Middleton at a glance
Middleton (ZIP 83644) sits just north of the Boise River in Canyon County, with Highway 44 running through the center of town toward Star to the east and Caldwell to the west. The older town center is surrounded by new subdivisions and, beyond them, farms and acreage homes.
New subdivisions
Most new Middleton homes are built over crawl spaces. Common sewage problems include:
- Drain line joints that separate or leak under bathrooms and laundry rooms
- Toilet seal failures that soak the subfloor and drip into the crawl space
- Main-line backups from wipes, grease or construction debris left in new lines
See crawl space sewage cleanup and sewage backup cleanup.
Who to contact about the public sewer
The City of Middleton operates the public sewer system. In August 2026 the city broke ground on a new wastewater treatment plant designed to meet Boise River discharge standards and add capacity for growth. Plant work does not change what to do about a backup at home: if neighbors are also backing up, contact the city about the public main. The private lateral from the house to the main is generally the owner’s responsibility.
Rural properties and septic
Farms and acreage homes outside city sewer around Middleton rely on septic systems, permitted in Canyon County through Southwest District Health. Overdue pumping, saturated drainfields and heavy water use can push sewage back into the lowest drains of the house. Keep surfacing sewage away from wells, gardens, livestock and irrigation ditches. See septic backup cleanup.
Older homes near downtown Middleton
Homes on the older blocks near Middleton’s original town center often have older sewer laterals and mature trees nearby, which raises the risk of root intrusion. Repeat backups in these homes are worth a camera inspection to find the cause.
Irrigation water or sewage?
Irrigation ditches and laterals run through and around Middleton. Water that seeps into a crawl space during irrigation season smells earthy and is not sewage, though it still needs to be dried. If the water smells like sewage, came from a drain or appeared when a fixture was used, treat it as contaminated Category 3 water.
Common Middleton cleanup jobs
- Crawl space sewage leaks found by odor
- Toilet and tub backups in new homes
- Septic backups on rural lots
- Blackwater contamination of flooring and drywall