Encinitas, Calif. — The California Department of Water Resources approved a grant package that will provide $2.8 million in state grant funding to three North County water and wastewater agencies to expand and upgrade recycled water infrastructure.
The Sweetwater Authority recently began a multiyear water main flushing program using innovative technology to clean all 400 miles of pipeline in its system. It’s part of Sweetwater Authority’s use of the latest technology to deliver a safe, reliable water supply to its South San Diego County customers.
Water main flushing cleans pipeline interiors by sending a rapid flow of water through them. Sweetwater’s program is the first in the region to use a new, innovative technology resulting in less environmental impact.
“We’re committed to providing our customers with high-quality water, ensuring that every drop meets safety standards and protects public health,” said Tish Berge, Sweetwater Authority general manager. “We’re also dedicated to providing the safe, reliable water through the use of best available technology and sustainable practices.”
See the system in action in the following video. A Spanish language version is also available.
New method avoids storm drain discharge
Traditional flushing methods release water from fire hydrants at a high speed in order to flush out naturally occurring sediments accumulating in water pipes over time. Although the sediment itself is harmless, it can eventually affect water color and taste. The water used to clean the pipes often cannot be captured and ends up in the storm drain system.
The bulk of Sweetwater Authority‘s flushing program now eliminates the need to discharge water from fire hydrants during the cleaning process while delivering the same results.
Crews identify all pipes, valves, and fire hydrants located in the area to be flushed. Next, crews connect one end of a hose to a hydrant and the other end of the hose to the no discharge, or NO-DES flushing unit. The process repeats, connecting a second hose to another hydrant and the other end back into the flushing unit, creating a temporary closed loop.
Once the NO-DES flushing unit is turned on and the hydrants are open, water will push through the loop at high pressure, disrupting any accumulated sediment on the inside of the pipes. The water is pushed through a series of sock-like filters, which remove those sediments and return clean, high-quality water back into the system.
Crews closely monitor the filtration system and water quality to determine when flushing of each pipeline segment is complete.
Innovative technology, efficient and environmentally responsible
With the closed-loop system and increased controls, crews are able to effectively and thoroughly flush large sections of pipeline with a single setup and staging area. This more efficient setup is less labor-intensive and allows the crew to maintain a safe hub for operations.
In the National City area 75.8 miles of pipeline was recently flushed. Crews are now completing work in the Bonita area, and then will start work in Chula Vista.
Additional water agencies have indicated an interest in the cost-effectiveness of purchasing the NO-DES flushing units for the region and collaborating to create a shared-use program with the innovative technology.
“Securing a local water supply to ensure the water delivered is of the highest quality through the best technology in our projects and programs helps to maximize value for our customers while also being sustainable,” said Berge.
For more information on the program, go to www.sweetwater.org/flushing.
Comments, questions and concerns are now being accepted, again, for the Lake Powell Pipeline. This comes after the Bureau of Reclamation issued the draft Environmental Impact Statement for the pipeline, which is designed to pump water to Washington County.
Any potential alignment of the Lake Powell pipeline would pass through lands that hold spiritual and cultural significance to Southern Paiutes, who fear the project would jeopardize their culture and upset the balance of nature.
The water rights behind the proposed Lake Powell pipeline are not actually coming from the project’s namesake lake, but rather from the major reservoir upstream on the Green River.
San Diego County Water Authority identified the need to rehabilitate sections of the pipeline while executing its strategy to make major investments in the region’s water delivery system.
The leak has been stopped, and there is no danger from flooding, said Roxanne Rountree, a spokeswoman for the Eastern Municipal Water District.
But until work is completed, customers in Moreno Valley, Lake Mathews, Orangecrest, Mission Grove, Woodcrest, Air Force Village West, Hillcrest and Lake Hills and on the on March Air Reserve Base were asked to help ensure reserves are not eaten up.
The request was made by the Metropolitan Water District of Southern California and the Eastern, Western and Temescal Valley water districts.
Next week, San Diego County Water Authority staff and contractors will begin crucial repairs on Pipeline 5 in rural North County between Fallbrook and Escondido.
The work is part of the Water Authority’s proactive asset management program, which monitors and maintains the condition of regional water infrastructure that includes 310 miles of large-diameter pipelines. The Water Authority’s approach, coordinated closely with its member agencies, has served the region well by avoiding large-scale, unexpected water outages for more than a decade.
Asset management program responds quickly to pipeline needs
After a leak in nearby Pipeline 4 was discovered in Moosa Canyon last summer, Water Authority staff assessed the conditions of Pipelines 3 and 5, which run parallel to Pipeline 4 as part of the Second Aqueduct. The assessment showed that a section of Pipeline 5 in Moosa Canyon was also under significant stress.
“Due to the very high operating pressure and the major consequences of potential failure of Pipeline 5, our staff immediately began planning a shutdown and repairs to mitigate risks,” said Jim Fisher, director of operations and maintenance at the Water Authority. “Our asset management program is designed to identify potential problems and respond quickly.”
Constructed in 1982, Pipeline 5 is a vital component of the Water Authority’s water system, delivering untreated supplies from Lake Skinner in southwest Riverside County to the Lower Otay Water Treatment Plant in southern San Diego County. The operating pressure exceeds 400 pounds per square inch in Moosa Canyon.
Carbon fiber technology extends pipeline life
Repairs will require that a section of Pipeline 5 in North County be shut down from March 30 until mid-May. Crews will start by installing bulkheads that isolate the Moosa Canyon section. Then, they will line the inside of the pipe with a carbon fiber liner, as was done to rehabilitate Pipeline 4. The carbon fiber liner will reinforce distressed areas and extend the life of the 96-inch, pre-stressed concrete cylinder pipeline.
The asset management program is a key element of the Water Authority’s commitment to providing a safe and reliable water supply to San Diego County. By making preventative repairs, the Water Authority ensures that water service will continue throughout the county.
Planning study seeks long-term solutions
Over the next 18 months, Water Authority staff will conduct a planning study to evaluate improvements required for all three pipelines in Moosa Canyon to ensure the long-term reliability of the Second Aqueduct. The results of the study will include recommendations about future projects as part of the Water Authority’s capital improvement program.
Encinitas, CA—Olivenhain Municipal Water District will begin construction to replace aging water infrastructure in El Camino Real the week of March 23. To reduce traffic impacts, all work will take place at night, between 8:00 p.m. to 6:00 a.m., Monday through Thursday.