SESSION: DEICER MANAGEMENT SOLUTIONS
Salt Management Research in Virginia
Jimmy White, Virginia Center for Transportation Innovation & Research
The Virginia Department of Transportation (VDOT) is responsible for maintaining more than 57,000 miles of roadway. A large part
of this maintenance effort comprises the implementation of VDOT's snow removal and ice control program. As a result, VDOT
purchases approximately 500,000 tons of sodium chloride annually. These chemicals are stored and managed at over 300 salt
storage facilities throughout the Commonwealth. The Department has undertaken a number of research projects with the intent of
identifying and developing methods to minimize the potential environmental burdens associated with salt storage. These efforts
include salt- laden stormwater characterization, minimization, storage, treatment, and reuse. The findings and outcomes of each of
these efforts will be discussed.
First went to work for the Virginia Department of Highways in 1967 as a Survey Party Roadman during the summers while attending the University of Virginia. Background
includes Highway Design & Construction, Construction Management, and Maintenance Management. Jimmy completed the VDOT Engineer Training Program and
participated in the construction of Several Major Bridge Projects and Two Underwater Tunnel Projects in the Hampton Roads region of Virginia. Jimmy served as the Resident
Engineer in Lexington, VA for 20 years where he managed the Maintenance and Construction Program for a 3 County Area with 100 centerline miles of Interstate Highway
and more than 1,500 miles of Primary and Secondary Highways. In his role as Implementation Coordinator Jimmy is responsible for the implementation of new technology and
research recommendations. Recently completed the refurbishment of the Mixing Pad runoff management at nearly 200 Maintenance Areas across Virginia, led the
implementation of the production and use of Salt Brine for anti-icing operations. Currently leading projects to recycle mixing pad and vehicle wash water into salt brine
production.
Pollution Prevention Efforts for
Managing Winter Maintenance
Chemicals: A Research Summary
Jimmy White
Implementation Coordinator
BACKGROUND
• VDOT typically purchases over 500,000 tons of
NaCl each year
• Chemicals are stored and distributed out of 300+
salt storage facilities
• Each has covered storage and open loading pad
• Runoff from loading pads directed to stormwater
ponds
3
Storage Site Locations
4
Typical VDOT
Salt Storage Sites
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PROBLEM
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•
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VDOT is collecting a lot of water
Evaporation is not always sufficient
Chloride levels are high
Disposal options are limited and costly
RESEARCH APPROACH
1. Characterize extent of runoff problem
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Quantity
Quality
Disposal options and costs
2. Examine Management Options
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Minimize capture
Storage options
RESEARCH APPROACH (cont.)
3. Examine relevant treatment technologies
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Reverse Osmosis
Ion Exchange
Electrodialysis
4. Determine feasibility of recycling stormwater
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Determine effect of “contaminants” on resulting brine
Determine what filtering is necessary
Determine quantities of brine potentially used by
VDOT
Cost analysis
PROBLEM CHARACTERIZATION
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Water Quantity
• Annual Treatment
Volumes (million gallons)
• Winter Treatment
Volumes (million gallons)
– Minimum = 19
– Average = 31
– Maximum = 36
Volume (million gallons)
– Minimum = 35
– Average = 59
– Maximum = 88
100
Annual
Volumes
60
Winter
Volumes
40
20
0
Maximum
Average
Minimum
Annual Rainfall
10
80
WATER QUALITY
• Chloride
– 140 to 3100 mg/L
– 1600 mg/L average
• TSS
– 3 to 270 mg/L
– 20 mg/L average
• Oil and Grease
– 0 to 193 mg/L
– 2 mg/L average
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MANAGEMENT OPTIONS
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Reduce Volumes
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Reduce Impervious Area
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Add Diversion Valves
4/13/2015
15
Tank Storage Instead of Ponds
4/13/2015
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TREATMENT
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Technologies Investigated
• Ion Exchange
• Electrodialysis
• Reverse Osmosis
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Most promising of the three
Could reach target concentration for Cl
Low cost ($0.05/gallon)
Portable
Waste stream may be reusable
• Cons
– Unknowns: maintenance and pre-filtering requirements
18
Reverse Osmosis Pilot
• Laboratory tests
– Removal efficiencies
– Maintenance issues
• Field tests
– True cost of operation
– Maintenance issues
– Unforeseen problems
19
Reverse Osmosis Pilot
• Maximum 50% volume
reduction
• Pre-filtering is not
feasible with current
system
• System throughput is
too slow
• Manpower requirements
• Still have not addressed
regulatory limit or fate of
product stream
RECYCLING
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Recycling Tests
• Produced brine in lab
using impaired
influent water:
– 100-5000 mg/L Cl– 0-100 mg/L TSS
– 0-20 mg/L Oil and
Grease
– Varying temperatures
• Produced brine in
field using salt water
from VDOT site
Recycling Volumes
Potentially Used
Recycling Conclusions
• Existing salt concentrations, TSS values,
and oil and grease levels do not inhibit the
production of brine
• No additional pre-filtering is required
• Significant cost savings could result from
the use of brine, depending on the
volumes generated
QUESTIONS?
4/13/2015
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