On January 18, 2018, Christopher R. Bryant, Senior Regulatory Specialist at The Acta Group (Acta^®), was quoted by Bloomberg Environment regarding the possible environmental ramifications of a recent California mudslide.

“That mud could contain everything from sewage, to oil and gas from ruptured lines, as well as pesticides, ash, maybe chemicals from inside houses,” said Chris Bryant, a regulatory consultant with Bergeson and Campbell, a Washington D.C.-based law firm focused on issues related to chemical regulatory compliance.

[…]

“Even if [the mud] does contain hazardous materials, it will likely be exempt from the federal regulations for disposal of hazardous waste in special landfills,” Bryant told Bloomberg Environment.

See - https://bnanews.bna.com/environment-and-energy/toxic-pollutants-in-california-mudslide-present-cleanup-challenges