An Isolation Zone is a specific area that a well will receive its’ water from. Instead of getting water from different depths and formations, a specific depth is targeted and perforated well casing is placed only in that depth. Then gravel is placed around the perforations. Next, either bentonite or cement is placed above the gravel and it seals off the poor water quality from another formation. The reason for this is that there may be better quality water that comes from a specific rock that is drilled through.
In our area, most deep wells are ‘comingled’ water wells. Usually a bore hole is drilled through the shale and then into the sandstone. The Mancos shale formation is famous for the ‘rotten egg’ smell of the water it produces. The water in the Dakota sandstone is known to be ‘good’ water. It might bring a little Iron in with the water, but the water doesn’t have the ‘butt smell’ and is usually lower in Total Dissolved Solids’ (salt). The normal deep well in our area that is drilled into the sandstone has water from both the shale and the sandstone. Many of these wells produce water quality that varies hugely. Sometimes it smells and other times it doesn’t. The water mixes together in the well. Thus we call it ‘comingled’ water.
‘Never’ is a big word. In the past twenty-one years in South-West Colorado, I have looked at thousands of well construction reports. I have NEVER seen a well construction report from our competitors indicating that a well had an Isolation Zone built into it.
We’ve now drilled a number of wells with our Isolation Zone. In a couple of the wells we haven’t noticed a difference in water quality. In all of the other wells we have noticed from a marked improvement to the Pentecostal experience of “It’s a miracle!” success.
A wonderful client in the North Piedra has a beautiful new home and had a shallow well that simply wasn’t keeping up. We drilled a 7.875 borehole to 740’. We drilled down through the shale and couldn’t believe how much Iron was mixed in with the shale cuttings. Sure enough, when I took a look at the cuttings, the shale was heavy in Iron. At 670’ the formation changed from shale to sandstone. We installed 40’ of perforated well casing with a cap on the bottom. Put 50’ of pea-gravel in the annular space – 10’ above the perforations, installed the bentonite for a total of 150’ above the gravel, then sealed off the top 40’ of the well. All four of this client’s surrounding neighbors have heavy Iron water from their deep wells and have spent thousands in water treatment to remove the Iron. There is no detectable Iron in our clients well. . . and he brought us another water sample over a year later and there is still no detectable Iron in his water.
We have installed the Isolation Zones successfully to prevent both the bad smell and the salts from the shale and also to prevent Iron from contaminating well water. So when we think there is a possibility of better water quality by installing an Isolation Zone in your new well, we will certainly recommend it as an option.
Hatred is a wonderful thing. We Hate bad water and the resulting costs of water treatment – FOREVER. So you could say that Hatred is what has propelled us in trying so hard to source good water. Well Built – Well Done! is not just a slogan.Next Page: Drill: Geothermal Well Drilling