On Friday, August 18th, water supply work at Well 2 was successful in removing the blockage in the well hole, freeing the old pump (see photo 1). On Monday, August 21st, the strainer, which is basically a wound wire intake screen attached and located below the pump, was retrieved from the well hole (see photo 2). All the new pumping equipment is expected to be on-site the week of September 18th for installation. The drill rig will be leaving the site this week and returning after the 2017 Round-Up.
City staff received and evaluated options for new pump equipment installation. With construction of the additional access pad, used for the second well rig that was needed to help break the blockage free, the city will pursue installation of alternative column pipe and shaft. Portions of the new column pipe will be in 20-foot lengths instead of the 10-foot that the city had used previously. This will add more flexibility in setting the new pump lower in the hole. The flexibility is needed to address the well hole that is crooked and doesn't hold a continuous 16-inch diameter for the entire well hole.
The city’s closed-circuit TV report shows several “pinch points” due the irregular nature of the well hole. The main pinch point is located at about the 400-foot depth. The old 14-inch diameter pump was not able to be lowered in the well hole past this point. The city has reduced the new pump size to 12-inch diameter and is also reducing about 220-feet of column pipe to 8-inch diameter from 10-inch diameter to help provide more flexibility for the column to “bend around” these outcroppings in the well hole. This will also allow the new pump to be placed deeper in the well hole – with the city targeting 440-foot depth.
Due to the lead time for replacement shaft pieces, work is being scheduled for the week of September 18, 2017, after Round-Up, to complete the installation of all the pumping equipment.
Further updates will be provided at that time.
With the cooler weather, the water supply remains balanced at about 6.5 million gallons per day with outside irrigation use. City staff will continue to coordinate with parks and our largest water customers.