Hulks were sunk at strategic locations to deter the British from entering the East River and other waterways.

One of the many problems with using a chromic acid bath is that chromium salts are very toxic, and should not be allowed to enter waterways.

More troubling, though, is the enormous quantity of raw sewage that enters waterways after rains.

The groups say the fish might enter natural waterways if people dump out their aquariums and upset the natural balance in ecosystems.

Some airports are now capturing and treating de-icing runoff before allowing it to enter waterways.

High levels of fertilizers entering waterways are a pertinent environmental concern associated with agricultural systems.

In the Mexican Border region, pollutants from both countries are entering shared waterways due to inadequately treated sewage.

Pollution can also enter waterways through runoff from agricultural fields or cattle farms.

By using these organic materials to help mend the soil, they will also help to prevent pollution from entering waterways and poisoning amphibian life.

Do not allow water runoff to enter sewers or waterways.