Pre Wetting

GeoffD

PlowSite.com Veteran
Ok, I know this is the plowing forum, and this is more ice controll related. However I believe that this information should be posted here because of how inportant it is.

On Wednesday I had the pleasure of attending a titled "Winning in Winter Road Maintmance" This class is put on by the state to try to keep Maine town's up to speed on snow and Ice Controll.

The following topics were covered.
1. Training
1. Opperator Training
2. Manager Training
3. Public Education
2. Equipment
A. The Plow
B. V-box Spreaders
C. Under the Tailgate Spreaders
D. GI and Front Dump Bodies
E. Side Dump and Flow and Dump
3. Chemicals
A. Salt
B. Calcium
C. Mag Cloride
D. Magic or Ice Ban
4. Spreader Calibration and Pre Wetting

Of all these topics I am going to share the two most important things that will bennefit most of the users on this board.

1. Pre wetting, if your not pre-wetting your salt or sand, you can't afford not to. The facts are simple pre wet systems have come down in price because more people are useing them. So you want to know how much pre wet cost? I can set up a single axel dump truck for 2500 with pre wet. Ok so know you have spent 2500 bucks what do you get back? Here are the numbers.

You spread 500 lbs of DRY salt over 1 road mile. Of that 500 lbs only 80.9 lbs pounds stays in the travel lanes. The rest ends up along the curb or road side, in ditches, or completly out of the roadway. The roadway is considered 15' from either side of the road edge.

If you spread 500 lbs of PRE WET Salt over 1 road mile 390 lbs of salt will stay on the road. A PRE Wetting system can save you that much. Ok so you are asking me where I got this information, Micigan DOT was awarded a 5 million dollar grant by the FHSA to study the difference between pre wetting and non pre wetting of material.

As for sand, the rates are about the same but the loss is a little less.

The second thing I learned was the importance of caliberating spreaders. If you calibrate you spreaders correctly, you will know exactly how much material you are spreading. I am in the process of getting this informatiom posted.

Just for a side note. For you sand lovers out there, you will be switching to salt, maybe not now, maybe 10 or even 20 years from now, but it will happen. The Federal EPA has approved a regulation called PB 10, well sand particles are smaller than 10 microns. There for sand is considered a toxin by PB 10. Ok so you say will PB 10 get inforced? Well it is, Industry has allready passed these standards. Many state DOTs are going to all salt, with some exceptions. However there primary response is salt, sand only when temperatures dempand. State DPWs are being forced to start to work toward these changes. After the public sector has achieved these results, they will go after the private sector. Just so you all know, there is one town in Maine that by Federal EPA laws to meet the clean air standard PB 10, is not allowed to use sand in there snow plan. If sand is used it must be swept as soon as possible, and this has been inforced.

Ok thats just a little bit of what I have learned. I will probably share more as time goes on.

Geoff
 

plowking35

2000 Club Member
Location
SE CT
The info regarding prewetting are items I learned at the first SIMA symposium over 4 yrs ago. That just shows you how advanced SIMA is with its education. That being said, those numbers are for traveled roadways at 25 MPH + speeds. The condition most of see on private lots would not 100% relate. I would be surprised if I lost more than 10-20% of my applied material in private lots.However what Geoff didnt mention about prewetting is that not only will more material stay where its layed down, the brine solution will get started much quicker. The wetting agent will not only melt on its own, but will activate the salt sooner. Not contradicting you Geoff, just a observation.
Dino
 

Taconic

PlowSite.com Veteran
Geoff you are on the money.It is amazing to see how out of touch alot of states are with using other alternatives to sand/salt mix.Some states have gone as far as to use only dry sand and no salt.Like Dino said SIMA is truly on the cutting edge and brings up to the date current info to contractors and is just another reason why such a group is so beneficial to the private contractor
John Parker
Taconic Maintenance Inc
 

EJK2352

Senior Member
Location
Salem,Ohio
I work for the Ohio Dept. of Transportation. All of our trucks have wetting tanks. As most of you know salt is not very effective when the temps. drop below 23 degrees. When temps are that cold we will pre-wet w/ liquid calcium chloride. The results are fantastic, you can burn a road off quickly. This saves lives and lowers the amount of salt we have to put on the roads. :) ;) :) ED
 
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