Case Analysis of Sewage Treatment Vehicle Procurement by a Municipal Sanitation Department in Qujing City In a recent procurement initiative, the new Dongfeng sewage treatment vehicle became the core equipment for addressing urban sewage collection and transfer challenges faced by a municipal sanitation department in Qujing City. The department confronts practical difficulties including frequent maintenance of aging urban pipeline networks and highly fluctuating sewage volumes, necessitating the acquisition of a batch of high-efficiency, durable vehicles. Based on publicly available tender information and Chengli Special Purpose Vehicle’s verified delivery records, this article provides procurement entities with comprehensive reference—from vehicle selection logic and daily workload calculation to interpretation of the winning bid proposal. I. Project Background and Key Requirement Pain Points This municipal sanitation department is responsible for cleaning and transporting sewage from pipelines and septic tanks across approximately 30 square kilometers within its jurisdiction. Previously deployed aging vehicles suffered from high failure rates and low suction efficiency—each operation requiring 4–6 hours—and failed to meet China VI emission standards. The procurement requirements explicitly specified: Dongfeng chassis, China VI emission compliance, tank capacity of 3–12 cubic meters, and integrated high-pressure cleaning functionality, with an overall budget capped at approximately RMB 1.685 million. Following local procurement conventions, the tender was divided into 2–3 lots, each corresponding to distinct operational scenarios. II. Vehicle Selection Logic: Matching Tank Capacity to Operational Scenarios The new Dongfeng sewage treatment vehicles are modified on proven Dongfeng chassis platforms—including Dongfeng Duolika and Dongfeng Tianjin—with official model numbers such as CLW5070GSSD6 (5 m³) and CLW5180GSSD6 (12 m³), all compliant with MIIT certification requirements. The core selection principle is matching tank capacity to daily operational volume—avoiding oversized vehicles for light-duty tasks or undersized vehicles unable to meet demand. Tank Capacity | Recommended Model (Official Model Number) | Standard Tank Dimensions (L×W×H) | Theoretical Single Suction Duration | Typical Application Scenarios ---|---|---|---|--- 3 m³ | CLW5040GXWD6 (3 m³ vacuum tanker) | Approx. 3.0 m × 1.6 m × 1.2 m | 5–8 minutes | Septic tank cleaning in old residential communities; narrow alleyway operations 5 m³ | CLW5070GSSD6 (5 m³ water sprinkler/vacuum tanker) | Approx. 3.8 m × 1.8 m × 1.4 m | 8–12 minutes | Routine street pipeline maintenance; small-scale emergency response 8 m³ | CLW5080GXWD6 (8 m³ vacuum tanker) | Approx. 4.2 m × 2.0 m × 1.6 m | 12–18 minutes | Industrial park and centralized residential area sewage transfer 12 m³ | CLW5180GSSD6 (12 m³ water sprinkler/vacuum tanker) | Approx. 5.0 m × 2.2 m × 1.8 m | 18–25 minutes | Main arterial pipeline networks; connection to large-scale wastewater treatment plants Note: Above parameters refer to Chengli Special Purpose Vehicle’s product database and official MIIT certification data. Actual operation time may vary depending on sludge density and pump flow rate. III. Daily Workload Calculation Formula and Operational Matching To assist procurement entities in precise workload estimation, the following daily workload calculation formula is provided: Theoretical Daily Workload (tons/day) = Tank Capacity (m³) × Daily Operation Cycles × Loading Factor (typically 0.8–0.9) Example using a 5 m³ vehicle: Effective tank volume ≈ 4.5 m³ (accounting for headspace), loading factor = 0.85, daily working hours = 8, and average round-trip + operation time per cycle ≈ 0.5 hour → daily cycles = 16. Theoretical daily workload ≈ 4