The facility on Battle Bridge Rd is the largest in Wake County. Sewage is treated, and what's left over - what is called bio-solids or sludge - has to go somewhere.
Much of it they give away to farmers who use it as fertilizer, but there's a lot left over and it's expensive to get rid of.
Twenty years ago it was dumped on the land around the facility and the result wasn't good. Water wells were contaminated and there was a huge settlement.
The city stopped dumping for years, but in April, the city applied for a new permit start again, saying the technology has improved and that they know what they're doing this time.
But, some who live around the area remember what happened two decades ago aren't convinced.
"I'm afraid that it's not better and I'm afraid that even if it did get better, when you put that much all around any particular area, the concentration levels are just going to make it right back to where it was before," offered resident Tonya Debnam.
A community meeting was set for Thursday from 6:30 p.m. - 8:00 p.m. at Good Hope Baptist Church, 4209 S. Smithfield Rd. Knightdale, NC 27545.