Pile of alkaline substance in Irish location (8)
I believe the answer is:
limerick
'irish location' is the definition.
(Limerick is an Irish city)
'pile of alkaline substance in' is the wordplay.
'pile of' becomes 'ric' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'alkaline' becomes 'lime' (I've seen this before).
'substance' becomes 'K' (K is an example).
'in' is an insertion indicator.
'lime'+'k'='limek'
'ric' inserted within 'limek' is 'LIMERICK'.
(Other definitions for limerick that I've seen before include "Type of humorous verse" , "port used in Ireland" , "Irish county - five-line poem" , "Witty poem from mid-western Irish city" , "Humorous verse form" .)