Water Hygiene Tender Specification: What to Include
A good water hygiene tender specification tells bidders exactly which systems they are taking on, which HSE standards apply, what must be done and how often, how performance will be measured and how the first weeks of the contract will run. Vague wording gets you vague prices. A specification built around your own risk assessments gets you quotes you can compare line by line, and a contractor who can start work safely.
This guide is for facilities managers, estate managers and compliance managers in England who are writing or reviewing a tender for Legionella and water hygiene services across one site or many. It covers the contents of the specification, how to word scope and remedial work, the service levels and reports to demand, what a mobilisation plan should contain, and how to check that the contractor is meeting the terms.
TL;DR
Build the specification around your current Legionella risk assessments and the written scheme, and cite HSE L8 and HSG274 as the standard the contractor must meet.
List every site, system and asset, with the checks, frequencies and remedial items expressed line by line, so bidders price the same thing.
Write measurable KPIs and reporting duties into the tender, with named responsibilities on both sides.
Require a mobilisation plan with a site walkover, baseline checks, competence evidence and a dated first-visit programme.
Hiring a contractor does not transfer your legal duty, so plan how you will check the work from week one.
Table of Contents
Start with the legal duty the contract supports
The specification exists to help the dutyholder meet their legal duty, so open by saying so. HSE’s approved code of practice L8 sets out the arrangement: identify and assess the risk, prepare a written scheme to prevent or control it, implement and monitor the precautions, keep records, and appoint a competent person to take managerial responsibility.
The technical guidance, HSG274 Part 2, ties those duties to the Health and Safety at Work etc Act 1974, the COSHH Regulations 2002 and the Management of Health and Safety at Work Regulations 1999. Your tender should name these documents as the standard of performance. A short clause is enough: all work must follow current HSE guidance, and where the contractor believes a requirement is unnecessary, it must say so in writing rather than quietly leave it out of the price.
One point belongs in the introduction to the tender itself. HSE says dutyholders should make reasonable enquiries about a contractor’s competence and make sure control procedures are carried out to the required standard. Employing a contractor does not remove your responsibility. The tender should therefore ask for evidence, not assurances. If you are unsure who holds the duty in your organisation, our note on the responsible person for Legionella explains what duty holders must do.
What the specification must contain
A working structure, in the order bidders will want to read it:
Background and objectives. Who you are, what the sites are used for, who occupies them, and the outcome you want: systems controlled in line with HSG274, with records that stand up to inspection.
Scope and asset register. Sites, buildings, systems and counts of assets.
Standards and legal references. L8, HSG274 Parts 1 to 3, and any sector rules you work under.
Services required. Risk assessment and review, monitoring, sampling, cleaning and disinfection, remedial work, training, records.
Service levels and KPIs.
Reporting and data.
Competence, accreditation and insurance requirements.
Mobilisation and transition.
Contract management and review.
Pricing schedule and evaluation criteria.
The sections below take the ones that cause most disputes later.
Defining scope: sites, systems and risk
The commonest weakness in tenders is a scope that says “all sites” and nothing more. Bidders then price their own assumptions, and the cheapest is often the one that assumed least.
Give each site a row in the asset register. Include:
hot and cold water systems, calorifiers, cold water storage tanks and any recirculating loops;
outlets by count and type: taps, showers, little-used outlets, and any with aerosol potential;
thermostatic mixing valves and where they are fitted;
other systems that can create aerosols, such as air conditioning or spray equipment;
closed heating and chilled systems if you want them covered;
site type and occupants, especially anyone more susceptible to infection.
Ask bidders to take the risk-assessment logic from HSE rather than invent their own. HSG274 Part 2 says the assessment should understand the water system and consider stored or recirculated water, temperatures between 20°C and 45°C, deposits or biofilms, aerosol generation, and exposed or susceptible people. Your scope should state that sites with those features are priority sites.
If you hold current risk assessments, attach them or summarise them. HSG274 Part 1 says the assessment should include an up-to-date schematic, safe operating procedures, monitoring, inspection and maintenance procedures and the results of checks, so ask whether the existing documents are complete and say who will correct gaps. If any site lacks an assessment or the assessment is out of date, make the first task a Legionella risk assessment, priced separately so you can see what it costs. Our published starting price for an assessment is from £185, one-off, with quotes for larger or multi-site portfolios.
Review triggers
L8 says the assessment should be reviewed when it may no longer be valid, including after changes to the water system or its use. Write that into the contract: the contractor reports any change they observe, and you commit to telling them about refurbishments, change of use and new equipment.
Monitoring, sampling, cleaning and remedial work
The specification should say what is done, to what standard, how often and by whom. HSE says the written scheme should specify checks and their frequency, so the schedule belongs in the tender, not in the contractor’s later proposal.
Temperature control and monitoring
State the HSG274 targets the contractor will test against. Part 2 says cold water should be kept below 20°C where possible, and hot water should be stored at 60°C or above and reach 50°C within one minute at outlets, or 55°C in healthcare premises. It also says the risk assessment should consider scalding risks for susceptible people, which matters for schools, care settings and any site where thermostatic mixing valves are fitted. A contractor who services these valves should be named in the scope, and TMV servicing and remedial works can be priced in the same schedule.
Decide how checks will be divided. Some organisations let trained site staff do simple temperature checks and flush little-used outlets, with contractors taking on the more complex work. One housing association’s published procedure takes this approach, and from 1 April 2025 it delegates temperature monitoring across its schemes to a competent independent organisation. Ark’s procedure is a useful example of how to make the division property-specific and competence-controlled. Whatever you choose, name it in the tender. Our guide to assigning four checks to facilities teams and the walkthrough on temperature monitoring checks show what that looks like in practice.
If you want continuous data rather than periodic readings, ask bidders to price automated water temperature monitoring as an option, with clear requirements for alerts, who receives them and how fast they must be acted on.
Sampling
Specify what is sampled, where, how often and by which laboratory standard. Ask bidders to state how samples are taken and transported, and to give turnaround times for results and the escalation route for a positive result. Decide whether you also want potable, microbiological, Pseudomonas or TVC testing, and list them as separate priced lines. Our Legionella water testing and analysis starts from £55 per sample.
Cleaning and disinfection
List the tanks and systems that need cleaning and disinfection, the circumstances that trigger it (a failed sample, a long period of disuse, commissioning) and the evidence you expect afterwards: method, chemicals, concentrations, contact times and post-treatment results. Ask for tank replacement and repair to be priced as a separate optional schedule, so you can compare it with system disinfection, flushing and tank work across bidders without it distorting the core price.
Remedial work
This is where tenders most often leave money on the table. Milton Keynes Council’s published Legionella specification takes a clear approach: remedial requirements are listed line by line and site by site from completed risk assessments, with standard remedial categories that can be filtered. Copy the principle. Take every remedial action from your risk assessments, give it a reference, a site, a priority and a category, and ask bidders to price each line or category. Add a schedule of rates for work that emerges later, plus a rule on approval: any remedial work above an agreed value needs written authorisation before it starts.
Service levels and KPIs
HSE tells you what to do. It does not tell you how fast the contractor must respond. That part is yours, and it needs to be measurable.
The UK Government’s model services contract is a useful template. Its performance schedule requires performance reports to show actual KPI results, failures, critical failures, root-cause actions for repeat failures and any service credits, with regular review meetings and minutes. You can write water hygiene equivalents of each.
Suggested KPIs, to be set against your own risk profile:
Measure | What to define |
Scheduled checks completed | Percentage done within the month or period due |
Out-of-range results reported | Time from finding a result to notifying your named contact |
Remedial actions closed | Time to complete by priority band |
Sample results issued | Days from sampling to written result |
Reports issued | Days from visit to report |
Positive sample escalation | Time to phone call, written notice and corrective plan |
Attendance | Time to attend an emergency call-out |
Define which failures are “critical”. A missed monthly check at a low-risk office is not the same as a missed check at a hospital ward, so allow different thresholds by site risk. State the remedy for repeated failure: root-cause report, corrective plan, service credits or termination rights.
Records, reporting and data
HSE expects records to be kept, and your tender should say exactly what the contractor produces. Ask for:
a visit report for each attendance, with outlet-level results and photographs where relevant;
an out-of-range exceptions list sent the same day for urgent items;
a live remedial action register with owner, priority and status;
updated schematics when the system changes;
logbooks maintained on site or electronically, with clear rules on who signs what;
a monthly or quarterly performance report against the KPIs above;
calibration certificates for the instruments used.
Say who owns the data and in what format it is returned if the contract ends. That clause saves a difficult handover later. If you want a structured logbook, ask bidders to describe how theirs works and whether your own staff can use it.
Competence, accreditation and training
The HSE guidance expects the dutyholder to make sure contractors are competent and that responsibilities and reporting lines are clear. In the tender, turn that into questions bidders must answer in writing:
Who will carry out the work, and what training and experience do they hold?
Which accreditations does the company hold, and for which activities? Ask for certificates, not statements.
Which laboratory will analyse samples, and what are its accreditations?
Which tasks will be subcontracted and to whom?
What insurance cover is held?
Can they provide references from sites similar to yours?
Decide whether you want the contractor to train your staff. Legionella awareness training for site teams, delivered on site or online, helps if some checks stay in-house. Ask bidders to price it as an option and to say how they record attendance and refresh dates.
The mobilisation plan
Mobilisation is the stretch between contract award and a service running normally. Weak tenders skip it, and the first months become a scramble. Ask each bidder to submit a draft mobilisation plan with their tender and agree the final one before the start date.
Thames Water’s contractor standard, HSI 22, says mobilisation and delivery plans should cover scope, programme, hazards, control measures, welfare, permits, plant, competence, PPE, safe systems of work, briefings, review arrangements and a pre-start meeting or site walkover before work begins. Adapted for water hygiene, a plan should contain:
Confirmed scope and asset register, checked against what is on site.
Review of existing risk assessments and logbooks, with a list of gaps.
Site survey and schematic verification.
A risk-priority and exceptions list: unsafe temperatures, stagnation, dead legs, poor cleanliness, sampling failures and overdue remedial work come first.
A control schedule: what is done, where and when.
Named responsibilities: the responsible person, your contract manager, the contractor’s manager and each site contact.
Staffing and competence evidence, including any subcontractors.
Access and security arrangements, working hours and welfare.
RAMS and permits, and the equipment and calibrated instruments to be used.
Reporting and data setup, with test reports before the first live visit.
Emergency contacts and escalation, including incident notification.
Induction and training for site staff.
Baseline checks and a dated first-visit programme.
Handover and sign-off, so you know when mobilisation ends.
Set a date for each stage. A plan with no dates is a list of intentions. Where you hold vulnerable occupants, such as those described in our piece on Legionella risk management for immunocompromised patients, require those sites to be visited first.
Evaluating bids
Price matters, but a low price on a thin scope is not a saving. Weight quality questions and score them against the written method statement. A sensible mix is a minority share for price and the majority for method, competence, mobilisation and reporting, adjusted to your procurement rules. If you are a public body, follow your own procurement framework for how scores are published.
To compare prices fairly:
ask for a schedule with the same line items from every bidder;
ask for unit rates for work outside the schedule;
check which visits, reports and call-outs are included in the fixed fee;
read the terms on price changes, notice and termination.
For tenders covering different building types, ask bidders how they would adapt the method. Social housing blocks, for example, have different risks from offices; see our examples of Legionella prevention in social housing and our page on offices and commercial premises.
How to check delivery once the contract starts
Because the legal duty stays with you, build assurance into the contract from day one.
Hold a pre-start meeting and walkover before the first scheduled visit.
Audit early. Re-check a sample of outlets in the first weeks against the contractor’s report.
Review KPIs monthly in the first quarter, then at the interval you set.
Check the remedial register against the risk assessments, so nothing quietly drops off.
Inspect the competence evidence of those who turn up, not just those named in the bid.
Escalate by the contract. Repeated failures trigger the root-cause report you required.
Keep your own record of reviews, decisions and approvals.
An independent audit by another competent party after the first six to twelve months is a sensible safeguard for larger portfolios.
Our view on writing the specification
We see the same pattern again and again: a tender is written fast, copied from an old one, and the real work is discovered during mobilisation. Our advice is to spend the time upfront on the asset register and the remedial list, because those two documents decide whether bids are comparable.
We also encourage buyers to ask for a bespoke method rather than a standard package. A primary school with a single tank, a dental practice with dental unit waterlines and a multi-building university campus do not need the same schedule, and a tender that forces them into one will either overcharge or under-deliver. Ask bidders how they will tailor the programme to each site, and mark them on the answer. Our method of works shows how we set that out for clients.
Finally, write the tender so that your own team can do their part. If site staff will carry out checks, they need training and clear forms. If they will not, the contractor needs access and a named contact. The contract works when both sides know who does what.
— Sammi
Where we can help
We provide Legionella risk assessments, water sampling and analysis, temperature monitoring, disinfection, TMV servicing, remedial works, training and ongoing consultancy for organisational sites across the UK. If you are preparing a tender and want the scope, asset register or remedial schedule reviewed first, or you want a priced starting point, speak to us about a Legionella risk assessment, which is the usual first step.
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For multi-site contracts we quote by site, and we can price testing, remedial work and ongoing maintenance as separate lines so your evaluation stays clean. See the full range on our website.
FAQ
What is a water hygiene tender specification?
It is the document that tells bidders what water hygiene and Legionella services you need, at which sites, to what standard and with what reporting. It should reference HSE L8 and HSG274, list systems and assets, and include service levels, records and mobilisation requirements.
Do I need a risk assessment before I go to tender?
Ideally yes. Current risk assessments let you list remedial work and monitoring requirements line by line, so bids are comparable. If assessments are missing or out of date, make them the first task in the contract or commission them before tender.
Does hiring a contractor transfer my legal responsibility?
No. HSE says employing a contractor does not remove the dutyholder’s responsibility, and you should make reasonable enquiries about competence and make sure control procedures are done to the required standard. Build checks and audits into the contract.
What should a mobilisation plan include?
A confirmed scope and asset register, review of existing assessments and logbooks, a site walkover, risk priorities, named responsibilities, competence evidence, access and permits, equipment, reporting setup, emergency contacts, baseline checks and a dated first-visit programme.
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