Responsive, quality service helps keep communities safe and ensure peace of mind
Operating nationwide with localized service, National Underground Group provides comprehensive solutions for underground infrastructure with utilities, municipalities, contractors and engineering firms. We are headquartered in Irvine, California, and serve customers throughout the U.S.
National Underground Group Headquarters 47 Discovery, Suite 250 Irvine, CA 92618 949-380-4161 Accumark Headquarters Benchmark Headquarters Tri-State Utilities Headquarters MARYLAND |
NORTH CAROLINA Accumark 1125 Corporation Parkway, Suite 161 Raleigh, NC 27610 800-542-2290 Tri-State Utilities OHIO VIRGINIA Accumark |
Service Lines

Tri-State Utilities
Tri-State Utilities provides turnkey pipeline rehabilitation solutions and utilizes industry-leading trenchless pipe lining technologies, including the cured-in-place-pipe (CIPP) lining method, on sanitary sewers and storm drains. Customers trust Tri-State Utilities for its in-depth expertise, local knowledge, faster response time, quality assurance and cost-efficiency.
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Accumark
Accumark provides locating services for a complete Subsurface Utility Engineering field services solution. Also offering subsurface utility designation, mapping and locating services, Accumark is recognized for its safety-first focus and outstanding customer service as well as accuracy and timeliness that lead to cost savings and damage prevention.
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Benchmark
Benchmark delivers damage prevention solutions, provides underground locating services through established 811 on-call contracts and also offers private utility-locating services. Its differentiated Single Source Damage Prevention Program delivers industry-leading accuracy ratios, on-time ticket responses and exceptional customer service. Its Single Source locating model means the company locates for one customer within a given group of locators and supervisors. By not layering multiple utilities and customers on top of each other, Benchmark is able to offer customers a professional service with quality locating, on time.
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Tri-State Utilities
Tri-State Utilities provides turnkey pipeline rehabilitation solutions and utilizes industry-leading trenchless pipe lining technologies, including the cured-in-place-pipe (CIPP) lining method, on sanitary sewers and storm drains. Customers trust Tri-State Utilities for its in-depth expertise, local knowledge, faster response time, quality assurance and cost-efficiency.
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Accumark
Accumark provides locating services for a complete Subsurface Utility Engineering field services solution. Also offering subsurface utility designation, mapping and locating services, Accumark is recognized for its safety-first focus and outstanding customer service as well as accuracy and timeliness that lead to cost savings and damage prevention.
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Benchmark
Benchmark delivers damage prevention solutions, provides underground locating services through established 811 on-call contracts and also offers private utility-locating services. Its differentiated Single Source Damage Prevention Program delivers industry-leading accuracy ratios, on-time ticket responses and exceptional customer service. Its Single Source locating model means the company locates for one customer within a given group of locators and supervisors. By not layering multiple utilities and customers on top of each other, Benchmark is able to offer customers a professional service with quality locating, on time.
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