Retirement Cake Designs How Can I Decorate A Cake To Resemble A Toxic Waste Spill? It's For A Retirement Party. Thanks!!!?

How can I decorate a cake to resemble a toxic waste spill? It's for a retirement party. Thanks!!!? - retirement cake designs

We have a retired man who was our company, our director of environment for many years. I would love a cake that is his line of work to be done.