On 1 July 2009 the US Coast Guard published an Interim Rule adjusting the limits of liability for vessels and deepwater ports under the Oil Pollution Act of 1990 (OPA-90) to reflect increases in the Consumer Price Index (CPI). In 2006, following a major oil spill from the tank vessel  Athos I  in the Delaware River (where the vessel’s limit of liability amounted to only about 20 percent of the total cleanup costs and damages),   Congress enacted the Delaware River Protection Act (DRPA) to increase OPA-90 liability limits to levels that would reflect a proper apportionment between responsible parties and the National Pollution Fund.  These limits were USD3000 per gross registered ton (grt) for single-hull tank vessels (previously USD1200); USD1900 per grt for double-hull tank vessels (previously USD1200); and USD950 per grt for non-tank vessels (previously USD650). However, Congress was also concerned that inflation would further erode responsible party liability and shift the economic risk of oil spills to the public.  The DRPA therefore also required that OPA-90 limits of liability be adjusted not less than every three years to reflect significant increases in the CPI in order to preserve the “polluter pays” principle embodied by OPA-90.   According to the Interim Rule, any cumulative increase in the CPI of 3 percent or greater over a three year period will be considered “significant” and will trigger new adjustments to the OPA-90 limits.   The Coast Guard also has discretion to adjust the limits before three years if necessary. The new OPA-90 limits of liability, which average about 6.8% and will take effect as of 31 July 2009, are as follows: Source category Previous limit of liability New limit of liability (a) Vessels: (1) For an oil cargo tank vessel greater than 3,000 gross tons with a single hull, including a single-hull tank vessel fitted with double sides only or a double bottom only. The greater of $3,000