By Nick Diamantides
Both wells that supply water for the City of Signal Hill have been shut down for repairs. Until at least one of them is back in service, the City will be purchasing water from the Metropolitan Water District (MWD), which imports water to the region from Northern California and the Colorado River. The problem with that scenario is that MWD water is much more expensive than water the City pumps from its own wells.
“To avoid the high cost of purchasing water from MWD, the City owns and operates two groundwater wells,” said Rick Olson, acting director of public works. “These two wells, number 7 and number 8, were put in service in 1978 and 1980, respectively, and have provided the City with its water since that time.”
Olson explained that, in the cooler months, the two wells normally produce enough water to meet the daily demands of Signal Hill residents and businesses, but, during the warmer summer months, the daily demands often exceed the pumping capabilities of the two wells, requiring the City to purchase MWD water to make up the shortfall.
Well number 8 was temporarily taken out of service several months ago due to excessive sand being drawn into the pump. In response to a question asked by Councilman Larry Forester, Olson said well number 8 was still out of service and he didn’t know when it would be able to produce water for the City again.
Olson noted that, in January 2010, the pump bowl assembly in well number 7 was replaced due to wear. “One of the factors contributing to pump wear is the fact that well number 7 produces a moderate amount of sand during pumping operations,” he added. “After replacement of the pump bowl assembly, the well was put back in service and was producing about 1,300 gallons of water per minute.”
According to Olson, for several months after the well was back in operation, public works staff noticed it was producing a moderate amount of sand, but that amount was consistent with the historic performance of the well. Things changed in early September, when staff observed an increase in the amount of sand as well as a small amount of gravel in the water coming out of the well.
“The problem quickly developed into larger gravel being observed, and the well was taken out of service,” Olson said. “The gravel appears consistent with the gravel pack that was installed around the outside of the original well casing when it was installed in 1978.”
Olson traced the well’s problems back to 2006, when crews relined its casing due to a rapid increase in sand production. He explained that inspections performed at that time indicated several holes in the casing, which required the installation of a smaller sleeve to be installed in the original casing from top to bottom.
“It is unlikely that the water flow from the well could pull gravity very far up the casing simply due to gravity,” Olson noted. “At this point, the assumption is that the problem is near or above the pump.”
Olson added that a video survey will be conducted during water-flowing conditions to identify the location of the problem, and, once that is done, the necessary repairs will be undertaken. He said he is hoping to have the well back in operation by the end of December.
In other actions, the Council: approved an $8,000 employment contract with James Davis, who will serve as interim public works director until a permanent replacement for former director Barbara Munoz is found; awarded a $90,347 contract to Mega Way Enterprises for upgrades to Reservoir Park; and authorized an agreement with the Gateway City Council of Governments for funding to improve the intersection of Orange Avenue and Willow Street.
The Council’s next meeting will be at 7pm on Nov. 2 in the Council Chamber of Signal Hill City Hall.
Wells that provide SH with water are temporarily out of service
October 22nd, 2010 · No Comments · Environment
By Nick Diamantides
Tags: Nick Diamantides