Residents of a townhouse complex in Calverton are suing Suffolk, saying the county is ordering them to put in a new sewage system they cannot afford. 

Calverton Hills residents are being required by the county to install a new sewage treatment system that serves the development's homes at a cost of $7 million. 

Daniel Hotchkin, the Calverton Hills Homeowners Association president, says the added cost would be a "hardship." 

Homeowners say the county signed a 1973 covenant, taking ownership of the sewage plant.

"It's not ours. They should have been maintaining it, and they dropped the ball on it," said Hotchkin. 

A Suffolk spokesman told News 12 in part that, "we do not think it is a viable claim against the county."

Residents say the county's Health Department is threatening to close the complex if the sewage system isn't replaced.

A federal judge will hear the lawsuit on Nov. 3.