Cistern Issue

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Feb 25, 2021
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Manitoba Canada
1st of many

I am putting a RTM on a ICF foundation. I am putting a 2000 gal water cistern in the 5'6" crawl space. To fill I will have a 2" ABS with a quick connect for the water delivery guy. The top of the cistern is going to be below grade by about 12"or so. My question is: How does the water delivery guy know when the cistern is full so he won't flood my crawl space.? I was thinking of a overflow tube but the outlet of that tube on the outside of the ICF would be below grade. My second thought was a 1-1/2" abs connected to the top of the side of the cistern with a bulkhead. Take that abs down to the sump pit. When the cistern is full the water will drain into the sump pit and thus the sump pump would come on. worst case scenario lose maybe 5 gallons of water. When the delivery person seeing the water drain outside he knows its full. Does this make any sense?? Is there a better or easy way to resolve this. Thank You

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