NuFlow Indy understands the challenges municipalities face when managing aging underground infrastructure, especially when new developments increase demand on existing systems. Our trenchless technologies provide long-term structural solutions for storm and sanitary environments, minimize disruption to residents, and maintain essential services.

This case study outlines how one municipality engaged NuFlow Indy to evaluate and rehabilitate sections of an existing sanitary sewer main before a contractor connected a new multiunit residential development to the system. The town needed to ensure the infrastructure was structurally sound and capable of accepting additional flow without the expense and disruption of open-cut replacement.

The Problem

A developer constructing a new multiunit residential building planned to connect to an existing sanitary sewer main that ran through a nearby neighborhood. The municipality was concerned about adding significant new flow to a line whose condition was unknown. Before approving the connection, a full CCTV inspection of the relevant segments was ordered.

The inspection revealed several issues:

• Deteriorated inverts
• Root intrusions
• Offset joints
• Sections of failing clay pipe

Because these defects could impact structural performance and hydraulic capacity, the municipality determined that rehabilitation was required before allowing the developer to connect.

NuFlow Indy was selected to perform the rehabilitation based on our experience with municipal infrastructure, our trenchless capabilities up to 72 inches, and our ability to work in challenging access conditions.

One of the runs involved an easement location, with one manhole in a sidewalk along a neighborhood street and the other down a ravine in wooded terrain. This created significant logistical challenges for equipment access and material handling. The line also contained a deteriorated invert and offset joints that needed to be addressed during installation.

How We Tackled It

1. Review of Municipal Inspection Data

The municipality provided the CCTV reports and videos from their contractor. After reviewing the footage and confirming the structural issues, we determined that trenchless lining was feasible across the affected segments.

2. Site Visit and Project Assessment

We conducted an on-site walkthrough with public works staff to evaluate:

• Manhole access
• Terrain limitations
• Entry paths for equipment
• Segment lengths
• Flow characteristics
• Any special municipal considerations

This step ensured that our installation plan and pricing accurately reflected real field conditions.

3. Proposal and Execution Plan

After completing our assessment, we prepared a formal quote and a detailed Schedule of Work / Execution Plan outlining:

• Cleaning requirements
• Installation sequencing
• Traffic and pedestrian coordination
• Resident communication plans
• Cure method selection
• Anticipated timelines

The municipality awarded us the project.

4. Pre-Construction Coordination

Once a start date was set, we began coordination with the affected neighborhood. When lining a sanitary main, water usage must be paused to prevent flow from entering the line during cure.

We provided door notices and attempted direct contact with homeowners whose service laterals fed into the segments being lined. For residents we could not reach, we left door hangers and made additional attempts to ensure clear communication – especially at homes with fenced yards requiring our access.

5. Execution of Work

Our crew mobilized daily at 7 a.m. and lined each segment manhole-to-manhole. Two of the three runs were completed using our UV-cured glass-reinforced pipe (UV-GRP) system. The third segment – the easement run – presented unexpected conditions:

• An unmapped lateral or inflow source began surcharging intermittently into the manhole, requiring us to set up an auxiliary bypass to maintain safe working conditions.
• The condition of the invert and offset joint created concerns that our light train could become impeded during UV curing.

Based on these findings, we pivoted from UV-GRP to an ambient-cure liner for this segment. Our ability to switch methods ensured the municipality still received a fully structural rehabilitation without delays or redesign.

What Makes Our Technology Stand Out

For this project, we utilized both UV-GRP and ambient-cure liners, selecting the method best suited to each segment’s structural condition and access constraints. UV-GRP provides:

• ✔ Strong structural performance with thin wall profiles
• ✔ Consistent, controlled cure times
• ✔ Low emissions and minimal odor, suitable for residential neighborhoods
• ✔ Reduced environmental impact with no styrene and no curing water discharge

Because NuFlow Indy maintains multiple lining technologies and equipment types, we can adapt in the field to overcome unexpected conditions, ensuring that municipal timelines and budgets remain protected.

The Results

To maintain uninterrupted service for residents whose homes were not directly tied into the affected segments, we implemented targeted bypass measures during installation. We also ensured that trash pickup, mail delivery, and neighborhood access were not disrupted.

By choosing trenchless rehabilitation instead of open-cut replacement, the municipality:

Restored the failing sewer main to like-new condition

Avoided costly and disruptive excavation of sidewalks, roads, and landscaped areas

Eliminated significant neighborhood traffic impacts

Protected homeowners from extended loss of water usage

Ensured the system was structurally prepared to handle increased flow from the new development

In short, the town received a long-term structural solution without the major cost, delay, or community disruption associated with traditional dig-and-replace work.