The Community Services District reports the discolored tap water residents on the North began seeing Monday is the result of sediment on the bottom of the Rio Oso water tank that was stirred up as an unforeseen consequence of pump tests the district conducted.
The Rio Oso tank holds 1.2 million gallons of treated, potable water, and supplies the needs of about 30 percent of Murieta.
"We apologize. We had no idea this was going to happen," CSD General Manager Ed Crouse said Tuesday. "When we do flushing or something that we know is going to cause debris, we send out widespread notices of the time and place, but this one was a test that caused debris in the water. We just didn't realize what was going to happen after the pump test."
He said samples of the water have been sent to a laboratory for analysis and the results will be available by noon Wednesday.
Crouse described the debris as "sediment and rust particles. … We have no reason now to believe that it's unsafe. It looks bad because of the color."
Water Department workers began flushing the line after reports of reddish-colored water started coming in between 11 a.m. and noon Monday, Crouse said. The calls continued throughout the day. By Tuesday, residents were reporting the discoloration had a yellowish tinge.
Crouse said the CSD has received "boatloads" of complaints about the discolored water, although he didn't have the total number of calls.
"We've been flushing the line since we got our first complaint. … We're going to flush until it's clear," he said, adding that the discoloration had been "dramatically reduced" since flushing began.
He cautioned residents not to wash clothes until the water clears. If wash has been discolored, he said to rewash it in clear water without using chlorine bleach, which will set rust stains. He asked residents to flush their household lines as part of the effort to get the debris out of the system.
Crouse said the problem occurred when pumps at the water treatment plant were tested for their capacity to supply water the Rio Oso tank now supplies when it's taken out of service for repair and maintenance work this fall.
The pumping test was conducted after the peak morning use Monday reduced the water level in the tank.
"We had higher than normal pump rates going in and low levels in the tank so it stirred it up. Normally the water we put in the tank doesn't come in as fast and it comes in over a longer period to fill the tank," Crouse said.
The Rio Oso tank rehabilitation project has been delayed since 2005 while a way was developed to provide adequate water flow and water pressure to residents during the period the tank is off-line.
The plan now is to use the water treatment plant pumps to supply water to the pressure pumps the Rio Oso tank feeds. "What we're doing is matching the capacity of the water treatment plant pumps to the capacity of the pressure pumps at Rio Oso," Crouse explained.
Crouse said the sediment is now resettling inside the tank and will be removed during the rehab project.
Tuesday afternoon, the CSD issued a statement about the situation:
In preparation for the Rio Oso Tank rehabilitation project, the District has been conducting certain system tests to insure that there will be no disruption in service while the tank is out of operation. Yesterday, during one of these tests, rust from the tank was inadvertently introduced into the water service line for areas of Rancho Murieta North, Units 3 and 4.
The rust created a reddish brown color in the water, and while this coloration is esthetically displeasing, the water is safe to use and does not pose any health risks.
The District is flushing the distribution water lines to restore the clarity of the water. We recommend that you also flush your internal water lines as well as your irrigation system lines.
We recommend that you do not wash clothing until your water clears up. If you have already washed white clothes, do not bleach them. Chlorine will fix the iron to your clothes. Rewash the clothes once water clarity is restored.
We are very sorry for any inconvenience this may have caused you. The District apologies for this temporary problem. We wish to emphasize that your water is safe. Please report any continuing problems to the Community Services District office at 354-3700.
Rancho Murieta Community Services District