After 13 years of litigation and three trials, the city of Pomona, California, has won its case against SQM North American Corporation after the corporation contaminated the city's groundwater with its defective fertilizer products.

SQM North American Corporation has agreed to pay the city $30.62 million to cover the costs the city incurred because of the contamination. Payment is expected to cover the full cost of the city's current expenses to decontaminate the water, along with future costs expected for the next 30 years. The city argued that it would need to implement a new water treatment method, which would cost tens of millions of dollars to implement and operate in order to decontaminate the city’s water source.

In September 2021, a jury ruled in favor of Pomona after the city’s legal team argued a successful case against SQM. The jury agreed with the city and its claims that SQM sold defective fertilizer which was tainted by perchlorate. The jury reached its verdict in the Court of Appeals for the Ninth Circuit in Pasadena after the case went through a series of appeals and trials.

After the jury reached its verdict, SQM filed an appeal to the decision. However, the trial judge denied the request, ruling that the city had provided sufficient evidence to back its claims. The trial judge found that the fertilizer had been defectively designed and contained excess levels of the toxic chemical.

SQM operated as a subsidiary of multinational mining company Sociedad Química y Minera de Chile. Through this operation, SQM provided fertilizer to the city's former citrus orchards. In doing so, the company contaminated Pomona’s drinking water wells with perchlorate.

Perchlorate poses a danger to humans who are exposed to it as it can interfere with iodine intake in the thyroid gland. Exposure to perchlorate at elevated levels can impact the function of the thyroid. In children, this chemical can be especially harmful as it interferes with growth and development. Although the chemical is found at very low levels in some drinking water sources, the standard by which it should be found in drinking water is still up for debate by the Environmental Protection Agency.

The city's legal efforts were led by Ken Sansone, partner at SL Environment Law Group. Following the verdict, Sansone shared, “The City of Pomona never gave up, and neither did our team of lawyers. I commend the resilience and tenacity of everyone involved in this fight to ensure that the polluters, not the taxpayers of Pomona, are held accountable for remediating perchlorate contamination.”

In 2007, the city officials found excessive levels of perchlorate in the city's water system. The discovery led to a thorough investigation by a scientist the city had hired. The scientist conducted what is known as a “stable isotope analysis” and determined the source of the toxic was a chemical fertilizer used for decades in the area's citrus orchards. The perchlorate had been imported to the city from Chile.

The city would go on to file its lawsuit, complete with expert testimony and an investigation conducted by state officials. After three trials spanning more than a decade, a jury found that SQM was “liable for importing, distributing, or selling defectively designed sodium nitrate fertilizer that contaminated the City of Pomona's water supply with perchlorate.”