Patagonia’s Wastewater Treatment Plant (WWTP) is aging. Treatment, at the rate of about 40,000 gallons a day, is a complicated process, with many tanks, pumps, valves, regulators, controls and equipment that can go awry in a system that must keep working 24/7. In the summer of 2019, as Town Manager Ron Robinson began working for the Town, he rapidly learned of the of the many problems and emergencies the Treatment Plant crew faced. Here is Robinson’s account of how the Town is dealing with this issue:
Knowing 16 months ago we had a major issue with the 15-year-old WWTP, I immediately looked around to see who had grant monies available. Because of its focus on the binational border region we live in, the North American Development Bank (NADB) seemed a good fit, so we applied for a Community Assistance Program Grant in the amount of $500,000, which was awarded this March. This grant was for construction, so in order to fund the engineering design work, we also applied for the NADB Technical Assistance grant in the amount of $100,000, which was awarded in May of this year.
We are now in the pre-design phase where all the priorities of construction are set, and the estimates of costs are put together. After we decide on the priorities and costs, the design phase is completed with bidding documents for construction. This whole process will take about 37 weeks to get ready for construction, and the clock started in August. We are looking at next summer for completion.
As you can see in the [accompanying] photo, the leakage in exterior walls needs repairing, and there are about 16 more leaks like these as you go around the main tank structure, in addition to some leaks in the internal partitions. The Plant also needs a remodel of the chlorine room and a new or rebuilt belt press, for the settled sludge. These three projects are the most urgent issues, and we are now working on the engineering specifics of leak repair and equipment replacement. The leak repair will be done from inside drained tanks, one by one, so there is complicated staging and pumping of liquids in various stages of treatment to be worked out, to provide dry walls for an advanced leak-prevention method before refilling each tank. To keep the WWTP working smoothly, we have already handled two other issues over the last year, upgrading the lift stations and replacing the big auger at the head works.
With these projects completed, we anticipate eight – ten years of great service from the plant, but further in the future probably lie more challenges and eventual total replacement.