Deliver Clean Water Under Reliable Pressure
Water main installation and repair for municipal and commercial systems in the Illinois Valley and surrounding areas.
When you turn on a faucet or fire hydrant in the Illinois Valley, the water comes through a network of underground mains that must hold pressure and stay sealed year-round. A new water main installation involves excavation, pipe laying, tie-ins to existing systems, and pressure testing before the line goes into service. If a main fails or a section needs upgrading, repair work requires isolating the damaged area, cutting out the old pipe, and splicing in a replacement without shutting down service longer than necessary.
Gillan Construction LLC installs and repairs water mains for municipal systems, commercial developments, and industrial sites. We handle everything from tie-ins that connect new buildings to the public water supply to emergency repairs that restore flow after a break. Each installation is pressure tested and disinfected according to state drinking water standards, and all materials meet specifications for potable water use. The work includes valve placement for future shutoffs and connections for fire protection where required.
If your project in the Illinois Valley requires water main construction or you need emergency repair support, contact Gillan Construction LLC to coordinate the work with minimal disruption to service.

Steps That Protect Water Quality and Pressure
After we excavate the trench and prepare the bedding, each section of water main is laid with joints that prevent leaks under system pressure. In the Illinois Valley, we coordinate shutdowns with the water department to tie into the existing main, then flush and disinfect the new line before it carries drinking water. Pressure gauges monitor the system during testing to confirm that the line holds the required PSI without dropping.
Once the main is in service, you will notice consistent water pressure at taps and hydrants, with no discoloration or air in the lines. Valves allow isolated sections to be shut down for future maintenance without affecting the entire system. Fire hydrants connected to the new main deliver the flow rates required for emergency response.
We use ductile iron or high-density polyethylene pipe depending on soil conditions, traffic loads, and local code requirements. The pipe is bedded in clean material and backfilled with compaction to prevent settlement. Repair projects follow the same steps but focus on minimizing downtime and restoring service as quickly as possible. The work does not include service line connections to individual buildings or meter installation.
What You Should Know Before the Work Starts
Questions about water main work usually focus on service interruptions, water quality during commissioning, and how the system is tested. Here are the details that help you prepare for the project.
Gillan Construction LLC handles water main projects in the Illinois Valley with careful attention to pressure testing, disinfection, and service coordination. If you need installation for a new development or emergency repair of an existing line, reach out at (815) 559-2088 to discuss your project schedule and system requirements.

