Workers trying to remove a huge fatberg clogging a Birmingham sewer hope high-pressure jets will tackle the "horrible, gunky mess".
If they do not work, workers will have to chip away at the mass with spades.
The 300-tonne berg in Hodge Hill, and which goes underneath the M6, is the biggest Severn Trent said it has ever had to tackle.
Wet wipes being flushed away or oil and grease being poured down sinks has allowed it to build up, the firm said.
The fatberg is about 8m (26ft) underneath the surface so a huge, deep trench has had to be dug to allow hoses in to start work.
The solid mass is estimated to be 1m (3ft) high and 1,000m (1,094yds) long and could take until June to clear.
If the jets do not work, then harder parts will have to be chipped away with a spade, Sarah O'Kane, from Severn Trent said.
'Start to solidify'
"So the biggest thing is actually getting at that pipe so that is 7/8m deep, so we've had to dig a massive massive hole, or big trench to get at it and now what the teams will do is use some really high pressure water jets to kind of break it up at little bit at a time," she said.
"Sometimes it's so hard, it's like concrete, we actually have to get in there and chip at it with a spade - we're hoping the jets will get this one out though."
The fatberg was discovered when sewer flows in the area were noticed to be moving slower than normal, she said.
She said people think washing bacon sandwich fat down the sink will not cause a problem but these things can build up and once it hits the cold sewers it starts to solidify.
Think twice about what is poured down your sinks or flushed down your toilets, she urged.
"So the wipes, when they start to get stuck in the fat, it's when they combine together they create this huge, horrible gunky mess... please don't put these things down the toilet and don't wash that down the sink because this is the consequence..." she added.