WASHINGTON — Illinois American Water customers in the Washington Estates and Sundale developments may see some unfamiliar faces in their back yards in the next few weeks.

The company is working with Urban GIS to collect GPS data on the wastewater system, including precise locations of wastewater mains and manholes, from next week through the end of July.

The data will allow company employees to use in-vehicle computers or handheld GPS locators to find things more easily in the field, decreasing response time to complaints, Illinois American said in a news release.

The Urban GIS employees will not need to enter customer homes to perform the work, but if residents have any concern over who is entering their back yards, Illinois American officials suggest asking employees to provide ID.