SOUTH SIOUX CITY, Neb. (AP) — A foul odor tied to a sewage line in South Sioux City has sickened some residents and forced some to flee their homes as officials look for a remedy.

South Sioux City administrator Lance Hedquist tells the Sioux City Journal (http://bit.ly/2esC7lr ) that the odor is coming from 15 houses in a five-block area of a neighborhood where about 40 people live.

Hedquist says there’s also a “horrific” odor coming from the Big Ox Energy plant, which recently started operations in the city’s Roth Industrial Park about two miles from the affected houses.

Big Ox, a Denmark, Wisconsin-based renewable energy firm, converts organic industrial waste into methane gas.

Hedquist said Friday that the new plant and the homes share the same sewer line.