Increasing numbers of DOTs are evaluating the
levels of chlorides in streams adjacent to highways
to ensure no impacts to water quality from deicing
liquids. Several state DOTs have undertaken strategic
planning efforts to reduce salt usage; examples are
provided below.
Caltrans Salt Reduction
Policy and Implementation
Caltrans implemented a reduced salt-use policy starting
in October 1989 that required transportation districts
to develop specific route-by-route plans. That policy
mandated that "Snow removal and ice control should
be performed as necessary in order to facilitate the
movement and safety of public traffic and should be
done in accordance with the best management practices
outlined herein with particular emphasis given to environmentally
sensitive areas." [N]
During the first winter, Caltrans reduced salt usage
by 62 percent statewide as compared to the previous
winter, helped by improved control of the application
frequency of deicing salt.[N]
NYSDOT's Salt Reduction
Strategy
NYSDOT's salt reduction strategy has revolved around "right
application at the right time with the right chemical." NYSDOT
has employed thorough management controls, keeping
track of amount of salt delivered to sheds and the
salt used on each beat, and doing calculations afterward
to see if the agency is within established guidelines.
If not, the first thing they check is the truck; if
calibrations are on target, a supervisor has a discussion
with the operator. With this system, NYSDOT does not
have a problem with operator over-application. Computerized
on-board systems allow application at any rate and
take into account weather information.[N]
PENNDOT District 10 Salt
Management "After Action Reviews" and Annual
Update of Salt Management Plan
PENNDOT is among the DOTs that have taken the lead
in the U.S. in reducing salt usage. PENNDOT District
1 relies on precise application rates to minimize contamination
in runoff from anti-icing and deicing operations. All
trucks are equipped with thermometers for informed
decisions on application rates; equipment operators
can make informed decisions on when to spread material
because each truck has a thermometer that displays
both air and road surface temperature. After every
snow event and every shift, PENNDOT operators complete
tracking forms and turn those in to the foreman; such "after
action reviews" utilize automatic data downloads
from spreaders. The foreman and the operator check
the application rate and discuss any variances. Summaries
are prepared with regard to stockpiles. PENNDOT's universal
database from each snow event allows them to evaluate
and compare application rates by district and by truck.
Information from spreader controllers can be downloaded
to a computer or output directly to a printer through
a data port on the controller at the end of each shift.
This information includes:
- Types and amount of material spread
- Miles spread
Each operator keeps a written log of:
- Routes spread at what time
- Air and road temperatures
- Type of storm
From this database, many different reports can be
run. The district has established application rate
goals for different types of storms and different temperature
ranges. PENNDOT's District 10's Strategic Environmental
Management Program Manual details the process and the
roles of various stakeholders. [N]
Listed in the Appendix is PENNDOT's Post-Storm Salt
Management Tracking.
PENNDOT District 10 updates their Salt Management
Plan annually, including the following activities:
[N]
- Analysis of previous year's winter data.
- Revision of materials application charts and tracking
sheets to improve application rates.
- Update of target application rates by snow lane
miles by truck and charts to collect actual results.
- Equipment evaluation, calibration, repair, and
purchasing plan.
- Update of winter training plan.
- Training of Equipment Operators on application
rates.
Ohio DOT Pretreatment,
Weather, Decisionmaking, and Routing System
Ohio DOT has a statewide initiative to reduce the
amount of salt used to treat snow and ice conditions
expanding anti-icing pre-treatment to a statewide level
starting in 2002. Storm tracking with the aid of pavement
sensors and mini weather stations placed strategically
around the state give vital information to the counties
to maximize their resources of time and materials.
Advances in equipment monitors enable the snowplow
truck drivers to be more effective in treating the
roads. Optimizing truck routing can save time and money
for districts through reduction in the "dead-head
time" where a truck must return empty to a yard
to refill. The initiative has received high level leadership
in the department, from ODOT's Assistant Director and
Deputy Director, and affecting District Highway Management,
Equipment, and Facilities areas. To date, the initiative
has: [N]
- Implemented a material matrix expressing the relationship
between pavement temperature and precipitation.
- Determined critical information for operational
decision including: surface condition, material freeze
point, precipitation type/amount, wind direction/speed,
and air temperature.
- Developed a plan to deploy pavement sensors along
the interstate system and weather systems at county
garages not along interstate system.
- Drafted a plan to display information from weather
and pavement sensor on statewide maps.
- Performed research to determine most appropriate
pavement sensors to measure freeze point.
- Evaluated computer truck routing software for route
optimization. Software modification needed to handle
multiple salt locations.
- Established base line parameters for application
rates, travel speed, and cycle time for evaluation.
- Developed draft process for long-range planning
from the computer truck routing parameters.
- Snow and ice procedures will be included in the
new Maintenance Manual being developed.
- Developed equipment evaluation forms and process.
- Developed an equipment matrix listing basic units
and auxiliary equipment.
- Testing friction device to monitor surface conditions.
- Purchasing a salinity device to mount on truck
to determine surface freeze conditions.
- Evaluating Automated Vehicle Location (AVL) device
to track vehicle location, monitor material application,
and record operational information.
Remaining goals of the initiative are to:
- Validate material matrix and pre-treatment plan
including research for pre-treatment effectiveness.
- Deploy pavement sensors and weather devices statewide.
- Develop enhanced application to display pavement
and weather information.
- Coordinate snow and ice operations through Central
Radio Center for weather bulletins and condition alerts.
- Implement computer truck routing process and resource
planning procedure for equipment and facility location,
and staffing.
Transportation Association
of Canada Recommended Practices for Developing
Salt Management Plans
Given the increased emphasis on salt discharges to
the environment in Canada, the Transportation Association
of Canada has identified best practices in planning
for salt management.[N]
Good plans for reducing salt usage and associated environmental
impacts should include: [N]
Current baseline/metrics for salt managementpractice
and progress. A situational analysis may include
the following to allow the DOT to measure and track
progress in managing the amount of road salt being
placed into the environment:
- Examination of On-Road Salt Use:
- Type and amount of chloride freeze point depressant
used (all sources including solids, liquids, and abrasive
mixes).
- Type and amount of non-chloride freeze point depressant
used (all sources including solids, liquids, and abrasive
mixes).
- Current application rate for each type of material.
- Percentage of fleet with pre-wetting.
- Percentage of fleet with liquid only applications.
- Percentage of fleet with electronic spreader controls.
- Number of road weather information systems (RWIS)
installations.
- Number of other surface temperature measuring devices
(hand-held or vehicle mounted).
- Use of dedicated pavement and/or atmospheric forecasting
- Identification of Salt Vulnerable Areas:
- Locations of salt vulnerable areas
- Description of winter maintenance practices in
the vicinity of salt vulnerable areas (e.g. alternate
treatment). Examples of possible salt vulnerable areas
include:
- Groundwater
recharge areas
- Areas
with exposed or shallow water tables with medium to
high permeability soils
- Sources
of drinking water
- Salt-sensitive
vegetative communities
- Salt-sensitive
wetlands
- Small
ponds and lakes
- Rivers
with low flows
- Salt-sensitive
agricultural areas
- Salt-sensitive
habitats for species at risk
- Evaluation of Sand and Salt Storage Sites:
- Number and capacity of storage sites
- Percentage of sand/salt piles covered and type
of cover
- Percentage of indoor loading
- Management of drainage from sand/salt mix piles
- Levels of environmental indicators (e.g. chloride
levels)
- Percentage of salt in winter sand
- Percentage of sites with washwater treatment
- Existence of a good housekeeping policy, and adherence
to the policy
- Snow Disposal Sites:(only necessary
in the most snowy regions of the U.S.
- Number and capacity of disposal sites (permanent
and/or temporary)
- Levels of environmental indicators (e.g. chloride
levels)
- Percentage of disposal sites with water management
systems
- Conformance with existing environmental standards
for snow disposal sites
- Existence of a good housekeeping policy and adherence
to the policy
-Training:
- Training includes such on-the-job elements as preseason "dry
runs." Drainage facilities, wildlife crossing
structures and other facilities requiring delineation
or special treatment in plowing operations should
be noted by foremen and equipment operators during
dry runs of routes in the fall along with possible
obstructions.
- Percentage and frequency of staff receiving training
in best salt management practices broken down into
categories (e.g. managers, supervisors and operators)
Comparison of current practices to best management
practices and document the gaps. The salt management
plan should then focus on closing these gaps. The
plan should include preseason, in-season, and post-season
actions to be taken to reduce the adverse impacts
of road salts. It should also include consideration
of equipment, labor, materials, and the local climate.
How general road use of salt, salt use in salt
vulnerable areas, and salt storage will be addressed.
Snow storage and disposal sites should be dealt with
in regions where this is an issue.
Clear tasks, schedules with milestones, budget
considerations, and assigned responsibilities for
implementing best salt management practices. The plan
will involve prioritizing in many cases. For example,
spreaders on the highest salt routes or in proximity
to vulnerable areas can be targeted first for replacement,
and the most versatile mechanical removal equipment
can be stationed where it will help lessen salt loadings.
Documented policies, procedures, and guidelines
in the following areas, aimed at introducing best
salt management practices with both in-house and outsourced
operations.
- Level of service for each roadway type
- Salt and sand application rates
- Managed sand and salt storage
- Good housekeeping practices for maintenance yards
consistent with TAC's Design and Operation of Road
Maintenance Yards Synthesis of Best Practices
- Equipment calibration & re-calibration
- Training
- Snow disposal
- Incorporation of salt management consideration
into road design and construction
- Salt vulnerable areas
Monitoring, Record Keeping, Reporting & Analysis
- Progress on implementation of the salt management
plan can only be confirmed by tracking specific indicators
and comparing these to the baseline that was benchmarked
at the outset of the program.
- Each salt management plan should assign responsibility
for monitoring and reporting on implementation of
the plan. These results should be reported annually
to the senior executive responsible for the salt management
plan.
- The monitoring and record keeping system should
document and assess the indicators identified in the
situational analysis. Where there are new issues or
activities being implemented as part of the salt management
plan, new monitoring initiatives may be required.
- Any changes from the baseline established in the
situational analysis need to be analyzed to assess
the degree of progress being made. The analysis should
also take into account the type of winter experienced
to ensure that realistic conclusions are being drawn.
For example, an increase in salt use may be due to
an unusually severe winter rather than the failure
of a plan.
- Similarly, a reduction in salt use may be due to
a milder than normal winter rather than the successful
implementation of a plan. Therefore the analysis must
be sufficiently in-depth to account for these variances.
Where there are known releases to the environment
being monitored (e.g. stormwater outfalls, water intakes,
water treatment plants, monitoring wells, material
storage sites or snow disposal sites), then these
data should be included in the annual progress report.
Management Review
- Each year, senior management within each administration
should review the results of the previous year's salt
management actions to confirm that the plan is achieving
the desired results and to adjust the next year's
salt management plan to respond to shortcomings and
new opportunities. Policies and procedures should
be updated prior to the next snow and ice control
season and communicated to management and operational
personnel.
- This review should be integrated into the budgetary
process to permit timely acquisitions of new equipment
and to identify other funding needs, including:
- Personnel commitments.
- Review of organizational equipment needs and fleet
management strategy, staying current with changes
in the business.
- A transition strategy to shift from the existing
fleet to a new fleet that incorporates available
technology. To gain experience in new methodology,
new equipment may be assigned to preferred "champions" in
the organization for demonstrated use on less significant
roadways until there is confidence in the new practices.
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