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Any contractor you hire should work to the EMSD Code of Practice (2023 edition), give you a dated written report after every visit, test your water in a laboratory with formal certificates, be able to respond in an emergency, match chemicals to your specific system, send trained staff who carry identification, and be willing to show references and produce tender documents. These seven things are the baseline — not a premium. If a contractor cannot show them, keep looking.
In Hong Kong, hiring a contractor does not move the legal responsibility for a cooling tower off the building owner. The EMSD Code of Practice assigns the work to the contractor — but the accountability stays with you. If the water goes bad, or the records are missing when EMSD asks for them, it is the owner who answers for it. We explain this in detail in Legionella and cooling tower compliance.
That changes what you are actually buying. You are not buying chemicals and a monthly visit. You are buying two things: water that stays safe, and a paper trail that proves it. Judge every contractor against both.
This checklist applies to any water treatment contractor — including us. Ask for evidence, not assurances.
| What to demand | Why it matters | What to ask for |
|---|---|---|
| 1. Works to the EMSD Code of Practice (2023 edition) | The Code is the benchmark your towers are inspected against. A contractor working to an older edition, or to no stated standard, leaves you exposed. | Ask which edition they follow and how their programme maps to Part 2 (operation and maintenance) and Part 3 (water treatment methods). |
| 2. A dated report after every visit | The Code requires records to be kept for at least 2 years and produced on inspection. No report means no defence. | Ask to see a sample report. Check it is dated, states what was done, and records the readings taken. |
| 3. Laboratory testing with formal certificates | Legionella cannot be seen. Only a laboratory test tells you where you stand, and only a formal certificate counts as evidence. | Ask which tests are included, how often, and what the certificate looks like. Test-strip readings on site are not a substitute. |
| 4. Emergency response capability | A high Legionella result or an EMSD notice starts a clock. A contractor who cannot mobilise quickly turns a bad week into a bad month. | Ask what happens, step by step, if your sample comes back at 1,000 cfu/mL or above. |
| 5. Chemicals matched to your system | Metals, water chemistry and operating pattern differ between buildings. A one-size-fits-all drum treats the average building — not yours. | Ask why each chemical was chosen for your system, and for the safety data sheets. |
| 6. Trained staff who carry ID | These people work on your roof and in your plant rooms. Safety training protects them; identification protects your building's security. | Ask whether technicians are safety-trained, uniformed and carrying company identification on site. |
| 7. References and tender documents | A contractor confident in its work will show you where it has done the work before, and can produce the paperwork a tender or committee requires. | Ask for a reference list of comparable buildings and for the documents you would need for a tender file. |
Notice what is not on this list: the lowest price. Price matters — but only after scope is equal. A cheap programme that fails an EMSD sample is the most expensive option on the table.
A good contractor answers these without hesitation. Vague answers to concrete questions are themselves an answer.
Most quotation comparisons fail because the quotes are not for the same thing. Before you compare prices, line up the scope:
A low quotation that excludes testing, reporting or cleaning is not the same service at a lower price — it is a smaller service. Make every bidder quote the same scope, in writing, and the real comparison becomes obvious.
Honestly: not every building needs a full-service water treatment company. If you run a single small standalone system — one small closed loop, one small tank — and you have in-house staff with the training, the time and the discipline to dose, test, clean and record on schedule, you can run a compliant programme yourself. The Code does not require you to outsource; it requires the work to be done and documented. Where owners get into trouble is when "in-house" quietly becomes "nobody" — the calendar slips, the records stop, and the first person to notice is an EMSD sampler.
We hold ourselves to the same checklist. Gotech has treated water systems in Hong Kong since 1982, with 500+ clients as of 2026 and a team of 20+ specialists, technicians and engineers. Our staff are uniformed and safety-trained, and they carry identification. Every job includes a free site visit, a written quotation, and a dated report after every visit — and we provide reference lists and documents for tenders on request. We have also delivered water-treatment works for the EMSD's E&M Services Department at Hong Kong public hospitals. Compare us against the seven points above; that is what they are for.
Seven things: work to the EMSD Code of Practice (2023 edition), a dated written report after every visit, laboratory testing with formal certificates, emergency response capability, chemicals matched to your system, safety-trained staff who carry identification, and a willingness to provide references and tender documents. A contractor that cannot show all seven is asking you to take its work on faith.
Ask which edition of the EMSD Code of Practice they work to, what a routine visit includes, what you receive in writing after each visit, which laboratory tests are included and how the results are certified, what happens when a Legionella result comes back high, whether they can respond in an emergency, and whether they can provide a reference list and documents for tenders.
Compare scope, not just price. Check the number of visits per year, whether chemicals and laboratory tests are included, cleaning frequency against the Code's six-month minimum, what reports you receive, and how emergency call-outs are handled. A low quotation that excludes testing, reporting or cleaning is not the same service at a lower price — it is a smaller service.
Not on price alone. Price matters only after scope is equal: line up visits per year, whether chemicals and laboratory certificates are included, cleaning frequency against the Code's 6-month minimum, reports, emergency call-outs and — read it twice — the exclusions. Make every bidder quote the same scope in writing. A cheap programme that fails an EMSD sample is the most expensive option on the table.
Yes, if you run a single small standalone system and have in-house staff with the training, time and discipline to dose, test, clean and record on schedule. The EMSD Code of Practice does not require you to outsource; it requires the work to be done and documented, with records kept for at least 2 years. Owners get into trouble when "in-house" quietly becomes "nobody" and the first person to notice is an EMSD sampler.
Ask us the questions on this page. We reply within one working day.