Unlike CERCLA, the Massachusetts Superfund law, Chapter 21E, does include oil within its ambit.  However, oil is not treated exactly the same as hazardous materials.  One difference is that, in 2007, MassDEP revised the Massachusetts Contingency Plan to provide that, in certain circumstances, where “Contamination is limited to oil,” the exposure point concentration is measured at the Public Water Supply well, rather than in each of the monitoring wells, as is otherwise the case.

It is understood that oil includes gasoline, but what if the spill was in 1994 and the gasoline was leaded?  Yesterday, the SJC ruled in Peterborough Oil Company v. DEP that “additives” are not covered by the oil exemption, so that compliance with MCP standards for lead must be measured at the monitoring wells and not at the Public Water Supply wells.

I think that this would have been a close question, but for one fact.  The exemption was promulgated by MassDEP by regulation in 2007.  At the time, MassDEP received a comment requesting that the regulation apply explicitly to additives, and MassDEP replied to the comment by stating that the “proposal was not extended to additives.”  I think that MassDEP gets interpret its own regulatory proposals, at least in this context.

It’s important to note that the decision in Peterborough Oil applies to any additive, so it would appear that the oil exemption also would not apply to MTBE – and any other hazardous substances that are not present in oil or products refined from oil, but which instead are added to the oil for some functional purpose.