Test designs and methodologies for two short-term static renewal tests, a 96-hr lethality test and a 5-day reproductive test, are described and statistically evaluated. The tests were developed specifically for use in the assessment of the toxicity of mixed effluents to copepods. Two tests using the calanoid copepod, Eurytemora herdmani, and one effluent yielded comparable results. The results indicate that mortality is a fairly sensitive measure of toxicant effect and is more easily quantified than the reproductive endpoint. The test designs allowed for the detection of a 7.8-22% difference in adult mortality between the control and any effluent treatment with a power of approximately 0.98 a 70% difference between the control and any other treatment was necessary to detect a difference in the chosen reproductive endpoint at a power of 0.98.