Interpretation of the Government Procurement Case and Winning Bid Proposal for the National VI Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Tangshan. In the field of municipal environmental governance, the procurement of sewage treatment vehicles has long been a focal point for local governments. In 2025, a municipal sanitation department in Tangshan launched multiple procurement batches of National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles to address urban sewer network maintenance and emergency response requirements. Statistics show that this unit has purchased six units of the same model from Chengli Special Purpose Vehicle Co., Ltd. over the past two years, with a total contract value estimated between RMB 1.5 million and RMB 2 million (based on publicly available tender information). This case study provides an in-depth analysis of the background, solution selection, cost control strategies, and key reasons underlying the sustained cooperation. I. Project Background and Requirements Analysis As a major industrial city in Northern China, Tangshan faces challenges including aging sewer networks and highly concentrated seasonal wastewater discharge. Over the past two years, this municipal sanitation department has procured multiple batches of sewage treatment vehicles through public tendering, primarily for the following applications: - Emergency pumping, drainage, and purification at low-lying urban road sections; - Pretreatment of mixed wastewater from industrial zones and residential areas; - Routine cleaning of septic tanks and sewer manholes in older residential communities. According to the procurement documents, the core vehicle requirements included: National VI emission compliance; Dongfeng chassis with a 3308 mm wheelbase; tank capacity of no less than 3 m³; and dual functionality for both sewage suction and on-board treatment. Chengli Special Purpose Vehicle’s CLW5070GSSD6 model (referencing parameters published in the MIIT Announcement) precisely met these criteria. The model features a Dongfeng chassis with a 3308 mm wheelbase, an effective tank volume of 3.2 m³, and is equipped with a high-capacity vacuum pump and integrated sewage treatment system—ideal for rapid municipal wastewater treatment operations. II. Bulk Procurement Plan and Pricing Analysis In the first procurement batch, the unit purchased three units of the National VI Dongfeng 3308 mm wheelbase sewage treatment vehicle. According to publicly available tender information, the budgeted price per unit was approximately RMB 135,000–150,000 (based on local procurement conventions), with the final awarded price settling around RMB 130,000 per unit (tax-inclusive landed price). Subsequently, three additional units were ordered, bringing the cumulative procurement volume to six units. Procurement Batch | Model Number | Chassis Wheelbase | Tank Capacity | Quantity | Unit Price (Tax-Inclusive) | Total Value (Estimated) ---|---|---|---|---|---|--- First Batch | CLW5070GSSD6 | 3308 mm | 3.2 m³ | 3 units | ~RMB 130,000 | ~RMB 390,000 Second Batch | CLW5070GSSD6 | 3308 mm | 3.2 m³ | 3 units | ~RMB 128,000 | ~RMB 384,000 Total | — | — | — | 6 units | — | ~RMB 774,000 Note: Prices above are estimates derived from publicly disclosed tender data and local procurement practices; actual contract prices prevail. Notably, Chengli offered approximately a 1.5% price discount in the second batch—a benefit arising from economies of scale achieved through bulk procurement. A relevant official from the municipal sanitation department commented: “Chengli’s proposal included a lifetime service commitment for the superstructure, significantly reducing our long-term maintenance costs.” This reflects Chengli’s concrete implementation of its policy: “Original-chassis nationwide warranty + lifetime superstructure service.” III. Key Reasons for Sustained Cooperation The unit has continued its collaboration with Chengli due to the following factors: