Publications

UNPAVED ROAD Chemical Treatments
State of the Practice Survey

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References

• References
• Appendix A - Dust Scan Steering Committee

References

JONES, D., A. Kociolek, R. Surdahl, P. Bolander, B. Drewes, M. Duran, L. Fay, G. Huntington, D. James, C. Milne, M. Nahra, A. Scott, B. Vitale, and B. Williams. 2013. Unpaved Road Dust Management, A Successful Practitioner's Handbook. Publication No. FHWA-CFL/TD-13-001, January 2013. Lakewood, CO. Federal Highway Administration, Central Federal Lands Highway Division.

Appendix A - Open-Ended "Other" Responses

The following are "other" responses to survey questions that allowed respondent-defined or open-ended comments. Responses have not been edited and are shown as they were received, unless otherwise noted.

I. Choose the best option that describes your affiliation or where you work (referenced in Figure 1).

1. Association of Counties
2. 33 miles of private road
3. Township
4. Township
5. municipalities, county roads, ski area
6. Independent road consultant specializing in unpaved roads
7. township
8. Paving and Reclaiming Contractor
9. supplier
10. township
11. TTAP
12. township trustee
13. Mining
14. retired
15. SDLTAP

Note: Most open-ended responses were deemed similar enough to be combined with existing survey text choices. Bold responses constitute the "other" responses in Figure 1.

II. Choose the best option that describes your role/job description (referenced in Figure 2).

1. Technical Support/Advise to multiple counties
2. District Foreman
3. Recreation Planner
4. Traffic engineering Tech.
5. sales
6. road committee
7. streets supervisor
8. safety
9. Inspector
10. Fiscal Officer
11. County Engineer
12. Regulator
13. Air Policy Advisor -
14. independent consultant
15. Planner
16. Outreach/Education air quality
17. Air Quality Planning
18. Decision maker, project engineer, AND maintenance supervisor
19. zoning inspector
20. President of Company
21. County Engineer
22. trainer
23. County Engineer
24. County Engineer
25. Road Manager
26. Project Manager
27. Staff Engineer
28. Technology Consultant
29. Consulting engineer
30. Construction Review, & new innovations
31. HPMS Administrator
32. Watershed Program Manager
33. Tribal Transportation Planner
34. Road Inventory taker
35. Admin support
36. Technical Assistance Provider to local gov't.
37. Technical Sales Representative

III. If your agency/organization manages unpaved roads but does not use any form of chemical treatment, please state reasons why (check all that apply; referenced in Figure 3).

1. Does not last with our dry climate & poor aggregates
2. County Policy permits landowners whose property abuts our county roads to purchase a permit to hire a county pre-approved contractor to apply county approved dust abatement chemicals, to be paid by the landowner.
3. Our agency does not manage unpaved roads but we are advocates for historic unpaved roads.
4. We are exploring the desirability of using dust control. There has been a past belief that it is too expensive and benefits do not justify the cost.
5. State Enforcement Agency - do not manage unpaved roads
6. no dirt or gravel roads to maintain
7. Dust s not a real big problem.
8. we do not have any unpaved roads
9. Serious durability issues
10. Almost all of the above, chemical treatments are toxic (poison), poor performance, medical repercussions, legal threats, corrosion of vehicles that use roads done with chemicals and the dangers to everything in the environment including our food chain and all human, animal, aquatic life and more.
11. I don't see any need for it. Taxpayer's are already paying for enough government.
12. Not effective with regular maintenance. Private residences put dust control down and those areas are not maintained regularly until they are in poor condition then it is graded out, so to do that on a large scale is not feasible or logical.
13. my agency does not have any gravel surfaced roads
14. Property owners requesting treatment for dust control are responsible for the cost of application
15. County Board Policy not to provide dust control
16. We are a vendor offering a chemical-free application for dust abatement/road stabilization.
17. we do use salt brine pumped from gas wells, and spread it only in the summer specifically for dust control. very cost effective
18. We do not have any unpaved roads on our system. Dust control however is managed on our construction sites.
19. cultural concerns
20. We do intend to start using products, particularly the chloride products.

Note: Bold responses share the common theme of not having unpaved roads to maintain and, therefore, are not included in "other" category in Figure 3 and are not included in the total number of responses (n) to this question.

IV. Why does your agency/organization use chemical treatments on unpaved roads? (check all that apply; referenced in Figure 9).

1. customer satisfaction
2. to aid in base stabilization prior to chip sealing
3. Not applicable
4. don't have unpaved roads
5. Flyash Base Stabilization
6. anti-skid (magnesium chloride sodium chloride)
7. comply with dust control regulations
8. curtesy to residents impacted by construction projects also allowed by permit by residents who desire to control dust, we do not use much but permit its use
9. We don't, due to social conscience and availability of certified proven environmentally friendly products that work better
10. Though we don't use chem. treatments, I train others to use chem treatments for dust control, improved level of service, reduced maint. costs, extend grader maint. intervals, preserve gravel, improve safety.
11. We will provide dust control if maintenance or construction activities cause temporary detour.
12. Do not use chemical treatment.
13. Response to citizen dust complaints.
14. See 4 (referring to: We do not have any unpaved roads on our system. Dust control however is managed on our construction sites.)
15. increase life of livestock teeth and improve general health
16. Dust is a Health issue and Enviornmental issue. Dust in food (drying fish as an example) and runoff into water is a problem for people, fish and other organisms.

Note: Bold responses were not applicable and, therefore, are not included in the "other" category in Figure 9 and are not included in the total number of responses (n) to this question.

V. What types of chemical treatments does your agency/organization use for each of the methods checked (previously)? (check all that apply; referenced in Figure 11).

1. EMc2
2. This is done in front of home sites only.
3. sodium chloride
4. used vegetable oils (used fryer oils)
5. water sprayed on road surface 6. M-70
6. We do not prescribe the use of any of the above, some are banned and some are carcinogenic and more
7. Do not use chemical treatment
8. Team Lab Base I
9. glycerol based suppressants
10. Base One from Team Lab

Note: Bold responses were not applicable and, therefore, are not included in the total number of responses (n) to this question.

VI. What equipment does your agency/organization use for applying chemical treatments for each of the methods checked (previously)? (check all that apply; referenced in Figure 12).

1. We typically contract out chemical treatments.
2. computerized asphalt distributor truck
3. chip spreader (50 psy class 5) over HFMS emulsified asphalt (0.5 gsy applied with distributor truck)
4. We use "picks" on our graders rather than smooth edges to scarify the gravel.
5. pug mill at the gravel crusher site
6. we are in the middle of purchasing a reclaimer
7. Again, we don't use anything that threatens the environment and everything in it as chemicals have proven to do
8. we do not apply it, use third party contractors
9. Contract to outside vendor
10. Vendor
11. Do not apply chemical treatment
12. Application is contracted out and tanker is owned by the contractor.
13. Outside contractor
14. Vein Feeder, excellent for controlled placement of hydraulic binders for base stabilization
15. These are the methods we do intend to use. Primarily spray, blade mix, or rototill.

Note: Bold responses were not applicable and, therefore, are not included in the total number of responses (n) to this question.

VII. For your agency/organization's most commonly used treatment, why do you choose this treatment? (check all that apply; referenced in Figure 13).

1. easily applied and cleanup of equipment and auto
2. Married to a successful past practice of Oil Stabilization, but the costs have risen dramatically.
3. It's free
4. don't use
5. minimal impact to indigenous flora and fauna
6. satisfactory experience
7. we recently ceased our program
8. zoning, gravel haulers must control there dust on county roads to and from the pit
9. Most agencies I work with choose treatments based on: cost-effectiveness, road user pressure, availability, and experience.
10. Do not apply chemical treatment
11. Direct experience

Note: Bold responses were not applicable and, therefore, are not included in the "other" category in Figure 13 and are not included in the total number of responses (n) to this question.

VIII. For your agency/organization's most commonly used treatment, how would you rate your satisfaction with performance? Provide most important reason for your answer (referenced in Figure 14).

For ease of reviewing, comments are categorized as negative, pro/con or neutral, and positive.

Negative comments

1. Mag. Chloride tends to "pot hole" unpaved roads when used continuously.
2. Stuck to vehicles better then it stuck to roads - no longer using this treatment.

Pro/con or neutral comments

1. It provides a solution that works, but only for a year.
2. While it works well for 3-4months and it is recognizable by the public, dust suppression drops off and the product isn't visible so we get less voluntary cooperation in reducing dust.
3. 50% +/- residents approve treatment, the other percentage of residents do not care or disapprove treatment.
4. Really works best where close to creeks, rivers for moisture.
5. Chlorides work fine when the weather is average, but hold moisture during wet weather, and don't work too good when it is dry. Asphalt gets potholes in wet weather, but works well in dry weather.
6. Always looking for something better
7. too early to tell.we are 3/4 of a year into the segments testing
8. Mag Chloride is not the most effective treatment for our region, but it is the least expensive (by a factor of 10).
9. Most common is Lignin Sulfonate. However, your poll assumes people stay in the same organization & same job forever. Most of my dust abatement work was in a prior job, and my former employer isn't doing much of anything anymore.
10. If funding was available, more applications per year would be more effective.
11. mag chloride works, but it gets slick and slimy when wet, and some people complain about the corrosiveness of it.
12. We used to treat roads twice per year, and have reduced to once per year due to budget constraints
13. Our use of CaCl for road dust control, is satisfactory, but not exemplary. We can't afford better control?
14. Sustainable road treatments are a must if we want to live longer and are concerned about the environment, health, equipment maintenance, hazardous effects on all life forms of using chemicals and all this is highly proven.
15. Spot locations
16. One always wishes it would last longer. Overall works the best with our maintenance practices.
17. We would be very satisfied but eventually the treated area develops washboards and blading is required for public safety. We could apply three times per year but have chosen two times.
18. Works well - tends to stay and rejuvenate after rain events, will build up and stay if done every year.
19. For dust control in fire camps and fire travel road, if approved by the hosting agencies.
20. Mixed results. having inconsistent gravel and lack of PI is probably the biggest reason for failure
21. Treatment is typically in front of occupied dwellings only.
22. Sometimes it does not hold up
23. Calcium chloride, mag chloride and lignon work adequately and give predictable performance. Continually increasing costs gives me concern for ability to maintain our application practices.
24. driving surface gravel must be to minimum spec.
25. Depending on traffic flow and percent of application
26. This is the first year we've used magnesium chloride, and it was late in the year, so we've really hadn't had time to observer how well it works.
27. None work 100%, mostly due to variations in surface mat'ls; type & quantity of fines, gradation, plus traffic volumes vary over road segments, etc.

Positive comments

1. My company has used almost every type of dust control/soil stabilizers on the market. We have found that the petroleum resin products to be the most satisfactory.
2. Good value and user satisfaction
3. Performance and public friendly application
4. it is easy to and pretty cost affective
5. Road preparation. We have found that properly preparing the road surface is the key to successful dust abatement. We have tried Calcium Chloride and have found Magnesium Chloride to work much better on our roads with the same preparation.
6. dust control and aggregate stabilization
7. Application has worked at keeping the dust down and extending the life of roadway.
8. The oil stabilized base can be reclaimed and rejuvenated successfully, on a predictable 7 year cycle for our weather and traffic. The initial cost can be recovered.
9. seems to work ok. Cheap.
10. Oil well brine controls the dust and doesn't cost us anything.
11. It helps to save money by not having to maintain and keeps complaints down from dust.
12. It works to control the dust and it serves to stabilize the road way so that it does not require as much grading.
13. The surface holds together, the dust is almost gone and the blading has decreased drastically.
14. No regulatory violations on unpaved road dust control in 10 years. Reasonably cost effective, yet expensive. Appropriate solution to citizen/stakeholder expectations to keep unpaved roads.
15. solves a problem
16. cost and effectiveness
17. Low cost per gallon and cost effectiveness.
18. The gravel surfacing sheds water, stays in place, and needs re-grading far less often.
19. Lower chloride content in oil field brine
20. Effective dust control at low cost, readily available from more than one supplier
21. Overall value
22. very cost effective
23. Reduces dust
24. We use CaCl2 for dust control because it works well for us and is our least expensive alternative.
25. Cost effective, we are able to use it for pre-wetting our sand in the winter as well.
26. Products hold up reasonably well to routine traffic and will last the season with two and sometimes one application.
27. It works to achieve goals set out.
28. Proven track record
29. Commissioners and public comments justify.
30. treatment has shown the results hoped for, with no undue problems.
31. Our retention of gravel and reduced maintenance intervals continue to save money.
32. Cost effective, simple, good durability, okay longevity
33. Performance satisfaction would be rated very satisfied where the amount and type of additive for in-place crushed aggregate is stabilized is determined by the mix design process developed by Steve Monlux, Low Volume Road Consultants, Missoula MT
34. It is economical and effective
35. It lasts all summer and I get almost no phone calls
36. Overall, we see good success with the chloride products which are the largest family of dust cntrl/stalztn products used; other products have not been as successful.

IX. How does your agency/organization assess performance of chemical treatments on unpaved roads? (check all that apply; referenced in Figure 15).

1. five year comparable road evaluation of treated and untreated.
2. measure residual chlorides and weight of loose-float material on surface
3. performance of base prior to chip seal
4. Health and food chain and much more are very negatively affected by hazardous chemicals
5. Most agencies I work with assess performance on: visual assessments, dust levels, ride quality, grader maintenance intervals, and user feedback.
6. Do not apply chemical treatment

Note: Bold responses were not applicable and, therefore, are not included in the "other" category in Figure 15 and are not included in the total number of responses (n) to this question.

X. How does your agency/organization design unpaved roads (gravel specifications, layer thickness, compaction and strength requirements, etc)? Please provide document name(s) or other comment. (Referenced in Figure 16).

Titles of, or references to, documents are categorized by type in Table 2. The following are "other" comments that make no reference to a specific document.

1. Material spec and layer thickness. Agency has generally eliminated gravel roads.
2. not designed, they evolved
3. we don't
4. Our soil types have a real bearing on what we do.
5. we do not construct unpaved roads
6. No design for unpaved roads
7. Gravel roads have just evolved and are not designed. We don't allow new gravel roads, because of maintenance issues like dust.
8. Continually evolve, using test segments on alternative techniques.
9. Grant provider
10. While we have engineered and board approved criteria, we are not creating "new" gravelled roads. Our existing gravel system is 75-100 years old and we provide basic routine maintenance. We incorporate fresh gravel when out townships can afford it, which isn't often.
11. We only subscribe to sustainable solutions. As is well known the present chemical treatments are much worse than the dust problem itself.
12. No unpaved roads allowed in Town Limits, just unpaved shoulders
13. Engineer's recommendation.
14. We apply mainly on state and federal road system. Sometime private landowners but mainly agency roads

XI. I would like to see the following output(s) from a national program of managed research on unpaved road management practices. (Referenced in Figure 20).

1. Need more information for dust suppression
2. I am tired of all the "green-washing" that is claimed by chloride and polymer vendors. I would like to see all dust control products have toxicity tests. I would like to see vendors that sell petro-chemically derived polymers admit that their product is derived from petroleum rather claiming that they are not a petroleum product.
3. Performance testing of products using mobile emission measurement techniques
4. A table of application rates for products that considers a range of variables such as soil type/silt, traffic type and volume and cost/reapplication frequency
5. Our agency has developed application practices and tactics that work extremely well, generally lasting the entire summer with minimal maintenance.
6. Cost analysis over time
7. Summary of reports about performance of product used for solidifying wear surface.
8. I have extensive prior experience with Lignin Sulfonate and Magnesium Chloride for Dust Abatement, and I have used Ionic Sulfonated Oils as a substitute for aggregate surfacing, and which also has dust suppression as a by-product of the subgrade stabilization. I would like to be involved in more research of sulphonated oils. In fact, I have considered entering Graduate Studies at a major University and making research on Sulphonated oils my Thesis. Or work with FHWA on such a research effort.
9. None
10. Life threatening and dubious chemical treatments should be banned outright and the sooner the better for everyone and everything
11. do not live or travel gravel road if you can't handle the dust
12. Do not apply chemical treatment
13. Cost-Benefit
14. One or two page summary flyers for field personnel.
15. Cost data on various products.
16. other than funding, National shouldn't there. These are regional issues. Dust abatement is geographically changing.
17. Std. performance methods using science to rate effectiveness - Dust & strength
18. ASTM STARNDARDS
19. Check with the US Forest Service

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