"Diquat, a non-selective herbicide, when properly applied and in the right amount, is not considered hazardous. This product has passed comprehensive federal Environmental Protection Agency (EPA) risk assessments for registration of aquatic use. The state Department of Energy and Environmental Protection (DEEP) permits all aquatic herbicide applications and certifies trained applicators to apply the product. The US Army Corps of Engineers in partnership with state and local organizations, is conducting an ongoing research program into the use of Diquat and new ways to combat the spread of Hydrilla. Environmental advocates support this program to combat Hydrilla to protect the Connecticut River, lakes, and waterways." 

https://www.housedems.ct.gov/lamark-muir/statement-use-diquat-combat-hydrilla-ct-river