Introduction

Infiltration and inflow (I&I) from deteriorated manholes is a dominant driver of surcharge, SSOs, and treatment costs across the Southeast. Since 2006, Hinterland Group Inc. has delivered trenchless manhole rehabilitation at municipal scale—integrating inspection, leak stoppage, structural rebuild, chemical corrosion protection, and rapid return-to-service—to stop I&I with minimal surface disruption. Our in‑house crews, 24/7 emergency response with 15‑minute callback, and rapid mobilization from Riviera Beach, FL and Morganton, NC enable dependable delivery across Florida, Georgia, Alabama, Louisiana, Texas, Tennessee, South Carolina, and North Carolina. See our broader capabilities on Services, Inspection, Repair & Replacement, Maintenance, and Evaluation & Assessment.

Municipal I&I context in the Southeast

• High groundwater tables, tidal influence, and intense rain events accelerate manhole leakage through chimney joints, corroded cones, cracked barrels, penetrations, and grade rings.

• H2S corrosion and sulfide microbiology attack concrete and mortar, while traffic loading and settlement open new leak paths.

• Trenchless manhole rehabilitation restores structural integrity, seals water paths, and provides long‑term chemical protection with minimal disruption to residents and businesses. Learn more about our municipal work on Markets We Serve and Case Studies.

Raven 405, OBIC, Geo

Krete, GeoSpray: OEM system overview We install owner‑specified manhole rehabilitation systems and maintain OEM training/certifications as required by project specifications. Certification letters are provided in submittals upon request. The systems most frequently specified by municipal owners include Raven 405, OBIC, GeoKrete, and GeoSpray.

OEM system	Material family	Primary purpose	Typical municipal use-cases
Raven 405	100% solids epoxy coating	Chemical corrosion protection and infiltration sealing on sound substrates	Wastewater manholes with H2S exposure; protection of benches/channels; post-leak-stoppage lining
OBIC	Polyurea/polyurethane hybrid lining	Fast-set, high-build lining to seal leaks and restore service quickly	High groundwater chimneys and cones; wet-weather I&I reduction with tight outage windows
GeoKrete	Geopolymer mortar (spincast/trowel)	Structural rebuild and corrosion-resistant resurfacing of deteriorated concrete/brick	Advanced corrosion, lost wall thickness, re-establishing geometry before topcoat
GeoSpray	Geopolymer mortar (spray-applied)	Structural rehabilitation and profile restoration with minimal excavation	Large-diameter or deep structures; oval/irregular profiles; rapid structural restoration

Notes: Owners may require combined solutions (e.g., geopolymer structural rebuild followed by epoxy or polyurea topcoat) to meet both structural and chemical-resistance objectives. Hinterland performs all trenchless technologies in‑house, including geopolymer spincast, ensuring single‑source accountability. See Pipe Rehabilitation.

Compliance: ASTM F2551 and owner specifications

• We align submittals, materials, and testing with ASTM F2551 Standard Practice for Rehabilitation of Existing Manholes when specified, along with owner/engineer requirements.

• Typical project controls: substrate evaluation and measurement, hydrostatic leak identification, surface preparation and pH conditioning, leak stoppage and injection grouting where needed, thickness control by wet‑film gauges and post‑cure verification, spark/holiday detection where specified, adhesion verification on mockups when required, and documented cure verification per the OEM.

• Where vacuum testing is specified, we coordinate pre‑ and post‑rehab tests on select structures to confirm leak elimination.

Certified installer documentation (PDFs on request)

Municipal bid packages commonly require proof of OEM authorization. Hinterland maintains current, project‑ready letters and training records and furnishes them in submittals or upon request:

• Raven 405 applicator authorization letter (PDF)

• OBIC applicator authorization letter (PDF)

• GeoKrete applicator authorization letter (PDF)

• GeoSpray applicator authorization letter (PDF)

• Safety program overview and EMR (< 0.87), insurance certificates, and OEM safety data sheets To request documentation, contact us via Contact Us.

End‑to‑end manhole rehab workflow to stop I&I

1) Condition assessment and I&I source mapping

• CCTV and robotic inspection to document defects; chimney/frame survey; infiltration mapping during wet weather. See Inspection.

2) Active leak elimination

• Chemical grouting at penetrations, frame/grade ring interfaces, and cold joints; weirs and bypass setups managed in‑house to keep systems online.

3) Structural rebuild (as required)

• Geopolymer spincast/trowel to restore wall thickness, reshape cones, and reconstruct benches/channels; integrate steps/ladder rehab per owner policies.

4) Corrosion protection and watertight lining

• Epoxy or polyurea/polyurethane build to specified thickness; chimney seals or grade‑ring encapsulation where required; frames reset or sealed.

5) QA/QC and documentation

• Thickness logs, holiday detection (as specified), visual acceptance with owner, photographs, and closeout package with warranties and maintenance guidance.

Municipal use‑cases and results

• Palm Beach County continuing rehabilitation program: Work Order No. 1 included approximately 63 manholes plus associated gravity mains and laterals, delivered under a multi‑site, multi‑basin scope—demonstrating our capacity to manage logistics, bypass, traffic control, and restoration at scale. Refer to Case Studies.

• Coastal Florida corrosion mitigation: Calcium‑aluminate and geopolymer rebuilds followed by chemical‑resistant linings in high‑H2S environments to extend asset life and reduce O&M. See Repair & Replacement.

• Urban neighborhoods with tight outages: Rapid‑set linings (e.g., OBIC) scheduled during low‑flow windows to eliminate chimney leaks and restore service before morning peaks. See Commercial.

• Storm recovery and emergency I&I control: 24/7 mobilization with 15‑minute callback for flood response, bypass pumping, and emergency coatings/leak stoppage to stabilize collection systems. See Maintenance – Emergency Services.

Why municipalities select Hinterland for manhole I&I rehab

• In‑house trenchless technologies (CIPP, geopolymer spincast, sliplining, pipe bursting) and electrical/bypass teams enable optimized, project‑specific methods without subcontractor markups. See Pipe Rehabilitation and Repair & Replacement.

• Proven safety culture with a full‑time OSHA‑certified Safety Manager and EMR under 0.87 supports predictable delivery and reduced risk. See About.

• Southeast coverage with headquarters in Riviera Beach, FL and a wetout facility in Morganton, NC supports 24‑hour mobilization across the region. See Home.

• PRIME lifecycle approach—Pipeline Rehabilitation, Repair & Replacement, Inspection, Maintenance, Evaluation & Assessment—backs capital work with preventive maintenance to preserve ROI.

Submittals and acceptance package (typical contents)

• OEM product data, SDS, and installation manuals for the specified system(s)

• Project‑specific surface prep plan, leak control plan, and cure/return‑to‑service plan

• ASTM F2551 compliance matrix and owner spec cross‑walk

• Inspector hold‑points, holiday testing protocol (if required), thickness measurement plan, mock‑up/adhesion test plan (if required)

• Crew qualifications, OEM training records/certifications, and safety plan

• Bypass pumping design and contingency procedures (performed in‑house)

• Final acceptance: inspection reports, photos, thickness/holiday logs, and warranty

Get a scope and price

For a rapid assessment, typical request‑for‑quote inputs include: manhole count and depths; materials (brick/concrete); groundwater conditions; frames/chimneys details; evidence of I&I; required standards (e.g., ASTM F2551); traffic and access constraints; and outage windows. Start a project conversation via Contact Us.