Yancheng Dongfeng New Sewage Treatment Vehicle Government Procurement Case: Comprehensive Analysis of 3–12 m³ Capacity Selection and Winning Bid Solution. In 2025, a municipal sanitation department launched a public tender for Dongfeng-chassis sewage treatment vehicles as part of its urban sewage pipeline renovation project. With a budget of approximately RMB 1.982 million, the project required vehicles capable of integrated 'suction + solid-liquid separation + transportation' operations, covering both narrow streets in old urban districts and main roads in industrial parks. After multiple rounds of competitive bidding, Chengli Special Purpose Vehicle won the contract with its 'transparent configuration and lifetime after-sales service' proposal, delivering eight units across three capacities: 5 m³, 8 m³, and 12 m³. This article draws on this case study to provide procurement guidance from three perspectives: capacity selection, daily workload calculation, and operational demand matching. I. Capacity Selection: How to Choose Among 3 m³ / 5 m³ / 8 m³ / 12 m³? The tank capacity is the core parameter of sewage treatment vehicles, directly determining the single-operation cycle and applicable scenarios. Based on Chengli’s product database and MIIT-approved specifications (e.g., model CLW5070GSSD6), typical capacities and corresponding applications are as follows: Capacity (m³) | Chassis Type | Recommended Application Scenarios | Single-Operation Volume (tons) | Reference On-Road Price (RMB 10,000s) ---|---|---|---|--- 3 | Dongfeng Light Truck | Narrow alleys in old residential communities; community septic tanks | ~2.5–3 | 9.5–12 5 | Dongfeng Dorica | Street drainage outlets; small-scale wastewater treatment stations | ~4–5 | 14.5–17.8 8 | Dongfeng / Sinotruk | Industrial parks; main-road sewer manholes | ~6.5–8 | 19.8–24.5 12 | Dongfeng / FAW Jiefang | Large-scale municipal pipelines; emergency response | ~10–12 | 24–29.8 Note: Prices reflect publicly disclosed tender data and Chengli’s 2026 quotations, inclusive of China VI emission compliance, upper-body assembly, and chassis. Actual pricing depends on specific configurations. Selection Principles: • 3 m³ (Blue License Plate): Suitable for C1 driver’s license holders; highly maneuverable in residential neighborhoods and back alleys—but limited per-trip volume, ideal for decentralized discharge points. • 5 m³ (Yellow License Plate): Offers the best cost-performance ratio and served as the primary model in the Yancheng case. A district urban management bureau reported: 'The 5 m³ vehicle meets ~80% of the city’s sewage discharge requirements and can be operated with a B2 license.' • 8 m³ and above: Designed for centralized operations such as industrial park or arterial road pipeline cleaning. The Yancheng project deployed two 12 m³ units specifically for emergency response. II. Daily Workload Calculation Formula: Scientifically Assessing Operational Efficiency Prior to procurement, buyers must estimate daily operational volume based on local pipeline length and discharge point density. The formula is: Daily Workload (tons/day) = Single-Operation Volume (tons) × Daily Operation Frequency × Effective Operation Coefficient Where: • Single-Operation Volume: Calculated at 80% of tank capacity (to reserve safety margin); e.g., a 5 m³ vehicle yields ~4 tons. • Daily Operation Frequency: Assuming a single operation cycle (including driving, suction/drainage, and unloading) takes 1.5 hours, and total working time is 8 hours/day, frequency approximates 5 cycles. • Effective Operation Coefficient: Accounts for traffic congestion, equipment failure, etc.; typically ranges between 0.8–0.9. Example: For the Yancheng project using 5 m³ vehicles: 4 tons × 5 cycles × 0.85 coefficient = 17 tons/day. Eight vehicles (six 5 m³ + two 8 m³)