Respondent, Big Oat' Oil Field Supply Company LLC, is the owner and operator of an onshore bulk oil storage facility, which could reasonably be expected to discharge oil to a navigable water of the United States. Operations commenced at the facility over fifty years ago. Respondent is subject to the SPCC regulations. The regulations of the Clean Water Act require that the owner or operator of an SPCC-regulated facility prepare and implement a written SPCC plan. On May 28, 2013 EPA inspected this facility and evaluated its SPCC plan, which was prepared on September 5, 2009. An owner is required to amend the facility?s SPCC plan when there is a change in the facility design that materially affects its potential for a discharge. Respondent did not amend the facility?s SPCC Plan within six months of removing a 13,000 gallon diesel tank in 2009, after installing three fuel tanks at the facility in 2010, nor after constructing or reutilizing an on-site Fuel Barn for storage of mobile or portable containers in violation of 40CFR Section 112.5. Respondent also did not include all applicable rule requirements in the SPCC Plan, such as those pertaining to mobile or portable containers or integrity testing in violation of 40 CFR Section 112.7. In addition, the regulations require to prepare an SPCC plan that describes the facility?s physical layout and includes a diagram of all regulated fixed oil storage containers, storage areas where mobile and/or portable containers are located, etc