Toxic-waste laws.
The environmental impact of the toxic waste is to create a new breed of more savory locust.
A koi pond should be able to stand-alone for hours without danger of quick suffocation or toxic waste build up.
Wind energy is infinite, pollution-free, and does not produce radioactive or toxic waste.
Non-renewable energy sources also use and pollute water supplies, harm plant and animal life, and increase toxic waste production.
Similarly, the game Toxic Waste seems simple enough.