Sustainability is no longer optional in water and wastewater treatment — it is a procurement requirement, a regulatory obligation, and an operational cost driver. Reynolds & Bauhm designs treatment systems with whole-life environmental performance as a core engineering criterion.
Energy is the largest operating requirement in water treatment, typically 30–60% of total Operating expenditure. We specify fine-bubble aeration (SOTE >20%), high-efficiency pumps (η >75%), and variable-speed drives on all major motors. SCADA-controlled aeration with DO cascade loops typically saves 20–40% versus fixed-speed operation. See our energy efficiency guide.
Treated effluent is a resource, not a waste. MBR and RO polishing systems produce reuse-quality water for process use, cooling tower make-up, or irrigation. In food and beverage industries, water reuse at 70–85% is now achievable with the right treatment train. See our circular water economy guide.
Sludge contains nitrogen, phosphorus, and energy. Anaerobic digestion recovers 50–70% of chemical energy as biogas; struvite precipitation recovers phosphorus as a slow-release fertiliser; heat recovery from effluent streams reduces boiler fuel demand. See our anaerobic digestion and biosolids management pages.
Scope 1 emissions in water treatment come primarily from N&sub2;O (biological nitrous oxide — 265× GWP of CO&sub2;) and direct energy combustion. Scope 2 comes from grid electricity. Scope 3 includes chemical procurement and sludge transport. We conduct whole-life carbon assessments and design to minimise total Scope 1+2+3 impact, not just energy requirement.
| KPI | Industry Average | Best Practice | Technology Enabler |
|---|---|---|---|
| Specific energy (kWh/m³ treated) | 0.4–0.8 | 0.2–0.4 | Fine bubble aeration, VSD, optimised HRT |
| Water reuse rate (%) | 10–30 | 70–90 | MBR + RO polishing; closed-loop design |
| Sludge disposal requirement (/tonne DS) | – | – | Anaerobic digestion + thermal drying + land application |
| Chemical oxygen demand (kgO&sub2;/kg BOD removed) | 1.2–1.8 | 0.8–1.1 | Process optimisation; VFA recovery |
| Net energy balance (energy recovered/consumed) | <30% | 80–110% | Anaerobic digestion + CHP + solar PV |
Water treatment is increasingly subject to ESG scrutiny from investors, lenders, and customers. The following reporting frameworks reference water treatment performance:
Requires disclosure of water withdrawal, consumption, and discharge quality. Water reuse rate and effluent quality are directly reportable metrics from a well-instrumented treatment plant.
CDP requires disclosure of water risk management practices and treatment performance. Plants with water reuse and energy recovery are positioned as low-risk assets in CDP reporting.
Environmental management (14001) and energy management (50001) certification programmes benefit directly from documented treatment performance, energy monitoring, and continuous improvement of water and energy KPIs.
We align water treatment decarbonisation pathways with SBTi 1.5°C scenarios, helping clients set and achieve credible net-zero commitments validated by independent assessors.
Design principles and technology options for maximum water recovery in industrial applications.
Water Reuse GuideTechnologies and design approaches to minimise energy consumption in water and wastewater treatment.
Energy EfficiencyBiogas generation and resource recovery from sludge and food-industry wastewater.
Anaerobic DigestionLand application, composting, and thermal treatment routes for stabilised sludge.
BiosolidsOur engineers are available to discuss your specific application, site conditions, and project requirements.
Our expertise spans multiple industries with sector-specific water treatment solutions.