Ecological assessments for hazardous waste sites should include acute toxicity tests as well as short-term tests which measure biological endpoints other than death. Toxicity and field assessment methods may be assembled into 'tool boxes' which reflect not only the site-specific demands made by the ecological assessment process, but the continuing progress in methods development. Toxicity assessment tools may yield information regarding acute biological responses elicited by site-samples as well as suggest longer-term biological effects potentially associated with subacute and chronic exposures to complex chemical mixtures characteristic of hazardous waste sites. Toxicity tests, however, are but one component of an ecological assessment for a hazardous waste site; field components must be given equal regard during the early phases of site evaluation. Through kriging, for example, areal distributions for site-specific toxicity and chemistry data sets may be derived, then 'maps' of site-sample toxicity and chemistries overlaid.