Dry Run Creek Watershed Improvement Project 1248-023: Final Project Report: July 2013-December 2015, October 11, 2016

In 2010 a group of farmers in the Dry Run Creek watershed, an Iowa High Quality Water Resource, formed the Dry Run Creek Watershed Improvement Association to learn more about and implement solutions to remedy a bacteria impairment in their stream. Through a partnership with Luther College, Iowa DNR Watershed Monitoring and Assessment and Iowa State University Extension the farmers were able to conduct an assessment of their stream and watershed. The assessment showed multiple potential sources of bacteria, dependent on whether water samples were collected following rain events or during dry conditions. This project will allow watershed farmers to implement solutions to reduce bacteria delivery during both wet and dry weather. Funding will be targeted to feedlot runoff control improvements, cover crops and vegetative filters, manure management strategies and livestock stream access. The council intends to continue intensive water monitoring to determine whether the strategies are successful. Research shows the bacteria reduction in water bodies can be seen relatively quickly, within 1-2 years, compared to other types of impairments.

Dry Run Creek Watershed Improvement Project 1248-023, Final Project Report: July 2013-December 2015, March 26, 2015

In 2010 a group of farmers in the Dry Run Creek watershed, an Iowa High Quality Water Resource, formed the Dry Run Creek Watershed Improvement Association to learn more about and implement solutions to remedy a bacteria impairment in their stream. Through a partnership with Luther College, Iowa DNR Watershed Monitoring and Assessment and Iowa State University Extension the farmers were able to conduct an assessment of their stream and watershed. The assessment showed multiple potential sources of bacteria, dependent on whether water samples were collected following rain events or during dry conditions. This project will allow watershed farmers to implement solutions to reduce bacteria delivery during both wet and dry weather. Funding will be targeted to feedlot runoff control improvements, cover crops and vegetative filters, manure management strategies and livestock stream access. The council intends to continue intensive water monitoring to determine whether the strategies are successful. Research shows the bacteria reduction in water bodies can be seen relatively quickly, within 1-2 years, compared to other types of impairments.

Development of an Economic Dust Palliative for Limestone Surfaced Secondary Roads, HR-297, 1990

This research project was directed at laboratory and field evaluation of sodium montmorillonite clay (bentonite) as a dust palliative for limestone surfaced secondary roads. It had been postulated that the electrically charged surfaces of the clay particles could interact with the charged surfaces of the limestone and act as a bonding agent to agglomerate fine (-#200) particulates and also to band the fine particulates to larger (+#200) limestone particles. Laboratory testing using soda ash dispersed bentonite treatment of limestone fines indicated significant improvement of compressive strength and slaking characteristics. It was recommended that the project proceed to field trials and test roads were constructed in Dallas and Adair counties in Iowa. Soda ash dispersed bentonite solutions can be field mixed and applied with conventional spray distribution equipment. A maximum of 1.5% bentonite(by weight of aggregate)can be applied at one time. Higher applications would have to be staged allowing the excess moisture to evaporate between applications. Construction of higher application treatments can be accomplished by adding dry bentonite to the surfacing material and then by dry road mixing. The soda ash water solution can then be spray applied and the treated surfacing material wet mixed by motor graders to a consistency of 3 to 4 inch slump concrete. Two motor graders working in tandem can provide rapid mixing for both methods of construction. Calcium and magnesium chloride treatments are 2 to 3 times more effective in dust reduction in the short term (3-4 months) but are prone to washboarding and potholing due to maintenance restrictions. Bentonite treatment at the 2-3% level is estimated to provide a 30-40% dust reduction over the long term(18-24 months). Normal maintenance blading operations can be used on bentonite treated areas. Vehicle braking characteristics are not adversely affected up to the 3.0% treatment level. The bentonite appears to be functioning as a banding agent to bind small particulates to larger particles and is acting to agglomerate fine particles of limestone. This bonding capability appears recoverable from environmental effects of winter, and from alternating wet and dry periods. The bentonite appears to be able to interact with new applications of limestone maintenance material and maintains a dust reduction capability. Soda ash dispersed bentonite treatment is approximately 10 times more cost effective per percent dust reduction than conventional chloride treatments with respect to time. However,the disadvantage is that there is not the initial dramatic reduction in dust generation as with the chloride treatment. Although dust is reduced 30-40% after treatment there is still dust being generated and the traveling public or residents may not perceive the reduction.

Development of an Economic Dust Palliative for Limestone Surfaced Secondary Roads, HR-297, Progress Report, 1988

Research activities during this period concentrated on continuation of field and laboratory testing for the Dallas County test road. Stationary ditch collection of dust was eliminated because of inconsistent data, and because of vandalism to collectors. Braking tests were developed and initiated to evaluate the influence of treatments on braking and safety characteristics of the test sections. Dust testing was initiated for out of the wheelpath conditions as well as in the wheelpath. Contrary to the results obtained during the summer and fall of 1987, the 1.5 percent bentonite treatment appears to be outperforming the other bentonite treated sections after over a year of service. Overall dust reduction appears to average between 25 to 35 percent. Dallas County applied 300 tons per mile of class A roadstone maintenance surfacing to the test road in August 1988. Test data indicates that the bentonite is capable of interacting and functioning to reduce dust generation of the new surfacing material. Again, the 1.5 percent bentonite treatment appeared the most effective. The fine particulate bonding and aggregation mechanism of the bentonite appears recoverable from the environmental effects of winter, and from alternating wet and dry road surface conditions. The magnesium chloride treatment appears capable of long-term (over one year) dust reduction and exhibited an overall average reduction in the range of 15 to 30 percent. The magnesium chloride treatment also appears capable of interacting with newly applied crushed stone to reduce dust generation. Two additional one mile test roads were to have been constructed early this year. Due to an extremely dry spring and summer, construction scheduling was not possible until August. This would have allowed only minimal data collection. Considering this and the fact that this was an atypically dry summer, it was our opinion that it would be in the best interest of the research project to extend the project (at no additional cost) for a period of one year. The two additional test roads will be constructed in early spring 1989 in Adair and Marion counties.