Add vinegar to bring pH to about 5. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website. Drain all water system accessories, such as water heaters and hot water tank, and allow them to refill with chlorinated water. Turn WH back on.
I've read that you should shock the well if you open the circuit. If you can't smell bleach after running the water for about 30 minutes, add another gallon.
Open all faucets inside the home and run the water until you notice a strong odor of chlorine bleach at each faucet. Allow the chlorinated water to rest in the well and the complete water supply system for at least 12 hours preferably overnight but not more than 24 hours.
A well owner should make an inspection of his or her well and take the necessary steps to ensure these safeguards are met.
Testing for bacterial contamination in a well and water supply system is recommended as follows: However, the water discharge should be monitored for excessive sediment as the level is being drawn down, and should be stopped if necessary Keep in mind too that jet pumps may not be rated for continuous duty and should be monitored for overheating.How to disinfect your well water - Shock chlorination
It looks like you have a check valve at the pump, so maybe no check valve between the tee and the sand point. Current Issue.
Do not attempt to repair the water system unless you are experienced with this type of work: I did not try to remove the cap - it looks like the glue-on type.
Water heater turned to vacation mode or off Drain water heater.
If there is between 10 and 50 ppm chlorine residual go to step 4; if there is less than 10 ppm, add more chlorine to the pressure tank and repeat this step. Then sample for the presence of coliform bacteria.
If the well has been disrupted for service or repair, it must be sanitized. The water should be tested again for bacteria after 2 weeks.