Two Community Water Supply Planning Group subcommittees made presentations to the Pagosa Area Water and Sanitation District Board of Directors Tuesday night, during a special meeting called to address issues not handled Sept. 14. The most gripping of topics, however, entailed discussion of a perceived 30-percent water loss seen in 2009.
Subcommittee 1 of the workgroup, which focuses on current district water resources, water rights and demand, submitted a written report and recommendation to PAWSD, dated Sept. 15. To begin, the report first described “the problem,” or the committee’s primary concern.
“In 2009,” the report began, “almost 220 million gallons of treated water was unaccounted for by the PAWSD. It is not known if this loss was the result of metering inaccuracies, leaking distribution pipes, unmetered deliveries to water users, or more likely, all three.
“The loss of 30 percent of our treated water is a financial and public relations disaster for the District ... .”
While asking how the district could ask ratepayers to implement conservation techniques and approve major capital expenditures, particularly in light of such “waste,” the report explained that, according to the district’s 2010 budget, $602,500 were spent treating water last year. The 30-percent loss, therefore, presumably cost the district nearly $181,000 alone.
With that, the subcommittee recommended a four-part approach to addressing the problem.
The first step, according to the subcommittee, would be the district purchase of two strap-on (portable) water meters that can be wrapped around a section of pipe between 4 and 24 inches in diameter. Each meter costs about $4,000, and would be installed in line with existing meters at district water treatment facilities.
Because treatment plant meters are the basis for all perceived water loss, the strap-on meters could be used in determining their accuracy. Should they be considered faulty, the plant meters would then be sent out for repair or re-calibration.
Too, the subcommittee believes such a cost-effective step would help determine if “the water losses are real losses or paper losses.” Apparently, this step can be achieved under any weather conditions.
The second approach to a solution would involve reading pump meters and storage tank levels at seven sub-networks within the district distribution system. Each pump fills a storage tank, where a flow meter shows volume passing into the tank. From each tank, water flows to customers within its respective sub-network.
By reading flow meters at noon on a Friday — while also reading tank levels and customer meters (which are connected to a computerized “firefly” system) — then comparing them with readings taken on a subsequent Friday, any discrepancy would point to a leak or unmetered water use in that sub-network.
As a third measure, once the accuracy of treatment plant meters is verified, workers could place the strap-on meters at strategic locations throughout the water distribution network. As an example, attaching them to either end of a main with no tributaries would provide a simple mathematic comparison, any discrepancy in which would again indicate a leak or loss there.
By systematically moving the strap-on meters through the network, technicians could eventually pinpoint the exact location of a loss and affix repairs. Of course, digging to the main would be necessary in places, thereby adding considerably to project costs. This approach would also require favorable weather conditions.
The final approach to eventually solving water loss entails the installation of meters connected to the firefly system, whenever an existing main is exposed for repair or replacement. A number of such projects are already included in the PAWSD 2010 capital improvement plan, where fixed meters would enable continuous monitoring through the use of automated software.
According to the subcommittee report, “At the conclusion of the testing identified in Part 3, all significant losses will have been found and repaired, all the permanently installed meters will be calibrated and accurate, and the unaccounted water loss problem should be a thing of the past.”
With that, Subcommittee 1 recommended the district immediately embark upon the prescribed program.
Because PAWSD believes the supposed water loss is actually on paper and not real, the board of directors asked staff to purchase two strap-on meters right away. According to PAWSD Special Projects Manager Renee Lewis, staff did so on Wednesday.
Lewis added that a review of the meter monitoring software might be in order next, if the strap-on meters fail to isolate water loss problems. Meanwhile, PAWSD staff is developing a water loss strategy to identify the next steps, should meter calibration and software revisions prove unsuccessful.
With approximately 30 years experience at the district, PAWSD Operations Manager Gene Tautges believes one or more of its existing water meters is likely inaccurate.
Time will tell.