loose bolts on well seal ~ contimainated well?

I have a 100 foot drilled submerisble pump well, static water around 75 feet. The water was great when it was new, but got worse over the past 2 years. It stinks of sulphur, runs blown, grey, yellow, red. I have ignored it because I do not live on the property full time and did not know what my options were.

I have read up on bacterias and disinfecting the well, and this past weekend I looked it over to get an idea of what I need to do. The well seal is a simmons single piece with a 1/2" plug. However, I noticed that nearly all of the well seal bolts are loose. On two of them I can actually see where contaminants could enter the well. I tightened one of them by hand, but another is too close to the water pipe egressing the top of the well and will not turn. (bad install I guess). Can I just clean the area up with a dremel and coat it in silicone? Will that seal it?

I want to chlorinate the well, but want to be sure I am addressing the possible problem before doing so. Any ideas on how I can get it to seal?

Tightening three of the four bolts will probably seal it. It has a rubber gasket that gets squeezed outward when you tighten the bolts. Silicon in any crack or where the wires go in won't hurt a thing.

In addition, if you can get a little lube on the threads now (we use silicone grease), you will be ahead of the game.

But don't take the nuts completely off the bolts, or the bolts will fall down the well.

Thank you for the replies.

I was able to get 3 bolts tightened, and the well seal no long can be turned. I used 100% silicone and ran a bead around the bolts and pipe coming from the top. I also built a wellhouse shed over it this weekend so that also will help keep contaminates out. I think it is sealed now.

Now, I still have a question or two regarding the shocking of the well.

I used 5 qts of household unscented bleach (5-7%) with 10 gallons of clean water to flush it. I ran the hose back into the well for about 6 hours in a continuous cycle. The next morning I shut everything off and let it sit for 14 hours. I ran the hose for about 10 minutes just to see what if anything could be determined. Water looked terrible, but I could not smell any bleach. Next morning, after a full 24 hours of being shutdown I began flushing the well. clear water. again very little to no bleach smell. the water would run clean, and then go cloudy with greyish or sometimes yellowish water - and happened exactly when the pump would kick on.

So I am thinking it is that when the well kicks on it is pumping clear water but it churns up the greyish sediment in the tank. Does that seem reasonable? If so, I cannot find a cleanup fitting or drain plug on the tank. Should there be one?

If so, would a repeat of the procedure I used be effective to kill it? Should I be able to smell bleach strongly in the process and if I do not would that indicate I used too weak a solution?