OPERATOR FAILED TO ASSURE THAT NO FLUID MOVEMENT INTO A SDWA COULD OCCUR THROUGH A TEMPORARILY ABANDONED WELL BORE. (40 C.F.R. SEC. 147.2903(B), 147.2905, AND 147.2909). OPERATOR HAD BEEN MONITORING THE WELLS BY DROPPING A ROCK DOWN THE TUBING. OPERATOR PLANS TO SET A BULL PLUG IN THE WELL AND SWAB THE FLUID DOWN TO ASSURE THE USDW IS PROTECTED. RESPONDENT IS A COMPANY AUTHORIZED TO DO BUSINESS IN THE STATE OF OKLAHOMA AND AS SUCH IS A PERSON WITHIN THE MEAN- ING OF SECTION 1401(12) OF THE ACT, 42 U.S.C. SEC. 300F(12). RESPONDENT IS THE OWNER/OPERATOR OF AN INJECTION WELL WHICH IS AN EXISTING CLAA II WELL AS THOSE TERMS ARE DE- FINED AT 40 C.F.R. SEC. 147.2902. THE INJECTION WELL IS I- DENTIFIED AS WELL NUMBER 4 ( WELL 4 ). THE WELL IS ALSO I- DENTIFIED BY EPA INVENTORY NO. OS4801, AND IS LOCATED IN THE SOUTHEAST QUARTER OF SECTION 16, TOWNSHIP 21 NORTH, RANGE 12 EAST, BIRD CREEK FIELD, OSAGE COUNTY, OK.