The objective of this research is to evaluate the influence of eight preselected treatment trains for fixed bed coal gasification wastewater treatment on chemical and health effects of residual sludges, sludge leachates, partially treated wastewaters and cooling towers blowdowns. Independent variables were: (1) incorporation of solvent extraction, use of MIBK or DIPE as extractant, solvent/wastewater ratio; (2) incorporation of free with/without fixed ammonia stripping; (3) incorporation of biological activated sludge processing; (4) cooling towers evaporation at ten cycles of concentration. Residual sludges, cooling tower blowdowns, ashed blowdowns and evaporate organics were leached in accord with the ASTM-A (distilled/deionized water), EPA-''EP''(acetic acid), and a self designed technique (pH=2 using HNO/sub 3/ at a 20/1 liquid/solids ratio). Leachates were evaluated for heavy metal content, Daphnia magna toxicity, bioaccumulative potentials and AMES mutagenicity potentials.