"The Housing Bubble" refers to the expected decline in housing values once factors that support high housing prices disappear (low interest rates, and jobs/income). A major decline in the value of the dollar against other currencies could in fact cause a rise in interest rates, and help bring down American employment and wage levels. At present, the business of Westford is housing. A crash in the value of housing would be a huge "environmental disaster" for Westford.
"Peak Oil" refers to the problem that many experts find that oil production cannot be substantially increased, and may in fact start declining in the next few years. This will happen at a point of rising foreign oil consumption, against the backdrop of a falling dollar. The price of oil is poised to increase substantially with these supply/demand pressures. Predicting the future is quite difficult. But I would guess that once gasoline is $4-$5 per gallon, it will be hard for many to justify living in Westford and commuting to Boston. This again would be another huge "environmental disaster" for Westford.
In case you think I am being pessimistic, check this out (dieoff.org).