Introduction

Tremie lift station installation in high groundwater and coastal soil environments presents unique engineering and construction challenges—especially in Florida and the southeastern United States, where groundwater is often near the surface and sandy coastal soils can destabilize traditional excavation.

Hinterland Group Inc. specializes in advanced tremie lift station construction methods designed to deliver reliable, long-lived wastewater solutions for municipalities, utilities, property managers, and private sector clients facing these demanding conditions (source).

What Is a Tremie Lift Station Installation?

A lift station is an essential component of municipal or private wastewater systems, using pumps to transport sewage from lower to higher elevations where gravity sewer flow is not feasible.

Tremie installation is a specialized construction approach for placing concrete or structures underwater or below the groundwater table. A “tremie” is a watertight pipe through which concrete or other fill material is placed with minimal contamination or washout, critical for ensuring integrity in high water table or saturated soils (external reference).

When Is the Tremie Method Used?

Sites with high groundwater table
Unstable, saturated, or loose coastal soils (common in Florida, Georgia, Carolinas, Gulf Coast)
Locations where dewatering is challenging or environmentally sensitive
To prevent floatation or structural shifting of wet wells, manholes, or precast structures during installation

Challenges in High Groundwater / Coastal Environments

Buoyant Forces: High water table can cause lift station structures to float or shift before backfill and structural weight counteracts buoyancy.
Soil Instability: Sandy, organic, and low-cohesion soils can cave in, collapse, or wash out around excavations.
Dewatering Complexity: Conventional dewatering may not be feasible or is environmentally restricted due to wetlands, saltwater intrusion, or adjacent water bodies.
Contaminant Migration: In coastal and flood-prone zones, uncontrolled groundwater flow can spread contamination.
Regulatory/Environmental Controls: Compliance with EPA, state, and local ordinances for temporary water management is stringent.

Hinterland Group’s Tremie Lift Station Installation Capabilities

Unique Tremie Installation System: Hinterland has developed and field-proven a proprietary approach, including watertight cofferdams and tremie concrete placement for new or replacement wet wells and pump stations (source).
In-house Bypass Pumping: Full design, set-up, and operational support for bypassing live sewage flows, avoiding service disruption or sanitary sewer overflows (SSOs).
Electrical Panel and Controls: Integrated installation by cross-trained mechanical and electrical crews, ensuring seamless station operation post-installation.
Rapid Emergency Response: Mobilization within 24 hours, with 24/7 on-call teams experienced in live, high-risk, or urgent lift station settings.

Key Features and Benefits

Watertight Construction: Prevents infiltration and exfiltration, essential for regulatory compliance and environmental protection in coastal zones.
Floatation Prevention: Tremie method, with continuous pour of low-slump concrete, ensures structures achieve required mass and bond to resist uplift during construction.
Soil Stabilization: Backfill and annular space grouting via tremie pipes enhances bearing capacity and reduces risk of settlement/collapse.
Minimal Surface Disruption: Compared to major sheet pile, driest pit, or open excavation, tremie methods minimize land disturbance—vital near wetlands, roads, or utilities.
Integrated Project Delivery: Hinterland’s vertical integration ensures cost controls, fast-tracked schedules, and cohesive project execution (source).

Typical Use Cases

Municipal wet well and submersible lift station installation in coastal cities (e.g., Hallandale LS #8 project)
Replacement of failed or aged lift stations in high water table neighborhoods
Industrial or commercial pump station installations where uninterrupted operations are critical (e.g., industrial parks, resorts, airports)
Emergency lift station replacement post-hurricane or flood event (see case studies)

Step-by-Step: Hinterland’s Tremie Lift Station Installation Sequence

Site Assessment & Controls:
Survey water table, soils, and adjacent infrastructure; implement environmental and safety controls.
Excavation & Shoring:
Carefully excavate to lift station invert, employing sheet piles, trench boxes, or cofferdams as needed.
Dewatering (as practical):
Draw down groundwater only as much as local conditions allow, using well points or sumps with strict regulatory compliance.
Placement of Precast/Steel Wet Well Structure:
Lower structure into position. If floatation risk exists, secure with ballast.
Tremie Concrete Placement:
Place concrete by tremie pipe into annular space around/under lift station structure; maintain positive head to push out water and prevent washout.
Setting Station Internals:
Construct pump bases, inlet, discharge piping, and electrical penetrations in a dry and stable environment provided by the cured concrete envelope.
Backfill and Site Restoration:
Place select backfill, compact, and restore surface according to civil plans.
Startup & Commissioning:
Final pump install, electrical commissioning, SCADA integration; test station functionality under live service.

Comparison Table: Tremie Method vs. Conventional Lift Station Installation

Aspect	Tremie Installation (Hinterland)	Conventional (Dewatered/Open Cut)
Buoyancy Control	Uses mass concrete to counter uplift	Relies on structural weight, or over-excavation
Groundwater Impact	Minimal, concrete displaces water	Water often needs to be pumped/lowered
Soil Support	Concrete supports/caps soft soils	Unstable soils may require major shoring
Environmental	Lower risk of washout, less drawdown	High risk of dewatering impact
Rapid Restoration	Yes, once concrete sets	May be delayed by continuous dewatering
Cost Predictability	High; controlled pour/placement	Variable, subject to groundwater behavior

Why Choose Hinterland Group for Tremie Lift Stations?

Regional Coastal/High Groundwater Expertise: Decades of work in Florida and the broader Southeast, dealing with the most challenging soils and water conditions (source).
Proven Project Portfolio: Experience with dozens of successful tremie lift station installations for municipalities, industrial sites, commercial and HOA clients (projects).
All In-house: Civil, mechanical, electrical, and bypass operations are unified, reducing schedule risks and change orders.
24/7 Emergency Response: Available for urgent situations such as station collapse, flood, or sanitary overflow events (emergency services).
Safety First: Leadership by a full-time, OSHA-certified Safety Manager; emphasis on rigorous site controls and trained crews (safety commitment).
Regulatory/Environmental Compliance: Proven ability to work with sensitive sites, wetlands, and utility corridors, adhering to EPA, FDEP, and local codes.

Frequently Asked Questions (FAQ)

Q: How is tremie installation different from standard wet well or lift station construction?

The tremie method allows concrete or gravels to be placed underwater or in a submerged environment without mixing with water. This results in a denser, more stable support for lift station structures—mitigating risk of floatation, groundwater infiltration, or soil washout. Standard approaches rely on full dewatering, which is usually impractical or risky in high groundwater or coastal soils (external reference).

Q: Can Hinterland Group install lift stations where the water table is above excavation depth?

Yes. Hinterland designs the project with the expectation of a submerged work area. With tremie and cofferdam construction, structures are set, annular space is filled with concrete/grout using tremie pipes to displace water, and floatation is counteracted.

Q: Are there regulatory, permit, or environmental requirements unique to these projects?

Yes. Projects often require wetlands permitting, documentation of water management/discharge, and compliance with EPA and state (e.g., FDEP in Florida) rules. Hinterland manages the submittal and compliance process in-house (source).

Q: Is the lift station operational during replacement or rehabilitation?

Hinterland offers in-house bypass pumping, allowing continued wastewater conveyance during lift station construction or replacement to prevent sanitary sewer overflows and service disruptions.

Q: What is the typical project duration for a tremie lift station installation?

Timelines depend on depth, station size, groundwater regime, and permitting. Hinterland’s vertical integration and rapid response reduce delays, with many projects completed on an expedited schedule in direct response to emergencies or municipal needs.

Q: What types of clients benefit from Hinterland’s services?

Municipal utilities, industrial sites, commercial/residential communities with high groundwater or coastal exposure, airports, and any entity needing reliable 24/7 station operation in difficult conditions (see markets served).

Project Example: Hallandale LS #8 Replacement

Hinterland Group performed a tremie-based lift station replacement in Hallandale Beach, FL—a location characterized by high groundwater and sandy soils—demonstrating:

Watertight structure installation
Bypass pumping of active flows
Restoration of subgrade and surface

See Hallandale LS #8 case study

Ongoing Maintenance & Support

After tremie lift station installation, Hinterland provides:

Continued O&M, inspection, and cleaning (maintenance services)
Troubleshooting and emergency SSO response
Upgrades, controls integration, and rehabilitation

Annual maintenance plans extend life, maximize regulatory compliance, and identify future rehab/upgrade needs (maintenance plans).

Contact Hinterland Group

For consultation, specification, or emergency mobilization related to tremie lift station installation, connect here:

Contact Us
Phone: (561) 640-3503
2051 West Blue Heron Blvd., Riviera Beach, FL 33404

Sources:

Tremie Lift Station Installation in Coastal/High Groundwater