Volunteers with the Nicomekl Enhancement Society are sounding the alarm after discharge from a cement plant triggered a mass die-off of fish and crayfish in the Nicomekl River on Sept 14.

"The kill was extensive," said NES president and biologist Jim Armstrong. "There were generations of crayfish that were killed off ... literally hundreds. And we went from hundreds of coho fry to zero coho fry."

News of the die-off was posted to the Nicomekl Enhancement Society Facebook page. (Nicomekl Enhancement Society)

Armstrong said fisheries officials traced the deadly discharge to a cement plant that was expelling wastewater into a ditch that flowed directly into an upper tributary of the Lower Mainland's Nicomekl system.

A test of the water showed the effluent caused the pH of the river to rise above eight, a level that was likely fatal to the fish in the stream.

A fisheries officer familiar with the case said the matter was now in the hands of Environment Canada, which oversees enforcement around unlawful dumping of "deleterious substances" into fish waterways.

Environment Canada was unable to respond to an interview request and questions submitted by CBC News in time for publishing.

A spawning salmon makes its way upstream along the Nicomekl River. (Nicomekl Enhancement Society)

The Nicomekl Enhancement Society hatchery raises and releases 400,000 coho, chinook and chum salmon fry every year.

Troubled waterway

According to Armstrong, the fish kill is the latest blow to the troubled waterway and the volunteers working to restore it.

Earlier this year, a truck spilled a full load of fine gravel into the Michael's Brook tributary of the Nicomekl, wiping out the salmon fry population.

Attempts to get ICBC to cover some costs of the restoration work have fallen on deaf ears.

Volunteers have since raised over $20,000 and spent countless hours on the waterway for a second time. It had earlier been wiped out in 2014 by a waterline construction blunder.

Armstrong believes changes weakening habitat protection brought in by the previous federal government are making conservation efforts of groups like the Nicomekl Enhancement Society almost impossible.

"We don't know how many times we can go through this," he said. "Industry is still not adhering to the regulations, knowing there is little or no enforcement."

The Nicomekl River originates in Langley and flows west to Crescent Beach in South Surrey where it drains into Mud Bay.​

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