A structured process-design package covering design conditions, load cases, calculations, process flow diagrams, equipment requirements, controls, monitoring and review criteria. It gives the client, consultant, EPC and suppliers one technical basis for detailed engineering and procurement.
The Process Design Pack formalizes the selected treatment or reuse route into a project-specific process basis. It brings together the design conditions, calculations, diagrams, equipment requirements, control requirements and performance checks needed for coordinated detailed engineering and procurement.
It can be prepared for a new plant, retrofit, expansion, recovery system or specific process package. Where professional stamping or multidisciplinary detailed design is required, the appointed engineer, consultant or EPC develops that work from the Process Design Pack. Coordination support can be included through a separate assignment where required.
Design conditions, load cases, mass balance, sizing basis, process flow diagrams, equipment requirements, control requirements and review criteria are developed as one connected package.
The pack gives consultants, EPCs, OEMs and suppliers a common basis for detailed design, specification, pricing and technical evaluation.
Operating ranges, sampling points, monitoring needs, test conditions and acceptance criteria are established before procurement and detailed design are finalized.
The content is adjusted to the wastewater or feed water, receiving duty, existing assets, utilities, site constraints, residuals route and responsibilities applicable to the assignment.
Work can begin once the required duty and process direction are sufficiently established. Available information may still contain assumptions or gaps that require confirmation during the assignment. Where the principal route or a major technical decision remains open, a Technical Study should be completed first.
How the Process Design Pack is applied
The pack is configured around the actual project rather than a predefined product or standard design. The examples below show common applications and the choices that can be set with the client. Site and stream conditions inform the design, while EnWater can confirm an existing preference, compare alternatives or develop the required response where a choice remains open.
Process design for municipal, institutional and decentralised sewage treatment.
Process: The route may include preliminary treatment, equalisation, biological treatment, separation, polishing, disinfection and sludge handling, selected for the actual wastewater and outlet duty.
Application: New plants, expansions and upgrades where the flow and load basis, population or occupancy profile, and receiving requirements must be established.
Design focus: Influent and load cases, treatment route, reuse or discharge requirements, sludge route, equipment requirements, controls and performance checks.
Core outputs: Mass balance, sizing calculations, process flow diagrams, equipment schedule, control requirements and test criteria.
Set the reuse focus, effluent-quality requirement and level of automation and monitoring early.
Process design for capacity, compliance and reliability upgrades of existing STPs.
Process: Existing tanks and equipment are assessed against current flows, loads, hydraulics and performance. The design defines what can be retained, modified, bypassed or replaced.
Application: Operating STPs with capacity, compliance, odor, sludge or reliability problems, including upgrades within constrained existing sites.
Design focus: Existing asset performance and suitability, bottlenecks, operating-continuity requirements, new process duties, connections to existing systems and upgrade constraints.
Core outputs: Existing-system review, retrofit mass balance, modified process route, equipment requirements, connection schedule and performance criteria.
Clarify civil and space reuse, the required performance uplift and the depth of the upgrade before the design is fixed.
Process design for industrial wastewater treatment, reuse and discharge duties.
Process: Stream segregation, equalisation, physico-chemical and biological treatment, polishing and residuals handling are defined from actual wastewater characteristics and production conditions.
Application: Food and beverage, metal finishing, chemical, pharmaceutical, textile and mixed industrial effluents where the treatment route depends on production and outlet duty.
Design focus: Stream characterisation, variability, treatability, production schedule, outlet requirements, residuals, utilities and operating model.
Core outputs: Design basis, mass balance, process route, sizing calculations, equipment schedule, monitoring requirements and acceptance criteria.
Balance compliance risk, reuse or ZLD ambition and the level of automation and monitoring from the start.
Process design for debottlenecking and upgrading operating industrial ETPs.
Process: Existing process units, hydraulics, operating data and production changes are reviewed to locate limiting conditions and define the upgrade route.
Application: Operating ETPs affected by capacity growth, changing product mix, variable effluent, new reuse targets or recurring non-compliance.
Design focus: Bottlenecks, segregation opportunities, retained assets, new equipment duties, connections to existing systems, operating continuity and risk controls.
Core outputs: Retrofit basis, updated mass balance, process modifications, equipment requirements, connection requirements and performance verification plan.
Align existing-asset reuse, compliance-risk reduction and production integration before the retrofit scope is fixed.
Process design for concentrate management and defined high-recovery or ZLD requirements.
Process: The full route is developed from feed and concentrate sources through pretreatment, membrane recovery, evaporation, crystallisation or other concentration steps, solids handling and final outlet.
Application: Sites where discharge or external disposal of concentrate is not acceptable, or where a defined high-recovery or ZLD requirement applies.
Design focus: Scaling and fouling risk, water recovery, energy and heat integration, concentrate composition, solids handling, operating range and final outlet.
Core outputs: Water and salt balance, pretreatment and recovery basis, thermal duties, solids route, equipment schedule and performance criteria.
Set brine complexity, the balance between recovery and robustness, and the heat and energy strategy upfront.
Process design for intermittent and variable chemical-treatment duties.
Process: Batch equalisation, pH adjustment, coagulation, flocculation, reaction and solids separation are defined for variable or intermittent streams.
Application: Campaign, cleaning, metal-bearing or mixed streams where batch control is more reliable than continuous treatment.
Design focus: Batch volume and frequency, chemistry and treatability, dosing sequence, reaction time, solids separation, filtrate destination and operator controls.
Core outputs: Batch design basis, tank and mixer sizing, dosing requirements, operating sequence, solids and filtrate routes, and test criteria.
Tune batch chemistry, operating mode and filtrate or brine use upfront.
Process design for UF, MF and RO systems serving defined reuse or recovery duties.
UF, MF, RO and associated pretreatment and polishing are configured from feed-water quality, receiving duty, recovery target and concentrate route.
The design addresses fouling and scaling risk, pretreatment, flux and recovery ranges, cleaning strategy, redundancy, monitoring, product-water quality and concentrate handling.
Core outputs: Membrane process basis, recovery and concentrate balance, pretreatment requirements, equipment duties, control requirements and acceptance criteria.
Set the reuse priority, account for feed complexity and establish the target recovery.
Process design for non-potable reuse in buildings, campuses and community developments.
Collection, equalisation, treatment, filtration, disinfection, storage and distribution requirements are coordinated around actual source segregation and demand.
The design considers source flows, occupancy, demand profile, storage, peak factors, water quality, residuals, odor risk, footprint and connections to building systems.
Core outputs: Water balance, process design basis, storage and hydraulic requirements, equipment schedule, control requirements and reuse acceptance criteria.
Define the building profile, reuse mix and footprint or integration constraints.
Process design for commercial, fleet and equipment-wash water reuse.
Collection, grit and oil separation, equalisation, physico-chemical treatment, filtration, disinfection, make-up and blowdown are defined from the wash operation.
The design considers bay use, wash chemistry, soiling, oil and suspended solids, water balance, storage, reuse quality, sludge and operator requirements.
Core outputs: Wash-water balance, process design basis, equipment duties, reuse and discharge requirements, residuals route and performance criteria.
Set the bay-utilisation range, soiling and oil risk, and the intended reuse target.
A coordinated process design pack for projects that combine several water, wastewater or residuals duties.
One design basis is developed where treatment, reuse, sludge, brine, heat or utility systems need to be considered together.
The design addresses stream segregation, dependencies, package boundaries, utilities, controls, residuals, operating continuity and project responsibilities.
Core outputs: Integrated mass balance, process configurations, equipment duties, connection requirements, control intent, review criteria and package-responsibility basis.
Start from the sector focus, constraint intensity and decision horizon.
The Process Design Pack sets the process requirements used by the teams that detail, supply and deliver the project. The client retains control of appointments and responsibilities. EnWater develops the process basis; the consultant, engineer of record or EPC completes the multidisciplinary detailed design; and OEMs and suppliers develop their package details against the specified duties.
We define the process route, design criteria, equipment duties, control requirements and performance basis. We issue the agreed pack and address process-design clarifications included in the assignment. Separate connected assignments can continue from the same basis where required.
The appointed team develops the detailed P&IDs, civil and structural works, MEP and electrical design, layouts, connections, construction documents and professional stamping where required. The Process Design Pack provides the process requirements and review basis for that work.
Package providers select and design their equipment and packages, then submit datasheets, skids, panels, guarantees and supporting documents against the specified duties. Deviations and alternatives are identified for review through the agreed project process.
The Process Design Pack does not replace multidisciplinary detailed design, professional stamping, supplier package design, construction documentation or project execution. Those responsibilities remain with the appointed parties. Separate sourcing and implementation assignments are available where required. Review Sourcing Advisory .
These cards describe the process-design work undertaken before detailed engineering. They cover the review, decisions and coordination completed during the assignment; the documents issued from that work are listed separately below.
Available drawings, analyses, operating records and project requirements are checked against the required duty. Confirmed inputs, assumptions, data gaps and verification actions are agreed before calculations and equipment duties are finalised.
The treatment route, stream connections, recycles, bypasses and residuals path are developed for normal, peak, low-flow, start-up and upset conditions. Open design-stage choices are resolved and the response of the complete process is checked.
Major process units and packaged systems are coordinated with existing assets, utilities, site constraints and adjoining disciplines. Equipment duties, package limits, standby philosophy and supplier responsibilities are established for detailed design and procurement.
The intended operating modes, staffing assumptions, sequencing, start-up, shutdown, interlocks, alarms, safeguards and monitoring approach are developed at process-design level. The limits of the detailed automation, panel and electrical work are also defined.
Performance criteria, sampling points, test conditions, commissioning checks and acceptance requirements are agreed before procurement. The required evidence is defined so proposals, installation and early operation can be checked against one basis.
Connections, utility dependencies, package boundaries, review points and responsibilities are coordinated with the client and appointed project parties. This establishes what each party must detail, supply, connect, review and verify.
The issued pack converts this work into a defined set of process-design documents. The exact document set and design depth depend on the project and the agreed assignment.
Sets out the confirmed inputs, assumptions, selected route, design cases, project limits, performance requirements and decisions that govern the process design.
Includes the applicable water, solids and chemical balances, unit-sizing calculations, hydraulic checks and utility duties for the agreed design depth.
Includes process flow diagrams and, where required, the hydraulic profile or hydraulic basis, showing main streams, recycles, bypasses, residuals routes and key connections.
Lists equipment duties, capacities, operating ranges, standby requirements, materials, utilities and connections, together with process datasheet requirements for supplier responses and detailed design.
Documents the required operating sequences, control loops, safeguards, alarms, monitoring points and sampling points for development by the automation and electrical teams.
Sets out the design review points, test conditions, commissioning checks, acceptance criteria, evidence requirements and operating records expected before handover.
The Process Design Pack can be commissioned on its own or linked to separate support during sourcing and implementation. The appointment defines the available project information, design depth, review points and responsibilities. Detailed engineering, supply and construction remain with the appointed project parties.
We develop and issue the agreed document set, present the basis to the client and appointed teams, and provide the process-design clarification included in the handover scope.
Separate Sourcing Advisory or Implementation & Applied Support assignments can use the same basis for procurement requirements, proposal comparison, process-related submittal review, change assessment, commissioning checks and performance evidence.
Data sources, reliability, assumptions, missing information, verification actions and approval status are recorded as the design develops.
Design decisions, supplier alternatives and project changes are assessed against the agreed requirements. Technical consequences, approvals and any resulting updates are recorded.
Document status, review comments, approved deviations, outstanding actions and issue history are consolidated so the process basis remains traceable through detailed engineering, procurement and commissioning.
The next step depends on how the project is being delivered. The pack can be handed directly to the appointed detailed-design and procurement teams or used through separate support assignments.
Any EnWater involvement after issue is agreed separately and does not alter the responsibilities of the appointed detailed-design, supply and construction parties.
