Fixed plant
Water and wastewater plant, with its history attached.
A treatment plant's knowledge is spread across the control system, the maintenance system, the manuals cupboard, the round sheet and the people who have been there longest. Mainte puts what each of them knows about a pump, a dosing line or a filter on that asset's record, beside its live condition.
Published 7 min read6 sources
Written for plant and operations managers · maintenance managers · process and reliability engineers
The problem: five places, no single picture
Ask why a recycle pump was rebuilt last year and the answer is in at least three places. The control system has the trend, if it has not been overwritten. The maintenance system has a work order saying the job was done. The reason, and what the operator noticed the week before, is in a log book or in someone's memory. The manual that says how the pump should be run is in a folder nobody opens at 2 am.
Usually: five places
- Control systemReadings and alarms, until the trend is overwritten.
- Maintenance systemWork orders, usually without the reason they were raised.
- Shared driveThe O&M manual and drawings, three folders deep.
- Log book or round sheetWhat the operator noticed, on paper.
- PeopleWhy it was changed in 2019, and what it does when the level is low.
In Mainte: one record
P-102
Recycle pump
- Live readings beside the engineers' own limits
- Every work order, with the reason it exists
- The manual, open at the page that applies
- Operator observations, in their words
- Technicians' notes and decisions, kept as written
The control system still runs the plant. Mainte reads; it cannot write back.
Each system is doing its job. What is missing is the picture across them: the alarm beside the work, the repeat failure beside the last repair, the operator's note beside the reading that confirms it.
What inquiries and prosecutions have found
Water and wastewater failures are investigated in public. Read for what was known beforehand, the same few things come up.
The earlier contamination was forgotten
Drinking-water supply, New Zealand · 2016 · Government inquiry 2017- The record
- An estimated 5,500 of a town's 14,000 residents became ill when its bore water was contaminated. The inquiry found the town had had a similar outbreak from the same bores in 1998, and that the lessons had been forgotten: 'Memory of the earlier outbreak simply faded.' It also found the water supplier 'did not properly manage the maintenance of plant equipment or keep records of that work'.[1]
- Our reading
- Source protection, treatment and regulation were the inquiry's centre, and no maintenance record replaces them. But the 1998 report and its recommendations were exactly the kind of history that should have been attached to those bores, open until done.
The same main, failing again
NSW council sewer rising main · 2023 · sentenced 2025- The record
- A sewage rising main failed and released about 1.83 million litres of untreated sewage into a creek. The court found the council had not properly maintained the main, and had failed to undertake preventative maintenance after a similar failure of the same rising main in 2020. The penalty totalled $418,562.[2]
- Our reading
- A second failure of the same asset is the pattern an asset-centred history shows most plainly. Whether to reline, renew or monitor is an engineering and funding decision. Seeing the first failure when making it is a records one.
Faults known, probes out of order
Sewage treatment works, England · 2016 · sentenced 2021- The record
- Effluent high in ammonia killed 1,144 fish. The court heard a failure to address equipment faults made the incident 'entirely foreseeable': aerators were not working, 'probes measuring the standard of the treatment process were also out of order', and 'alarms warning of problems were given a delayed response or none at all'.[3]
- Our reading
- Three known equipment faults, each with an owner somewhere, none adding up to a decision. Held as open defects on named assets, with their age, they are reviewable before the day they combine.
Fifty alarms in five hours
Sewage treatment works, England · 2016 · sentenced 2021- The record
- After a power failure stopped the pumps, 'almost 50 warning alarms were set off over the next 5 hours. Every one was left unchecked.' The regulator noted it was not the first time sewage had escaped at the works.[4]
- Our reading
- An alarm that nobody acts on is not information. That is one reason Mainte raises a condition once, on the asset, for a person to decide on, rather than adding to the alarm count. The alarms themselves stay in the control system.
What the guidelines already expect
The Australian Drinking Water Guidelines ask for a documented maintenance program covering all equipment from catchment to consumer, including the instruments that do the monitoring:
“operational procedures and records for the maintenance of equipment, including the calibration of monitoring equipment”
Most plants can produce those records. The question an auditor, a regulator or a new plant manager asks is harder: show me this analyser's calibration history, its faults and what was done about them, together.
How Mainte handles it
- One record per asset
- Each pump, dosing line, filter and instrument has one page: what it is, where it sits in the process, its open work, its history, its manuals and its certificates. Seen from Plant it shows what is happening; from Maintenance, what work it needs.
- Live condition, from your own instrumentsFixed plant connected through Mainte Edge
- Where the plant is connected through Mainte Edge, readings from the control system sit on the asset they belong to, in plain words: healthy, watch, action needed, no comms, awaiting data. Edge can only read, and it buffers through internet outages.
- Your engineers' limits, raised onceFixed plant connected through Mainte Edge
- A reading held past a limit your engineers set becomes one condition on the asset, not one alert per reading, and, where you have set it to, a request. A person triages it: raise a request or a work order, acknowledge and keep watching, mark it as an instrument problem, or dismiss it with a reason. The job that follows keeps its cause.
- Observations that show their numbersFixed plant connected through Mainte Edge
- Mainte compares equipment with its own plant: a pump performing below its twin, a process that has stalled while its pumps report running, two instruments measuring the same thing that no longer agree. Each observation carries the readings behind it, and a person decides what it means. There is no prediction involved.
- Outages without false alarmsFixed plant connected through Mainte Edge
- Readings buffered through an outage arrive with their original times. A limit breached while the site was offline is recorded when it happened but does not alarm hours late as if it were live; one still breached when the data returns is raised as live.
- A gap stays a gap
- An instrument that stops reporting is shown as no comms, with the time of its last reading. Nothing is held forward or filled in to make the plant look healthy, and impossible readings or mismatched units are flagged rather than trusted.
- The shift log and the morning reportFixed plant
- Operators keep handover notes, routine tasks and chemical dose changes by process area in the shift log, linked to the work they touch. A daily shift report goes out by email each morning; its summary keeps only sentences it can cite to the log.
- The manual, at the page
- O&M manuals, drawings and certificates are read and filed against the asset they describe, and anything uncertain is held back for a person. A work order shows the procedure that applies and points to its page.
- The plant overview, mimic and kioskFixed plant
- Process areas in the order they run, a mimic with live readings on the equipment, and a read-only panel in the plant room for operators who were never going to log in.
Northbank Water Recycling · Recycle train
P-102Recycle pump
Vib 9.4 mm/s
DOS-02Dosing pump
Flow 0.82 L/h
LT-301Feed tank level
Last read 41 min ago — nothing held forward
MF-FEEDMF feed pump
Run 1,214 h
FP-01Filter press
No commissioned limits yet
What it changes
- The plant's state and its maintenance backlog are in the same place. A supervisor can see which assets need attention and what work is already open on them, without asking three people.
- A repeat failure is visible before the next one. The second time a pump fails, the first failure, what was found and what was done about it are already on the asset.
- Evidence is assembled as the work happens. Calibration certificates, inspections and repairs sit on the instrument they belong to, ready for an auditor or a regulator rather than reconstructed for one.
- Less depends on the longest-serving operator. What they know about the plant goes onto the asset in their own words, where the next shift can read it.
Mainte reads more than 150 live equipment channels on fixed plant in daily use today, around the clock and through internet outages. More on how it connects in Mainte Fixed Plant, and on why one recurring fault deserves its own page in The fault that keeps coming back.
Sources
- [1]Report of the Havelock North Drinking Water Inquiry: Stage 1, part 1 overview · Government Inquiry into Havelock North Drinking Water, Department of Internal Affairs (NZ) · May 2017 · Government inquiry reportQuoted at paragraphs 1, 10(j) and 14.
- [2]Central Coast Council fined for spilling 1.8m litres of untreated sewage · NSW Environment Protection Authority · 9 January 2025 · Regulator media release on a Land and Environment Court sentence
- [3]Thames Water fined £2.3 million for foreseeable pollution · Environment Agency (UK) · 2 March 2021 · Regulator press release on a Crown Court sentence
- [4]Thames Water fined £4 million after catastrophic sewage blunder · Environment Agency (UK) · 27 May 2021 · Regulator press release on a Crown Court sentence
- [5]Australian Drinking Water Guidelines, Part 1, 3.4.4 Equipment capability and maintenance · National Health and Medical Research Council · Current edition · National guidelineGuidelines, not a legally enforceable standard; each state and territory decides how they apply.
- [6]Buncefield: Why did it happen? The underlying causes of the explosion and fire at the Buncefield oil storage depot · COMAH Competent Authority (HSE, Environment Agency, SEPA) · February 2011 · Major incident investigation reportQuoted at paragraph 99. Copy hosted by IChemE; the official HSE copy is in the UK National Archives.