So far laboratory experimental pitting tests have mostly focused on sulfate reducing bacteria (SRB). Various pitting rates in these tests have been reported and they are often less than or not much greater than 1 mm/year. There are also some limited data available for nitrate bacteria (NRB) and acid producing bacteria (APB). Seawater injection pipe failures have been reported in the literature pointing to very high pitting rates that are 100X higher than pitting rates observed in short-term laboratory tests for SRB. This paper explores the possibility of very high MIC corrosion pitting rates due to low pH and organic acid (represented by acetic acid) corrosion through mass transfer and microbial metabolic rate calculations and mechanistic modeling to help answer the question of whether APB are capable of very fast MIC pitting. Organic acid production by microbes and their mass transfer across an APB biofilm as well as consumption by corrosion will be considered.