Chloride, MC-70 and Seal Coat are your dust control options.  Please contact the Engineering and Secondary Road office at 319-892-6400 for more information.

Chloride

• May be applied 2 times/year
• Sprayed in liquid form
• Normal maintenance to road by county maintainer after applied
• Works by drawing water from the air, thus maintaining some effectiveness in dry weather.
• Water soluble

MC-70 (oil)

• Single application
• Sprayed on rock surface
• Light layer of sand applied to allow traffic to use road immediately and blot excess oil
• May last multiple years if maintained well by owner. Factors affecting performance are traffic, weather, owner care and base stability.
• Patching is the responsibility of the owner and must be done through the permit process which allows access to patch material at our shop locations at no additional cost

Seal Coat

• Asphalt slurry and rock chips placed on a prepared base and then rolled
• Care of seal coat is responsibility of permit holder.
• Average life 2-6 years if properly cared for and placed over a solid base and multiple applications
• Patching needs to be done through the permit process which allows access to patch material at shops