Technical proposal for water & wastewater: WWTP, networks, drinking water

The Water Framework Directive requires achieving good status for all water bodies. In France, the LEMA (2006 Water Act) transposes these requirements. The proposal must demonstrate that proposed solutions align with the SDAGE and local SAGE objectives. The decree of July 21, 2015 sets minimum performance requirements for collective sanitation systems.

Discharge standards vary based on plant capacity and receiving environment sensitivity. In sensitive zones (nitrogen or phosphorus), treatment requirements are significantly strengthened: TKN < 15 mg/L, total phosphorus < 2 mg/L. The proposal must specify guaranteed treatment efficiencies for each parameter (BOD5, COD, TSS, TKN, TP) compared to applicable regulatory thresholds.

Self-monitoring is mandatory for any WWTP above 200 PE. The proposal must detail the proposed monitoring program: measurement points (inlet, outlet, bypass), analysis frequency, monitored parameters, continuous measurement equipment (flow meters, turbidimeters), and data transmission to the Water Agency and water authority.

This is the core of the proposal. Present the complete process: pre-treatment (screening, grit/grease removal), primary treatment if applicable, biological treatment (activated sludge, SBR, MBR, constructed wetlands depending on capacity), clarification, and tertiary treatment in sensitive zones (dephosphatation, denitrification). For each stage, detail sizing, retention times, volumetric loads and expected efficiencies.

Sludge management is a major scoring criterion. Detail the entire process: thickening, dewatering (centrifuge, filter press, belt filter), storage, and final destination (agricultural spreading, composting, incineration, drying). Provide sludge production estimates (kg DS/day) and predictive analyses (heavy metals, trace organic compounds).

In combined sewer systems, stormwater management is critical. The proposal must present: storm overflow sizing, storm tank design, reference flows (dry weather, wet weather), bypass strategy and overflow treatment devices.

For pipe installation, the proposal must comply with French Fascicule 70 and NF EN 1610. Detail: installation techniques (open trench, pipe jacking, microtunnelling), materials (concrete, PVC, HDPE, GRP, cast iron), acceptance tests (water tightness, air tightness, CCTV inspection), and connection management. For rehabilitation, specify techniques: CIPP lining, sliplining, resin spraying, spot repairs.

Drinking water contracts are governed by Fascicule 71 and NF EN 805. The proposal must cover: health compliance of materials (ACS certification), pressure testing, disinfection before commissioning, and live connection procedures. ARS approval for materials in contact with drinking water is a mandatory prerequisite.

CCTV inspection is often a prerequisite for rehabilitation works. Detail your equipment (pan-tilt cameras, multi-sensor robots), reporting capabilities (anomaly coding per EN 13508-2), and data processing software. Diagnostic quality determines the relevance of proposed works.