From the link provided to the CT regulation; I hadn't seen the post with the link until now.
Slip joint couplings may be used to join well casing but provide the lowest joint strength. These couplings are often used when the old and new sections of well casing have slightly different dimensional characteristics. Commonly, older well casings may have thinner wall construction than the minimum casing thicknesses required by the current well drilling code. Many manufacturers have compression couplings available to account for these dimensional differences and provide a positive seal to both sections of well casing. When slip joint couplings must be used, the top of the coupling shall be located below the frost line, as determined by the applicable building codes, to reduce the possibility of premature separation of the joined sections of well casing due to frost heave. Only slip joint couplings conforming to the current American Water Works Association (AWWA) Standard C219 or pitless units conforming to the Water Systems Council’s (WSC) Pitless Adapter Standard 97 (PAS-97) shall be used to extend well casings for public water systems. Pitless units meeting the PAS-97 standard can found by accessing the WSC website at
www.wschome.org.
That sounds a bit like a Fernco fitting but if not, it will have a rubber type seal, like a Fernco. I couldn't find the picture they refer to in Fig 2.
In a previous life I was a welder. I did some stick and A LOT of long large and continuous gas inershield and submerged arc welds; 10-15' was common. The majority was on high tensile strength steel. All my welds were permanently stamped and visually inspected and then x-rayed an/or magnafluxed. I never had a failed weld in the 3+/- years that I was employed as a production welder in the railroad car manufacturing industry.
By enlarging the pictures and looking at the welds of that casing, I can say that they are good enough to hold it from falling over until the hole is backfilled and that is about it. He did not do continuous welds, he dabbed one weld to another and the only way he could have done a good weld would have been vertical up all around. But it's "welded"...
The top weld on the pitless looks flat to me, it should be like 45*. Looking up the MAASS pitless, I wouldn't want one.
What is the flat round plate on top of the casing? Is it just to keep something from falling down the well now and you have a real cap to install later?
I think he charged you 35- 50% too much. A regular pitless is like $150-200 installed (with a hole saw to cut the hole and about 30 minutes total to cut the hole and tighten the pitless through the casing). PE pipe is much less than PVC and the time and effort it takes to install 20' sections of it with couplers at $140/hr! while PE pipe is about $200 for a 300' roll installed; taking like 30 minutes to drop it down the well including taping the cable to it every 10'. And why 1.25" drop pipe with a 1 hp pump when 1" would have been fine?