The City of Edmonton will pay a penalty of $165,000 for spraying an industrial-grade herbicide in a southwest residential neighbourhood three years ago.

Hyvar X-L, a federally regulated herbicide not intended for use in residential areas, was sprayed on pathways in Haddow on May 11, 2016.

The herbicide damaged nearby trees and shrubs on residential properties and forced the city to close the pathways to excavate, dispose and replace portions of soil.

The city admitted to the error, pleading guilty to a charge under the Environmental Protection and Enhancement Act, the city said in a news release Monday.

"This product has been in use for a number of years in the city and other jurisdictions." said Gord Cebryk, deputy city manager for city operations, at a press conference Monday afternoon.

"As time progressed, we've been moving away from the use of that product."

Hyvar X-L was once used to control weeds growing in hard surfaces like roadways, Cebryk said.

In an agreement with the province, the city will pay a penalty of $14,600 and contribute a total of $150,400 toward three environmental projects:

A University of Alberta research project to control invasive slugs without pesticides;

An Edmonton Native Plant Society initiative to enhance the Wagner Natural Area near Spruce Grove;

Two projects sponsored by the Alberta Invasive Species Council, including work with a goat herder to control invasive weeds in the North Saskatchewan River watershed.

The city has also settled four claims "in the immediate area," Cebryk said Monday.

The city has since started tracking herbicide use digitally to improve oversight and accountability and improved training for staff, he said.

Hyvar ​X-L is no longer used by the city for any purpose.