A UK water utility needed tertiary phosphorus removal at an existing works, to a discharge limit, where a conventional build was not the right fit. The answer was designed as a containerised plant: process, equipment, power and controls in one transportable unit, with the discharge obligation written into the design basis and every drawing and document held in a register with a revision log. The client, the site and the programme are not named, no figure is quoted, and the pack makes no claim that the plant was built: what can be shown is the shape of the engineering.
01
The brief
Phosphorus removal where a conventional build was not the right fit.
- Client — a UK water utility; not named.
- Need — tertiary removal of phosphorus and suspended solids at an existing works, to a discharge limit.
- Constraint — limited space and time on site, which pointed to a plant inside a single shipping container.
02
The plant
A containerised unit, designed as a whole.
- Process — coagulation, self-washing prefiltration and ultrafiltration membranes as the polishing step, inside one high-cube shipping container.
- Power and control — a motor control centre, a PLC with an operator HMI, and a Modbus register map for the dosing and power units.
- Layout — the general arrangement and a 3D model, so the equipment, the access and the maintenance space were checked before anything was priced.
03
The design pack
What the client received, document by document.
- Process — the P&ID set and the process description.
- Electrical — the MCC schedule, with the single-line diagram behind it.
- Controls — the control philosophy (functional design specification), the Modbus register map and the HMI screens.
- Safety — the HAZOP worksheet, drafted for the human HAZOP team to run.
- Operations — the O&M manual skeleton and the commissioning plan.
- Commercial — the bill of quantities and the OPEX estimate.
04
The method
How a pack like this is produced, and what it does not claim.
- Sequence — requirements sheet, process selection, P&ID, control philosophy, register map, HMI prototype, HAZOP worksheet, then O&M, BoQ and OPEX.
- Checks — tags on the P&ID were cross-checked against the Modbus map and the MCC schedule before review.
- Document control — a document register and a revision log on every drawing and document.
- Review — drafted with the division's document pipeline and reviewed by an engineer before release; handed over for engineer-of-record review and adoption.
- Status — a design pack, produced for the client's review. It makes no claim that the plant was built or put into service.
05
What it led to
The template for the Design-Pack Factory.
- Template — the pack's structure is the requirements sheet and section list the Design-Pack Factory drafts from, now in development.
- Method — the same cross-checks, register and review run on every pack the factory produces.