From the Iowa DNR –
Untreated wastewater, starting as a slow leak from a force main, has pooled below Greenwood Avenue in Nashua.
The Chickasaw County town discovered the leak about 7 a.m. Tuesday and used dye testing to find where the pipe is leaking.
The leak is on the north side of town downstream from a dam in the Cedar River. City officials say the leak is very slow and may have been ongoing. It is more noticeable now because of low levels in the river. The city plans to repair the pipe temporarily, and then determine how to fix it permanently.
The DNR encourages residents to keep children and pets away from the area east or south of Greenwood Avenue near the river until Thursday or until the problem is corrected.