed to a third party unless we are instructed by you to do so.
For further details download our landfill document here (PDF Format, 164kb). Please contact us first to discuss your sampling requirements before collecting or submitting samples.
Home | About RCD | Carbon-14 | Tritium | Industrial Applications | Environmental Applications | Sampling Equipment | Contact Us |