Built to Carry What Needs Carrying

Sanitary sewer construction for municipal and commercial projects in the Illinois Valley and surrounding areas.

When you need a sanitary sewer system that functions every day without fail, the work starts below ground where most people never look. In the  Illinois Valley, soil conditions and existing utilities determine how deep we dig and how carefully we route each section of pipe. What you see at the surface is the finished grade and restored pavement, but what matters more is the slope, the joints, and the testing that happens before anything gets backfilled.

Gillan Construction LLC installs mainline and lateral sewer lines that connect buildings to municipal systems or treatment facilities. We set manholes at strategic intervals for access and maintenance, then pressure test every connection to confirm there are no leaks before the trench is closed. The work follows local and state regulations for depth, material specification, and inspection timing. Whether the project serves a commercial development or ties into an existing public system, the installation sequence remains the same: excavation, bedding, pipe laying, jointing, backfill, and final grade restoration.

If your project in the Illinois Valley requires sanitary sewer construction with proper permitting and inspection coordination, contact Gillan Construction LLC to discuss your site layout and timeline.

What Happens Between Excavation and Backfill

After we excavate the trench and prepare the bedding layer, each section of pipe is laid to a precise slope calculated during the engineering phase. In the Illinois Valley, we coordinate with utility locators to avoid conflicts with water, gas, and electric lines that may cross the sewer route. Laser levels and grade stakes keep the alignment accurate, and every joint is sealed according to the pipe manufacturer's specifications.

Once the system is assembled, you will notice that water and waste move through the lines without backing up or pooling in low spots. Manholes provide access points that allow future maintenance crews to inspect and clean the system without excavating again. Leak testing confirms that groundwater stays out and sewage stays in, which protects both the environment and the structural integrity of nearby foundations.

We use compaction equipment to backfill the trench in lifts, preventing settlement that could crack pavement or damage the pipe over time. The final surface is restored to match the surrounding grade, and all inspection reports are submitted to the local authority before the project is closed. If the site requires traffic control or phased construction to keep access open, we build that into the schedule from the start.

Questions That Come Up During Planning

Most questions about sanitary sewer construction come from people who need to understand what happens underground and how long the site will be disrupted. Here are the details that help you plan around the work.

What determines the depth of a sanitary sewer line?
The depth depends on the elevation of the connection point, the required slope for gravity flow, and the depth of frost penetration in Illinois. We also account for any utilities that cross the sewer route to avoid conflicts.
How long does a typical sewer installation take?
A straightforward lateral installation may take two to three days, while a mainline project with multiple manholes and tie-ins can take several weeks. Weather, soil conditions, and inspection scheduling all affect the timeline.
What type of pipe is used for sanitary sewer systems?
Most systems use PVC or ductile iron pipe, depending on depth, traffic load, and local code requirements. The material is specified during the design phase and approved by the municipal engineer.
Why is pressure testing required before backfilling?
Pressure testing confirms that every joint is sealed and that the system will not leak sewage into the ground or allow groundwater to infiltrate the line. It is a code requirement and part of the final inspection process.
What happens if the trench crosses an active roadway?
We coordinate with local authorities to set up traffic control, and the work is often phased to keep at least one lane open. Temporary trench plating may be used to restore access during off hours.

Gillan Construction LLC manages sanitary sewer projects in the Illinois Valley with attention to grade, compaction, and inspection timing. If your site needs a sewer system that meets municipal standards and functions as designed, reach out at (815) 559-2088 to discuss your project scope and permitting requirements.