STORMWATER CULVERT REHABILITATION USING SLIP LINING IN EAST HADDAM, CT

The Town of East Haddam, Connecticut, was facing a critical issue with the Sheep Skin Culvert, a key component of its stormwater infrastructure. The twin 96-inch stormwater culverts were showing signs of failure, raising concerns about roadway stability and long-term system performance. With full replacement presenting a costly and disruptive option, the Town sought a trenchless culvert rehabilitation solution that would extend the life of the existing infrastructure while minimizing impact to the community.

East Haddam turned to Savy & Sons for our expertise in slip lining, pipe rehabilitation, and grout injection. Our team developed a comprehensive rehabilitation plan that stabilized the underlying soil, restored the culverts’ structural integrity, and delivered significant cost savings compared to traditional replacement methods.

PROBLEM

The Sheep Skin Culvert consisted of twin 96-inch stormwater pipes that had deteriorated over time due to aging infrastructure and soil instability. As the culverts continued to degrade, the risk of roadway settlement and structural failure increased, posing a potential safety concern and long-term maintenance issue for the Town.

Replacing the culverts would have required extensive excavation, prolonged road closures, and a substantial financial investment. The Town of East Haddam needed a solution that would address both the failing culverts and the unstable soil conditions—without the disruption and expense of full replacement.

SOLUTION

Savy & Sons implemented a trenchless culvert rehabilitation approach combining slip lining and targeted grout injection. This solution stabilized the existing infrastructure, restored functionality, and extended the service life of the culverts at approximately 15% of the cost of full replacement.

Key components of the solution included:

• Soil Stabilization Grout Injection: Approximately 100 gallons of AV-275 polyurethane grout were injected to stabilize the soil between the culverts and the roadway, filling voids and preventing future settlement.
• Culvert Cleaning & Preparation: The existing culverts were thoroughly cleaned to ensure proper installation and performance of the new liner sections.
• Slip Lining Installation: New liner sections were installed inside the twin 96-inch culverts, creating a structurally sound, corrosion-resistant flow path.

Bulkhead Construction & LDCC Injection: Bulkheads were constructed at both ends of the culverts, followed by the injection of low-density cellular concrete (LDCC) to fully encapsulate and support the new liners.

PROJECT EXECUTION

The Sheep Skin Culvert Rehabilitation project was completed in just two weeks through careful planning, specialized equipment, and efficient execution.

Key execution elements included:

• Polyurethane grout injection using a dedicated grout injection pump and trailer
• Cleaning and preparation of existing stormwater culverts
• Slip lining of twin 96-inch pipes
• Construction of bulkheads and injection of low-density cellular concrete
• Use of a Richway LDCC trailer to ensure precise material placement

Throughout the project, Savy & Sons prioritized roadway stability, safety, and minimal disruption to the surrounding area. The entire rehabilitation was completed over a two-week period with zero road closures, allowing traffic to flow normally for the duration of the project.

RESULTS

The project delivered measurable, long-term value for the Town of East Haddam and its residents:

• Significant Cost Savings: The rehabilitation solution cost approximately 15% of what a full culvert replacement would have required, saving the Town and taxpayers substantial funds.
• Extended Culvert Service Life: Slip lining and grout injection restored the structural integrity of the stormwater system, significantly extending the lifespan of the culverts.
• Improved Roadway Stability: Soil stabilization and LDCC placement eliminated voids beneath the roadway, reducing the risk of future settlement or failure.
• Zero Road Closures: The trenchless rehabilitation approach allowed the project to be completed without closing the roadway, minimizing inconvenience to residents and maintaining normal traffic patterns.
• Minimal Disruption: The project was completed quickly without extensive excavation or prolonged impacts to the surrounding area.

Why This Matters for Municipal Owners

This project demonstrates how trenchless stormwater culvert rehabilitation can provide a durable, cost-effective alternative to full replacement—reducing disruption, accelerating timelines, and maximizing the value of existing infrastructure.

KEY TAKEAWAYS

The Sheep Skin Culvert Rehabilitation project highlights the effectiveness of combining slip lining and grout injection to address failing stormwater infrastructure. By stabilizing the soil, reinforcing existing culverts, and avoiding full replacement, Savy & Sons delivered a long-term solution that met the Town’s technical, financial, and operational needs.

Savy & Sons continues to support Connecticut municipalities and infrastructure owners with innovative rehabilitation solutions that extend asset life, reduce costs, and improve system reliability.