Metaldehyde Aquatic Half-Life Data

I am researching the behaviour of micro-pollutants in surface waters and drinking water treatment systems.  I am currently reviewing data for a number of surface water resources impacted by metaldehyde. I am unable to find any reliable data relating to the half-life of metaldehyde (hydrolysis and photolysis). Does anyone have any data that could aid me? Or perhaps any working assumptions they make when determining the probable half-life of metaldehyde, for instance when modelling the persistence of metaldehyde in an impounding reservoir? Thanks in advance.