Posts

An employee looks into a section of pipeline. One of the projects receiving an award.

Water Authority Wins Four Awards for Outstanding Projects

The American Public Works Association and American Society of Civil Engineers recently presented the San Diego County Water Authority with four awards for construction projects that exemplified outstanding skill, dedication and collaboration from staff in many departments. All of the projects were underway or completed during the COVID-19 pandemic, and project teams navigated shutdowns, adapted to health and safety restrictions, and overcame many other uncertainties – in addition to typical challenges encountered during construction projects.

1) APWA Project of the Year: Northern First Aqueduct Structures and Lining Rehabilitation

With extensive coordination between the Water Authority’s Asset Management, Operations, Maintenance, Right of Way, Water Resources, Engineering and Public Affairs teams, the First Aqueduct rehabilitation project was completed in early 2021. Significant work had not been performed on the First Aqueduct since the completion of Pipeline 1 in 1947 and Pipeline 2 in 1954. The Operations and Maintenance Teams worked closely with multiple member agencies to ensure no impacts to water deliveries over the extended shutdowns required to reline both Pipelines. These extended shutdowns allowed the Asset Management team to inspect 27 miles of pipeline along the aqueduct using innovative technologies – the first time this had been done in nearly 75 years.

“Since the project included more than 35 work sites spread out over 15 miles, many in rural areas of the county, we collaborated closely between different departments and member agencies to ensure that water service was not disrupted,” said Emma Ward-McNally, Water Authority engineer.

2) APWA Honor Award: Vallecitos 11/Vista Irrigation 12 Flow Control Facility

This new facility replaced the existing Vallecitos 2/Vista Irrigation 1 facility that was built in 1954. The Water Authority’s Operations and Maintenance team worked closely with the Engineering team to develop a construction sequence to build the new facility while maintaining water service to member agencies.

“A meticulous level of detail in the design process allowed for the project to be completed with minimal changes during construction,” said Jim Zhou, Water Authority senior engineer.

3) APWA Honor Award: San Diego 28 Flow Control Facility

The new flow control facility replaced the San Diego 12 flow control facility. The Water Authority’s Right of Way team worked closely with the City of San Diego to acquire property rights for the facility. During construction, electrical and rotating technicians from Operations and Maintenance provided support to ensure that the facility was constructed correctly and that electrical relay protection was coordinated when connecting to San Diego Gas & Electric.

“The new facility repurposed an existing building at the site, but it was forward-looking – the project included the installation of a second pipe train for a future inline hydroelectric turbine,” said Aaron Trimm, Water Authority senior engineer.

4) ASCE Award of Excellence: Pipeline 5 Emergency Repair

After nearby Pipeline 4 was repaired in late 2019, the Asset Management team inspected Pipeline 5 in early 2020, and found it needed repairs as well. Multiple Water Authority departments and teams collaborated to launch the emergency repairs on Pipeline 5, despite the uncertainty of the growing pandemic. The Engineering Contracts group executed five contracts and task authorizations for design, construction and inspection within a few weeks to make the project happen, and the work was completed in April 2020.

“The project was a true team effort that required collaboration from multiple departments to ensure that the emergency repair could be completed even as the region was shutting down due to the pandemic,” said Colin Kemper, Water Authority senior engineer.

This temporary bridge allowed Vallecitos Water District crews to repair a manhole without affected sensitive habitat. Photo: Vallecitos Water District rehab manhole

Vallecitos Water District Crews Rehab Manhole, Protecting Environment  

Vallecitos Water District crews sprang into action to repair and rehabilitate a manhole in danger of failing, successfully preventing a spill, which could have resulted in significant environmental damage.

Located just off Palomar Airport Road in a shared 30-foot easement with the Buena Sanitation District in Carlsbad, the manhole is part of a 30-inch outfall providing a main sewage drain for the City of San Marcos. The line feeds directly into the Encina Wastewater Treatment plant a half-mile from the project site.

Originally constructed in the 1980s, turbulence generated by a hard right-turn along the sewer easement creates hydrogen sulfide gases. These gases corrode concrete and weakened the manhole over the years. Flooding also occurs in the area and allows rainfall to infiltrate the manhole.

Preventing harm to sensitive habitat areas

Vallecitos Water District staff became concerned the structure could fail. The result would be a major sewage spill affecting the nearby Encinas Creek Habitat Conservation Area, ultimately spilling into the Pacific Ocean a mile downstream. The Habitat Conservation Area is owned by the Center for Natural Lands Management, which supports its management through an endowment.

The Encinas Creek HCA is also part of the City of Carlsbad’s habitat management preserve. It includes riparian habitat and is known to be home to state and federally protected species. The Center for Natural Lands Management works to protect the property from trespassing, nonnative invasive plant and animal species, and other issues.

The District determined emergency repairs were required. Although the Vallecitos Water District has proper easement rights to access, operate, and maintain the pipeline, the agency must avoid any impact to the existing habitat while repairing the manhole. This required some creativity by the work crews.

Creative thinking provides access for repairs

A look at the newly repaired manhole. Photo: Vallecitos Water District

A look at the newly repaired manhole. Photo: Vallecitos Water District

The District kept all construction activities within its existing easement to avoid any impacts to existing riparian vegetation. Crews constructed a temporary bridge over an existing stream obstructing access to the manhole. The bridge installation was designed to be temporary, and not affect the existing stream with footings or other supports. Constructing the bridge for access turned out to be the most complex part of the repair project.

District crews working with a contractor team took advantage of the lower sewage flow during the early morning hours, starting work at 3 a.m. to get as low into the waterline as possible. Repairs like this take advantage of the low flows to keep critically important sewer systems in operation.

Instead of replacing the manhole, the District used a polymer concrete replacement product to build a new manhole within the old manhole. As a result, no excavation was needed. Unlike regular concrete, the new material is corrosion-proof and should provide District customers in San Marcos with many years of reliable service while protecting the environment.

Carbon fiber - Pipeline Repair-WNN primary phto

Water Authority Begins Pipeline 5 Repairs in North San Diego County

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.”

After a leak in nearby Pipeline 4 was discovered near Moosa Creek 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. Photo: San Diego County Water Authority

After a leak in nearby Pipeline 4 was discovered near Moosa Creek 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. Photo: San Diego County Water Authority

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.

FPUD is embarking on a number of prevention, maintenance and improvement projects to safeguard and maintain its pipes and infrastructure. Photo: Fallbrook PUD

Fallbrook PUD Goes With the Maintenance Flow to Provide Reliable Service

Water pipeline blowouts like the one the day before Thanksgiving 2017 at the intersection of Stagecoach Road and Ranchwood Lane in Fallbrook provide periodic reminders about the realities of aging infrastructure.

Preventing these type of emergencies is the driving force behind planned shutdowns at water agencies such as the Fallbrook Public Utility District; investments today will avoid similar emergencies and unplanned water outages in the years ahead.

Many of FPUD’s pipes are more than 50 years old. A pipeline’s life can be 80 to 100 years, but many of the early lines that were installed were not put in at today’s standards and have shorter lives.

In fact, some of the early pipelines installed in the area were originally excavated from March Air Force Base in Riverside County and re-installed in Fallbrook, said FPUD general manager Jack Bebee. Many of these pipelines have reached the end of their useful lifespans.

That’s why FPUD is embarking on a number of prevention, maintenance and improvement projects to safeguard and maintain our pipes and infrastructure. Waiting to fix them after they break isn’t the most cost-effective and convenient way to operate.

“We’re trying to prevent a continued Band-Aid approach,” said Bebee.

Proactive approach prioritizes greatest need first

The shutdowns and retrofits are part of FPUD’s proactive approach to pipeline and valve replacement. By identifying pipes that are in the worst condition, the agency is prioritizing those needing to be replaced first, resulting in fewer pipe failures, blowouts and spills.

As part of its ongoing maintenance program, FPUD has refurbished six of its eight steel tanks over the past several years. It is also working on systematic valve replacement covering the entire community area. Valves are a critical component of water and sewer system infrastructure to limit the size of any shutdown.

Annually, the district also replaces or relines sewer manholes and sewer lines. Some of the manholes date so far back they are made of brick. Only FPUD’s sewer customers pay for sewer improvements, and only water customers pay for water improvements.

All FPUD construction work will be on weekdays between 7 a.m. and 4:30 p.m., with an exception for projects that disrupt businesses. Those projects may be scheduled overnight. FPUD customers will receive both a letter and phone call if the planned shutdown will affect their water service.

FPUD posts regular updates to its website at www.fpud.com and on its Twitter account, @Fallbrook water

Residents can also visit the FPUD Facebook page for other water-related updates.

 

A wooden dam helped allow Operations and Maintenance crews to make repairs to a leaking pipeline valve. Photo: Water Authority Dewatering project

Quick Solution Keeps Pipeline Repairs on Track

When Water Authority crews began dewatering part of the region’s pipeline system for a 10-day shutdown in mid-November, they discovered a leaking valve that threatened to disrupt the time-sensitive operation.

At issue was a six-foot diameter valve in the Second Aqueduct that was designed to isolate a section of pipeline so workers could safely make repairs inside a dry section of the massive pipe. Instead, the valve was seeping water, which made it impossible to start the welding work slated for the relining project in Bonsall and Fallbrook.

The leaking valve was installed in 1980 and is at the end of its useful service life. While valve failure wasn’t an immediate threat, staff had to find a quick solution to avoid delays that could have impacted water deliveries to customers.

Each winter, the Water Authority coordinates with its 24 member agencies to schedule pipeline shutdowns when water demands are low so crews can conduct routine inspections and make repairs. Timing is always critical to ensure water agencies have adequate supplies while pipes are offline.

Strategy devised to allow successful and swift repairs

Water Authority Operations and Maintenance workers made repairs to a leaky pipeline valve. Photo: Water Authority

Crews begin installing an isolation bulkhead after seepage stopped by repairs. Photo: Water Authority

The leaking valve threatened to disrupt this year’s refurbishing plan, forcing the Operations and Maintenance Department to quickly assess several potential solutions, including using absorbent materials such as rice or oats to soak up excess water. The team quickly settled on a strategy to construct temporary dams inside the pipeline and divert the seepage while repairs were made.

First, crews built a dam with 200 sandbags just upstream of the leaking valve, redirecting water into another pipeline and away from the contractor’s workspace. Then, they constructed a secondary wooden dam to collect the trickle of water seeping past the sandbags.

The solution was successfully deployed in less than 48 hours, allowing the welding project to begin on time.