Low Uncertainty Flow Calibration Facility for Large Water Main Metering Systems

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Low Uncertainty Flow Calibration Facility for Large Water Main Metering Systems

The key to water sustainability is the maximization/stabilization of the difference between total available water supply at a given time and the actually delivered water during the same time period.  Distribution system losses/leakage are significant factors in the water sustainability problem.

The attached excerpt, Section 1 of a Proposal for a Low Uncertainty Flow Calibration Facility for water main metering systems up to 24", is entitled " Introduction: Briefing for Water Policy Makers, Environmental and Legal Background ". 

A leak is by definition the loss of material (mass or standard volume) from the contents of a pipeline.  Hence, pipeline section balance is the only truly rigorous/direct method of leak detection .  (See attached white paper.)  Since water distribution systems have an average of ~20% water loss, corresponding to ~1,800 gallons per mile of water main per day, the recovery of said losses is a major water sustainability issue. 

Detection of leakage at low levels would frequently save many years of water loss, that would otherwise go unnoticed until water is observed running down the middle of a street or a sinkhole appears.  Detection of small leaks also allows early repair/remediation (e.g. via saddle patch) before long term flow erosion causes major distribution pipeline section blow-outs (that can no longer support internal lining/sleeving).

Note that the recovery of lost water is universally considered the most economical means of augmenting and conserving water supplies -- thus also saving water transportation and processing energy and costs.

However, low level on-line near real-time leak detection by system balance remains impossible without significantly improved flow measurement.  A large low cost low uncertainty flow calibration facility is proposed that should be affordable to all but the smallest water distribution companies.  It is configured to facilitate accurate/reliable water audits , and -- by improving measurement -- subsequently pipeline leak detection, location, and prioritization .  (Inasmuch as most water systems are aging / near end of life and have a large number of leaks, repair/replacement prioritization -- via quantification of loss and its rate of change, etc. -- provides very significant logistical advantages to the water distribution utility.)

Calibration of measurement instruments is also a basic legal metrology requirement of all quality management systems, e.g. ISO 9000, and obviously the lower the calibration uncertainty the better -- especially in leak detection applications.  It provides earlier notice of impending failures.

Improving measurement requires reducing calibration uncertainty.  Thus, viewed from the long term perspective, improved calibration is the  fundamental first step on the long path to rigorous distribution system management .  Water sustainability is a matter of water quantities.  We can't control rainfall and snowpack.  Isn't it time that we begin to better measure/monitor/control those water distribution areas that we actually have control of?

The full proposal with technical details and supporting documents/appendices may be requested.

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