Italian Lab Report: Our UF Membrane on Well Water, Tested to ISO 6222

An Italian customer installed our ultrafiltration membrane on a well-water treatment system, drew samples of the filtered water, and sent them to TecnoLab Alimentare S.r.l. in Emilia-Romagna for microbiological analysis. The report that came back puts numbers on something we otherwise have to describe in words.

Who issued the report

TecnoLab Alimentare S.r.l. is a food-analysis laboratory recognised by the Emilia-Romagna region, and it carries both the ILAC-MRA mark (International Laboratory Accreditation Cooperation) and ACCREDIA accreditation (the Italian national accreditation body). Results issued under those marks carry legal and technical weight in Italy and across Europe.

What was tested, and how

The samples were drawn from a newly installed membrane and sent for analysis — the initial performance acceptance scenario for a system going into service. That is the most demanding moment to test a membrane, because none of the conditioning that a running system accumulates is there to help.

The laboratory applied UNI EN ISO 6222:2001, the international standard for enumerating culturable micro-organisms in water, counting colonies at two incubation temperatures:

• 37°C colony count: < 1 CFU/mL — not detected, by method UNI EN ISO 6222:2001.
• 22°C colony count: 3 CFU/mL — by method UNI EN ISO 6222:2001.

How to read those two numbers

"< 1 CFU/mL" is not a small number — it is the detection limit of the method itself. Nothing able to grow at 37°C was recovered from a one-millilitre sample, so retention of those organisms sits at or beyond the resolution of the test.

The 22°C count of 3 CFU/mL is a single-digit figure, and the context is what makes it meaningful. Untreated well water typically carries background colony counts in the hundreds or thousands per millilitre. Bringing that to single digits is physical retention doing real work, not a cosmetic reduction.

What ultrafiltration can and cannot do

Ultrafiltration works by size exclusion. With pore sizes between roughly 0.01 and 0.1 micron, a UF membrane holds back bacteria, viruses, colloids and suspended solids while letting water molecules and dissolved minerals through. No chemicals and no additives are involved, and the mineral content of the water is unchanged.

That is also the honest boundary of the technology, and buyers should know it. Because the mechanism is a physical barrier, UF does not remove dissolved contaminants. Hardness ions, nitrate and dissolved PFAS pass through a UF membrane and need a different stage — activated carbon for chlorine, taste and many organics; reverse osmosis or ion exchange where dissolved species have to come out. A UF membrane is the microbial and particulate barrier in a system, not the whole system.

The same size-exclusion principle is why UF is now standard equipment in drinking water purification, industrial wastewater treatment, food and beverage processing, and biopharmaceutical purification.

From the tested membrane to a finished product

As the source manufacturer, we supply more than the membrane itself. Our customisation chain runs from membrane formulation and housing construction to laser-engraved logos and packaging that meets international safety standards such as NSF.

A third-party report is one data point in a supplier decision. For OEM and private label partners who want to see the rest — the membrane line, the test bench, the audit trail — the factory is open. Send us the water conditions your product will meet, and we will tell you what the membrane will and will not do.