New data from the Energy Information Administration (EIA) confirms that the unplanned outage earlier this month of a 240,000-barrels-per-day unit at a refinery in Whiting, Indiana, caused gas prices to spike throughout the Midwest.

The outage occurred on August 8 and EIA notes that regular gasoline prices in the Midwest increased by 32 cents a gallon within the following week, from $2.47 the week of the outage to $2.79 a gallon on August 17. EIA says it was “the largest weekly increase for Midwest gasoline prices since the aftermath of Hurricane Katrina in 2005.”

“The EIA data show that the refinery outage made a serious dent in the wallets of consumers,” said Bob Dinneen, President and CEO of the Renewable Fuels Association, which released a statement in response to the unplanned shutdown. “The Environmental Protection Agency and the Obama Administration have all the tools they need at their disposal to assist in blunting the consumer impacts of the refinery outage. We, once again, call on EPA to immediately waive RVP requirements for E15 and also allow E12 blending in the Midwest region.”

According to EIA, it can take markets days or weeks to adjust to the sudden loss of production during unplanned outages, often resulting in sudden price increases. The severity and duration of the higher prices depend on how quickly the refinery problem can be resolved, how soon alternative sources of supply can arrive, and the marginal cost to bring alternative supply to the region.