Acreditación: MVA-053
Autoridad: ema · CONAGUA

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NMX-AA-179-SCFI-2018, explained

What the standard requires, who it applies to, how often verification is due and what happens if you do not comply. Every claim cited.

GlossaryThe terms that come up again and again in this process, defined as the authority uses them. Most expensive misunderstandings start by confusing two of them.

PSI and Verification UnitTwo distinct and deliberately incompatible roles. Whoever supplies, installs or maintains a metering system cannot be the one who rules on whether that system complies.

The three types of inspectionInitial, periodic and extraordinary. These are not service tiers: they are three distinct moments, and every water use goes through all three over the life of its metering system.

The verification reportThe document evidencing before CONAGUA that a metering system was assessed against the standard. It is not a certificate you buy: it is the outcome of a procedure, and it can be unfavourable.

Validity and deadlinesThere are two different clocks and they are often confused: how often a metering system must be re-verified, and how long the approval of the unit verifying it lasts.

What NMX-AA-179-SCFI-2018 isThe Mexican standard that sets how the volume of national water used or extracted must be measured. It determines what a metering system must satisfy, how compliance is checked and who may check it.

What happens if you do not complyNot measuring, measuring with non-compliant equipment or letting the report lapse carry different consequences, and none of them is merely technical: the measured volume is the base on which duties are paid.

Who must complyTo anyone holding a concession or allocation title for national water. Measuring the volume you use is not good practice: it is a legal obligation, and the system you measure with must meet the standard.