PHILADELPHIA (CBS)–British engineers say they have launched a “sewer war” against a giant fat blob clogging London’s sewers.

Thames Water officials said on Tuesday it is likely to take three weeks to dissolve the outsized ‘fatberg’.

They caution against expecting quick results as the fatberg is 250 yards long and weighs as much as 11 double-decker buses.

The unsavory mass consists of congealed wet wipes, diapers, fat and oil.

Eight workers are using high powered jet hoses to break up the fatberg before sucking it out into tankers for disposal at a recycling site.