This report details environmental occurrences reported in 1990, analyzing trends and providing comprehensive data on spills. The Ontario Ministry of the Environment's Spills Action Centre compiled this summary, comparing the year's events to previous years to identify significant patterns. It categorizes general occurrence types and outlines ministry record-keeping practices. The report offers a granular breakdown of spills, including material types, affected media, quantities, environmental impacts, cleanup efforts, sectoral origins, and causal factors.

This report serves as a factual record and analytical tool for environmental monitoring in Ontario. Its value lies in the detailed data collection and trend analysis, providing a baseline for understanding and managing environmental incidents. The comprehensive nature of the spill information, from material type to cause, makes it a resource for regulatory bodies and environmental professionals. The inclusion of comparative data across years enhances its utility for identifying long-term environmental patterns and policy effectiveness.