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3 Citizen Group 6-29-15 Email Almer MonluxFrom: "Steve Monlux" <stevemonlux@gmail.com> To: "Carl Almer" <calmer@eorinc.com> Cc: "Pam Smith" <nwpsmith@cox-internet.com>, "Jim Shaver" <jshaver@cmscwd.org>, <steve@kronmiller.us>, "Kristin Tuenge" <ketuenge@frontiernet.net>, <christine@poplarhillfarm.com> Subject: Re: Follow Up with Steve Monlux Date: June 5, 2015 at 1:04:19 AM CDT Carl: The primary difference between the different materials is not the gradation itself, it is the clay content that is represented by the plasticity index requirement. Since there is no plasticity index specified for the MN Class 1 or 5 aggregate, I strongly suspect they are intended to be free draining and are mostly used as aggregate base under pavements. However, it is quite common to add clay to gravels that do not have plasticity when crushing new gravel or fixing existing gravel surfacing in-place on the roadway. Although the average clay particles are about 30 times smaller than silts, they are less subject to erosion since they stick together, especially when the small amount needed as binder in 'bound aggregate' is compacted within the aggregate-sand mixture. Also, another primary difference between clay and silt is particle shape - clay particles are flat and platy, whereas silt particles are primarily round like sand. This shape is important since water goes through and around the round silt particles but has a much more arduous path around the smaller flat clay particles. Clay particles are much less prone to erosion than silt and sand particles, which is why the bound aggregates containing clay are less prone to erosion. I hope this is helpful and that it addresses the questions adequately. Please feel free to give me a call if discussion is desired. Thanks! Steve 406-544-1919 On Thu, Jun 4, 2015 at 9:25 AM, Carl Almer <calmer@eorinc.com> wrote: Pam, My question was how does the recommended gradations compare to what is commonly applied as surface aggregate (in this case MnDOT Class 5) with respect to the highl y mobile particles. See attached gradations with Class 5 added on the far right column. Comparison of gradations reveals that:  Class 5 may have as much as 10% particles greater than ¾-inch  While the range of percent passing for the mid-size particles of Class 5 varies greatly it is generally specified to have less sand  Class 5 is specified to contain less fines (silts/clays) The take home for me is that the recommended bound aggregate gradations are not drastically different than Class 5 and evidence has shown that all of the Class 5, larger particles included, have been mobile in the past and found their way into the adjacent waters. Carl K. Almer EOR: water | ecology | community d: 651.203.6024 o: 651.770.8448 From: Pam Smith [mailto:nwpsmith@cox-internet.com] 
Sent: Wednesday, June 03, 2015 4:28 PM
To: Carl Almer
Cc: Jim Shaver; steve@kronmiller.us; Kristin Tuenge; christine@poplarhillfarm.com; stevemonlux@gmail.com
 Subject: Follow Up with Steve Monlux Hi Carl, As a follow up to our meeting on Monday, I know that I had offered to relay a question to Steve Monlux, but I don’t believe that I can do your question justice. I’ve thought about the issue you raised regarding potential fines and sediment if the bound aggregate surface does not perform as anticipated, but I’m really not sure how best to word the question (or even if I understand exactly what you were asking,) particularly because you referenced a specific band on the gradation chart. Would you mind communicating your question directly to Steve Monlux (he is cc’d on this email.) I know that he would be more than happy to answer any questions. Thank you, Pam Smith 651-433-5859