The hidden costs of a bag of lime.

$4 for a 50lb bag of barn lime seems like an incredible deal! How can that be possible? I figure I am missing some hidden cost so I decided to do a little research.

Barn lime from what I could find is either sourced from mining the earth or as a byproduct of water treatment. The water treatment requires extra handling to create a more customer friendly product so the majority of it comes from mining. Disregarding the issues that come from that entire process I am more interested in the transportation aspect of the product from its source to my location.

941 Miles.

That is what separates the processing center and my local farm store. An average tractor trailer could expect an average six and a half miles per gallon. Some quick math works out to roughly 156 gallons of fuel consumed.

HOLY COW! It is a testament to the associated businesses and their ability to survive on razor thin margins but the math isn't mathing for me. Personally, I feel dismayed that I purchased the bag without doing the consideration first but now I know. I'm lucky where there are local lime sources IF I truly needed to use it but I'm going to pursue alternatives to dolomite lime.  

Surely the freight fuel cost needs to be divided by the number of bags. You could load 2200 bags on a 40-ton truck. Of course that truck isn't going to haul a full load of nothing but bags of lime from the depot to the store where you bought it, but we'd expect the logistics to be at least somewhat sane. A more realistic estimate would have a full load of bags going part of the journey, then smaller loads (pallets) going to the stores on smaller trucks alongside other goods. So the embodied energy cost is there, but it's not off the charts.

I agree, it is an overly simplified estimate because who knows how many warehouses/distribution centers/way stations it ended up before hitting the shelf. I had the same realization with some other ingredients I first started using at home like coconut coir or azomite.

Sometimes what I initially consider a 'need' is really moreso a 'want'. Local substitutions have luckily been found but every once and a while an outside input it in order. Its a balance of personal convenience and personal conviction towards being greener in some cases.