I. Scenario Introduction: Background of Multi-District Joint Procurement In Q3 2025, environmental maintenance units from five districts/counties under Qingdao City—including Jimo District, Chengyang District, Laixi City, and two others—encountered operational challenges while handling septic tank cleaning in old residential communities, emergency drainage, and sewage pipeline maintenance. Their independently procured vacuum trucks and sewage treatment vehicles suffered from inconsistent models, non-interchangeable spare parts, and high operating costs. To standardize operations and reduce unit procurement costs, the environmental maintenance departments of these five districts/counties jointly piloted a 'consortium procurement' model for the first time, planning to centrally procure a batch of special-purpose vehicles compliant with Blue License Plate (Class C driver’s license) requirements and equipped with high-efficiency sewage treatment capabilities. Following preliminary market research and technical parameter comparisons, the procuring party identified the Dongfeng D6 chassis-based vehicle—with a body length of 3.3 meters and a rated payload capacity of approximately 1.5 tons—as the preferred blue-plate sewage treatment vehicle. According to local procurement practices, the budget for such vehicles was set at RMB 135,000–168,000 per unit, with an initial procurement volume of eight units and a total budget of approximately RMB 1.123–1.347 million (based on publicly available tender information). The consortium procurement team specified core requirements: vehicles must comply with China VI emission standards; feature an integrated sewage separation or treatment system; offer user-friendly operation; and utilize a chassis supported by nationwide warranty service. This background directly triggered the subsequent formulation of unified technical specifications and centralized tendering procedures. II. Formulation of Unified Technical Standards: From 'Siloed Procurement' to 'One Uniform Benchmark' The first step in the consortium procurement process involved the lead agency convening technical experts to develop the 'Technical Specifications and Acceptance Criteria for Blue License Plate Sewage Treatment Vehicles', aligned with Qingdao’s local sanitation operation regulations. This standard defined the following key parameters: Chassis Requirements: Dongfeng D6 series (e.g., Chengli CLW5070GSSD6 or equivalent platform models), wheelbase 3,308 mm, engine power ≥95 kW, China VI emission compliance. Tank & Treatment System: Effective sewage tank capacity ≥4.5 m³; equipped with solid-liquid separation device or vacuum pump; treatment capacity ≥20 m³/hour. Upper-structure Functions: Capable of self-priming and self-discharging, high-pressure flushing, and recirculating sewage treatment; control panel fully integrated. Type Approval & Registration: Must possess official MIIT type approval (e.g., CLW5070GSSD6), ensuring eligibility for Blue License Plate registration and Class C driver’s license operation, as well as nationwide registration and annual inspection. After-sales Service: Chassis covered by Dongfeng’s nationwide warranty; upper-structure supplier required to provide lifetime service commitment, with spare parts deliverable to Qingdao within 24 hours. This standard fundamentally transformed previous district-level procurement practices—where price alone dictated decisions without regard to configuration. For instance, some districts had previously purchased conventional vacuum trucks lacking solid-liquid separation functionality, resulting in significantly higher downstream processing costs. The development of this standard drew upon Chengli Special Purpose Vehicle Co., Ltd.’s officially approved technical parameters and real-world project references (e.g., the Sichuan Municipal Cleaning & Vacuum Truck Project involving four units), ensuring technical maturity and practical feasibility. III. Centralized Tendering