ISO 14001 is a management system standard that can be implemented as a binding or non-binding requirement.
This is a good standard to use because its the international recognized standard for environmental management. This allows for operations to lay a groundwork for legal protections anywhere in the world.
Water discharge and waste water can impact legal compliance, sustainability benchmarks and profitability for any operation. Having a clear cut standard to follow, helps executives implement standards to control and monitor this.
Many organizations use benchmarks as a way to standardize environmental management for the purpose of controlling investor's risk. Water waste can be a friction point between organizations and local governments that can delay projects or cause unforeseen reputational problems.
Simple standardization of water waste performance through ISO 14001 is often the best way to build confidence with shareholders who are looking for risk management techniques related to environmental impact.
To summarize the standard, if an organization wants to manage their water discharge effectively, they need to identify what needs to be measured, what equipment needs to be implemented, when and how the data is going to be analyzed, and how that equipment is going to be verified or calibrated. (ISO 14001 Section 9.1)
“The organization shall ensure that calibrated or verified monitoring and measurement equipment is used and maintained, as appropriate.” Section 9.1.1
Section 9.1.1 states that either a verification or calibration procedure should be implemented and that procedure should be implemented appropriately for the application. In order for the organization to provide strong legal protections and validity to their data analysis process, they need some sort of process to verify if the data is valid.
With specific regards to water discharge levels, Flow meters can be installed at various points in the process to collect data for analysis and management. Flowmeters are instruments that can either be installed inside or onto the pipe to measure flow rates. This data then can be used to analyze for waste management.
When implementing a performance evaluation plan, its important to identify if the measurement points are going to be placed at water discharge points or not. Water discharge is usually defined as water that is being released back into the environment.
For example if the water is going back to the environment, this may need to be handled differently then if a measurement point is in a closed loop system. A closed loop measurement point may not be subject to the same legal requirements as the discharge point is. Water leaks may be considered discharge depending on local and regional legal requirements.
ISO 14001 does not have a definition of the terms calibration or verification, however you can find definitions in ISO/IEC 99:2007 International Vocabulary of Metrology:
Verification: "provision of objective evidence that a given item fulfils specified requirements"(ISO/IEC Guide 99:2007 Section 2.44)
Calibration: "operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication" (ISO/IEC Guide 99:2007 Section 2.39)
Stated in another way, calibration is a process to create an unbroken chain of measurements that are traceable back to a national standard’s laboratory controlled by that regions government.
A calibration report normally has two outputs, the result of the measurement and the “uncertainty” of that measurement. The uncertainty of that measurement is a probability distribution of the potential doubt of the calibration itself which is usually represented with a 95% confidence rating. In order to ensure traceability back to a national standard, most organizations hire laboratories that are certified to ISO 17025.
Hiring a certified ISO 17025 laboratory to calibrate a flowmeter installation may not be appropriate in many situations. Most ISO 17025 certified calibration laboratories are not capable of handling liquid flow meter systems in complex or dangerous environments.
Alternative verification procedures may be required as stated in the ISO 14001 standard. Appropriateness of the verification or calibration procedure needs to be carefully evaluated.
Often times, onsite field support is the only appropriate method for verification or calibration of a flowmeter setup. The equipment used in a verification process can be calibrated by an ISO 17025 laboratory in order establish clear traceability.
Every situation is different and its important to use common sense.
A bench calibration refers to an instrument that is calibrated at an external laboratory rather then in the production environment. Bench calibration would require technicians to pull the flowmeter offline and send it to a either an in-house or third party laboratory for testing. In many situations this is complex and unsafe.
Bench calibration setups may not represent the pipe size, pipe material, and environmental conditions of the application. Field calibrations have their own challenges as well, including logistical challenges and additional components of measurement uncertainty caused by the environment itself.
Calibration is a probabilistic endeavor and should never be thought of in terms of absolutes. Financial accountants think in terms of deterministic measurements where every dollar represents an exact measurement. This is not the case in metrological measurements. Calibration is stochastic in nature. All metrological measurements that are traced through calibration laboratories have elements of randomness which is referred to as “uncertainties.” Its important to set tolerances and draft procedures appropriately based on realistic standards.
The following plot is an example of how measurement uncertainties can grow during each step of the traceability process. The first measurement was measured at the National Laboratory while the final measurement was taken after the instrument had been in production for a year.
The uncertainty grows throughout each phase in the calibration process. This plot is logarithmic in order to improve the visibility of the smaller uncertainties.
Test Uncertainty Ratios are an industry standard to measure how much of the measurement uncertainties consume the actual operation tolerance. “TUR” is often reported on calibration reports. Most calibration laboratories aim for a 4:1 TUR but there is no operating standard for flowmeters. TUR of 4:1 might not be appropriate in many situations.
Illustration: This laboratory verifies the TUR status with a checkmark to confirm they're hitting their internal 4:1 requirement.
The following Test Uncertainty Ratio (TUR) we’re going to use for this example is reported by our lab at 1125:1. That is a pretty high test uncertainty ratio. TUR ratios at this range would be high because of a few factors including large calibration tolerances, extremely controlled laboratory environment, and highly trained technicians.
Tolerances themselves impact the Test Uncertainty Ratios. For example a larger process tolerance would lead to higher TUR numbers. This method can also be used to determine if a process tolerance is realistic or not. Most organizations would have a calibration tolerance for the flowmeter itself and then a process tolerance for the flow of the water. If the TUR seems too high, then perhaps the tolerances may be too large. If the TUR is too low, then there could be a problem with the measurement process itself.
Illustration: This is the visual simulation of the calibration report's uncertainty output. TUR = 1125:1
This is the simulation of the same equipment running in production with a sizable drift. Final TUR output from this simulation is 0.9:1. The actual uncertainties that would be running in normal production could be much higher then expected impacting water discharge reporting. All of the input data from this simulation can be sourced from a standard calibration report.
Illustration: This is a simulation of the uncertainties which included a production drift along with additional components of uncertainty. TUR = 0.9:1
Uncertainties have various components and causes which can easily be quantified for troubleshooting purposes. This allows for easier debugging and risk management.
Illustration: This is a plot of the various quantified components that could add to the uncertainty of a flow meter measurement.
SO 14001:2015 - Environmental Management System
ISO 17025:2017 - Calibration and Testing Lab Management
ISO 98 Series- Procedure for Guide to Uncertainty of Measurement
ISO/IEC Guide 99:2007 - International vocabulary of metrology - Basic and general concepts and associated terms (VIM)