Black pieces in the sceen of my taps

GOD I HATE WELLS THEY CAN CAUSE SUCH PROBLEMS, I HAVE ONE MYSELF. A HIGH BACTERIAL READING COULD MEAN A LOT OF THINGS DID THE SAY WHAT KIND OF BACTERIA THEY FOUND. GROUND WATER HAS A CERTIAN AMOUNT OF BACTERIA ANYWAY. MY WELL HAS HAD THE SAME PROBLEM FOR 18 YEARS NOW AND I'VE CLORINATED THE WELL EVERY 5 YEARS AND IT STILL READS THE SAME. THE ONLY THING I HAVE DONE IS PUT IN TWO FILTERS WHERE IT EXITS THE EXSPANTION TANK THE FIRST ONE IS FOR SEDIMENT AND THE SECOND IS A CHARCOAL FILTER FOR TASTE AND BACTERIA. AS FOR THE TREATMENT OF YOUR WELL IF YOU CLOINATE YOU MUST FILL YOU WELL WITH WATER TO THE TOP OF YOUR PIPE THIS WILL PUSH THE CLORINATION INTO THE CRACKS AND ALL AREAS TO CLEAN THEM. DON'T KNOW NWHAT ELSE TO TELL YOU. A WELL COMPANY COSTS AN ARM AND A LEG

More than likely those are bits of plastic from the new piping. Take the strainers off and flush the lines to get the remaining material out, clean the screens and aerators and reinstall them, then have the water tested again. If it comes back high in bacteria again, call your well driller.