Water leak investigation and potential immediate/future repair on the Northwest Municipal Joint Action Water Agency (NSMJAWA) 90-in Transmission Main

The Northwest Municipal Joint Action Water Agency (NSMJAWA) has informed the village of a possible leak on their 90-in transmission main that delivers Lake Michigan water to the member communities including the Village of Elk Grove Village, Village of Hanover Park, Village of Hoffman Estates, City of Rolling Meadows, Village of Schaumburg, Village of Streamwood, and the Village of Mount Prospect. 

NSMJAWA staff were informed of standing water next to the roadway potentially originating from its 90-inch watermain, near O’Hare International Airport. The 90-inch watermain is the single source that delivers water to NSMJAWA’s member communities. 

The potential leak is not currently impacting water service in any way.  Further, NSMJAWA has not yet confirmed a leak on its watermain. The potential leak does require NSMJAWA, however, to assess its possible source and scope so that it can develop a plan to repair it. 

Determining the source and scope of a leak, on a 90-in watermain, will likely require exploratory excavation work.  That exploratory work is tentatively scheduled for  this spring.  The purpose of performing the exploratory excavation is to determine the exact location of the leak and to ascertain what materials will be needed for the repair.  The leak could be on a NSMJAWA water main or on a City of Chicago water main located nearby.

If the leak is on the NSMJAWA main, the agency may direct repairs to commence which may result in a shut-down of water supply to the Village. The repairs will take three (3) to seven (7) days to complete. 

If there is a shut-down, the Village will utilize various interconnects with other suppliers and/or utilize the existing potable water deep well systems.  All the other NSMJAWA members will also have to use alternate water sources.

What does this mean for you the water customer

 During that time, the Village will utilize various interconnects with other suppliers and/or utilize the existing potable water deep well systems.  All of the other NSMJAWA  members will also have to use alternate water sources. 

The Village will initially utilize existing interconnections with the Village of Arlington Heights, the City of Des Plaines, and the Illinois American Water Company.  These water purveyors all source Lake Michigan water from a supplier other than NSMJAWA and, therefore, are not affected by the shut-down.  There should be no discernable difference between the water you normally consume, and the water received from Arlington Heights, Des Plaines, or Illinois American. 

However, some customers may initially notice a drop in water pressure.  To receive water from Arlington Heights, Des Plaines, and Illinois American, the Village-owned water system must operate at a relatively lower pressure. 

If the pressure drops too low, or the emergency interconnections with Arlington Heights, Des Plaines, and Illinois American cannot convey enough water to meet demand, the Village will produce water from artesian deep wells. 

Deep Well Water Use

These wells are each over 1,000 feet deep.  The water is safe to drink but almost everyone will notice that it tastes, smells, and may even appear different than the Lake Michigan water that normally flows from Mount Prospect faucets. Public Works will disinfect the water with chlorine prior to distribution.  

For detailed information on the chemistry of the Village's deep wells review the following:

Water Quality Reports

Comprehensive Well Chemical Analysis

Limit Water Use

Should the Village need to use alternate water source we ask customers to limit water usage until the Village returns to its primary water source.  Limiting water use includes: 

• Wait to run the dishwasher or washing machine.
• Minimize shower and bath use.
• Flush less frequently.
• No outdoor water uses.

 The Village began using Lake Michigan water purchased through NSMJAWA in 1988. Prior to that time, the Village utilized these deep wells exclusively as its only source of water. 

If you have questions or concerns about this matter, please check the Village website and the Public Works Department’s social media for additional information.  You can also contact the Mount Prospect Public Works Department directly at 847-870-5640 or publicworksdept@mountpropsect.org.