The contractor’s perspective. Before bid day.
Independent cost opinions, bid-readiness, and constructability reviews for municipal and industrial water and wastewater infrastructure across the Upper Midwest.
Independent, contractor-informed project support
GX3 Limited provides experienced judgment where it matters most, delivering practical insights across every stage of water and wastewater project planning and procurement.
Cost opinions & benchmarking
Conceptual and facility-plan OPCs, quantity audits, material allowances, and installed-price reality checks rooted in real market conditions.
Bidability & constructability
Detailed 90–95% plan and specification reviews evaluating equipment sequencing, access routes, discipline interfaces, and scope conflicts.
Scope & procurement clarity
Refining bid schedules, evaluate alternates, define clear contract interfaces, and establish pre-bid risk registers to protect budgets.
Post-bid market calibration
Compare pre-bid estimates against actual market bid outcomes to analyze competitive dynamics and carry lessons forward.
Senior expertise. Direct access.
Led by Gregg Schreiner, GX3 Limited brings 40 years of direct general contractor experience in water and wastewater estimating, field sequencing, and project management. We complement, but do not replace, the Engineer of Record—providing owners and design engineers with the practical operational insight required to build with confidence.
Built on real project experience
From the $120M multi-phase facility program in Le Mars, Iowa, and continuous-operation biological aeration upgrades in Northfield, Minnesota, to fast-tracked design-build projects in Lake Norden, South Dakota—our advice is backed by decades of actual construction delivery.
"GX3's estimate for the Howard Lake WTP was within 4% of the responsive bid average—predicting our $18.3M market spread with remarkable accuracy."
Market bid benchmark
Howard Lake WTP
"Having a seasoned general contractor's perspective during the 90% review phase identified critical sequencing conflicts before they became costly change orders."
Municipal treatment facility
Upper Midwest program
"Gregg's practical insight into equipment procurement, crane access, and live facility staging kept our complex industrial upgrade on schedule."
Industrial wastewater program
Food & dairy processing sector
Start with one focused review
Whether you require an early scope check, a 90% constructability review, or bid schedule clarity, GX3 Limited delivers clear, decision-ready findings to safeguard your project budget and schedule.
Get in touch
GX3 Limited
Greenfield, Minnesota
Gregg Schreiner, President
Phone: 612-616-9506
Email: gregg.schreiner@gmail.com