Monterey Mushroom agrees to pay $1.2 million after polluting Elkhorn Slough.

The largest grower of mushrooms in the country has agreed to pay $1.2 million in a settlement over charges that the company discharged industrial waste into waters that reached the Elkhorn Slough. 

It was the fourth time in recent years that Monterey Mushroom, which is based in Watsonville and operates growing facilities in north Monterey County, reached settlements for environmental violations. 

The most recent settlement, announced July 20, was with the Central Coast Regional Water Quality Control Board, which says the company illegally dumped about 4.6 million gallons of water containing ammonia, excessive nutrients, and other harmful materials in 2017. 

“We take these violations and threats to the environment very seriously,” Jean-Pierre Wolff, the chair of the water board, said in a statement. 

The company says the spillage was the result of flooding from winter storms in late 2016 and early 2017. “Our farms in Monterey County were inundated by these record storms and rainwater volume, during the events alleged,” reads a statement provided by spokesperson Bruce Knobeloch. “To ensure no further issues, the company collaborated with county and state agents and spent millions of dollars in facility improvements, as well as engineering the separation of stormwater and process water.”

As part of the settlement, $600,000 will go to pay for remove toxins known as 1,2,3- trichloropropane from the drinking water of 20 “disadvantaged” households in North County. 

Monterey Mushrooms had already paid $300,000 in 2018 to settle a lawsuit brought by the District Attorneys of Monterey, Santa Cruz and San Luis Obispo counties over a related violation. 

In April, the San Francisco Bay Regional Water Quality Control Board ordered Monterey Mushrooms to pay $912,000 for discharging polluted stormwater into Fisher Creek in San Jose. That order followed a $2.24 million settlement with the Santa Clara County District Attorney in 2019 with over the pollution of the same creek. 

Founded in 1971, Monterey Mushroom has grown to become the largest company of its kind in the United States, producing 200 million pounds of fresh mushrooms a year, according to the company’s website.