Agricultural runoff from vegetable and grain farming is one of the largest sources of water pollution. The millions of tons of coffee grounds discarded annually could help soak up the widespread toxic agricultural pollutant herbicide bentazone. Excess quantities of it move easily through water and soil, where it has been detected in unsafe quantities worldwide for years, endangering ecosystems and human health. In experiments, coffee waste removed 70% of this chemical from water samples.
www.goodnewsnetwork.org/coffee-grounds-show-potential-to-clean-up-common-water-contamination-from-agricuausefullture/