Minimizing Environmental Consequences of Chemical Dust Suppression (TPD1111022)

Dust control issues

• Efficacy
• Cost
• Potential environmental impacts

Fugitive dust in northern New Zealand. Photo courtesy of Northland Regional Council: www.nrc.govt.nz

Ecological receptors

Products

• Water
• Salt-based
• Organic petroleum
• Organic non-petroleum
• Synthetic polymer
• Electrochemical

Project design

Phase One

Aquatic toxicity screening

Screen products across multiple categories and vendors for aquatic toxicity using standardized tests with a representative vertebrate, the rainbow trout

Phase Two

Expanded species tests

Select several products of low toxicity for expanded tests with additional invertebrate, vertebrate, and plant species

Phase Three

Experimental field tests

Confirm environmental safety of selected products through field applications with subsequent monitoring of roadside plant and animal communities

Phase One—Toxicity screen

• 96-hour tests with rainbow trou
• Original products and products aged under UV-radiation
• Calculate LC50 values
  • Concentration required to kill 50% of test organisms during test period
  • Lower LC50 value= more toxic product

Phase One—Toxicity screen

Phase Two—Expanded species tests

Crayfish—Orconectes virilis

Gray treefrog tadpole—Hyla versicolor

Juvenile fatmucket mussel—Lampsilis siliquoidea

Ryegrass—Lolium perenn

Pond snail—Lymnaea stagnalis

Phase Two—Electrochemical B

Phase Two—Organic D

Phase Two—Polymer A

Phase One and Two conclusions

• In a toxicity screening, many dust suppressants were practically non-toxic to rainbow trout, including some polymer, organic, hydrocarbon, and chloride products.
• By product category, electrochemical products were most toxic, although some other formulations raised potential toxicity concerns.
• Short-term weathering under UV-radiation did not substantially change product toxicity.
• Rainbow trout appear to be useful test surrogates for several other aquatic vertebrates and invertebrates.
• Under recommended use conditions, any of the low-toxicity products selected for Phase Two testing should result in low risk of environmental impacts.

Phase Three—Field tests

Pre-application biological surveys (roadside plants, animals, and water quality)

Pre-application assessment of road condition

Replicated applications of five products identified as low-toxicity by previous tests

Monitoring of roadside organisms, water quality, and product performance (dust control/road condition) for 12 months following applications

Proposed field site—Hagerman NWR

Big Mineral Arm of Lake Texoma

Proposed field site—Hagerman NWR

Overall goals

• Provide scientifically defensible information on environmental impacts of dust suppressant products, with the goal of identifying products for use in sensitive habitats such as wildlife refuges
• Facilitate the development of appropriate standardized environmental testing for new products
• Help road managers anticipate and minimize potential environmental consequences of dust control on unpaved roads

Related study

• Collaboration with US Forest Service to screen the toxicity of products on the USDA BioPreferred List, funded through CTIP

Partners and Stakeholders

• A collaboration with the US Fish and Wildlife Service, funded by the Public Lands Highway Discretionary Program through the Federal Lands Highway Refuge Roads Program
• National Parks Service, US Forest Service, and county road managers
• US EPA