8 June 2017 | Sacramento Municipal Utility District Cloud Seeding with Silver Iodide

SACRAMENTO (CBS13) —As California dries out from its historic wet winter, the Sacramento Municipal Utility District is already planning for the next drought, with plans to use new ground-to-air cloud-seeding devices called flare trees.

SMUD wants to increase the amount of water that will flow into its reservoirs when the next California drought hits. The utility wants to double the size of its cloud seeding operation.

”We’re in a wet period it seems right now, but every year is different so we need to be ready for whatever comes our way,” SMUD civil engineer Dudley McFadden said.

McFadden says hydropower is key to decreasing SMUD’s reliance on fossil fuels.

Cloud-seeding works when silver iodide particles are sprayed up into a saturated cloud. They act like a nucleus, which attracts super-cooled water vapor, which freezes into ice. Once the ice becomes heavy enough it falls and melts to become rain.

How much more rain exactly has yet to be proven.

“We estimate 3 to 7 percent and I can’t be any more precise than that,” McFadden said.

There are critics.

“Under certain circumstances, it works but in a marginal way and even then its difficult to prove how much increase has occurred,” Center for Climate Sciences Graeme Stephens said.

Despite the unknowns, SMUD is seeking to expand its cloud-seeding ahead of the next drought, planning for the time any extra rain will be welcome.

I would like to have their new cloud seeding flares in place by November, the start of the next rainy season. The publicly-elected board still has to approve the plan.

Link To Article

October 2019– California Fires

10.1.2 Hazards Summary 
The major hazards encountered in the use and handling of silver iodide stem from its toxicologic properties. Toxic by all routes (ie, inhalation, ingestion, and dermal contact), exposure to this odorless, light yellow, crystalline substance may occur from its use in seeding clouds for rain-making, as a photosensitive agent in photography, as a local antiseptic, and as a chemical intermediate. Effects from exposure may include skin rashes, conjunctivitis, argyria (a permanent ashen-gray discoloration of skin, conjunctiva, and internal organs), headache, fever, hypersensitivity, laryngitis, and bronchitis. Exposure should be minimized by engineering controls (eg, local exhaust ventilation, or process enclosure). In activities where over-exposure may occur, workers should wear impervious clothing, gloves, face protection, and a self-contained breathing apparatus. Such clothing and equipment should be removed before leaving the worksite. Skin that becomes contaminated with silver iodide should be promptly washed. Eating and smoking should be prohibited in silver iodide work areas. Silver iodide may form explosive compounds with sodium, potassium, acetylene, ammonia, and hydrogen peroxide. Silver iodide should be stored in cool, dark areas, away from the above materials. Before shipping silver iodide, consult with the regulatory requirements of the US Department of Transportation. For small dry spills of silver iodide, collect the material and deposit in sealed containers for reclamation. Before implementing land disposal of silver iodide waste, consult with environmental regulatory agencies for guidance.

Link To Pub Chem Silver Iodide

Link To _Document_California Wildfires: Role of Undisclosed Atmospheric Manipulation and Geoengineering