THE CASE INVOLVES A PUBLIC WATER SUPPLY COMMONLY REFERRED TO AS THE CONCHO VALLEY SYSTEM. IT SERVES ABOUT 23 FAMILIES JUST OUTSIDE OF GILLETTE, WYOMING. RUBY DRILLING COMPANY AND DALE RUBY APPARENTLY HAVE OWNED THE WATER SYSTEM SINCE IT WAS BUILT, BUT THEY HAVE NOT TAKEN RESPONSIBILITY FOR COMPLYING WITH THE NATIONAL PRIMARY DRINK ING WATER REGULATIONS OR FOR INSURING THAT THE SYSTEMS WATER IS PROPERLY CHLORINATED. AS A RESULT, THE SYSTEM HAS EXCEEDED THE MAXIMUN CONTAMINANT LEVELS FOR BACTERIOLOGICAL CONTAMINANTS, HAS FAILED TO MONITOR FOR SEVERAL TYPES OF CONTAMINANTS, AND HAS FAILED TO NOTIFY EPA AND ITS CUSTOMERS OF THESE VIOLATIONS.