Use of fresh, composted, or pelletized poultry litter (PL) as a fertilizer to agricultural land and home gardens may be impeded by recent findings on roxarsone degradation to the more toxic inorganic arsenic (As) in PL. This contemporary environmental problem requires the development of technologies that decrease As extractability from land-applied PL. Aluminum-based, drinking-water treatment residuals (Al-WTRs) present a low-cost amendment tool for As in PL, similar to the use of alum to reduce soluble phosphorus concentrations in PL. The effects of WTR application rates (2.5-15 % by wt.) and reaction time (32-d) at two temperatures (23 and 35 oC) on decreasing total soluble As concentrations in PL water extracts were assessed. Incubation temperature did not significantly (p> 0.05) influence total soluble As concentrations in the WTR-amended PL samples. The 10 % WTR amendment lowered total soluble As content by half of that of the unamended (no WTR) PL. The decrease in As availability of WTR-amended PL samples was kinetically-driven, being complete in a 13-d time period. A coupled HPLC-ICP-MS analysis showed similar decrease in roxarsone, As(V) and DMA concentrations in the PL water extracts; As(III) and DMA were always < 5 % of total soluble As. Further experiments are needed to ensure that sorbed As by the WTR is stable in WTR-treated, PL-amended agricultural/garden soils.