'JA4f~/ck Jvv ~+Rll CONTAMINANTS IN URBAN RUNOFF AND THEIR IMPACT ON RECEIVING WATERS

This paper describes a sampling program to determine the potential impact of contaminants in urban runoff introduced to Santa Monica Bay through low flow (dry weather) conditions. A sampling protocol was developed whereby four selected storm drains were sampled and analyzed for conventional water quality parameters (e.g., chemical oxygen demand, total suspended solids, etc.), and short-term chronic toxicity using three marine organisms (red abalone Haliotus rufescens, purple sea urchin Strongy1ocentrotus purpuratus, and giant kelp Macrocystis pyrifera). The obtained results show that some of water quality parameters (e.g., chemical oxygen demand) of the selected storm drains were comparable or worse than typical secondary effluents. Several storm drains also exhibited toxicity. However, the most likely source of toxicity varied from metals to organic contaminants