Installation and Construction Instructions for PP Modular Water Storage Tanks and Rainwater Harvesting Equipment

I. System Components
The rainwater harvesting system consists of a debris interception basket, a first-flush diversion device, a pre-treatment filtration unit, a PP modular storage tank, an HDPE anti-seepage system, a reuse pump group, disinfection and purification equipment, and a PLC intelligent control system, thereby realizing a “collection—purification—storage—reuse” closed-loop cycle.

II. Core Installation Process for PP Module Reservoirs

1. Excavation and Foundation: Excavate and provide shoring in accordance with design specifications; compact the subgrade; and lay a graded gravel cushion topped with a C15 concrete leveling layer to ensure proper flatness and load-bearing capacity.
2. Impermeable Protection: Install a “two-geotextile-one-geomembrane” lining system; perform double-track hot-wedge welding on the HDPE geomembrane; and conduct successful air-pressure testing to prevent leakage and root penetration.
3. Module Assembly: Assemble modules using a staggered-joint pattern and secure them with specialized interlocking clips; ensure stable structural ties between upper and lower layers; and reserve space for inspection wells and pump pits to guarantee uniform load distribution across the structure.
4. Piping Integration: Connect the inlet, outlet, overflow, and backwash pipes; ensure all connections are sealed tight; and install filtration screens and flow meters.
5. Layered Backfilling: Backfill the top 50 cm of the reservoir using medium-to-coarse sand, compacted in layers; strictly prohibit the use of sharp or hard objects during this process to protect the modules and the impermeable lining.
6. Equipment Installation and Commissioning: Install the pump assembly, water purification and disinfection units, and control cabinets; conduct water-filling and watertightness tests, as well as simulated rainfall commissioning, to ensure stable and reliable operation.

III. Key Points for Equipment Installation

• Diversion and Filtration: Implement upstream interception of impurities to reduce the operational load on downstream components.
• Reservoir: Ensure the impermeable lining passes inspection, the structural integrity is sound, and the ventilation and overflow systems are properly installed and functional.
• Water Reuse Equipment: Ensure reliable linkage and coordination between the pump assembly, disinfection units, and variable-frequency water supply system.
• Control System: Implement a fully automated control system that monitors water levels, flow rates, and fault alarms.

IV. Quality Assurance and Project Handover
Adhere strictly to “Sponge City” initiatives and rainwater utilization standards; ensure 100% pass rate for impermeable lining welding, zero leakage during watertightness testing, and compliance with compaction standards for backfilling; provide complete project completion documentation; and guarantee timely response for after-sales maintenance and support.