MAG Specifications and Details
The Maricopa Association of Governments
This Section shall govern the application of dust control palliatives (agents) on unpaved roads, traffic surfaces, vacant lots,
construction sites and road shoulders. Dust palliatives may also be used to protect erosion of slopes, embankments, sediment
control and re-vegetated areas.
Dust palliatives may be applied as topical treatments to penetrate an undisturbed surface, or may be applied to larger areas using
mixing methods that blend the product with surface material and then compact the mixture to provide a stabilized, dust
resistant, surface course.
Materials to be used as dust palliatives shall conform to the requirements of Section 792. The specific dust palliative to be used
shall be as shown on the plans or as directed by the Engineer.
Water used for diluting dust palliatives and for pre-wetting of treated subgrade shall be either potable or from a source
compatible with dust palliative ingredients.
230.2.1 Product Verification: The Contractor, in the presence of the Engineer or his designee, shall obtain samples of the
bulk, undiluted liquid dust palliative/stabilizer product as it is delivered to the job site. Samples shall be taken from each bulk
tanker that delivers the liquid dust palliative/stabilizer for product verification testing purposes. If the bulk undiluted liquid dust
palliative/stabilizer is delivered in containers, a sample must be taken from each container delivered to the job site. The
Engineer will select the exact locations and times of sampling. The obtained liquid dust palliative/stabilizer samples will be
split in three equal portions (minimum 2 ounce each), whereby the Contractor may retain one sealed portion for verification
testing, and the Engineer will retain two sealed portions. One portion of the Engineer’s samples will be provided to an
AASHTO accredited test lab chosen by the Contractor. The other sample will be held for backup until the testing is completed.
Sample containers will be labeled and sealed under the supervision of the Engineer.
The accredited lab will test the product in accordance with ASTM D2834 to confirm that the liquid dust palliative/stabilizer
meets the requirements of Section 792.2 for active solids. Contractor is responsible for the cost of product verification testing.
If the test reports indicate that the minimum acceptable active solids content value as specified in Section 792.2 is not met, the
quality of the liquid dust palliative/stabilizer product shall be deemed deficient by the Engineer. The delivery and application of
a deficient product shall be stopped. Work shall not resume until all product verification testing is complete or the Contractor
replaces the product and initial tests on the new material show compliance.
The Contractor may perform additional verification testing on the split samples. In case of dispute where the verification tests
produce different results by the Contractor than the Engineer, the Engineer will hire a different independent AASHTO
accredited testing laboratory to perform a third round of testing. Such testing and the results of the testing shall be considered
final by both the Engineer and Contractor for verification.
At least two weeks prior to the start of work, the Contractor shall provide the Engineer the following Applicator qualifications:
(a) Information showing that the Applicator has at least three years of experience within the last five years serving as either a
primary contractor or subcontractor in delivering and applying dust palliative/stabilizer product services, (b) A minimum 3
local references (including company/organization name, contact person and telephone number) to demonstrates that the
Applicator is familiar with local environmental and permitting requirements associated with soil stabilization and dust
palliative, and (c) Copy of the Applicator’s State of Arizona Registrar of Contractors License.
At least two weeks prior to the start of work, the Contractor shall provide the Engineer the proposed application methods and
equipment for the project. The information provided shall include: (a) curing time for each application method required for the
project, (b) application and dilution rates proposed for the project, and (c) equipment to be used during all phases of application
that are in conformance with Section 230.4.
Prior to the commencement of any work, the Contractor shall provide copies of all required environmental/dust control permits,
any required notices of intent, and the current Material Safety Data Sheet (MSDS) for the dust palliative/stabilizer product. The
MSDS must include all chemical compounds present in concentrations greater than 1% for dust palliative/stabilizer product.
The Contractor shall provide all equipment necessary to complete the work. The equipment may include but not be limited to
motorized graders, distribution trucks, mixing and pulverizing equipment, pneumatic-tired rollers, sprinkler systems, etc. All
equipment used for this work is subject to approval by the Engineer. Equipment which fails to provide an acceptable application
of properly diluted dust palliative/stabilizer product or does not perform satisfactorily shall be removed from the job and
replaced with acceptable equipment meeting the requirement of this specification.
Distributor trucks shall be designed, equipped, maintained and operated so that dust palliative/stabilizer product may be applied
uniformly on variable widths of surface up to 16 feet at readily determined and controlled rates from 0.03 to 1.0 gallons per
square yard, with uniform pressure, and with an allowable transverse variation from any specified rate not to exceed 10% or
0.02 gallon per square yard, whichever is less. The maintenance and calibration of this vehicle shall be checked periodically.
The record of maintenance and calibration shall be submitted to the Engineer for review upon request.
Distributor trucks proposed for use shall have been tested within 6 months from the date of spreading to determine the rate of
the transverse spread. If requested, the Contractor shall furnish the Engineer with evidence that the transverse spread of the
distributor truck, when the trucks were approved for use, was as uniform as practicable and under no condition was there a
variance on any of the test pads greater than the allowable transverse variation; however, the Engineer may require that each
distributor truck be tested to determine the rate of the transverse spread. The rate of the transverse spread shall be determined in
accordance with the requirements of Arizona Test Method 411.
230.5 PREPARATION OF SURFACE:
All surface preparation shall be in conformance with Maricopa County Rule 310 and 310.01 as applicable.
230.5.1 Topical Preparation: Prior to the application of the dust palliative, the surface shall be graded to provide drainage.
Dust palliatives shall not be applied when the surface is excessively wet or saturated. Surfaces shall be pre-moistened only if
required by the product manufacturer.
230.5.2 Surface Course Preparation: Areas to receive dust palliative shall be graded and scarified to at least the minimum
depth and width shown on the plans. The soil shall be scarified/loosened by tilling, disking, ripping, or by other soil preparation
methods, which achieves uniform results to the minimum depth shown on the plans. The material shall be damp at time of
scarification to reduce dust and aid in pulverization. Soil clods shall be pulverized until all material, exclusive of gravel or
stone, will past a 2-inch sieve.
All debris, weeds, organic material, stone larger than 4 inches, etc., shall be removed from the site. Surface gravel or stones
shall be removed or thoroughly mixed with the surrounding soils to obtain a homogeneous mixture.
If pre-wetting is required, ample amount of water shall be added and mixed with the in-place material to obtain a moisture
content near optimum. This moisture content shall be established prior to and maintained until the application of the dust
palliative. The methods to establish and maintain the moisture shall be done in accordance with manufacturer’s
recommendations. The moisture must be uniformly distributed throughout the surface course and over the underlying
undisturbed soil. Dust palliatives shall not be applied when the soil is excessively wet or saturated. Moisture content shall be
determined in accordance with either ASTM D6938 or ASTM D4944.
230.6.1 General: The dust palliative shall be applied by a pressure type distributor vehicle equipped with a power unit for the
pump, full circulation spray bars adjustable laterally and vertically, and computer controls. The distribution vehicle shall be
calibrated to ensure a controlled application method. Spray bars and extensions shall be of the full circulating type. Valves
which control the flow from nozzles shall be of a positive active design so as to provide a uniform, unbroken spread of dust
palliative on the surface.
Corners or surface that cannot be accessed by the distributor truck shall be hand sprayed by means of hoses or bars pressurized
by a gear pump or air tanks.
Distributor equipment shall be equipped with a tachometer and pressure gauge. To provide for accurate, rapid determination
and control of the amount of dust palliative being applied, distributor equipment shall include one or more of the following:
accurate volume measuring devices, a calibrated tank, and/or a certified meter or weight tickets and calibration charts relating
to the specific gravity of the concentrate and/or dilution.
The dust palliative shall be applied at the dilution ratio and application rate specified in accordance with Section 792, unless
otherwise directed by the Engineer. The Contractor shall dilute the dust palliative product as needed, with the dilution ratio
adjusted within the ranges specified in Section 792, to bring the mixture to the desired moisture content. Products may be
applied in multiple passes at reduced application rates to meet the total application rate specified and/or assure uniform
The Contractor shall notify the Engineer a minimum of 5 working days prior to any application of dust palliative.
230.6.2 Topical Application: Topical applications shall be rolled only when recommended by the manufacturer. Complete
penetration of palliative will be required prior to the surface rolling. Complete penetration occurs when the compaction
equipment will not track or pick up the dust palliative and/or the top layer of the surface material.
230.6.3 Surface Course Application: The stabilization product shall be applied, incorporated and thoroughly blended into the
soil until the homogeneous mixture is obtained to the full depth of treatment. Mixing shall be done in-place using mixing
equipment or by motorized grader (blade mixing). The blending methods utilized shall result in a uniformly treated mixture of
soil and dust palliative at or near optimum moisture content (minus any post-compaction dust palliative top coat application
quantity). The dilution ratio may be adjusted to bring the mixture to the desired moisture content. The amount of area treated
each day shall be limited to that which the Contractor can thoroughly mix and compact within that work day.
Complete penetration of palliative will be required prior to compaction. Complete penetration occurs when the compaction
equipment will not track or pick up the blended material.
The blended material shall be shaped to the required grade line and cross-section shown on the plans and be compacted at least
95% of maximum density in accordance with ASTM D698, unless otherwise directed by the Engineer. The final surface shall
be rolled to a smooth and even grade. Sufficient grading shall be done to provide reasonable drainage within the limits of
existing drainage patterns. Immediately after the compaction, a top coat of dust palliative shall be applied.
No equipment or traffic will be permitted on the treated surface for 24 hours unless otherwise approved by the Engineer. Once
cured, the dust palliative final coat shall form a skin at the surface or a crusted surface. For purpose of this work, a “skin” on the
surface will be a formation of any palliative on the surface of the soil that cannot be dislodged from the soil by winds. Any
formation of the palliative on the soil surface must adhere to the underlying soil to a depth of 1/8th inch when applied topically.
230.8 WEATHER CONDITIONS:
Dust palliative/stabilizer product shall be applied only when the ambient temperature is above 50°F. Application should be
avoided during high wind or when there is the chance of rain within the next 8 hours. The Contractor shall be responsible to
retreat at no additional cost if the application is degraded by weather within the first 24-hours of placement.
230.9 QUALITY CONTROL
The Contractor must provide manufacture-trained personnel for on-site technical assistance during initial delivery and
application. This technical assistance is to assure that the dust palliative/stabilizer product is applied at proper dilution ratios
and application rates on various soil, and subgrade types for optimum results.
At the start of each work day, the bulk tanker will be measured to verify the gallons of liquid dust palliative/stabilizer product
brought to the job site. At the end of the day, the bulk tanker will be measured to verify the gallons of liquid dust
palliative/stabilizer product remaining at the job site. The distributor truck shall be inspected to insure it is empty at the end of
the day. The total gallons of liquid dust palliative/stabilizer product used for the day will be established by the start and end of
day measurements of the bulk tanker.
A daily “Gallon Use Report” will be filled out by the distributor truck driver. The report will also identify the size of area treated
for the day. It will be verified and signed by the Engineer or his designee. This report will be used to verify application rate and
total product used. If the report indicates that the minimum application rate was not achieved, the work shall be deemed
deficient by the Engineer.
230.10 DEFICIENCIES AND WARRANTY
If applied product active solids content is found deficient per Section 230.2.1, the Engineer may allow the Contractor to apply
to any surfaces already treated by the deficient product additional topical coats of the dust palliative/stabilizer product to
remedy the deficiency. Otherwise, the Contractor shall be required to repeat all work as directed by the Engineer with a
different approved liquid dust palliative/stabilizer product that is compatible with the original product and will not result in
adverse effects. The Contractor shall bear the cost of all remediation work for deficient product.
If the application rate as determined by the methods described in Section 230.9 or as agreed to in the contract documents is
found to be deficient, the Contractor shall apply additional product within 24-hours of the original application to bring the total
application rate to at least the minimum specified amount. If liquid dust palliative/stabilizer product was used as a soil stabilizer
per Section 230.6.3, as directed by the Engineer, the Contractor shall re-scarify the stabilized section to its full depth and
re-apply product at the original application rate. The Contractor shall bear the cost of all remediation work for deficient
For non-traffic areas (less than 150 vehicle trips per day), application of the dust palliative/stabilizer product placed in
accordance with this Section shall provide a surface meeting the stabilization requirements of Maricopa County Rule 310
Section 302 and Maricopa County Rule 310.01 Section 302 for a minimum of 12 months from acceptance by the Engineer.
During the warranty period, the Contractor shall provide and install the product free of charge if the finished product fails to
meet the performance requirement and specification/criteria outlined under this technical specification. The Contractor shall
provide additional applications when within five working days of notification from the Engineer of performance failure.
Dust palliative surface course application shall be measured by the square yard, in place, treated, compacted, to the proper depth
Dust palliative materials will be measured by the ton of undiluted material. Any conversion from volumetric quantities shall be
done with Contractor-supplied calibration charts relating to the specific gravity of the concentrate and/or dilution.
Payment will be made for the applicable items at the Contract unit price and shall constitute full compensation for the item
complete in place.