The Village of Mount Prospect is partnering with two regional water suppliers, Northwest Water Commission (NWC) and Northwest Suburban Municipal Joint Action Water Agency (NSMJAWA), to construct an emergency interconnection to reduce the Village’s reliance on its backup groundwater wells. The Village awarded the contract to Airy’s, Inc., an underground General Contractor. A new water main will be installed along Elmhurst Avenue between Kensington Road and Highland Avenue. Additional work will occur at the Village’s Pump Station No. 5 site at Highland Street and Emerson Street (see attached map). The contractor plans to mobilize in mid to late March. Street paving and parkway restoration will be performed after the pipe has been installed, pressure tested, and disinfected. Temporary road closures will be necessary.

The Village owns and operates a water distribution system that provides potable water to approximately 42,000 residents at an average rate of 3.2 million gallons per day (MGD). Illinois American Water Company, a privately-owned utility regulated by the Illinois Commerce Commission, provides water to the remainder of the community. 
Source water for the Village-owned system is drawn from Lake Michigan and treated by the City of Chicago. It is subsequently distributed to the Village and six (6) other northwest suburban municipalities: Elk Grove Village, Hoffman Estates, Schaumburg, Hanover Park, Streamwood, and Rolling Meadows. Water is distributed via a system of reservoirs, pumps, and pipelines owned and operated by Northwest Suburban Municipal Joint Action Water Agency (NSMJAWA, commonly known as JAWA).

NSMJAWA facilities include 54 miles of transmission water main ranging in size from 16 to 90 inches in diameter that provide drinking water to a 95 square mile service area. The main pumping station is situated at O'Hare airport and features seven (7) pumps that have the capacity to move 130 million gallons of water per day. The main pumping station also hosts two (2) 10 million gallon water storage reservoirs. There are also two (2) 5-million gallon standpipes on the west end of the system in Hoffman Estates. 

The Village-owned water system also has 8.8 million gallons of water storage held in seven (7) tanks accessed via a combination of 16 booster pumps. This storage and booster pumping capacity could satisfy the Village's water demand for 2-3 days in the event water delivery from NSMJAWA is interrupted. In addition, the Village has four ( 4) interconnections with neighboring water supplies including the Village of Arlington Heights, City of Des Plaines, and Illinois American Water Company. Generally, these interconnections are small and capable of supplementing the Village's water supply for short periods of time but not completely replacing it. 

As an emergency back-up source of water, the Village has maintained five (5) deep wells that access groundwater from the Mount Simon sandstone aquifer. The pumps are set an average depth of 900 feet and are capable of generating up to 8.9 million gallons of raw water per day. This well water system is capable of satisfying the Village's average demand (3.2 MGD) and peak demand (6.6 MGD) for an extended period of time. The Village has maintained this back-up well water system since transferring to Lake Michigan water in 1987. These wells, along with several others, used to form the primary source of drinking water for the entire Village-owned system. To date, there has been no need to utilize the wells for source water beyond routine water quality testing and exercising of the equipment. 

Northwest Water Commission Emergency Interconnect 

The Northwest Water Commission (NWC) is a joint action water agency similar in purpose and organization to the Northwest Suburban Municipal Joint Action Water Agency (NSMJAWA). It distributes potable water drawn from Lake Michigan by the City of Evanston to the Villages of Palatine, Arlington Heights, Buffalo Grove, and Wheeling. It also provides water to a portion of the City of Des Plaines. Its main pumping station is located just outside Mount Prospect corporate boundaries near the intersection of Wolf Road and Kensington Road. Its primary distribution main dissects the Village, from east to west, along the Kensington Road right-of-way. 
This proximity to the Village of Mount Prospect water distribution system offers a unique opportunity to access a separate, distinct, ample source of fully treated, finished Lake Michigan drinking water. In essence, a second "straw" into Lake Michigan. 

Four ( 4) potential interconnect location alternatives were considered and four ( 4) scenarios were evaluated: two (2) considered NWC supplying the Village's average and maximum day demands, one (1) pondered the Village supplying water to NWC, and one (1) tested NSMJAWA supplying water to NWC. The evaluation found that NWC can supply the Village's average day, maximum day, and peak hourly demands through any of the interconnect location alternatives evaluated. It was also determined that the Village can supply NWC with approximately 7.8 MGD (5,400 gallons per minute (GPM)) at approximately 40 to 45 pounds per square inch (PSI). NSMJAWA can supply approximately 8.5 MGD (5,900 GPM) to NWC if a connection between the NSMJAWA and NWC transmission mains is made while still meeting Village demands.

The proposed interconnection will be constructed on Elmhurst Avenue between Kensington Road and Highland Street. A NWC transmission main in the Kensington Road right-of-way will be tapped and connected to existing NSMJAWA transmission mains located in the Elmhurst Avenue and Highland Street rights-of-­way. Attachment A presents this concept in greater detail. By operating valves installed along the interconnection piping, NWC can deliver up to 7 million gallons of water per day (MGD) to the Village and NSMJAWA can deliver a like amount to NWC should the need arise. This rate of delivery will satisfy the Village's maximum day requirements and provide approximately one-third of NWC's average daily demand. 

Due to substantial differences in operating pressures, NWC cannot deliver water to the NSMJAWA system. Therefore, NSMJAWA will not be participating in the cost of the interconnection. However, NSMJAWA has allowed their existing infrastructure to be utilized for the improvements and they have agreed to provide NWC with an emergency source of water should their normal connection to the City of Evanston fail. The project includes approximately 1,300 LF of 30-inch diameter ductile iron pipe water main, a new meter, and a control valve vault. The scope of work also includes various improvements to the Village's existing Pump Station 5, including new pumps and motors, HVAC, electrical, and instrumentation improvements, new site piping, new fencing, and new pipe connections to the Village's two (2) existing water storage reservoirs. 

The contractor is mobilizing back to Elmhurst Ave the week of July 29, 2024. On Monday, July 29, 2024, Airy’s will excavate and install protective shoring in the pit on the north side of Kensington Road at Elmhurst Ave. On Tuesday, July 30, 2024, the contractor will begin to prepare to perform the hot tap on the Northwest Water Commission 36” transmission water main. The hot tap will be made on Wednesday, July 31, 2024. We anticipate this to take 10 hours to complete. Last, on Thursday, August 1, 2024, trenching across Kensington Road will occur to connect the water main previously installed. We anticipate this work will take two days to complete. 

- Material for the final hot tap onto the Northwest Water Commissions 36” transmission water main is expected to be delivered on July 18, 2024.
- If the material is delivered on time, the hot tap will be scheduled during the week of July 22, 2024. All work associated with the hot tap could take up to 5 days to complete. 
- The contractor will also continue working on items associated with the control vault structure at the intersection of Elmhurst Avenue and Highland Street during this time. 
- It is our goal to have the street lights on Elmhurst Avenue energized by July 19, 2024.

Here is a tentative schedule of the next steps while we wait for the material to do the final connection. The critical material items are expected to be delivered early July.
Week of 5/28 – Connect 30” to meter vault, install reducers, etc. for the storm sewer replacement
Week of 6/3 – Begin prepping for restoration; concrete curb / sidewalk restoration to begin
Week of 6/10 – Asphalt Restoration
Week of 6/17 – Landscape Restoration

- Contractor will be excavating the discharge piping for the sump pit located in the control vault pit at the northeast corner of Elmhurst Avenue and Highland Street.
- On Wednesday 5/15 and Thursday 5/16, the contractor will be installing the underground flush hydrant on the southeast corner of Elmhurst Avenue and Highland Street adjacent to the existing NSMJAWA underground flush hydrant. 
- On Wednesday 5/15, Concrete is scheduled to be poured at booster pumping station 5 located at 112 E. Highland Street. Curb, sidewalk and the apron to the pump station will be poured. Asphalt and sod restoration to follow. 
- Electrical contractor is currently working on running conduit inside of the pump station for the new pumps. The pumps are currently being tested by the manufacturer in Georgia and are expected to ship the week of 5/20/2024.

- Street lights will be temporarily out of service on Elmhurst Ave. and notices will be left at the effected homes. 

VOMP_RIB_9-24-2024

RIB Update 5-22-2024

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VOMP_RIB_Final_2024-2-29

HOW CAN I GET MORE INFORMATION?
Call the Public Works Department (847) 870-5640

or email to publicworksdept@mountprospect.org.

VILLAGE OF MOUNT PROSPECT
PUBLIC WORKS DEPARTMENT
1700 W. Central Road
Mount Prospect, IL 60056
www.mountprospect.org
Phone: 847-870-5640
TDD: 847-392-1235