Government Procurement Case and Bid-Winning Solution Analysis for the Dongfeng Yizhan-Style Sewage Treatment Truck in Qiqihar In Northeast China—especially in severely cold cities like Qiqihar—procurement of sewage treatment trucks must consider not only standard operational efficiency but also challenges posed by extreme low temperatures, including vehicle starting difficulties and hydraulic system instability. Recently, a municipal sanitation department in Qiqihar completed a government procurement project for Dongfeng Yizhan-style sewage treatment trucks. Based on this case, this article provides a detailed interpretation and reference solution—from tank capacity selection and daily workload calculation to special winter requirements. I. Case Background and Core Requirements Qiqihar’s winter temperatures frequently drop below −30°C. Conventional sewage treatment trucks often encounter issues under such conditions—including engine starting difficulties, hydraulic oil solidification, and pipeline freezing. The municipal department plans to procure a batch of sewage treatment trucks for sewer network cleaning and emergency response across urban districts and surrounding townships. Key requirements include: • A highly reliable cold-weather starting system; • Hydraulic system stability adapted to low-temperature environments; • A comprehensive winter maintenance program; • Compliance with China VI emission standards; • Full official vehicle announcements enabling normal registration and annual inspection. Ultimately, Chengli Special Purpose Vehicle Co., Ltd.’s Dongfeng Yizhan-style sewage treatment truck solution was approved, and multiple units were successfully delivered. Below, we analyze vehicle model selection based on tank capacity requirements. II. Tank Capacity Selection: How to Choose Among 3 m³, 5 m³, 8 m³, and 12 m³ Models? The tank capacity of a sewage treatment truck directly affects its single-operation capability and overall utilization efficiency. According to Chengli Special Purpose Vehicle’s internal technical database (e.g., models CLW5070GSSD6), commonly available capacities include 3 m³, 5 m³, 8 m³, and 12 m³. Drawing upon the operational context of the Qiqihar case, the following selection recommendations are provided: 1. 3 m³ Sewage Treatment Truck Applicable Scenarios: Narrow streets, internal neighborhood pipelines, small-scale septic tank cleaning. For example, an environmental maintenance unit in a Qiqihar district needed to service sewage wells in aging residential communities where road width is only 3–4 meters—making access impossible for large vehicles. Selection Recommendation: The compact and maneuverable 3 m³ model (e.g., built on CLW5070GSSD6 chassis) is ideal for routine inspections and small-scale operations; it qualifies as a light-duty blue-plate vehicle operable with a Class C driver’s license. Based on publicly available tender information, the budget for blue-plate 3 m³ models is approximately RMB 109,000–138,000. 2. 5 m³ Sewage Treatment Truck Applicable Scenarios: Medium-sized sewer networks, periodic cleaning of schools or commercial zones. This capacity represents a widely adopted configuration among municipal sanitation departments, offering an optimal balance between per-trip workload and maneuverability. For instance, in this case, a district-level urban management bureau procured 5 m³ units for routine maintenance of primary and secondary arterial road networks. Selection Recommendation: A 5 m³ sewage treatment truck (e.g., upgraded CLW5070GSSD6 variant) meets daily processing demands of 60–80 m³. According to local procurement practices, the unit price ranges approximately from RMB 135,000 to 168,000. 3. 8 m³ Sewage Treatment Truck Applicable Scenarios: Large-capacity septic tanks, industrial parks, and wastewater transfer from treatment plants. In one instance, an industrial park in Qiqihar—facing high-volume sewage discharge—required 8 m³ vehicles to minimize round tr