processing equipment such as scrubbers , compressors , reflux pumps , control valves and product lines . NORM contaminated sludge and scale accumulate inside oil production and processing equipment . NORM contamination tends to be greatest in equipment where produced water is handled or stored , such as water lines , flow lines , injection wellheads , vapour recovery units , water storage tanks , heater / treaties , and separators . When contaminated equipment is taken offline , the NORM presents inside can cause disposal problems . Some types of equipment can be cleaned to remove the contaminated sludge and scale . Cleaned equipment may be reused if it is in good condition , however , the cleaning process generates radioactive wastes that require disposal . ( Smith , 1992 ) 2.1.4 Seawater Injection Systems It has been mentioned that sulphate-reducing bacteria have the ability to enhance the Uranium that is located in the bio-fouling deposits . The Uranium exists in parts per billion in the seawater and does not represent a significant hazard unless the seawater systems use large amounts of seawater during its life . High concentrations of Uranium ( up to 2 %) have been found in seawater systems , presenting a hazardous risk for the workers at site and the workers in the process of waste disposal ( OGP 2008 ). Uranium exists in seawater in part per billion concentrations . The use of seawater for recovery of oil from a reservoir can potentially introduce an
additional enhanced NORM scenario . In an anaerobic environment ( such as in a 19