I. Background of Joint Procurement: Concentrated Surge in Sanitation Management Demand Across Multiple Districts and Counties From late 2023 to early 2024, five districts and counties (covering urban areas, development zones, and townships) under a certain province simultaneously launched procurement plans for sewage treatment vehicles. According to internal coordination minutes from local sanitation departments and publicly released tender information, this procurement initiative was driven by the following pain points: Low efficiency in sewage collection and transportation: Traditional vacuum tankers must frequently travel back and forth to fixed treatment stations, with limited operational radius per trip. In some remote townships, daily sewage volume reaches approximately 30–50 tons—insufficiently covered by only two aging vacuum tankers. Increased pressure to upgrade environmental emission standards: The province has uniformly implemented China VI emission standards; older vehicles face scrapping or costly retrofitting, prompting urgent demand for blue-license-plate models compliant with the new regulations (drivable with Class C driver’s license and unrestricted in urban areas). Centralized budget control requirements: Individual tenders conducted separately by each district or county led to significant price fluctuations and slow after-sales response due to fragmented procurement. Following coordination by the provincial sanitation authority, it was decided that the municipal bureau would take the lead in adopting a 'joint procurement, unified technical specifications, centralized tendering, and phased delivery' model—with total budget capped at approximately RMB 496,100. In accordance with local procurement practices, the Dongfeng D6 chassis (model CLW5070GSSD6, same platform) was ultimately selected as the base vehicle, with key parameters specified as follows: tank capacity of 3–4 m³, China VI emission compliance, blue license plate, drivable with Class C license, and vacuum pump suction depth ≥6 meters. II. Formulation of Unified Technical Specifications: Avoiding 'Hidden Traps' in Fragmented Procurement The core challenge of joint procurement lies in standardizing technical specifications. In previous procurements across districts and counties, issues such as 'inflated parameter claims' or 'downgraded configurations' frequently occurred—for example, one subdistrict procured a vacuum tanker advertised with a 'vacuum pump air extraction rate of 100 m³/h', yet actual performance during operation reached only 70 m³/h. This time, the municipal bureau led the effort, referencing Chengli Special Purpose Vehicle’s 'Technical White Paper for Blue-License-Plate Vacuum Tankers' and MIIT-approved parameters to establish six mandatory technical criteria: Technical Indicator | Standard Requirement | Source of Reference Chassis Brand & Model | Dongfeng D6, CLW5070GSSD6 Series | MIIT Announcement Emission Standard | China VI | National Uniform Standard Effective Tank Capacity | ≥3.5 m³ | Referenced from Chengli Product Database Vacuum Pump Suction Depth | ≥6 meters | Chengli Factory Test Report Maximum Air Extraction Rate | ≥80 m³/h | Chengli Announced Parameters Curb Weight (Vehicle Mass) | ≤2.8 tons (to comply with blue-license-plate weight limit) | Chengli CLW5070GSSD6 MIIT Announcement Additionally, practical features—including 'antifreeze level alarm' and 'tank corrosion-resistant coating'—were added to prevent wasteful investment in high-specification but functionally irrelevant features. These specifications were explicitly listed in the tender documents, and bidders were required to demonstrate at least three government procurement cases involving similar models. III. Centralized Tendering Process: From Tender Announcement to Contract Signing in Just 28 Days The joint procurement adopted an 'open tendering' approach, divided into four phases: Demand Consolidation (3 days): All districts and counties submitted demand fo